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Also available from City & Guilds and Hodder Education The City & Guilds Textbook: Site Carpentry and Architectural Joinery for the Level 2 Apprenticeship (6571), Level 2 Technical Certificate (7906) & Level 2 Diploma (6706) Stephen Jones, Stephen Redfern, Colin Fearn
9781510458130
The City & Guilds Textbook: Site Carpentry & Architectural Joinery for the Level 3 Apprenticeship (6571), Level 3 Advanced Technical Diploma (7906) & Level 3 Diploma (6706) Martin Burdfield, Stephen Jones, Stephen Redfern, Colin Fearn
Help realise your ambitions of becoming a specialist site carpenter or joiner in the construction industry with these comprehensive textbooks published in association with City & Guilds. ⊲ Study with confidence, using the most up-to-date information available for the new specifications and industry standards ⊲ Enhance your understanding of tools and concepts in carpentry and joinery with clear and accurate technical drawings and step-by-step photo sequences ⊲ Get ready for the workplace with industry tips and case studies ⊲ Develop core skills with expert authors who draw on their extensive teaching and industry experience
Find out more at hoddereducation.co.uk/construction
Hodder Carpentry IFC ad 216x282.indd 1
9781510458154
LEVEL 1 DIPLOMA (6706)
The City & Guilds textbook
Carpentry & Joinery Stephen Jones Stephen Redfern EDITOR: Martin Burdfield
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Every effort has been made to trace all copyright holders, but if any have been inadvertently overlooked, the Publishers will be pleased to make the necessary arrangements at the first opportunity. Although every effort has been made to ensure that website addresses are correct at time of going to press, Hodder Education cannot be held responsible for the content of any website mentioned in this book. It is sometimes possible to find a relocated web page by typing in the address of the home page for a website in the URL window of your browser. Hachette UK’s policy is to use papers that are natural, renewable and recyclable products and made from wood grown in well-managed forests and other controlled sources. The logging and manufacturing processes are expected to conform to the environmental regulations of the country of origin. Orders: please contact Hachette UK Distribution, Hely Hutchinson Centre, Milton Road, Didcot, Oxfordshire, OX11 7HH. Telephone: +44 (0)1235 827827. Email [email protected] Lines are open from 9 a.m. to 5 p.m., Monday to Friday. You can also order through our website: www.hoddereducation.co.uk ISBN: 978 1 3983 1937 0 © The City & Guilds of London Institute and Hodder & Stoughton Limited 2021 First published in 2021 by Hodder Education, An Hachette UK Company Carmelite House 50 Victoria Embankment London EC4Y 0DZ www.hoddereducation.co.uk Impression number 10 9 8 7 6 5 4 3 2 1 Year
2025 2024 2023 2022 2021
All rights reserved. Apart from any use permitted under UK copyright law, no part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording, or held within any information storage and retrieval system, without permission in writing from the publisher or under licence from the Copyright Licensing Agency Limited. Further details of such licences (for reprographic reproduction) may be obtained from the Copyright Licensing Agency Limited, www.cla.co.uk Cover photo © Stockphoto-graf/stock.adobe.com Illustrations by Integra Software Services Pvt. Ltd., Pondicherry, India. Typeset in India by Integra Software Services Pvt. Ltd., Pondicherry, India. Printed in Slovenia A catalogue record for this title is available from the British Library.
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Contents Acknowledgements v About the authors vi vii Picture credits How to use this book x 1
Principles of building construction, information and communication How to identify information used in the workplace Environmental considerations in construction Construction of foundations Construction of internal and external walls Construction of floors Construction of roofs How to communicate in the workplace
1 1 11 16 23 35 39 48
2
Carpentry and joinery hand tools Types of modern and traditional hand tools How to safely use, sharpen and maintain hand tools How to safely store and transport hand tools
54 54 65 110
3
Power tools Power sources used with portable power tools Power tool safety Personal protective equipment (PPE) Types of power tools, tooling and their safe use Transporting, storing and maintaining power tools
114 114 118 120 121 172
4
Produce woodworking joints Select and store materials used to produce woodworking joints Select and use hand tools to produce woodworking joints Identify the resources required to mark out woodworking joints Mark out woodworking joints Select and use hand tools and materials to produce basic woodworking joints Understand how to manufacture a frame using woodworking joints Form a frame using woodworking joints Construct and fix hatch linings Cut and fix skirtings and architraves
177 177 193 196 198 202 205 211 217 220
5
Types of fixings and ironmongery Materials used in the manufacture of fixings and ironmongery Fixings used in carpentry and joinery Types of ironmongery Installing ironmongery
228 228 229 242 256
iii
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6
Health, safety and welfare in construction Health and safety regulations, roles and responsibilities Accident and emergency procedures and documentation Hazards in the workplace Health and welfare in the workplace Handling materials and equipment safely Access equipment and working at height Working with electrical equipment in the workplace Using personal protective equipment (PPE) Causes of fire and fire emergency procedures
268 268 279 284 295 298 301 307 311 315
Test your knowledge answers 319 Glossary 322 Index 327
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Acknowledgments
Acknowledgments This book draws on several earlier books that were published by City & Guilds, and we acknowledge and thank the writers of those books: l
Colin Fearn l Stuart Raine l Tim Taylor l Martin Burdfield. We would also like to thank everyone who has contributed to City & Guilds photoshoots. In particular, thanks to: Andrew Buckle (photographer), Tony Manktelow, Victoria Lockwood, Lindsay Cotte, David Hartsilver and all the staff at Burton and South Derbyshire College and at Central Sussex College, models Charlie Barber, Kieran Kelly, Jake North, Joe Smith and Martin Standbridge, and Colin Fearn and Steve Redfern. Contains public sector information licensed under the Open Government Licence v3.0.
From the authors I’d like to dedicate this book to my Dad, who sadly passed away during my time working on this project. He was a true craftsman in his own right and a real inspiration to me. Stephen Jones I would like to thank my wife, Sharon, children, Katie and Shaun, and grandchildren, Lewis, Charlotte, Evie and Emily. Without your support and love this work would not have been possible. To Brian, a former tutor and dear friend, thank you for all your encouragement, and last but not least to my editor, Rachel, a big thank you for all your hard work and patience. Stephen Redfern
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma
About the authors Stephen Jones I was born and grew up in Newport, South Wales. After leaving school at 16, I started an apprenticeship with a local Joinery business where I completed my training. I then met my wife and later moved to Torquay in Devon where we got married and raised three children. During my career in the South West, I have worked as a shopfitter and joiner and self-employed site carpenter, travelling all over the country on various contracts. I had my own shopfitting and joinery business for a number of years, working on retail, leisure and domestic projects, and employed a small workforce. In 2004, I began teaching at South Devon College. During my time in further education, I have continued to develop my knowledge and skills by completing the Postgraduate Certificate in Education (PGCE), Higher National Certificate (HNC) in Construction and the National Examination Board in Occupational Safety and Health (NEBOSH) Certificate. I am still employed as a full-time lecturer, assessor and internal verifier of Site Carpentry and Architectural Joinery courses from Levels 1 to 3. When I first left school, I never dreamt that I would do or see many of the things that I have during my time in the construction industry. I have been able to travel the length and breadth of the country with work and to visit other countries. This year, I have been fortunate enough to have the opportunity to write my third and fourth Carpentry and Joinery textbooks, a feat I never thought possible when I was at school. If you have a passion and enjoy what you do, ‘the world is your oyster’.
Stephen Redfern I was born and grew up in the Midlands, where I continue to live. I am married with two children and four grandchildren. On leaving school at 16, I managed to get an indentured apprenticeship with a joinery manufacturer. I have spent the better part of 40 years working in joinery and the construction industry, 26 of which were at a further education college from which I have now retired as a course leader for Joinery. During my time as a course leader, I delivered courses from Level 1 through to Level 3 in Wood Machining, Carpentry and Joinery to apprentices, full-time students and adult learners. In my spare time, other than working on construction projects, I like fishing, working my spaniels and clay shooting.
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Picture credits
Picture credits Fig 1.7 © jackie ellis/Alamy Stock Photo; Fig 1.8 © Panupong/stock.adobe.com; Table 1.4 1st © Jesus Keller/ Shutterstock.com, 2nd © Smileus/Shutterstock.com, 3rd © Sky Light Pictures/Shutterstock.com, 4th © tchara/ Shutterstock.com, 5th 1st © Studio Harmony/stock.adobe.com, 6th © Proxima Studio/stock.adobe.com; Table 1.5 1st © Steve Jones, 2nd © fotoivankebe/Shutterstock.com, 3rd © Alena Brozova/Shutterstock.com, 4th © BanksPhotos/ E+/Getty Images, 5th © Alena Brozova/Shutterstock.com, 7th © CORDELIA MOLLOY/Science Photo Library/Alamy Stock Photo; Fig 1.10 tl © Paul Wishart/Shutterstock.com, bl © Stephen Finn/Shutterstock.com, r © TonyV3112/ Shutterstock.com; Fig 1.15 © Mr.Arthid Vongsawan/Shutterstock.com; Fig 1.17 © krsprs/stock.adobe.com; Fig 1.24 © MrSegui/Shutterstock.com; Table 1.6 1st © Chloe Johnson/Alamy Stock Photo, 2nd © mafffi/stock.adobe.com, 3rd © Chris Rose/stock.adobe.com, 4th © Colin Fearn, 5th © Alena Brozova/Shutterstock.com, 7th Image courtesy of Sabrefix, 8th © IG Lintels, 9th © Saint-Gobain Weber UK & Ireland; Fig 1.27 l © PonyFriday/Shutterstock.com, r © Hervé Rouveure/stock.adobe.com; Fig 1.28 © Simon/stock.adobe.com; Table 1.7 1st © bright/Shutterstock.com, 2nd © Oleksandr Tsybulskyy/stock.adobe.com, 3rd © mafffi/stock.adobe.com, 4th © City & Guilds, 5th © British Gypsum, 6th © KNAUF; Fig 1.30 © MiTek Industries Ltd; Fig 2.1 © Alexander Tekuchev/stock.adobe.com; Fig 2.2 l © Phil Jones Photography, r © Phil Jones Photography; Fig 2.3 © Phil Jones Photography; Fig 2.4 © Phil Jones Photography; Fig 2.5 © Roman Ivaschenko/stock.adobe.com; Fig 2.7 © Phil Jones Photography; Fig 2.8 © Construction Photography/ Avalon/Hulton Archive /Getty Images; Fig 2.9 © Robert Bosch Power Tools GmbH, 2020, all rights reserved; Fig 2.10 © Phil Jones Photography; Fig 2.11 t © Ravl/Shutterstock.com, b © Constantine Pankin/Shutterstock.com; Fig 2.12 © Amlbox/stock.adobe.com; Fig 2.13 © City & Guilds; Fig 2.14 © Steve Jones; Fig 2.15 © City & Guilds; Fig 2.16 © Shinwa Rules Co., Ltd.; Fig 2.17 © Richard Heyes/Alamy Stock Photo; Fig 2.18 © Natsmith1/Shutterstock.com; Fig 2.19 © Mipan – Fotolia; Fig 2.20 © 2007 Colin & Linda McKie/istockphoto; Fig 2.21 © Martin Burdfield/Building Crafts College; Fig 2.22 © Rosinka79/stock.adobe.com; Fig 2.28 © Mark Humphreys/123RF; Fig 2.29 © Jeffrey Banke/stock.adobe.com; Fig 2.30 © Faithfull Tools; Fig 2.31 © Faithfull Tools; Fig 2.32 © City & Guilds; Fig 2.33 © Colin Fearn; Fig 2.34 © City & Guilds; Fig 2.39 © Faithfull Tools; Fig 2.42 © Faithfull Tools; Fig 2.43 © Threecups/ stock.adobe.com; Fig 2.44 © Theo Alers/Alamy Stock Photo; Fig 2.45 © Faithfull Tools; Fig 2.46 Courtesy of Axminster Tool Centre Ltd; Fig 2.47 © Faithfull Tools; Fig 2.48 Courtesy of Axminster Tool Centre Ltd; Fig 2.49 Courtesy of Axminster Tool Centre Ltd; Fig 2.51 © Krys Bailey/Alamy Stock Photo; Fig 2.52 © Phil Jones Photography; Fig 2.54 © Phil Jones Photography; Fig 2.55 © City & Guilds; Fig 2.56 © City & Guilds; Fig 2.57 © City & Guilds; Fig 2.58 © City & Guilds; Fig 2.59 © City & Guilds; Fig 2.60 © City & Guilds; Fig 2.61 © Phil Jones Photography; Fig 2.62 © City & Guilds; Fig 2.63 © 2013 City & Guilds of London Institute; Fig 2.64 Illustration by Lorna Johnson. Reprinted with permission from WOOD® magazine. © 1996 Meredith Corporation. All rights reserved.; Fig 2.65 Courtesy of Axminster Tool Centre Ltd; Fig 2.66 © Faithfull Tools; Fig 2.68 © Faithfull Tools; Fig 2.69 © Faithfull Tools; Fig 2.70 Illustration by Lorna Johnson. Reprinted with permission from WOOD® magazine. ©1996 Meredith Corporation. All rights reserved.; Fig 2.71 Illustration by Lorna Johnson. Reprinted with permission from WOOD® magazine. © 1996 Meredith Corporation. All rights reserved.; Fig 2.72 © Phil Jones Photography; Fig 2.74 © Veritas Tools Inc. 2021; Fig 2.76 © Faithfull Tools; Fig 2.77 © Veritas Tools Inc. 2021; Fig 2.78 © Charles Stirling/Alamy Stock Photo; Fig 2.79 © Charles Stirling/Alamy Stock Photo; Fig 2.80 Used by permission, The Taunton Press, Copyright © 1998.; Fig 2.82 © City & Guilds; Fig 2.90 Used by permission, The Taunton Press, Copyright © 1998.; Fig 2.91 Used by permission, The Taunton Press, Copyright © 1998.; Fig 2.92 © City & Guilds; Fig 2.100 © Phil Jones Photography; Fig 2.101 © Phil Jones Photography; Fig 2.102 © City & Guilds; Fig 2.104 © Gresei/stock.adobe.com; Fig 2.106 © Steve Jones; Fig 2.112 © Kuzmick/stock.adobe.com; Fig 2.113 © Will Burwell/ Alamy Stock Photo; page 92 Step 1 tl © City & Guilds, tr © City & Guilds, bl © Steve Jones, br © Steve Jones, Step 2 © Steve Jones; page 93 Step 3 © Steve Jones, Step 4 © Steve Jones; page 94 © City & Guilds; page 95 © City & Guilds; Fig 2.114 © Axpitel/stock.adobe.com; Fig 2.115 Courtesy of Axminster Tool Centre Ltd; Fig 2.116 © Phil Jones Photography; Fig 2.123 © lcswart/stock.adobe.com; Fig 2.126 © City & Guilds; Fig 2.127 © City & Guilds; Fig 2.128 © Faithfull Tools; Fig 2.129 © Faithfull Tools; Table 2.2 1st © Punyaphat/stock.adobe.com, 2nd © Kilukilu/ vii
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Shutterstock.com, 4th Courtesy of Axminster Tool Centre Ltd, 5th © Steve Jones, 6th © Faithfull Tools, 7th © Faithfull Tools, 8th © Travis Perkins, 9th © Faithfull Tools, 10th © Steve Jones; Fig 2.131 © Phil Jones Photography; Fig 2.135 © Faithfull Tools; Fig 2.136 © Faithfull Tools; Fig 2.137 © Faithfull Tools; Table 2.3 1st © Faithfull Tools, 2nd © Steve Jones, 3rd © Faithfull Tools, 4th © Faithfull Tools, 5th © Faithfull Tools, 6th © Faithfull Tools; Fig 2.138 © Steve Jones; Fig 2.139 © Phil Jones Photography; Fig 2.140 © jaimeskaggs/stock.adobe.com; Fig 2.141 © Phil Jones Photography; Fig 2.142 © Van Vault; Fig 2.143 © Stanley Black & Decker, Inc.; Fig 3.1 Construction Photography © David Burrows; Table 3.1 1st © Rigsbyphoto/Shutterstock.com, 2nd © RTimages/stock.adobe.com, 3rd © David J. Green - electrical/ Alamy Stock Photo, 4th © Ornot38/Shutterstock.com; Fig 3.3 © Vulcascot Cable Protectors; Fig 3.4 © Makita UK; Fig 3.5 © Dizfoto1973/stock.adobe.com; Fig 3.6 © Hoomoo/stock.adobe.com; Fig 3.7 © Faithfull Tools; Table 3.5 1st © Ian Pilbeam/Alamy Stock Photo, 2nd © Makita UK, 3rd © Oner/stock.adobe.com, 4th © Ian Pilbeam/Alamy Stock Photo, 5th © Faithfull Tools, 6th © David J. Green - tools/Alamy Stock Photo, 7th © Screwfix; Fig 3.9 © Phil Jones Photography; Table 3.6 1st © City & Guilds, 2nd © City & Guilds; Fig 3.10 © City & Guilds; Fig 3.11 © Phil Jones Photography; Fig 3.15 r © Phil Jones Photography; Fig 3.16 © City & Guilds; Fig 3.17 © City & Guilds; Fig 3.18 © City & Guilds; Fig 3.21 © Phil Jones Photography; Fig 3.22 © scharfsinn86/stock.adobe.com; Fig 3.26 © Screwfix; Fig 3.37 © Makita UK; Fig 3.40 © Eugene Shatilo/stock.adobe.com; Fig 3.41 © Makita UK; Fig 3.42 © Phil Jones Photography; Fig 3.43 © City & Guilds; Fig 3.51 © Robert Bosch Power Tools GmbH, 2020, all rights reserved; Fig 3.52 © City & Guilds; Fig 3.54 © Tiero/stock.adobe.com; Fig 3.55 © City & Guilds; Fig 3.56 © Trend Tool Technology; Fig 3.57 © City & Guilds; Fig 3.58 © Phil Jones Photography; Table 3.7 1st © Trend Tool Technology, 2nd © Trend Tool Technology, 3rd © Trend Tool Technology, 4th © City & Guilds; Fig 3.59 © City & Guilds; Fig 3.63 © Piotr/stock. adobe.com; Fig 3.64 © Screwfix; Fig 3.65 © Phil Jones Photography; Fig 3.66 © Phil Jones Photography; Fig 3.67 © Phil Jones Photography; Fig 3.68 © Phil Jones Photography; Fig 3.69 © Phil Jones Photography; Fig 3.70 © Fotos 593/ stock.adobe.com; Fig 3.71 © creative soul/stock.adobe.com; Fig 3.72 © Phil Jones Photography; Fig 3.73 © Phil Jones Photography; Fig 3.74 © Fototocam/stock.adobe.com; Fig 3.75 © Makita UK; Fig 3.76 © vvoe/stock.adobe.com; Fig 3.78 © Phil Jones Photography; Fig 3.79 © Makita UK; Fig 3.80 © Uwimages/stock.adobe.com; Fig 3.81 © 2019 GMC Global Machinery Company; Fig 3.82 © ungvar/stock.adobe.com; Fig 3.83 © Phil Jones Photography; Fig 3.84 © Phil Jones Photography; Fig 3.85 © Phil Jones Photography; Fig 3.86 © JRJfin/stock.adobe.com; Fig 3.87 © Phil Jones Photography; Fig 3.88 © cegli/stock.adobe.com; Fig 3.89 © leo_photo/Shutterstock.com; Fig 4.7 © Steve Jones; Page 181 a © Steve Jones, b © Steve Jones; Fig 4.8 © Protimeter Moisture Meters; Fig 4.10 © romaset/stock. adobe.com; Fig 4.11 © Steve Jones; Fig 4.12 © Steve Jones; Fig 4.13 l © marilyn barbone/stock.adobe.com, r © Evgeny Skidanov/stock.adobe.com; Table 4.3 1st © Barnaby Chambers/Shutterstock.com, 2nd © The Wood Database, 3rd © The Wood Database, 4th © deepspacedave/stock.adobe.com, 5th © Raimund Linke/Photolibrary/Getty Images; Table 4.4 1st © The Wood Database, 2nd © Peter Guess/Shutterstock.com, 3rd © ireneromanova/stock.adobe.com, 4th © The Wood Database, 5th © Bambuh/Shutterstock.com; Table 4.5 1st © Steve Jones, 2nd © Steve Jones, 3rd © Steve Jones, 4th © Steve Jones, 8th © Steve Jones, 10th © Steve Jones, 11th © Steve Jones, 12th © Steve Jones, 14th © Henrik Larsson/Shutterstock.com, 21st © taviphoto/stock.adobe.com, 23rd © Steve Jones; Fig 4.16 © City & Guilds; Fig 4.17 © Martin Burdfield/Building Crafts College; Fig 4.18 © City & Guilds; Fig 4.19 © City & Guilds; Fig 4.20 © City & Guilds; Fig 4.21 © City & Guilds; Fig 4.23 © City & Guilds; Table 4.9 1st © Vaaka/Shutterstock.com, 2nd © Jocic/Shutterstock.com, 3rd © City & Guilds, 4th © Tashatuvango/Shutterstock.com, 6th © Alexandra/stock.adobe. com, 7th © Chiltern Timber, 8th © Luis Carlos Torres/Shutterstock.com; Fig 4.25 © Phil Jones Photography; Fig 4.37 © scharfsinn86/stock.adobe.com; Fig 4.41 © City & Guilds; Fig 4.42 © City & Guilds; Fig 4.43 © City & Guilds; Fig 4.44 © City & Guilds; Fig 4.46 © City & Guilds; Fig 4.47 © Steve Jones; page 223 Steps 1–2 © City & Guilds; page 224 Steps 3–4 © City & Guilds; Fig 4.50 © Faithfull Tools; Table 5.1 1st © Bert Folsom/123RF, 2nd © Scphoto48 / stock.adobe.com, 3rd © scott/stock.adobe.com, 4th © Creative soul/stock.adobe.com, 5th © nathan_0834/stock. adobe.com, 6th © Fotos 593/stock.adobe.com, 7th © rsooll/stock.adobe.com, 8th © Phil Jones Photography; Fig 5.2 © 2019 Screwfix Direct Limited; Fig 5.3 © Toolstation; Fig 5.4 © W. Wirth/imageBROKER/Alamy Stock Photo; Fig 5.5 © Phil Jones Photography; Fig 5.6 © Артур Ничипоренко/stock.adobe.com; Fig 5.7 © salita2010/stock.adobe. com; Table 5.2 1st © Ilja/stock.adobe.com, 2nd © Nuclear_lily/stock.adobe.com, 3rd © Al/stock.adobe.com, 4th © W. viii
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Picture credits Wirth/imageBROKER/Alamy Stock Photo, 5th © SNEHIT PHOTO/stock.adobe.com, 6th © Hexstone Ltd, 7th © 2019 Screwfix Direct Limited; Table 5.3 1st © PROXXON S.A., 2nd © PROXXON S.A., 4th © Toolstation, 5th © G. Socka/ stock.adobe.com, 6th © Vaccaro/stock.adobe.com; Fig 5.9 © William Richardson/stock.adobe.com; Fig 5.10 © Roadknight/stock.adobe.com; Fig 5.11 Image courtesy of Sabrefix; Fig 5.12 © Coprid/stock.adobe.com; Table 5.5 1st © ANDY RELY/stock.adobe.com, 2nd © Михаил Жигалин/stock.adobe.com, 3rd © Phil Jones Photography, 4th © 2021 UK Building Products Ltd; Fig 5.13 © Toolstation; Table 5.7 2nd © Toolstation, 4th © 2020 Screwfix Direct Limited, 6th © Nikita/stock.adobe.com, 8th © johnanthony/Alamy Stock Photo, 9th © Toolstation, 10th © Steve Jones, 11th © Bombaert/123RF.com; Fig 5.15 © Dorling Kindersley ltd/Alamy Stock Photo; Fig 5.16 © Steve Jones; Table 5.8 1st © 2019 Screwfix Direct Limited, 5th © Upvc Spares 4 Repairs; Table 5.9 1st © Uncle_Bob_666/ Shutterstock.com, 2nd © Bank215/stock.adobe.com, 3rd © Alona Dudaieva/stock.adobe.com, 4th © Fotomatrix/ stock.adobe.com, 6th Image provided by Frank Allart & Company Ltd., 8th © Toolstation, 9th © Toolstation, 10th © Toolstation, 11th Photograph of Raised Edged Covered Escutcheon 2032, courtesy of Croft Architectural Hardware Limited., 12th © Liudmila/stock.adobe.com, 13th © 2019 Screwfix Direct Limited, 14th © Zerbor/123 RF, 15th © 2019 Screwfix Direct Limited, 16th © 2019 Screwfix Direct Limited, 17th © Steve Jones, 18th © Stuart Raine, 19th © Smuay/Shutterstock.com, 20th © Banepx/123RF, 21st © Steve Jones; page 257 Steps 2–3 © City & Guilds; page 258 Steps 4–6 © Steve Jones, Step 7 tl, tr, bl © Steve Jones, br © City & Guilds; page 259 Step 8 © Steve Jones; Fig 5.19 © Steve Jones; Fig 5.20 © Steve Jones; Fig 5.21 © Steve Jones; Fig 5.26 © Phil Jones Photography; Fig 5.27 © Phil Jones Photography; Fig 5.28 © Phil Jones Photography; page 263 Step 3 © Phil Jones Photography, Step 4 © Phil Jones Photography; Fig 5.29 © Phil Jones Photography; Fig 6.1 l © Darkkong/Shutterstock.com, m © Dermarcomedia/Shutterstock.com, r © phiseksit/Shutterstock.com; Fig 6.3 © BuildPix/Avalon/Construction Photography/Alamy Stock Photo; Fig 6.4 © HSE; Fig 6.5 © Igor Sokolov (breeze)/Shutterstock.com; Fig 6.6 © Kalpis/ stock.adobe.com; Fig 6.7 © CONSTRUCTION SKILLS CERTIFICATION SCHEME LIMITED; Fig 6.8 © Kadmy/stock. adobe.com; Fig 6.10 © Avalon/Construction Photography/Alamy Stock Photo; Fig 6.11 © Alexander Erdbeer/ Shutterstock.com; Fig 6.12 © British building and construction photography/Alamy Stock Photo; Fig 6.13 © Steroplast Healthcare Limited; Fig 6.14 © Anchels/stock.adobe.com; Fig 6.16 © Steve Jones; Fig 6.17 © Steve Jones; Fig 6.18 © City & Guilds; Fig 6.19 © Steve Jones; Fig 6.20 © Steve Jones; Fig 6.21 © Marbury/Shutterstock.com; Fig 6.23 © danheighton/stock.adobe.com; Fig 6.24 © Adrian Greeman; Table 6.4 1st © ambassador806/stock.adobe. com, 2nd © stringerphoto/stock.adobe.com, 3rd © oblong1/stock.adobe.com, 4th © Ford Photography/Shutterstock. com, 5th © luca pb/stock.adobe.com; Fig 6.25 © DeiMosz/Shutterstock.com; Fig 6.27 © 29september/Shutterstock. com; Fig 6.28 © Mint Images Limited/Alamy Stock Photo; Fig 6.29 © mike.irwin/Shutterstock.com; Fig 6.30 © George Dolgikh – Fotolia; Fig 6.31 © Virynja/stock.adobe.com; Fig 6.33 © Israel Hervas Bengochea/Shutterstock. com; Fig 6.35 © objectsforall/Shutterstock.com; Fig 6.36 © Blackboard Associates Media/Alamy Stock Photo; Fig 6.37 © Roman Milert/stock.adobe.com; Fig 6.38 © An-T/stock.adobe.com; Fig 6.39 © Rob Kints/Shutterstock.com; Fig 6.40 © Steve Jones; Fig 6.44 © Simon Turner/Alamy Stock Photo; Fig 6.46 © Euro Towers Ltd; Fig 6.53 © fotosen55/stock.adobe.com; Fig 6.54 © Faithfull Tools; Fig 6.55 © RZ/stock.adobe.com; Fig 6.56 l © Rigsbyphoto/ Shutterstock.com, m © David J. Green - electrical/Alamy Stock Photo, r © Ornot38/Shutterstock.com; Fig 6.59 © Makita UK; Fig 6.60 © Steve Jones; Fig 6.61© Steve Jones; Table 6.7 1st © James Hughes/Alamy Stock Photo, 2nd © George Dolgikh – Fotolia, 3rd © Virynja/stock.adobe.com, 4th © Stockbyte/Getty Images/Entertainment & Leisure CD35, 5th © Nd700/stock.adobe.com, 6th © Valentin/stock.adobe.com, 7th © Petrik/stock.adobe.com, 8th © Pixelrobot/stock.adobe.com, 9th © Modustollens/stock.adobe.com, 10th © IRC/stock.adobe.com; Fig 6.64 l © Mr. Zach/Shutterstock.com, ml © Mark Sykes / Alamy Stock Photo, mr © Science Photo Library/Alamy Stock Photo, r © Colin Underhill/Alamy Stock Photo; page 318 9a © Tribalium88/Shutterstock.com, 9d © Alex White/stock.adobe. com
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma
How to use this book Throughout this book you will see the following features: Industry tips are particularly useful pieces of advice that can assist you in your workplace or help you to remember something important.
INDUSTRY TIP Any electricity that is not used after it has been created with renewable energy can be sold back to the National Grid. This means that there is not only a saving on the cost of the electricity, but also a profit to be made. Key terms in bold purple in the text are explained in the margin to aid your understanding. (They are also explained in the Glossary at the back of the book.)
KEY TERM Tamping: the process of gently tapping the surface of wet concrete with a batten or plank after it has been laid. Tamping releases trapped pockets of air in the concrete and causes them to rise to the surface, therefore strengthening the concrete.
Health and safety boxes flag important points to keep yourself, colleagues and clients safe in the workplace. They also link to sections in the health and safety chapter for you to recap learning.
HEALTH AND SAFETY Always read and follow the paint manufacturer’s instructions on how to transport, use, store and dispose of their products. They may recommend that you wear personal protective equipment (PPE) to protect your skin, eyes and lungs from the effects of chemicals in some paints, stains and preservatives. Some products may also be highly flammable, therefore you should avoid smoking or using naked flames around them.
Activities help to test your understanding and enable you to learn from your colleagues’ experiences.
ACTIVITY Research the areas of the United Kingdom that will be affected by rising sea levels in the next 10 years and the steps being taken to protect those areas from flooding.
Improve your maths items provide opportunities to practise or improve your maths skills. Improve your English items provide opportunities to practise or improve your English skills. At the beginning of each chapter, there is a table that shows how the main headings in the chapter cover the learning outcomes for each qualification specification. At the end of each chapter, there are some Test your knowledge questions and Practical tasks. These are designed to identify any areas where you might need further training or revision.
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CHAPTER 1
PRINCIPLES OF BUILDING CONSTRUCTION, INFORMATION AND COMMUNICATION
INTRODUCTION Planning and organising building work in the construction industry requires the co-ordination of many different tradespeople, materials and equipment. Delays caused by poor communication can often lead to missed deadlines and have financial implications. Carpenters and joiners are part of the building team; therefore, they must have a sound understanding of the methods and documentation used in the construction industry. You should also recognise the systems used to construct various elements of a building, from the foundations to the roof, and the impact that construction has on the environment.
LEARNING OUTCOMES In this chapter, you will learn about: 1 how to identify information used in the workplace 2 environmental considerations in construction 3 construction foundations
4 5 6 7
construction of internal and external walls construction of floors construction of roofs how to communicate in the workplace.
1 HOW TO IDENTIFY INFORMATION USED IN THE WORKPLACE Many different sources of information are used in the construction industry to make sure that things are built accurately, safely and to Building Regulations. This section looks at different types of drawings that are used and interprets some of the information that can be obtained from them, as well as the written documentation that supports the technical drawings and their uses.
Sources of information used in construction Drawings and Building Regulations
It is particularly important in the construction industry to give the correct information at the right time to workers and ensure that it can be easily interpreted. Architects, engineers and designers produce technical drawings to communicate building information that meet British Standards. This means that any symbols, hatching or abbreviations drawn to represent materials or components are consistent and understood by everyone in the building team. 1
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma
KEY TERMS First fixing: the primary work completed in a building before the walls and ceilings are plastered, such as installing windows, door frames and stairs. Second fixing: carpentry work completed after the walls and ceilings have been plastered, such as installing skirting, architraves and doors.
It is impractical to produce some building drawings at full size, so they are scaled down so that they can fit onto a sheet of paper. The types of drawings that carpenters and joiners commonly use are known as ‘working drawings’. These are referred to when calculating costs and the quantity of materials required for producing work. Carpenters may also refer to them for the measurements of partition walls, floors and roofs during the first fixing stage of building work, and again when they are fitting kitchens, doors and so on at the second fixing stage. However, joiners may use working drawings to price work, estimate quantities of materials and produce full-size setting out rods to make joinery items, such as windows, doors and stairs. Drawings provide an easy and accurate way to communicate information from one person to another through a visual representation of an item or object. Construction drawings are often created with two dimensions (2D): length and width. However, they can also be drawn in three dimensions (3D): length, width and depth. Copies of large technical drawings are sometimes (though increasingly rarely) referred to as blueprints, because the method traditionally used to print them used white lines on a blue background. Most building projects require different types of drawings to be drawn and submitted to the local authority for approval before work can start. The application usually includes plans of the area, the proposed construction site and detailed elevation drawings of one or more buildings. All proposed construction work must be completed to industry-recognised Building Regulations. These regulations provide detailed information on every aspect of building work, from the foundations to the roof.
ACTIVITY Use the following link to look at the main areas covered by Building Regulations in the UK: www.gov.uk/guidance/ building-regulations-andapproved-documentsindex
Specifications and schedules Because it is not always possible to include all the information needed on a drawing, it is usually written down in a document known as a specification. Specifications are usually produced by an architect, engineer or designer. They include details of products, materials, dimensions and the standard of work expected. Figure 1.1 is an example of a specification. To further support the drawings and specification, schedules are usually created for large construction projects. A schedule is a chart containing details about a particular aspect of a project; for example, doors, windows, kitchens and sanitary items such as baths, showers and toilets. Schedules can be useful when estimating and ordering materials; they may also be referenced when the items are being installed. The components on a schedule are usually identified on the drawings with references. For example, a door on the plan could be labelled ‘D1’. In the example schedule shown in Figure 1.2, D1 is referenced along with other useful information.
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Chapter 1 Principles of building construction, information and communication
Specification 102 External cavity walling Walling below ground: - Type: - Masonry units: - Mortar: DPC at ground floor: Walling above ground: - External leaf above ground: Masonry units: Bond or coursing: - Internal leaf above ground: Masonry units: - Mortar: Type: Joint profile to external faces: - Wall ties: - Cavity insulation: - Ventilation components: Openings: - Lintels: Type: Cavity tray cover: - Cavity closers: - Sills: Type: DPC below: Abutments: Cavity trays and DPCs: Flashings built into masonry:
Cavity wall, concrete filled. Common bricks. Class M6 mortar. Flexible cavity trays.
Facing bricks. Flemish bond. Aerated concrete blocks. Class M4 mortar. Bucket handle. Insulation retaining wall ties. Full fill cavity insulation. Air bricks and sub-floor ventilation ducts.
Manufactured stone lintels. Flexible cavity trays. Flexible insulated DPCs.
Manufactured stone sills. Natural stone sills. Precast concrete sills. As drawings.
p Figure 1.1 Example specification
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Master Internal Door Schedule Ref
Door size
S.O. width
S.O. height
Lintel type
FD30
Selfclosing
Floor level
D1
838 × 1981
900
2040
BOX
Yes
Yes
GROUND FLOOR
D2
838 × 1981
900
2040
BOX
Yes
Yes
GROUND FLOOR
D3
762 × 1981
824
2040
BOX
No
No
GROUND FLOOR
D4
838 × 1981
900
2040
N/A
Yes
No
GROUND FLOOR
D5
838 × 1981
900
2040
BOX
Yes
Yes
GROUND FLOOR
D6
762 × 1981
824
2040
BOX
Yes
Yes
FIRST FLOOR
D7
762 × 1981
824
2040
BOX
Yes
Yes
FIRST FLOOR
D8
762 × 1981
824
2040
N/A
Yes
No
FIRST FLOOR
D9
762 × 1981
824
2040
BOX
Yes
Yes
FIRST FLOOR
D10
762 × 1981
824
2040
N/A
No
No
FIRST FLOOR
D11
686 × 1981
748
2040
N/A
Yes
No
SECOND FLOOR
D12
762 × 1981
824
2040
BOX
Yes
Yes
SECOND FLOOR
D13
762 × 1981
824
2040
100 HD BOX
Yes
Yes
SECOND FLOOR
D14
686 × 1981
748
2040
N/A
No
No
SECOND FLOOR
p Figure 1.2 Example door schedule
Programme of work A well-organised building project will have a start date and an expected completion date agreed in writing between a construction company and the client; this is known as a contract. They may also agree to have a penalty clause built into the contract stating that if the work is not completed on time, the contractor will need to pay compensation to the client. To complete the building project on time, a document known as a programme of work is produced. The programme contains a list of all the activities that need to be completed and a breakdown of the number of weeks in which to complete them. Each task has an amount of time allocated to it so that the construction site manager can organise materials, resources and the tradespeople to arrive on site in the correct order and at the right time. Time (days) Task
1
2
3
4
5
6
7
Prepare the ground Spread foundations Lay cables for services Build walls up to DPC Proposed time in green p Figure 1.3 Example programme of work (Gantt chart)
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Chapter 1 Principles of building construction, information and communication If materials are delivered to site too early there may not be enough room to store them; they may also get lost, damaged or stolen. Additional documents used to communicate information in the construction industry are outlined in Table 1.1. q Table 1.1 Documents used to communicate information in the construction industry Document
Description
Bill of quantities
A bill of quantities is a document produced by a quantity surveyor (further information about the quantity surveyor’s role is given later in this chapter). It contains a breakdown of all the different aspects of a building project contained on the working drawings and specification. The bill of quantities forms part of a package of documents, including the drawings and specification, that are sent to potential contractors so that they can price for a job. This is known as the tendering process. The contractors complete the bill of quantities by providing unit costs and labour rates against each aspect of the work, so that a total cost can be calculated and returned to the client.
Delivery note
Materials and products that are delivered to the workplace will be accompanied by a delivery note from the supplier. A delivery note is a bit like a receipt for the goods; however, it is usually on the company’s headed paper (with a logo and address). It contains information about the quantity of materials that have been delivered, the delivery address and a reference number. The delivery note should be signed by the person receiving the goods after they have checked that: l no items are damaged l the correct type of materials have been delivered l no materials are missing l the correct quantity of materials have been delivered.
Invoice
An invoice is like a delivery note. An invoice is given by suppliers to people who have received goods or services on credit, showing a breakdown of the costs they are expected to pay.
Job sheet
Job sheets are usually issued by supervisors or managers to employees. They are documents detailing work to be carried out and sometimes materials to be used, and an allocated timescale.
Requisition order
A requisition is a document used to formally request materials from suppliers. They are used to keep a record of purchases made for each job, and control who can use a credit account with their suppliers.
Site diary
A site diary is normally completed by a construction site manager, to record day-to-day events that have happened. This could include weather conditions, deliveries and site inspections.
Statement
A statement is a document sent by a business to people or businesses that have credit accounts with them. The statement lists all the invoices that have been sent that month, the amount of credit for each one and a total amount of money expected to pay. Statements usually must be paid within 30 days of receiving them.
Timesheet
Hours worked on every job are usually recorded by employees daily on a timesheet. This information is then used to calculate wages and to estimate labour costs for future contracts.
Architect’s instruction
When an agreement has been made between a contractor and a client to undertake work, they usually sign a contract. If a change is made to the terms of the contract during completion of the work, then a document known as a ‘variation order’ must be completed before progressing. Agreeing changes in writing during the project avoids conflict between the client and contractor at the end of the project.
INDUSTRY TIP Materials are best ordered ‘just in time’ for a building or joinery project. This means that they are requisitioned with enough lead time between the order being placed and the time they will arrive at the site or workshop.
KEY TERMS Lead time: the time between the start of a process until its conclusion. Labour: a term used to describe physical work.
ACTIVITY Create a simple programme of work for your next task, with a breakdown of the stages of work and the number of minutes/hours/days that it should take to complete.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma It is important to look after and store records and other forms or written information correctly to prevent them being lost or damaged. Some documents may contain personal information or confidential data and must therefore be stored where they cannot be viewed by other people who are not authorised, in accordance with data protection legislation, such as the General Data Protection Regulation (GDPR) 2018. Examples of confidential documents include bank statements, health records, accident report forms and employment records. GDPR also requires that personal data must only be used for the purpose for which it was collected.
Scale used with drawings It is not possible to draw buildings and other structures at full size on a sheet of paper, so they are scaled down. Several different scales are commonly used in the construction industry to produce drawings in true proportion. A full-sized drawing such as a setting out rod (see Chapter 4) is produced at a scale of 1:1 (‘one to one’), more commonly called ‘full size’. This means that every millimetre drawn represents one millimetre in the real world. To reduce this scale further to, say, 1:2 means that every millimetre drawn represents two millimetres in the real world. Scales can be measured directly off a drawing with a scale rule, or by measuring with a standard ruler and multiplying the measurement by the scale. Table 1.2 gives examples of some of the technical drawings used in construction, the scales used to produce them and their purposes. q Table 1.2 Examples of technical drawings used in construction, the scales used to produce them and their purposes Technical drawings used in construction
Scale(s)
Uses
1:1
A full size setting out rod is typically used by bench joiners to mark out joinery components.
1:5, 1:10, 1:20
Assembly drawings provide detailed sections of how components fit together, such as the joint between two walls where they meet at a corner.
Construction drawings Setting out rod Rod no. 25 Contract no. 8 7/12/14 Penburthy House Internal door 2 No. req. 2 off
Width rod Height rod
Assembly drawings Detail showing typical exterior corner detail External walls
Exterior cladding
Breather membrane paper
Exterior cladding Wall plate stud Breather membrane paper
Vapour control membrane on the inside of the timber frame
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Chapter 1 Principles of building construction, information and communication Technical drawings used in construction
Scale(s)
Uses
1:1, 1:2, 1:5, 1:10
A component range drawing illustrates a full range of a particular component. For example, a ‘Window component range drawing’ would show views of every window for a particular building and their dimensions, and the positions of any openings.
Section drawings
1:10, 1:20, 1:50
Section drawings illustrate various views through a building or structure. They are used to see how different elements fit together in relation to the whole job. A section through a building might illustrate the depth of the foundation, the heights of the windows and the pitch of a roof.
Elevation drawings
1:10, 1:20, 1:50
Typical elevation drawings show the views of a building from every angle. They provide a true representation of a building by illustrating the positions of the doors, windows and roof shape. Elevation drawings may be used by joiners to measure joinery items for estimating purposes.
Floor plans
1:50, 1:100, 1:200
Floor plans show the arrangement of the walls to form rooms on each level of a building. They also illustrate the positions of doors, windows, stairs, kitchens, bathrooms and so on. Carpenters may refer to floor plans when they are hanging doors, so that they know which way they swing. Some floor plans may also illustrate heating and ventilation ducting.
Construction drawings Component range drawings 2970 mm
1030 mm
1030 mm
400 mm
W2 970 mm 600 mm
600 mm
W1 970 mm
W3
W4
Planning drawings
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Technical drawings used in construction
Scale(s)
Uses
1:200, 1:500
A site plan is a bird’s eye view of the building plot, or multiple plots on bigger construction sites. They illustrate the boundary (perimeter) of the site, roads, parking, footpaths, waterways and existing trees. Site plans show services, also referred to as ‘utilities’, such as: l mains water pipes l drains l electrical cables l gas l communication (telephone, internet and cable television connections).
1:1250, 1:2500
Block plans are usually produced to illustrate a building plot in relation to the surrounding area. These drawings are used by the client when submitting plans for approval to the local authority’s planning department.
Location plans Site plans PRESENT FRONT LOT LINE SIGN
30’ SETBACK
PROPOSED FUTURE FRONT LOT LINE (WIDENED SR23)
ADJUSTED LOT LINE (20’ S. OF BUILDING)
Block plans
Drawing symbols and hatchings Usually, when location plans are drawn, they are arranged to make the best use of the paper size, and the top of the drawing is not necessarily the direction of north. The true direction of north in relation to the site is usually illustrated on the drawing with a symbol. Drawing symbols, hatchings and abbreviations are often used by architects and other designers to represent different materials and objects. They are also used to prevent drawings from becoming cluttered with excessive written information. It is important that drawing symbols, hatchings and abbreviations are standardised, so that everyone recognises and understands them. The British Standards Institute (BSI) provides the benchmark for the drawing symbols used and understood by everyone in the building industry. Table 1.3 and Figure 1.4 illustrate some of the basic symbols, hatchings and abbreviations used.
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Chapter 1 Principles of building construction, information and communication q Table 1.3 Examples of basic symbols, hatchings and abbreviations used on technical drawings
Drawing symbol Toilet
Hatching Brickwork
Abbreviations
C/C – Centre to centre
PSE – Planed square edged (timber)
DPC – Damp-proof course
PAR – Planed all round (timber)
DPM – Damp-proof membrane
BLK – Blockwork
H/W – Hardwood
FFL – Finished floor level
S/W – Softwood
MDF – Medium density fibreboard
WB
Sink
Sinktop
Wash basin
Bath
Shower tray
WC
Window
Door
Radiator
Lamp
Switch
Socket
North point
Sawn timber (unwrot)
Concrete
Insulation
Brickwork
Blockwork
Stonework
Earth (subsoil) Stairs up Top
Bottom
1234567
1234567
Stairs down
Side Cement screed
Damp-proof course/ membrane
Timber – softwood. Machined all round (wrot)
Timber – hardwood. Machined all round (wrot)
Hardcore
Hinging position of windows
Stairs up and down
p Figure 1.4 Drawing symbols and hatchings
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma
INDUSTRY TIP Laser levels that produce a green line are clearer to see and more accurate than those that produce red lines.
ACTIVITY Mark a 1 metre high datum around a room or workshop and take reduced heights at several points to determine the actual floor level values. (Make sure you have permission to mark the wall before completing this exercise.)
Datums used in construction A datum is a reference point from which all other levels are taken and transferred. When a site is set out for the construction of a building, a reference point known as a temporary benchmark (TBM) will be set up on site. The height of the temporary benchmark will be recorded as the number of metres it is above the mean average sea level at Newlyn in Cornwall, UK. This point is used because of its relatively stable coastline. The heights of the foundations, windows, floors and roof can all be referenced back to this universal point. Many years ago, permanent ordnance benchmarks (OBM) would have been marked on public buildings and churches, and the heights recorded on an Ordnance Survey map. Today most construction sites are set out by a surveyor using GPS (the Global Positioning System). Carpenters and joiners use a datum as a reference point to install first and second fix work. A temporary line is often transferred around a room, approximately 1 m above the floor level, either with a long spirit level or a laser level. The datum line is then used as a reference to mark the heights of, for example, door frames and kitchen units. It is far more accurate to use this method than it would be to measure the heights from the floor, especially if the floor is unfinished or uneven.
Laser beam
p Figure 1.5 Datum line
p Figure 1.6 Temporary benchmark
p Figure 1.7 Ordnance benchmark
p Figure 1.8 Laser level
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Chapter 1 Principles of building construction, information and communication
2 ENVIRONMENTAL CONSIDERATIONS IN CONSTRUCTION Construction is one of the biggest industries in the UK. A huge amount of CO2 (carbon dioxide) is generated when manufacturing and transporting the materials used in the construction industry. This carbon dioxide and the other greenhouse gases released into the atmosphere as a result of manufacturing and construction are harmful to the environment and contribute to global warming. Global warming is the effect of the Earth’s atmospheric temperature rapidly rising because of an increase in the levels of carbon dioxide and other pollutants. About 10% of the land area on Earth is covered with snow and ice, which helps to reflect the heat from the Sun and regulate the Earth’s temperature. As the Earth’s surface and air temperatures rise, the ice caps are beginning to melt, causing rising sea levels and coastal flooding. Global warming also affects our weather, with more extreme dry and wet periods throughout the year causing flooding and droughts. The changing climates and warming seas also impact on wildlife and their habitats, many of which cannot adapt and survive in the changing conditions.
ACTIVITY Research the areas of the United Kingdom that will be affected by rising sea levels in the next 10 years and the steps being taken to protect those areas from flooding.
Sources of energy Energy is a term used for a source of power. Most buildings use electricity and gas as sources of power for heating, lighting, electrical sockets and running appliances such as ovens and fridges. Mains electricity comes from the National Grid. This source of energy is made in thermal power stations around the country. The energy is created at the power stations by burning coal or oil to generate steam, which is then used to drive turbines. Coal and oil are known as fossil fuels, which means they are sourced from the Earth, having been naturally created in the ground over millions of years. Fossil fuels are therefore not renewable and are damaging to the natural world. The demand for coal, gas and oil is on the increase as the world’s population grows; however, these resources are starting to run out. For this reason, alternative sources of renewable energy are increasingly being used to fuel and power buildings and vehicles.
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KEY TERM Infinite: used to describe something that will last indefinitely (forever), such as water. Natural materials like oil, coal and gas are finite resources, which means that they cannot be replaced once they have been used.
q Table 1.4 Renewable sources of energy Source of power
Description
Wind
Wind is an infinite source of power that is used to turn a wind turbine to generate electricity. Groups of large wind turbines, known as wind farms, are often used in coastal areas and at sea where the conditions are suited to this source of energy.
Sun (solar)
The Sun’s heat can warm the water contained in solar panels to provide a source of heating. Alternatively, PV (photovoltaic) panels can be used to convert sunlight into electricity.
Water
The natural movement of water can be used to create power. An early example of this is the wheel on a water mill. There are now more efficient methods of creating power (electricity), using turbines on the surface of and below the sea. This is called tidal power. Water can also be used to generate electricity as it flows through the turbines in a hydroelectric dam.
Biomass heating
A biomass boiler generates heat by burning recycled wood pellets. The energy is then used to heat water and provide heating through radiators or an underfloor heating system.
INDUSTRY TIP Any electricity created with renewable energy that is not used can be sold back to the National Grid. This means that people who use renewable energy can not only save on the cost of the electricity, but also make a profit.
INDUSTRY TIP Do you know that petrol and diesel are made from refined oil? Do you know that plastic is also made from oil? You could help to reduce the amount of oil you use by car sharing or using public transport and by recycling your plastic waste where possible. You can reduce the amount of energy consumed for lighting in your home and workplace by switching to LED lights.
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Chapter 1 Principles of building construction, information and communication Source of power
Description
Ground source heating
A small amount of heat can be absorbed from the ground through a fluid in buried pipes. The low heat captured in the fluid can be raised to a higher temperature through a compressor; this is used to heat a building and provide hot water.
Air source heating
Air source heating uses a similar principle to a refrigerator, but in reverse. An air source heat pump raises the level of heat in the air and pumps it into the building. This system does require electricity to operate the pump; however, it will reduce the amount of energy needed to heat and power the building.
Sustainable materials Using building materials that can be found locally will reduce the amount of carbon produced in comparison with transporting the materials from further away. We should consider where the materials that we use to build with have come from and what impact their use will have on the environment. For example, timber is a sustainable resource that is often used in construction; however, if it is transported from a rainforest in Brazil then its use has a negative impact on the planet. Trees are good for the Earth and our health because they absorb carbon dioxide and produce oxygen. For this reason, we need to replace the trees that are cut down. In some regions of the world, huge areas of trees and rainforest are being cleared for other uses without replacing them: this process is known as deforestation. The timber that we use should come from a managed source, which means that for every tree used at least one is replanted.
ACTIVITY Make a list of all the parts of your home that you consider to be sustainable and energy efficient, and the parts of your home that could be made more sustainable.
Features of a building that improve efficiency The energy that we use in our homes can be expensive, and the price continues to rise as the demand for it increases. Apart from using one of the alternative energy sources outlined above, we can also reduce the amount of energy used to heat a building by insulating it. Building design is extremely important for any sustainable home; for example, maximising natural light with large energy efficient windows or skylights can reduce the need for artificial lighting. The building can also store the energy from the Sun during the day to keep it warm in the night, therefore reducing the amount of energy that is needed for heating. A well-designed building must also be a healthy environment for the occupants, with a good source of clean fresh air ventilating the spaces through ventilation systems or naturally through doors and windows.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Figure 1.9 shows the areas of a building where most heat is lost. Roof 26%
Through the walls 33%
Windows 18%
Floors 8% Draughts 12% Doors 3%
p Figure 1.9 The areas of a building where most heat is lost
Later in this chapter, we will look at the main components of a building and where insulation is used to prevent heat loss and conserve energy. Table 1.5 illustrates some of the most commonly used types of insulation. q Table 1.5 Most commonly used types of insulation Type of insulation
Description
Draught excluder
Energy efficient doors, frames and windows will be sealed with draught excluder to prevent warm air leaving the building and cold air entering. Many different types of draught excluders are available; however, they are generally made of foam or soft rubber.
Double or triple glazing
All modern homes are constructed with double or triple glazed windows and doors, with either two or three panes of glass. 18% of heat generated in a building can be lost through its windows.
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Chapter 1 Principles of building construction, information and communication Type of insulation
Description
Mineral wool
Mineral wool is made of molten rock woven into slabs or rolls of bulk insulation. Bulk insulation traps air within the material to retain heat.
Blue jean and lamb’s wool
Blue jean insulation is made from recycled denim and lamb’s wool is made from the wool of sheep. Both types of insulation work by trapping pockets of air in them to retain heat. Thicker layers of these types of insulation are needed to achieve the same insulation levels that can be achieved with reflective foil.
Reflective foil insulation board
Manufactured from rigid polyisocyanurate (PIR), with foil faces. The reflective foil insulation boards prevent heat loss by reflecting heat off the foil surfaces back into the building. Standard sheet sizes are 1200 mm × 2400 mm, and vary in thickness from 12 mm to 150 mm.
Multifoil reflective insulation
Multifoil insulation works in a similar way to the reflective foil insulation board; however, it comes on a roll and is substantially thinner.
We rely heavily on the use of electrical devices to make our lives easier. Appliances such as televisions, washing machines, tumble dryers and dish washers consume a lot of energy. Some of these products are available with energy-saving features, which make the products cost more to purchase but over time they will save you money. 15
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma For example: l
energy-saving washing machines only use a cold-water supply and consume less water, which results in reduced waste l low-energy light bulbs and fittings that take LED bulbs use up to 90% less power than conventional lighting and have a longer lifespan. The water that runs through the pipes in our homes to the taps is clean drinking water, but we do not always drink it. Water is also used to shower, wash the car, water the grass and flush the toilet. A huge amount of energy is used to filter, clean, purify and pump water to our doorsteps, therefore we should use it wisely without wasting it. The rainwater that lands on ours roofs and down through the guttering system can be saved and reused. This is known as brown water. The recycled water can be used to water plants and grass in the garden or flush our toilets; this system is known as ‘rainwater harvesting’. Again, this is a simple design idea that will reduce the consumption of water, reduce bills and save energy.
Waste management Disposing of construction waste is an extremely expensive business. To reduce the amount of waste disposed, multiple skips and bins are usually provided on construction sites to segregate waste according to the materials they are made from. Skips and bins that only contain one type of material are usually cheaper to hire, use and empty than one filled with mixed waste. Glass, metal, bricks and blocks, plasterboard and timber are examples of materials that are either reused or recycled in the construction industry. Plasterboard should not go to landfill sites with other waste materials because it contains gypsum, which can produce toxic hydrogen sulphide gas if it is mixed with other biodegradable materials. In the past, waste was usually sent to landfill sites, where it was buried in the ground. The problem with this method of waste disposal is that many of the materials do not break down (degrade) in the soil, and those that do break down create dangerous gases that are harmful to the environment. Wherever possible, you should try to reduce the amount of waste produced by: l
KEY TERMS Dead load: the weight of all the materials used to construct a building or structure. Live loads: the additional weights that a foundation supports after it has been constructed and is in use. People, furniture, wind and snow are just some of the live loads that a building has to be designed to support.
not over-ordering materials accurately measuring and cutting l storing materials correctly to avoid damage l reusing materials whenever possible l recycling waste. l
3 CONSTRUCTION OF FOUNDATIONS All structures and buildings must be constructed on a solid base, known as a ‘foundation’, to prevent them from sinking into the ground and becoming unstable. The shape and size of a foundation must be accurately calculated and designed by a professional structural engineer, to ensure that it will support the dead load of the building and the live loads that will also be imposed upon it. In addition
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Chapter 1 Principles of building construction, information and communication to these weights, the type of foundations used may be influenced by the ground conditions and the type of soil. The construction site may also be on a slope, next to a river or a road with heavy traffic, which could affect the strength of the foundations. This section looks at the different types of foundations commonly used to construct low-, medium- and high-rise buildings, as well as the materials used and how to calculate the quantities required.
p Figure 1.10 Low-rise (top left), medium-rise (bottom left) and high-rise (right) buildings
Types of foundation The conditions on the ground we walk on vary dramatically and can have a huge influence on the type of foundation used. The strongest and most stable ground is made of rock, such as granite and limestone, but this can be extremely hard and sometimes expensive to dig through when building. Firm clay is an example of poor soil conditions that is likely to expand and swell, causing an upward movement in the ground; this is referred to as ‘ground heave’. Other soils that contain gravel, sand and peat are also known to be unstable, and therefore require deeper or more costly foundations. Before any building work can start, samples of soil are usually taken from the building site and tested to determine which type of foundation is most suitable. There are four main types: l
strip (including wide strip and deep fill foundations) raft l pile l pad. l
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Strip foundation
KEY TERMS Building control officer: a professional who represents the local authority’s planning department or an independent organisation. Part of their role is to visit construction sites and monitor the standard of the building work at various stages throughout the project, to make sure it meets with national Building Regulations. Damp-proof course: a layer of plastic, supplied on a roll, used to prevent damp rising from the ground through the brickwork.
Low-rise domestic buildings, such as bungalows and houses, will usually have a strip foundation to support the weight of the building. A strip foundation consists of a trench dug into the ground at a depth required by the local planning authority or as soil sample testing determines, depending on its bearing capacity. Once the trench has been approved by the building control officer, it can be filled with 150–500 mm of concrete. Once the concrete has set, the bricklayers will start to build the walls of the structure out of the trench to approximately 150 mm above the ground level. The bricks and concrete blocks used below the ground level are likely to absorb water, therefore special engineering bricks and trench blocks are used to prevent moisture or frost damage. At this height, a damp-proof course (DPC) is laid on top of the brickwork before any further brickwork is laid. The term used for the foundation and brickwork up to this level is known as the substructure.
p Figure 1.11 Strip foundation
HEALTH AND SAFETY A trench for a foundation is considered a confined space and can be an extremely dangerous place to work. One cubic metre (1 m³) of soil weighs approximately one tonne. The sides of a trench have the potential to collapse; it could flood; oxygen levels in a trench can be reduced. You should only work in a trench as a last resort after a risk assessment has been completed and all the necessary safety precautions have been taken.
Wide strip foundation If the ground conditions are found to be weak while digging a trench for a strip foundation, you should either dig deeper until firm ground is reached, which could be expensive, or increase the width of the trench and reinforce the concrete with steel. A reinforced foundation is known as wide strip.
p Figure 1.12 Wide strip foundation
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Trench fill foundation Sometimes, the depth of a strip foundation needs to be increased until firm, stable ground is reached. In this case, it might not be practical or safe to work in a deep and narrow trench, so it may have to be filled with concrete to just below the ground level. This is known as a trench fill foundation.
p Figure 1.13 Trench fill foundation
Raft foundation When the soil has a weak load-bearing capacity to support a building with strip foundation, a raft foundation may be used. A raft foundation is not only built directly underneath the load-bearing walls, but also extends across the entire footprint of the building. This type of foundation is reinforced with steel as well as concrete, to prevent any uneven subsidence causing cracks in the foundations and walls.
Hardcore
KEY TERM Subsidence: when the weight of a building or structure sinks into the ground.
Foundation concrete
p Figure 1.14 Raft foundation
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Pile foundation Pile foundations are commonly used for multi-storey, high-rise buildings or where the soil is not strong enough to support the weight of the building. Piles are made by drilling holes deep in the ground, filling them with concrete and reinforcing them with steel. These are referred to as ‘replacement’ or ‘non-displacement’ piles. Alternatively, hollow piles can be knocked into the ground with a pile driver and reinforced with concrete and steel. These are referred to as ‘displacement’ piles.
ACTIVITY Follow the link below to watch an animation on how pile foundations are constructed: www.youtube.com/ watch?v=aAZoTG0EY3U
KEY TERM Pier: a brick, block or concrete pillar that is not connected to a wall.
p Figure 1.15 Pile foundation
Pad foundation Industrial buildings and warehouses are usually built with cost-effective large steel frames, infilled with low high walls and insulated panelling. Most of the weight in these types of buildings is supported where the steel frames meet the ground; therefore, the ‘pad’ foundations are constructed at these points. Pad foundations may also be used to construct independent structures such as detached piers.
Brick pillar
INDUSTRY TIP Tree roots can cause damage to foundations, driveways, footpaths and underground pipes; therefore, you should never plant trees too close to a building without considering the local authority requirements and how big the trees could eventually grow.
Pad foundation
p Figure 1.16 Pad foundation
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Chapter 1 Principles of building construction, information and communication
Materials used in concrete foundations Concrete is made from aggregate, cement and water, and sometimes reinforced with steel. Aggregate is a technical term for different sized crushed rock; this can vary from sand (known as fine aggregate) to gravel or crushed stone (known as coarse aggregate). As soon as the cement and water are mixed, they form a paste which covers the aggregates and binds them together like glue. Once water is added to cement, it causes a chemical reaction that makes it harden or cure; this process is called hydration. The fine and coarse aggregates are more stable than cement, therefore they strengthen the concrete and prevent it from cracking. Most buildings and structures such as bridges rely on the strength of concrete to support them. If the ratio of materials mixed is wrong, the concrete will crumble under load and crack. The correct ratios of materials for concrete are: l
concrete strength grade M5 = 1 part cement + 5 parts sand + 10 parts gravel + water l concrete grade M10 = 1 part cement + 3 parts sand + 6 parts gravel + water l concrete grade M20 = 1 part cement + 1.5 parts sand + 3 parts gravel + water. The amount of water added to the mixture depends on how much water there is already in the aggregate. If too much water is added it will weaken the mix, but if too little is used it will make the concrete difficult to work with. Chemicals known as additives can be included in concrete mixes to control setting times, increase the durability of the concrete, reduce potential cracking due to excessive water, and so on. It may also be necessary to increase the curing time of concrete in the colder seasons to prevent cracking or to slow down curing times to allow large quantities to be poured and levelled in warmer conditions. Plasticiser is an additive that is often used in concrete and mortar to make these materials more flexible and easier to work with by decreasing any friction as they are used. The standard ratio of mortar mix is 4 parts building sand to 1 part cement plus water until it sticks together, but is not too dry. Plasticiser is usually added to mortar to reduce the amount of water needed by trapping air in the mix, making it more workable (easier to work with). Large amounts of concrete for foundations, floors, walls and so on can be pre-mixed and delivered to site in a concrete mixer truck. The concrete can then be offloaded down a chute into wheelbarrows or directly where needed. It can also be pumped from the truck through a flexible pipeline when access is difficult, for example at the back of a property. Smaller amounts of concrete can be mixed with a cement mixer or by hand; however, it is slower to do this and the ratios could vary. Wet concrete contains pockets of air that could weaken it, so these air pockets have to be removed before the concrete cures. There are several methods that can be used to remove air pockets; each one involves vibration so that the air rises to the surface to compact the concrete. Tamping the top of the concrete with a sturdy plank of timber will remove some of the air and help to level the surface; using a vibrating concrete poker is more effective.
p Figure 1.17 Course aggregates
KEY TERMS Mortar: a building material produced when building sand, cement and water are mixed together. Mortar is the glue that sticks or bonds bricks and concrete blocks together to build walls. Tamping: the process of gently tapping the surface of wet concrete with a batten or plank after it has been laid. Tamping releases trapped pockets of air in the concrete and causes them to rise to the surface, therefore strengthening the concrete. Vibrating concrete poker: a power tool used to remove pockets of air from freshly poured concrete. When the vibrating poker head is submerged into the wet concrete the vibrations cause any bubbles present to rise to the surface.
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ACTIVITY Concrete is not very sustainable or good for the environment. Use the internet to research alternative materials that could be used to construct the foundations for a building.
Calculating the volume of concrete used in a single strip foundation It is important to accurately calculate the amount of concrete needed for a project, such as a strip foundation. Information required to work out the quantity of materials needed can be obtained from the architect’s drawings and specification. Underestimating the amount of materials required could mean that you may price too low for the job. It could also mean that you run short of concrete, which could cause a delay in the programme, and if you are unable to get the remainder of the concrete to complete a job on the same day, the foundation would have to be joined, which could cause a weakness. Overestimating the amount of concrete needed for a foundation could impact on your profits and result in difficulties disposing of the unwanted material.
Volume The volume of concrete is measured in cubic metres and is calculated using the following formula: Length × width × depth = m³
Example 1
Figure 1.18 shows a simple strip foundation. 9m 0.2 m 0.45 m
p Figure 1.18 A simple strip foundation Volume of concrete required = 9.00 × 0.450 × 0.200
Answer = 0.810 m³ of concrete
Example 2
Figure 1.19 shows a strip foundation for a small building. 12 m
0.45 m
0.25 m
A
D B
7.3 m
C
p Figure 1.19 A strip foundation for a small building
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Chapter 1 Principles of building construction, information and communication To calculate the volume of concrete needed for this foundation you can apply the same method used for Example 1. However, you need to be careful not to include the widths of the foundation for the two end lengths. Volume of concrete required for A and C = 12 m × 0.45 m × 0.25 m = 1.35 m³ × 2 = 2.7 m³
Volume of concrete required for B and D = 7.3 m – (0.45 m + 0.45 m = 0.9 m) = 7.3 m – 0.9 m = 6.4 m × 0.45 m × 0.25 m = 0.72 m³ × 2 = 1.44 m³
Total volume of concrete required = volume of concrete required for A and C + volume of concrete required for B and D Total volume of concrete required = 2.7 m³ + 1.44 m³ Answer = 4.14 m³ of concrete
IMPROVE YOUR MATHS Calculate the volume of concrete needed for the raft foundation shown in Figure 1.20. 9.75 m 0.4 m
8.65 m
p Figure 1.20 Pad foundation
KEY TERM
4 CONSTRUCTION OF INTERNAL AND EXTERNAL WALLS The purposes of the external walls of a building are to support the weight of the upper floors and roof, as well as keep the interior secure, warm and dry. Internal walls can also be load-bearing; other internal walls are simply used to divide up spaces and offer privacy. This section looks at the key differences between internal, external and load-bearing walls. We also analyse the materials used to construct them, and various wall finishes.
Load-bearing: supporting a weight. Elements of a building that are loadbearing could include a floor, wall, roof or chimney. Internal or external load-bearing walls should never be removed without consulting a structural engineer first.
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ACTIVITY Investigate rammed earth walls and write a short report on the advantages and disadvantages of this method of construction.
Types of internal and external walls External walls Solid walls Solid walls with a single layer (known as a ‘skin’ or ‘leaf’) have been used to construct buildings for many years, and examples may still be found today in older properties around the country. Solid walls can be made from: l l l l l l l
p Figure 1.21 Solid wall
stone timber straw bales concrete masonry (bricks and blocks) cob (a mixture of soil, clay and straw) rammed earth.
Although the mass of a solid external wall can provide excellent thermal insulation in the winter and keep a building cool in the summer, moisture and damp can often still penetrate through these walls. If a building becomes damp on the inside it creates not only an unhealthy environment to live and work in, but it can also cause damage to the structure. To prevent this from happening, a second inner wall needs be built with a space between, typically 100–150 mm, which is known as a ‘cavity’. The internal cavity walls usually support the roof and upper floors of a building.
Masonry cavity walls The inclusion of an inner wall prevents water travelling from the outer skin to the inner skin. Any water that passes through the outer wall will travel down the internal surface and be directed out of the cavity by a cavity tray and weep holes.
KEY TERMS Thermal insulation: a product used to retain the heat in a building, therefore making it more energy efficient. Other types of insulation include sound insulation and fireproof insulation. Loose fill: insulation used in a cavity; commonly made from waterresistant polystyrene beads.
The inner and outer walls are connected with stainless steel wall ties so that they act as one wall, thereby increasing the wall’s stability. The wall ties are designed with a twist in them, so that water cannot travel or bridge from one wall to the other to cause damp. The cavity between the two walls should also be partially filled with thermal insulation while still allowing an air gap to ventilate the space. Sheets of rigid insulation are held tight against the external face of the inner wall with plastic retaining clips that fit over the wall ties. If the insulation is not retained against the inner leaf, moisture could travel across the cavity to cause damp and mould growth. If the wall already exists in an older property that was built without insulation in the walls, small holes can be drilled in the wall and loose fill insulation can be injected. However, care should be taken to ensure this does not create a path for moisture to pass from the outside to the inside walls.
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Chapter 1 Principles of building construction, information and communication Decorative finish
INDUSTRY TIP Inner leaf
Wall tie
Insulation
Floor
Bricks can be either solid, perforated or frogged. Hollowed bricks are shaped with holes in them to reduce their weight; frogged bricks have a cavity on one face. When you lay frogged bricks, the cavity must be facing upwards, so that it can be filled with mortar to construct a strong wall.
KEY TERMS Outer leaf
p Figure 1.22 Cavity wall
ACTIVITY Use the internet to research different ‘brick bonds’. Make sketches of the three most used brick bonds to illustrate the arrangement of the bricks.
Traditional timber frame Using timber to construct walls is a more sustainable method of construction than using concrete bricks and blocks. Traditional timber-framed buildings consisted of large timber beams, morticed and tenoned together at the joints, to form the main structure. The spaces in between the wall beams were usually filled with brickwork or wooden strips and plastered with a mixture of wet soil, clay and sand known as wattle and daub. Heavy timber-framed buildings are sometimes constructed these days to achieve a similar appearance, although modern materials and strict building standards mean they are better insulated and more energy efficient.
Modern timber frame Cavity walls can be constructed with a combination of timber inner walls and a brickwork or blockwork outer skin. The benefit of this system is that all the walls, upper floors and roof can be prefabricated in a factory in sections and delivered to site for assembly by the carpenters. This system reduces construction costs and allows the building to be made watertight very quickly, so that any poor weather will not delay the work schedule.
Mortice and tenon joint: a traditional woodworking joint used to build frames. For further information about this joint see Chapter 4. Watertight: used to describe a stage of building, usually when the walls and roof have been constructed and waterproofed, at least with breathable felt. All the doors and windows should be installed at this stage, or the openings in the walls need to be covered to protect the building from the weather. Breathable felt: a lightweight waterproof material used in roofing and external wall construction. Water cannot penetrate through the felt from the outside face, but air from the inside can pass through it to provide ventilation to a building.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Stainless steel wall tie
Structural timber frame Plasterboard
Vapour control layer Sheathing board Thick insulating quilt – CFC-free Waterproof breather membrane
Masonry outer cladding
Ventilated cavity
p Figure 1.23 Timber frame cavity wall
p Figure 1.24 Traditional timber frame
HEALTH AND SAFETY
Internal walls
Mortar contains cement which can cause burns to your skin. You should always follow the manufacturer’s instructions/risk assessment when using mortar and take the necessary precautions, such as wearing protective gloves and safety googles and washing your hands after use. For further information on risk assessments, see Chapter 6.
A partition is a wall used to divide a room into smaller spaces. Load-bearing partitions are commonly made from dense concrete blocks that run at 90° to the floor or the ceiling joists above. Non-load-bearing walls usually run parallel to the joists. These types of walls can be made from lightweight concrete blocks, timber or metal studs. The main parts of a stud partition are the head plate (top), the sole plate (bottom) and the vertical studs in between. In a timber stud partition, the wall is strengthened further with short pieces of wood called noggins, which are fixed in between the vertical uprights. It can be difficult to fix heavy items, such as kitchen units or a basin for a bathroom, on a stud partition wall because it is hollow. You can use hollow wall fixings, but the best fixings are secured directly into the studs or noggins. If the rows of noggins are not where you need them to be, then additional noggins should be added at the correct height before it is covered in plasterboard.
ACTIVITY Make a list of the different types of plasterboard that could be used to cover a stud partition wall and explain their purposes.
Partition walls
Metal stud partitions are surprisingly cheap and quick to erect. They also do not contain any natural defects, unlike timber. (More information on timber defects can be found in Chapter 4.) The framework of a stud partition wall usually has plasterboard sheets screwed on both sides to strengthen it and to provide a smooth surface to receive plaster. Alternatively, the joints between the plasterboard are covered with a special tape and filled to cover the gap; this is known as ‘dry lining’.
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Head plate
Puncheon
‘H’ section stud
Noggins ‘C’ section stud Head
‘U’ section door and wall studs
Studs
‘U’ section for soles and heads
Sole plate
p Figure 1.25 Timber stud partition wall
p Figure 1.26 Metal stud partition wall
Whenever possible, service pipes and cables should be hidden from view in a building. This can be achieved by running them between joists in a ceiling or floor to the point where they are needed. In solid walls, the pipes and cables are either fixed on the face of the wall and covered with plastic trunking/conduit, or they are chased into it. Services can easily be hidden in the hollow of metal and timber stud partition walls.
ACTIVITY Carpenters and joiners frequently fix materials to different types of walls so need a good understanding of a range of fixings and their uses. Can you match the possible fixings to the different types of walls given below? Types of walls: a Timber stud partition wall b Concrete block partition wall c Metal stud partition wall d Brick and block cavity wall Wall fixings: 1 Brown plastic plug with a screw 2 Concrete screw 3 Wood screw 4 Cavity fixing
KEY TERMS Trunking: a hollow plastic tube or box section, commonly used by electricians and plumbers to hide pipes and cables. Some trunking has a removable cover for easy access and maintenance to the services. Chasing: channelling out a wall to allow pipes and cables to be buried in it and covered with plaster.
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External walling materials and components The main building resources used to construct cavity walls are illustrated in Table 1.6, together with a brief description of their purposes. q Table 1.6 Building resources used to construct cavity walls and their purposes Wall building material
Description
Brick
A standard brick measures 215 mm long × 102.5 mm wide × 65 mm high. Clay is the main material that bricks are made from, but they can also be made from concrete or calcium silicate. Decorative bricks are referred to as ‘face bricks’ and are available in a range of different textures and colours, including cream/yellow, orange, blue and red. Coloured dyes can also be added to the mortar that is used to bond the bricks together for different effects. Engineering bricks are heavier and stronger than face bricks and are non-porous. These are mostly used in the substructure of a foundation or in structural columns.
The frog
Block
A standard concrete block measures 440 mm long × 100 mm wide × 215 mm high. Blocks are less expensive than bricks and quicker to build with; as a result, they are often used in positions where appearance does not matter or when they will be covered with other materials. There are three different densities of concrete blocks: ultra-low, medium and high density.
Stone
Limestone, granite and sandstone are types of stone that can be used to construct external walls. Building stone walls is more expensive than masonry walls because the stone is usually irregular in shape and therefore is more difficult to lay, compared with square bricks and blocks.
Timber
Timber used for external walls must be of structural grade, therefore free from any significant defects, such as dead knots and splits. The most used structural grade softwood is C16 and C32. (Further information on timber grading is given in Chapter 4.) Timber that may be exposed to the weather or damp conditions must be pressure treated with a preservative: this is known as tanalised timber. Structural timber that has been planed smooth and has radiused (rounded) edges is referred to as Canadian lumber stock (CLS).
Insulation
Building Regulations state that insulation must be used in walls, floors and roofs to prevent heat loss and make buildings more energy efficient. Many different types of insulation are used in the construction industry, but the main two are reflective foil insulation and mineral wool (known as bulk insulation). Rigid sheets of reflective foil insulation are commonly used in cavity walls and roof spaces, whereas mineral wool is rolled out between floor and ceiling joists. Reflective foil insulation works by reflecting heat off the surface of the material back into the building. Mineral wool retains heat by trapping air in the material to keep a building warm.
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Chapter 1 Principles of building construction, information and communication Wall building material
Description
Damp-proof course (DPC)
A damp-proof course (DPC) is built into the external walls of a building, 150 mm above ground level. The DPC prevents moisture being sucked up from the ground through the brick, blockwork and stone walls, a process known as rising damp. DPC is made from plastic and supplied on a roll, typically 100 mm or 112.5 mm in width to suit the thickness of the wall. DPC can also be used vertically to prevent moisture bridging the cavity where there are openings for windows and doors in the external walls.
Wall ties
Wall ties are used to hold the inner and outer leaves of a cavity wall together to strengthen it. They are positioned in between the mortar joints in a masonry wall as it is being built; they can also be used in timber frame construction. Building Regulations state that the maximum spacing for the wall ties should be no more than 900 mm horizontally and no more than 450 mm vertically.
Lintels
Internal and external brick and block walls will have openings in them for doors, windows and walkways. The masonry above these openings is usually supported with a beam known as a lintel. Nowadays, lintels are made from reinforced concrete or prefabricated (shaped) galvanised steel. In older buildings, lintels will have been made from stone or heavy timber; however, these can be expensive and the timber can decay over time. Sometimes the tops of the openings in external walls are shaped with arches and curves to create an architectural feature. The brickwork around these shapes can be arranged so that it is self-supporting, therefore lintels are not always required.
Render
Render is similar to mortar; it is used to plaster external masonry walls to make them flat and suitable for a decorative paint finish. Internal masonry walls, such as those made from concrete blocks, may have render applied to them as a base before finishing plaster is used to make the wall surface smooth.
KEY TERMS
ACTIVITY
Non-porous: when water cannot soak through a material or building component. Bridging: when moisture travels through a cavity wall in the materials used to construct it. Poorly installed cavity wall insulation and wall ties are examples of materials that can result in water bridging a cavity in a wall.
Perform an experiment with two types of insulation: reflective foil and mineral wool. Put on a pair of protective gloves before placing your hands on the surface of the mineral wool, then do the same with the reflective foil insulation. Write a short report to explain what you experienced and why.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Lintel
Lintel
p Figure 1.27 Brickwork openings in walls: arched (left) and square (right)
IMPROVE YOUR ENGLISH A DPC is an ‘impermeable’ material, which means that water cannot pass through it. Write a sentence describing another building material that includes this word. Check your answer with your teacher or tutor.
Brick bonds When bricks and concrete blocks are laid by bricklayers, they are arranged so that the vertical joints are staggered. If all the bricks and blocks were aligned, this would make the wall or column weak and the mortar joints would crack. The arrangement of the brickwork is known as the bond in the construction industry. Several different types of brick bond are commonly used in house building; the simplest method is known as the stretcher bond. This bond is where each course of bricks or blocks is positioned centrally over the vertical joints in the row below.
KEY TERM Courses: arrangements of bricks and blocks laid in rows by bricklayers.
INDUSTRY TIP Mortar can be made with lime rather than cement and is often used for sustainable homes because it is less harmful to the environment when it is made this way.
p Figure 1.28 Stretcher bond
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Internal walling materials and components The main building materials used to construct internal walls are illustrated in Table 1.7, with a brief description of their purposes. q Table 1.7 Building materials used to construct internal walls Material
Description
Timber (stud)
Timber stud walls are constructed with a series of vertical uprights, known as ‘studs’, nailed between a ‘head’ (top plate) and the ‘sole plate’ (bottom). The studs are spaced out to suit the plasterboard wall covering, typically either 400 mm or 600 mm between the centres. Rows of short noggins are fixed mid-height between the studs to prevent them from twisting. Timber internal walls are constructed with rough sawn fir, spruce or pine. This often varies in width and thickness, which can make it difficult to install. It is preferable to build timber walls with CLS because of its uniform size; CLS also has smooth surfaces and rounded edges, which make it more comfortable to handle. The most commonly used rough sawn timber sizes are 75 mm × 50 mm and 100 mm × 50 mm, which are often referred to by their imperial sizes of 3” by 2” and 4” by 2”. CLS is slightly smaller than these dimensions because it is planed. It can also vary in size by a few millimetres between different suppliers; it is approximately 63 mm × 38 mm and 89 mm × 38 mm.
Metal (stud)
Metal stud walls are similar in many ways to timber stud walls, in that both have a head, sole and studs. The main difference between the two types of walls is that metal studs do not usually have noggins to support them. The metal head and sole plates are ‘U’ shaped to allow the vertical ‘C’ shaped studs to slide in between them, before they are fastened together and the plasterboard is secured to each side.
Low density blockwork
The low density of these concrete blocks means that they are lighter than standard concrete blocks and easier for the workers to handle, thus creating a lower risk of manual handling injuries. These blocks are designed to improve the thermal insulation of internal and external load-bearing walls that are up to two storeys high.
Render
Render is made by mixing sand, cement and water together. The first coat (known as the scratch coat) is applied to the surfaces of walls in a layer that is 10–15 mm thick with a trowel by a plasterer and levelled out with a straight edge. Further thinner coats of render may be applied on top if needed. Cement render can take a long time to dry fully before it is plastered, which is why alternative methods of finishing internal walls are now sometimes preferred.
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Description
Plaster
Various types of plaster can be used to finish the surface of a wall so that it is perfectly flat and smooth. Some plasters are designed to be applied to cement-rendered walls reasonably thickly, while others are used to cover plasterboard to only 3 mm thick. Plaster is usually supplied in a powder form and mixed with water until it is completely smooth and ready for use. Ready mixed plasters are available in tubs and can be used to repair small holes in previously plastered walls.
Plasterboard
Plasterboard, also known as drywall, is the sheet material used to cover stud partitions and concrete walls. Plasterboard is made from gypsum plaster and covered with a layer of paper on both sides to improve its strength. A standard sheet of plasterboard is 2400 mm × 1200 mm × 12 mm, although other sizes are available. Plasterboard can be cut to size by scoring one face with a craft knife and bending it along the cut to snap the board cleanly in two. It is usually fixed to stud partition walls with drywall screws or glued to concrete walls with plasterboard adhesive. The plasterboard provides a flat, smooth surface to the wall that can then be plastered or decorated.
INDUSTRY TIP Plaster contains chemicals known as retarders that prevent it from drying too quickly when it is being applied. However, if the use by date on the packaging of the plaster has been exceeded, it will set fast, making it difficult to achieve a smooth finish.
Calculating the area of a wall You may need to calculate the area of a wall accurately for many reasons, such as to estimate how many sheets of plasterboard are required or how many wall tiles are needed for a kitchen or bathroom. The area of a wall can be calculated by multiplying its length by its height (L × H = area), which is expressed in square metres (m²). This is demonstrated using the following examples. Example 1 Calculate the area of the wall shown below. 2.6 metres
2.4 metres
2.6 metres (long) × 2.4 metres (high) = area m² 2.6 m × 2.4 m = 6.24 m²
The area of the wall is 6.24 m². 32
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Chapter 1 Principles of building construction, information and communication Example 2 Calculate the area of the wall below. 4.9 m 45°
3m
5.3 m
To find the answer to this question, you must multiply the length of the wall by its height and then subtract the area of the missing corner. Area of the wall including the missing corner 5.3 metres (length) × 3 metres (height) = area 5.3 m × 3 m = 15.9 m²
The area of the wall including the missing corner is 15.9 m². Area of the missing corner To find the area of the missing corner, you must first subtract the length at the top of the wall from the length at the bottom of the wall to find the length of the missing corner. 5.3 m (length at the bottom) – 4.9 m (length at the top) = 0.4 m² (the length of one side of the missing corner) 0.4 metres × 0.4 metres = 0.16 m²
0.16 m² is the area of the square illustrated in the corner, not the area of the missing triangle, therefore you must divide your answer by two. 0.16 m2 ÷ 2 = 0.08 m²
The area of the missing corner is 0.08 m² Area of the wall shaded 15.9 m² (total area of the wall including the missing corner) – 0.08 m² (area of the missing corner) = 15.82 m² 4.9 m
0.4 m
Missing corner
0.4 m
3m
5.3 m
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IMPROVE YOUR MATHS How many full sheets of 2.4 m × 1.2 m plasterboard are needed to cover both sides of the stud partition wall illustrated below? 15.7 m
1m
KEY TERM Backing plaster: an alternative material to traditional cement render. Browning, Bonding coat and Hardwall are three examples of backing plasters that can be used on masonry walls to make them flat, before applying the finishing coats of plaster. Backing plasters dry much faster than cement render and are often preferred for use on internal walls. Porous: a porous surface or material absorbs moisture because it contains lots of small holes.
HEALTH AND SAFETY Always read and follow the paint manufacturer’s instructions on how to transport, use, store and dispose of their products. They may recommend that you wear personal protective equipment (PPE) to protect your skin, eyes and lungs from the effects of chemicals in some paints, stains and preservatives. Some products may also be highly flammable, therefore you should avoid smoking or using naked flames around them.
3m 2m
Door opening
Paint systems for new plaster Before decorating a freshly plastered wall, you must first make sure that it has dried fully. If it has not, then this could cause a problem with paint or wallpaper sticking to it. Wet plaster on top of plasterboard can take between 2 to 3 days to dry out; this will depend on the climate, and the thickness of the plaster. Plaster that has been applied to cement rendered walls or where backing plaster has been used will take much longer to dry. The surface of a newly plastered wall will be porous, which can result in the paint not sticking to it. To overcome this problem, the wall must be sealed with a mist coat of emulsion paint. A mist coat of paint is simply a diluted mixture of 70% emulsion paint and 30% water. The water in the mist coat soaks into the plaster to seal it, making it less absorbent and as a result creates a good foundation for the topcoats of paint. An alternative to using a mist coat is to use a breathable (also known as microporous) paint that has been specially designed for newly plastered walls. As these paints do not have to be watered down like a mist coat, they do not drip as much. Another advantage of breathable paint is that it allows the plaster to continue drying after it has been applied to the walls. The main disadvantage is that these paints are usually more expensive. After the first coat of paint has dried, you will be able to see any areas of the wall that need to be filled and sanded before the topcoats of paint are applied. The type of emulsion used for the final coats of paint will largely depend on the areas in which it is to be used. l
Matt is commonly used for walls and ceilings, and its non-reflective finish makes it ideal for use in areas that have an uneven surface. l Eggshell, as the name suggests, has a low sheen similar to the shell of an egg. Eggshell is perfect for bedrooms and living rooms.
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Chapter 1 Principles of building construction, information and communication l
Vinyl silk has a shiny, washable finish, making it ideal for communal areas such as hallways and staircases. Light will reflect off the surface of vinyl silk, therefore it is not recommended for use on walls with an uneven surface. l Satin provides a soft-sheen finish that is harder wearing than matt emulsion. The painted surface can be maintained by lightly wiping over with a damp cloth. Emulsion can be applied with a roller, and a brush when cutting in, or a spray gun. The disadvantage of spraying is that you will need to prepare the area by masking up (covering) to protect some surfaces from over-spray, which can be time-consuming, but spraying does provide a better finish.
5 CONSTRUCTION OF FLOORS Floors provide a flat, level surface to live and work on. There are two main categories of floors: the ground floor and upper floors. Ground floors are constructed completely differently to upper floors, as they prevent moisture rising from the ground beneath and insulate the building against heat loss. Upper floors usually span longer distances unsupported compared with ground floors. They also have openings left in them for staircases.
KEY TERMS Cutting in: carefully painting up to a surface with a different colour, paint, stain or material using a brush. Masking up: protecting areas of a wall, floor or ceiling from paint with masking tape and paper. Domestic building: a property that no more than one family lives in, such as a house.
This section looks at some of the methods and components used to construct floors in domestic buildings.
Types of floors Ground floors There are two methods used to construct ground floors, known as solid and suspended. Solid concrete floors may be used if the construction site is relatively flat rather than inclined (sloped), because less material will be needed to level the floor. Concrete cures at a rate of 1 mm per day. Therefore, if the concrete layer in a solid floor is 100 mm thick it will take over three months for it to harden fully. Although it is possible to walk on a solid concrete floor after 24 hours, it is still susceptible to damage, therefore suspended floors are often preferred because they are quicker to install and can be used straight away. Suspended ground floors used to be constructed with timber joists spanning between walls, supported from below by low height walls, known as sleeper walls. You will find many examples of this method of construction in homes today. However, the ends of the timber that are built into the walls often rot because of poor ventilation and the high level of moisture trapped under the floor. New suspended ground floors are now often built with reinforced concrete beams, with concrete blocks placed in between them. This system is known as block and beam. This type of floor does not have the maintenance problems of timber floors; they also have an added advantage in that they can be walked on as soon as they have been positioned. The space under a suspended hollow floor should be ventilated through air bricks built into the external walls, to prevent a build-up of moisture. It is important that the air bricks are kept clean and not covered by raising the ground level outside or building over them. 35
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Joist supported on hangers
Honeycombed sleeper wall
DPC min 150 mm above ground level
p Figure 1.29 Suspended ground floor
Slab on hardcore or blinding on polythene membrane
Upper floors KEY TERMS Joist hangers: metal brackets shaped to support the ends of timber floor joists. Notch: a shallow recess cut into a piece of timber. Concrete slab: the solid mass of concrete poured to create a floor.
Upper floors are constructed by site carpenters with timber beams known as joists that span from one load-bearing wall to another. Timber joists on upper floors are less likely to decay as they would on the ground floor because they are further away from the moist ground. The joists in upper floors are supported with metal joist hangers secured to load-bearing walls. Engineered timber joists have been developed in recent years as an alternative to solid timber joists. Eco joists and ‘I’ beam (TGI joists) are examples of manufactured/engineered joists made from materials such as orientated strand board (OSB), plywood and metal. Engineered joists can span longer distances without being supported from below. Pipes and cables (for use in services) can also be passed through the engineered joists, without weakening them with holes and notches. The block and beam system described for use on ground floors can also be used for upper floors. A solid concrete slab reinforced with metal can also be built on upper floors; however, both of these types of floor are much heavier than timber floors and would therefore need bigger foundations to support them.
p Figure 1.30 Suspended upper floor
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Chapter 1 Principles of building construction, information and communication Ground floors and upper floors built with timber joists are usually covered with sheets of chipboard panels, to provide a flat level surface. The underside of upper floors is normally clad with plasterboard, fixed with drywall screws to hold it in position, to create the ceiling. Suspended floors are sometimes insulated to improve their thermal and sound insulation.
Components of solid concrete ground floors The main building resources used to construct solid concrete ground floors are illustrated in Figure 1.31 and described in Table 1.8. Screed Insulation Concrete DPM Sand blinding Hardcore
p Figure 1.31 A section through a solid concrete floor q Table 1.8 Main building materials used to construct solid concrete ground floors Material
Description
Hardcore
Hardcore provides a firm base to support a solid concrete ground floor. It is usually made of solid materials that will not be affected by water, such as reclaimed/recycled brick rubble, tiles, crushed rock and gravel. Alternatively, a granular (gritty or coarse) material referred to as MOT Type 1 can also be used for the sub-base. The hardcore layer must be compacted down with a machine known as plate compactor to prevent it from moving and cracking the completed solid floor.
Sand blinding
A layer of sand is spread over the hardcore base to prevent any sharp edges from puncturing the damp-proof membrane.
Damp-proof membrane (DPM)
A layer of thick plastic sheeting known as a damp-proof membrane (DPM) is spread over the sand blinding to prevent moisture and weeds coming through the floor.
Oversite concrete
Concrete is poured over the DPM to a depth of at least 100 mm; it is sometimes reinforced with metal to create a strong base. Although the oversite concrete will be reasonably level, it will not be perfectly flat.
Insulation
Sheets of rigid reflective foil insulation are laid on top of the oversite concrete to improve the thermal efficiency of the floor. The layer of insulation prevents heat from being absorbed into the ground.
Screed
Screed provides a perfectly level and flat surface to the solid floor. There are two different types of screed that can be used, known as dry mix screed and liquid screed. Dry mix screed is made of 1 part cement and 3 parts sand with a small amount of water to bond them together. The dry mix screed is laid by hand with a towel and a straight edge to make sure that it is flat and level. Liquid screed is a watery cement-based product that is pumped through pipes to the areas where it is needed. Just like water, the liquid screed is self-levelling and fills any air pockets that could be left if using with the dry mix screed instead.
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INDUSTRY TIP Underfloor heating is more energy efficient than radiators because it heats an entire room from the floor. Underfloor heating is usually created by laying hot water pipes on top of the insulation. When the water is pumped through the pipes it heats the floor above.
IMPROVE YOUR ENGLISH Use the internet to look at videos of liquid screed and dry mix screed being installed. Write a short paragraph about the benefits of each method.
Components of timber floors The main building resources used to construct timber ground floors and upper floors are described in Table 1.9. q Table 1.9 Main building materials used to construct timber ground floors and upper floors Material
Description
Oversite concrete
Oversite concrete is the solid base that is constructed under the footprint of a building. It provides a foundation for the sleeper walls, prevents weed growth and stops moisture entering the building.
Sleeper walls (also referred to as honeycomb walls)
Sleeper walls are low height walls built underneath timber suspended ground floors to support the joists mid-span. The bricks in these walls are arranged so that they have spaces between them to allow air to flow through the void under the floor.
Wall plates
Wall plates are fixed to the top of the sleeper walls to help spread the weight of the joists evenly across them. Wall plates are made of timber; therefore, the joists can easily be nailed to them to secure them in position.
Damp-proof course (DPC)
A damp-proof course is laid between the top of the sleeper walls and the underside of the wall plates. The DPC protects the timber wall plates and floor joists from moisture being drawn up from the ground through the walls.
Joists
Joists are the structural timber beams that ground floors and upper floors are built on. They can either be solid timber or manufactured engineered beams. The joists are usually spaced out between 400 mm and 600 mm, to suit the size of the floor covering and plasterboard below.
Insulation
Mineral wood insulation is commonly used to insulate between floor joists to improve the floor’s thermal efficiency. Suspended floors can also be insulated to reduce sound passing through them and to protect them from fire.
Floor covering
Narrow softwood boards were commonly used to cover floor joists; however, these can be expensive and timeconsuming to fit. Nowadays large chipboard sheets are used to create floors. The chipboard edges are profiled with a tongue and groove that allow them to be connected together to create a strong joint.
KEY TERM Footprint: the area of ground that a building is constructed on.
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6 CONSTRUCTION OF ROOFS The timber framework of roofs is usually constructed by site carpenters before roofers weatherproof it with felt, slates and tiles to keep the building dry. This section looks at basic roof shapes and the components of a roof. Some basic maths is used to calculate the materials needed for some roof components. As you progress through your training as a carpenter or joiner, you will learn more about roofs and how to build them.
Types of roofs A roof is used to keep a building dry. It is also designed to keep us warm in the winter and cool in the summer. So why are roofs different shapes? Usually this is down to the cost of constructing them and the design of the building.
Flat roofs The simplest and most cost-efficient roof is a flat roof. Despite the name, flat roofs have a slope, known as a fall, to allow water to run off the roof surface into the guttering and the drainage system below. The maximum pitch of a flat roof is 10°; if the angle of the roof is greater than this it then becomes a ‘pitched roof’. Flat roofs cannot be tiled or covered in slates because the pitch is too low. Therefore, they are protected from the elements with one of the following materials: l l l l l l l
bitumen felt lead copper zinc rubber (Ethylene Polypropylene Diene Monomer – EPDM) fibre glass green flat roof.
Bitumen felt is mostly used for sheds and outbuildings because it is cheap and not as durable as alternative products, though it needs regular maintenance to prevent leaks. Lead and copper coverings can last hundreds of years, but these materials are expensive and highly skilled craftsmen are required to install them. These materials are now generally used to maintain older historical structures, such as churches and listed buildings. EPDM is a modern alternative flat roof covering to bitumen felt. The rubber is supplied on a roll, cut to length with a craft knife and glued to the sheet materials (known as decking) underneath it. A flat roof covered with EPDM has an expected lifespan of over 50 years. Fibreglass roofs are extremely strong, but the materials are more expensive than the EPDM and their expected lifespan is substantially shorter. Zinc is a lightweight metal that is resistant to corrosion, making it ideal for flat and pitched roof coverings. It is a malleable (soft) metal that is fitted to roof structures in sheet form because it can be easily shaped, curved and cut to fit. Zinc has the added benefits of having a long lifespan, being entirely recyclable and using less energy to produce compared with other roof materials.
p Figure 1.32 Flat roof
KEY TERM Pitch: describes an angle or slope. The term is often used by carpenters and joiners when referring to roofs and stairs. Listed building: an old structure that has special architectural or historical interest. When a building or structure becomes listed it is registered on the British Listed Buildings database, whose purpose is to protect and maintain buildings for future generations. It is a criminal offence to carry out any work on the inside or outside of a listed building without the consent of the local planning office.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma A green flat roof is a living roof, consisting of a layer of vegetation planted over a waterproofing membrane below. There are many environmental benefits of using a green roof, including absorbing pollution and carbon dioxide in the atmosphere. A green roof also has the added benefit of regulating the temperature of a building by keeping it cool in the summer months and warm in the winter.
Pitched roofs KEY TERM Rafters: the main structural timbers in a roof; they are used to support the roof covering.
A basic pitched roof has a single slope above 10° on one face. This is known as a mono-pitch, or a lean-to if it is against an existing building. Where the width or span of a building is too great, it may be more economical to divide the roof with two pitches known as a double roof. As the length of the rafters for a roof increase to suit longer spans, the size of the timbers also must increase, or the roof must be supported with heavy timber or steels known as purlins. A building that has an external end wall that extends to the top (apex) of the roof is known as a gable-ended roof. This type of roofs is often used because it is simple and quick to erect.
p Figure 1.33 Gable-ended roof
p Figure 1.34 Lean-to (left) and mono-pitch (right) roofs
Where a building changes direction on plan (the view from above), the surfaces of a pitched roof will meet on the inside to form a valley and on the outside to form a hip. Hip and valley roofs are more complex to construct and therefore more expensive; however, they do add character to a building to make it more desirable.
Valley
Pitched
Eyebrow
Hip
p Figure 1.35 ‘Hip and valley’ roof
Flat
Segmental
p Figure 1.36 Dormer roofs
Some roofs have loft spaces big enough to create additional rooms, providing they are constructed to Building Regulations, and sometimes with permission from the local authority. Roof windows can be installed between the rafters to provide a source of natural light; dormers are a better option because they increase the headroom.
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Components of roofs
KEY TERM
Pitched roofs are traditionally built with pairs of rafters fixed to a wall plate and a central beam known as a ridge. This method of construction is known as a cut roof; it requires carpenters to cut and fix all the roof components on site by hand. Although this method is still used to build many roofs and is sometimes preferred due to the complexity of a roof shape, most roofs are constructed with trusses. Trusses are prefabricated sections of a roof made in a factory before they are delivered and erected on site. This method requires less cutting on site and uses less timber, which means that trusses can be erected faster and more cheaply than cut roofs.
Wall plate: a length of timber positioned on top of a structural wall so that rafters and joists used for a roof (or floor) can be nailed to it. Wall plates provide a good fixing point and help to spread the weight of the roof evenly along the length of the wall down to the foundations below. Wall plates used for roofs are secured to the wall below with metal restraint straps, also referred to as wall plate straps.
25 mm gap left above these braces to clear diagonal brace
Node point
p Figure 1.37 Trussed roof Rafter Purlin
Ridge board Slate
Hip rafter
Cripple jack rafter Valley rafter
Jack rafter
Felt Insulation
Wall plate
Tiling batten
p Figure 1.38 A section through a roof
These are some of the main components of a pitched roof. are used to create a level ceiling in a roof by spanning from one external wall to another. Trusses already have joists built into them, while a cut roof will require them to be cut and fixed as the roof is constructed. The underside of ceiling joists is usually covered with plasterboard, to provide a smooth and level surface to finish with plaster. l Underlay covers the framework of the roof, under the tiles or slates, to provide a second barrier to prevent moisture entering the building. The underlay used l Joists
INDUSTRY TIP All the angles of lengths of timber needed to construct a pitched roof can be found in a book or smartphone app known as a Roofing Ready Reckoner. Once the first rafter has been marked out and cut, this pattern rafter can then be used to mark out further common rafters needed to build a basic roof. 41
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KEY TERM Verge: the edge of a pitched roof on a gable end.
HEALTH AND SAFETY Cement-based boards containing asbestos were used for undercloaking on roofs up until the year 2000, when their use was completely banned. You must make sure that an asbestos survey and risk assessment has been carried out on any buildings constructed before the year 2000 before you undertake any work on them.
ACTIVITY Use the internet to research other sustainable materials that can be used to cover a pitched roof.
on pitched roofs is known as a breathable membrane or semi-permeable membrane. This means that it will ventilate the roof space to prevent the roof timbers from rotting. l Timber roof battens, also known as laths, should be evenly spaced and nailed over the entire roof surface on top of the breathable membrane at right angles to the rafters. The battens provide support and something to nail the tiles or slates onto. l Fascia is the wide board fixed to the rafter feet (known as the ‘eaves’) that continues around the perimeter of the roof. It is used to protect the lower part of the roof from the weather and to prevent water penetrating into the building. The fascia is also used to fix the brackets to secure the guttering. l Soffits are boards used to finish the eaves on a roof, by allowing the rafters to project over the external wall and covering the underside of the eaves with a soffit. Fascia and soffits can be made of timber; however, these require regular maintenance to prevent them from rotting. Alternatively, low maintenance plastic (uPVC) can be used. l Undercloaking is the fibre cement board that is sometimes fixed to the underside of the overhanging roof battens along the verge on a roof. Its purpose is to cover and protect the roof battens and also to support the mortar used to fill the gaps under the slates or tiles to finish the verge. l Barge board is the continuation of a fascia around the gable end of a roof. l Slates can either be cut from natural rock from the ground or man-made from materials such as fibre cement to give the appearance of real slate at a cheaper price. Natural slate has a life expectancy of over 150 years and is often recycled from old properties and reused on new builds, therefore is a sustainable building material. l Clay tiles have been used for roofs for thousands of years because they are strong, durable and fire-resistant. Concrete tiles are also available in a variety of colours and shapes that often replicate natural clay tiles. Both types of tiles have a similar life expectancy; the cheaper concrete tiles are less sustainable, because of the amount of pollution that is produced when they are manufactured. l Shingles are a lightweight, cheaper alternative to traditional tiles, although they are rarely used in the UK for domestic houses because of the wet climate. Shingles are flat and either square, rectangular or hexagonal in shape, and they are made from asphalt felt, cedar (wood) or metal. l Thatch is a natural and sustainable building material that is used to weatherproof and insulate a building. Water reed, rushes or straw are typically used. The dried, tightly packed dense thatch is laid by a skilled tradesman known as a thatcher. A well-maintained thatched roof could last up to 40 years, depending on the type of thatch used, the geographical location of the property and any damage from vermin and birds.
Modern construction methods This chapter has looked at methods of constructing low, medium and high-rise buildings, the benefits of using different materials and the impact that these materials have on the environment. 42
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Chapter 1 Principles of building construction, information and communication Modern construction methods have been developed in recent years to reduce the amount of construction that takes place on site. These new methods, which are more efficient and increase productivity, include the use of prefabricated, sectional and modular parts manufactured in controlled factory environments. Manufacturing offsite reduces the amount of time spent on site by skilled tradesmen, improves the quality and the standard of work, and reduces the overall building costs. Some common modern methods of construction are: where building components or sections are manufactured in a factory, delivered to the construction site and assembled (for example, roof trusses) l sectional/pods, where sections of a building are constructed offsite (for example, en-suites and kitchens) l modular, where buildings or homes are constructed in factories and fully fitted out with internal fixtures and fittings such as kitchens and bathrooms. l prefabrication,
Calculating the linear quantity of fascia board Carpenters and joiners calculate sizes, costs, materials and time routinely as part of their work. It is important that you can complete these tasks accurately. In this section you will learn how to calculate the lengths of fascia board or soffit needed for a given task.
IMPROVE YOUR MATHS Metres (m) and millimetres (mm) are the metric units of measurement used in the construction industry in the United Kingdom. (Note: although you may have used centimetres (cm) in maths lessons at school, you should avoid using centimetres in your work as a carpenter or joiner to avoid causing confusion, as this can lead to mistakes being made.) Remember: l 1 metre equals 1000 millimetres (1 m = 1000 mm) l 1 centimetre equals 10 millimetres (1 cm = 10 mm). Imperial units of measurement were used in the UK until 1971, but today there are only three countries in the world that mostly use them: the USA, Liberia and Myanmar in South East Asia. 1 inch equals 25.4 millimetres (1˝ = 25.4 mm). 1 foot or 12 inches equals 304.8 millimetres (1ft or 12˝ = 304.8 mm).
ACTIVITY Find out which metric units are used to measure liquids and weight.
Linear measurement It is not always practical to obtain the exact lengths of materials required for tasks such as installing skirting, flooring or fascia. Therefore, the total amount (known as the ‘linear measurement’) is calculated. To put this into practice, the following house shapes are used as examples of how to calculate the linear amount of fascia board needed. 43
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Example 1 8m
5.5 m
New fascia boards are required for a building that measures 8 m long by 5.5 m wide. The linear amount of fascia board needed is the same length as the total perimeter of the building. The perimeter is calculated by adding together all the lengths of the sides of the building: 2 sides × 8 m long = 16 metres
2 sides × 5.5 m long = 11 metres 16 + 11 = 27 m
The perimeter of the building is 27 m, therefore the total amount of fascia board required is 27 m.
Example 2 6.2 m (A)
? (B)
9 m (F)
12 m (C)
6.2 m (D)
? (E)
Replacement soffits are required for the building illustrated above. To calculate the linear amount of material needed to complete the task, you should find the perimeter of the building by adding together all the lengths of the external sides: Side A = 6.2 m
Side B = 9 m (F) – 6.2 m (D) = 2.8 m Side C = 12 m
Side D = 6.2 m
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Chapter 1 Principles of building construction, information and communication Side E = 6.2 m (A) + 12 m (C) = 18.2 m Side F = 9 m
Amount of material needed = A + B + C + D + E + F = 6.2 + 2.8 + 12 + 6.2 + 18.2 + 9 = 54.4
The perimeter of the building is 54.4 m; therefore, 54.4 m of soffit is required for the building.
IMPROVE YOUR MATHS Calculate how many linear metres of fascia are required for the building shown in the illustration below. 5.5 m (E)
? (C)
? (F)
11.2 m (H)
5.6 m (B)
5.6 m (D)
5.5 m (A)
18 m (G)
Percentages The amount of fascia board that should be ordered for the previous two examples is slightly more than calculated, to allow for the joints to be cut on the corners and to extend them in length (lengthening joints). It would also avoid the need to use short off-cuts of timber to make up the full lengths required. Usually you add between 5% and 10% of extra material to the total amount calculated; this is referred to as the ‘waste’. There are several ways of calculating a percentage of waste. Four examples are given below.
Example 1 To calculate 10% of 27 m, you could divide 27 by 10, which would give you the answer of 2.7 m. Although this is a simple method, it would not work for figures other than 10%. 27 ÷ 10 = 2.7 m
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Example 2 To calculate 5 % of 72 m, you can divide the whole number (72) by 100 to calculate 1% and then multiply that by the percentage you are trying to work out; in this case 5%. 72 ÷ 100 = 0.72 (1 % of 72 m) 0.72 × 5 = 3.6 m
Example 3
Percentages can also be calculated by multiplying them as a decimal by the whole number. To calculate the answer to the question 7% of 39 m, you need to know that 7% as a decimal is 0.07. Therefore: 0.07 × 39 = 2.73 m
Example 4
Multiply the total amount of material required by the total percentage of the linear length (100%) plus the percentage of the amount of waste to be added on (9%). For example, if 200 m of fascia has been measured and an allowance of 9% waste is needed:
INDUSTRY TIP When painting with a brush, you should always apply the paint with strokes in the direction of the grain to achieve a professional finish.
HEALTH AND SAFETY Make sure that you have read and understood your employer’s risk assessment for working at height before carrying out any work where there is a risk of falling. Working at height should be a last resort after all other options have been considered to avoid the hazard. See Chapter 6 for more information on risk assessments.
200 m × 1.09 m = 218 m of fascia is required including the wastage.
Paint systems for timber
Most timbers that are left untreated with preservative, paint or wood stain will decay over time if left exposed to the elements. Fascia, soffits and barge boards on a roof are good examples of where timber is especially exposed to the weather. However, if they are prepared correctly and maintained they should last for many years. Paint is usually applied with a brush or roller on construction sites, although these methods will leave brush marks and a slightly textured finish. Alternatively, the paint can be sprayed onto timber to give it a perfectly smooth finish. This method is normally used for high-class joinery, where the paint can be applied in a spray booth with extraction to safely remove the paint mist from the air. Approximately 80% of all paints used in the construction industry are water-based, with the remaining paints being solvent-based. Solvent-based paints are extremely durable and give a better appearance than water-based paints; however, they can take between 16 to 24 hours to dry and the brushes used must be cleaned with white spirit. The process of making and disposing of paints containing solvents is harmful to the environment, so water-based paints are now preferred. In the right conditions, water-based paint dries quicker and the equipment used to apply it can be easily cleaned with water. It also does not smell as offensive as solvent-based paints.
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Chapter 1 Principles of building construction, information and communication The following list is a step-by-step guide to preparing bare timber to receive a painted finish. 1 The process for painting some species of timber may be slightly different than for others. The first stage for painting redwood (which is a softwood) is to apply several coats of clear preservative with a brush, roller or spray. It is important that the preservative soaks deep into the grain of the timber. You should wait for each coat of preservative to dry fully before applying further liberal coats. This stage is only necessary if the joinery is going to be used externally, such as for doors and windows. 2 After redwood has been painted, the knots can progressively start to show through the painted finish long after it has dried. To avoid the process of knots ‘burning’ through the paint, all the knots need to be brushed with a substance known as ‘knotting’. The first coat of knotting will be touch dry in 5–10 minutes, although if a further coat is required you should wait at least 30 minutes before painting. 3 To achieve a good quality finish, bare timber should be coated with ‘primer’ to seal the grain and allow further coats of paint to stick. Once the first coat of primer has dried, it can be lightly sanded to achieve a smooth finish with abrasive paper and dusted off, before applying a second coat. (Note: if the timber has previously been painted it does not need to be repainted with primer. You should start at step 4.) 4 Lightly sand the surface of the timber and remove any dust particles with a dusting brush or vacuum. 5 The timber is now ready to receive one layer of undercoat paint, which you can apply with a brush, roller or spray. The undercoat prepares the surface for the final topcoat of paint and protects it from moisture. If the timber has been previously painted, it should be sanded and repainted with undercoat so that the topcoat will adhere to the paint underneath. White primer/undercoat can be used as base layer before applying a final coat of paint. Grey primer/undercoat is preferred to white if the topcoat is a dark colour, as a white base layer may show (‘grin’) through the finished coat of paint. 6 Lightly sand the surface of the timber and dust it off. It is now ready to receive the topcoat of paint. The final coat will determine the colour and finish. You should refer to the specification for this information. In addition to the colour, the specification will also suggest one of the following finishes: matt, satinwood, eggshell or gloss. It is easier to apply preservative and several coats of primer and undercoat to all the faces of fascia, soffits and barge board before cutting it and fixing it. Any cut ends must be treated before fixing in position to prevent the exposed grain soaking up moisture and rotting. Avoid using paint straight from the tin with a brush, as this will result in a build-up of dry paint forming around the top and make it difficult to seal it after use. It is better to pour some of the paint into a small pot known as a ‘kettle’ and top it up when needed.
IMPROVE YOUR ENGLISH Write a short sentence to explain the word ‘liberal’ as used in step 1.
KEY TERMS Touch dry: a surface that has not fully hardened, such as paint, but has formed a thin dry layer, referred to as a ‘skin’. Timber that is touch dry can usually be handled with care; soft paint can easily get damaged if it is not stored and moved correctly. Abrasive: having a rough surface that will rub away at another surface. Dusting brush: a small hand brush used by painters and decorators, to prepare surfaces to be painted by removing any loose dirt and dust.
INDUSTRY TIP Paint colours are usually standardised and referenced from either ‘British Standards BS4800’ or ‘RAL’ colour charts. For example, 20 E 56 is a shade of blue on the British Standards colour chart and RAL 2005 is luminous orange. Use the following links to view the extensive range of British Standard and RAL colours available: www.britishstandardcolour. com www.ralcolor.com
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ACTIVITY Prepare and finish a piece of bare timber for external use in a colour of your choice, following the step-by-step process on page 47.
IMPROVE YOUR MATHS Calculate how much it would cost for one litre of primer, undercoat and gloss required to paint a length of fascia and soffit. The supplier is offering a 5% discount on painting and decorating materials this month. What is the total cost of the paint after the 5% discount has been applied?
7 HOW TO COMMUNICATE IN THE WORKPLACE HEALTH AND SAFETY Mobile phones are an excellent way of communicating with other people on different platforms, but they should not be used for personal calls or contact during working hours. Mobile phones could be a distraction for yourself and others that could result in an accident or near miss so should only be used carefully and when necessary.
Good communication between people with different job roles in the workplace plays a particularly important part in the success of any building project. If people do not communicate effectively then information is not passed from one person to other, which could cause delays and missed deadlines. We can communicate with each other without saying a word, just from our body language or with the use of hand signals. Signalling is often used by workmen, for example, to direct construction site traffic and cranes in the workplace. Although these are effective methods, they are not suitable for communicating technical information and they are usually one-way only. Verbal communication is quick, easy and often used, but can be forgotten and misinterpreted. Written information and drawings can be clear and effective ways to share building information; they can also be referred to later if needed. This section looks at the various job roles within construction, methods of communication and how to record verbal messages.
Job roles within construction Everyone involved in a construction project is part of the building team. The most important person in the building team is the client: without them, there is no project or money to fund it. The building team consists of various professionals, technicians, trades people and general operatives. Table 1.10 provides an overview of the building team and their roles within it.
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Chapter 1 Principles of building construction, information and communication q Table 1.10 Overview of the building team and their roles The building team Category
Role
Description
Customer
Client
A client could be an individual or an organisation. They usually start a building project with an idea, referred to as a concept, and appoint an architect to produce technical drawings. Most building projects require sets of plans to be sent to the local authority for planning permission before any building work can begin. The client is usually responsible for funding the construction project.
Professional Architect
Architects are normally appointed by clients to produce technical drawings for a construction project; they may also provide advice and guidance for them through the building work. They are known as professionals because they have achieved degree-level qualifications to enable them to perform their job.
Structural engineer
Structural engineers design the strength and stability of buildings and structures, such as bridges and tunnels.
Building control inspector
Building control is a department within the local authority responsible for granting permission and overseeing construction work to protect people’s health and safety. It is also responsible to enforcing Building Regulations.
Quantity surveyor
Quantity surveyors are sometimes appointed by the client to calculate the costs of the building work and control the budget.
Civil engineer
Civil engineers are similar in many ways to architects. Rather than designing buildings, they plan roads, bridges, railways and airports.
Construction Construction managers help to prepare the schedule for a building project and oversee the day-to-day manager running of the site, to make sure that it finishes by the deadline and on budget.
Technician
Tradesperson
Clerk of works
The clerk of works represents the client on construction sites to monitor the quality of the work, and to make sure that building plans and specifications are followed correctly.
Supervisor
If a building project is large enough, there may be supervisors for each trade to oversee the quality of working as it is completed.
Surveyor
Surveyors are responsible for measuring and marking out levels and boundaries on a building plot.
Estimator
Estimators are sometimes employed by building contractors and joinery businesses. Their role is to study plans and specifications sent by the client. They will research building materials, equipment and labour costs to calculate how much a project is likely to cost. They are then responsible for returning the estimated costs to the client before any building work starts.
Plant technician
Plant technicians service and maintain construction plant and machinery.
Buyer
Buyers are usually employed by the building contractor to source and purchase building materials for the best price.
Carpenter
Carpenters build, install and fix carpentry work on site such as floors, roofs, doors, kitchens and staircases.
Joiner
Joiners are mainly based in a joinery workshop making staircases, windows, doors and frames. They sometimes install purpose-made items they have built on construction sites.
Plumber/ heating engineer
Plumbers are responsible for installing and fixing plumbing such as boilers, radiators, underfloor heating systems and bathrooms.
Electrician
Electricians install and fix electrical work, such as fuse boards, lighting, sockets and switches.
Plasterer
Plasterers apply surface finishes, such as cement render and gypsum plaster, to ceilings and walls (internal and external).
Bricklayer
Bricklayers lay masonry bricks and blocks to build internal and external walls, columns and archways.
Roofer
Roofers cover flat and pitched roofs with felt, roof battens, slates and tiles to make buildings waterproof.
Painter and decorator
Painters and decorators apply paints, lacquers and stains to walls, ceilings and woodwork. They also hang wallpaper.
Plant operator
Plant operators use heavy machinery and industrial vehicles to dig, lift and move materials. Forklifts, bulldozers, dumper trucks and cranes are some examples of ‘plant’ used in the construction industry.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma The building team Category
Role
Description
General building operative
Labourer
Labourers are not required to have specific trade qualifications; they should have a good knowledge of health and safety. A labourer’s role is to work closely with tradesmen to complete manual tasks, such as mixing concrete and mortar, moving materials and cleaning up.
KEY TERM
Clear and effective communication
Plant: a piece of heavy machinery or equipment, or a construction vehicle, such as a dumper truck, crane or generator.
Communication between colleagues and others in the workplace is vital to maintain a safe working environment and avoid errors. In the construction industry tradespeople, supervisors and managers work closely together every day. To do this effectively, they need good working relationships to avoid mistakes and confrontation. To keep people informed about developments and progress during a construction project, site meetings are usually held daily with representatives from the management team, supervisors and sometimes the client and designers (such as the architect). On smaller projects, you may be part of a smaller team, but you may still have regular meetings, although these may be less formal.
INDUSTRY TIP Supervisors are usually experienced tradespeople who have been promoted from within a company. If you are looking to progress your career in the future, this could be a route that you could consider.
Positive and negative communication with colleagues and others The way we communicate information can have either a positive or negative effect on people. Positive communication between managers and workers often makes workers feel happier and more productive. Negative communication can have the opposite effect. The way that you dress, sit and speak can be interpreted by someone as either negative or positive. For example, when you go for a job interview you will want to impress, so you will dress smartly, carry yourself well and speak clearly. Below are examples of how positive and negative communication can affect the workforce. Positive communication in the workplace can:
ACTIVITY Make a list of all the positive communication skills you have and any communication skills that you think you could improve.
l l l l l l l
prevent accidents and near misses improve motivation improve customer service avoid conflict increase confidence boost morale help build relationships and a strong team
l l l l l l
make you seem friendly and approachable encourage helpfulness prevent and avoid errors improve efficiency and productivity break down barriers build a pleasant working environment.
Negative communication in the workplace can: l l l l l l l
reduce productivity cause mistakes damage morale cause conflict and confrontation cause stress, leading to illness and staff absences increase the turnover of staff cause an unpleasant working environment.
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Chapter 1 Principles of building construction, information and communication Everybody in the workplace should be treated fairly, with respect and be given the same opportunities. Excluding or discriminating against people because of their race, gender, religion or sexuality should not be tolerated and is against the law (see the Equality Act 2010). If you feel that you or anyone else is being discriminated against in the workplace or anywhere else you must tell someone, such as your parents, guardian, carer, support worker, friends, tutor or teacher.
ACTIVITY Research the Equality Act 2010 and familiarise yourself with the main points of the law.
Communication methods used to pass on information to colleagues Many different forms of communication are used in the construction industry. You may be familiar with some of the methods outlined in Table 1.11. q Table 1.11 Communication methods used in the construction industry Communication method Drawing
Description A drawing could be anything from a simple sketch to a full set of plans produced on a computer by an architect, engineer or designer. Drawings are an excellent way of communicating information quickly and clearly, and they can also be referred to later. Joiners may refer to building drawings to produce full size setting out rods, while carpenters will refer to them at various stages of a building project on a construction site. Most technical drawings are made on a computer programme known as computer-aided design (CAD) because they are more accurate than drawings that are produced with a pencil and paper. CAD drawings are simple to store on a computer and amend. They can also easily be duplicated to share with other people.
Email
Professional people communicate information, such as drawings, quotations and invoices, via email.
Memo
A memo (short for ‘memorandum’) is a short written message, normally used to communicate information within a business or organisation. Memos are often sent as reminders to individual people or groups.
Radio
Radios/walkie talkies (also referred to as ‘two-way radios’) are often used on construction sites to communicate brief information verbally between the workers, supervisors, managers and security staff. Calls can be made quickly on these mobile devices because you do not have to dial a number; they transmit directly to each other. You also do not need a phone signal for them to work, so they can be used in remote locations.
Signs
Safety signs, posters and notices are important ways to communicate health, safety and welfare information to workers and visitors to the workplace. The main types of safety sign are: mandatory (things you must do) l prohibition (things you must not do) l warning l safe conditions (such as first aid) l fire (such as fire extinguishers). l
Safety signs are identified by their shape, colour and pictogram (symbol or picture to represent something). Some signs and notices must be legally displayed in the workplace, whereas others provide useful information. The disadvantage of this method of communicating is that it may be ignored. Telephone/mobile phone
Phones are an excellent way of communicating verbal information quickly in the workplace. Mobile phones need to be charged and have a good signal to work effectively.
Text messages/ social media
Social media is often used by employers to advertise and promote their company to a wide audience. It is also used to network with other businesses and recruit new staff. However, text messages are used as a quick informal method of writing a brief message to one or more people.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma q Table 1.11 Communication methods used in the construction industry (continue) Communication method
Description
Verbal
Most people communicate verbally every day without thinking about it. When we use this method to pass information from one person to another, it can be questioned to make sure that it is understood by both parties. The disadvantage of verbally communicating with people is that there is no record to refer to, which can often lead to misunderstandings, mistakes or conflict.
Written
Written information is an excellent method of communicating because it can easily be understood by everyone and can be referred to later. Examples of written information used to communicate with others in the construction industry are given earlier in this chapter. Risk assessments, contracts, site rules and maintenance records are just some examples of written information that legally must be recorded.
KEY TERM Networking: professional people interacting with each other to exchange information and create new contacts.
ACTIVITY The next time you are at work or your training centre, look around your workshop to see how many different methods of communication are displayed. Are you familiar will all the safety signs? If not, take a picture of those you do not know and research their meaning.
Information to record when taking a message There will be occasions when you need to take a verbal message at work and pass that information on to a colleague. It could, for example, be a phone call from a client, an architect, a timber supplier or a manager, so you need to be prepared and act responsibly. It can be overwhelming at first for a young or inexperienced person to take a verbal message at work; however, the more you do it the more confident you will become. On most occasions, all you need to do is speak clearly and professionally and record the message. Remember that you are representing the company. To begin with, answer the phone call with a greeting such as ‘good morning’ or ‘good afternoon’, and then introduce yourself and the company that you work for. You may then ask the person calling, ‘How can I help?’. Sometimes you or the person calling may be in a noisy environment, so if you do not clearly hear the message then politely ask them to repeat it. Whenever possible, you should always record the following details from a phone call: l l l l l l l
date time the name of the person for whom the message is intended the name of the caller the name of the person that received the phone call a contact phone number message content.
If messages are not recorded legibly and accurately, they could easily be forgotten or misunderstood, which may lead to people not receiving important information at the right time.
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Test your knowledge 1 Draw the symbols/hatching to represent the following building components. a Brickwork b Blockwork c Sawn timber d Insulation 2 Explain the purpose of a programme of work. 3 Name four different types of foundations. 4 What is the maximum pitch of a flat roof? 5 What is the name of the component in a wall used to support brickwork and blockwork above a door or window opening? 6 Why is the client the most important person in the building team? 7 What is the name of the product used to stop knots from ‘burning’ through the completed paintwork? 8 Name one situation where a carpenter or joiner might use a datum. 9 Why is it important to insulate a building? 10 What information is needed when you are recording a message?
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CHAPTER 2
CARPENTRY AND JOINERY HAND TOOLS
INTRODUCTION A wide variety of hand tools are available for use in carpentry and joinery. Most are used for specific tasks, but some can be used for many different tasks. Choosing which hand tool to use for a specific task can at first be confusing and daunting, as can be understanding how to correctly use your chosen hand tool. This chapter discusses the most common types of hand tool in use today, as well as some of the more traditional types. It will discuss how to safely use the hand tools, along with the type of tasks they are typically used for. As most hand tools require maintenance, a description of the equipment used and methods of sharpening and maintaining hand tools are also included. Hand tools can be expensive but could last you for a lifetime if they are well maintained and stored safely. Not only will this save you money in the long term, but it will also ensure you to have well-maintained sharp tools whenever they are required. It also shows that you are a careful and conscientious professional.
LEARNING OUTCOMES In this chapter, you will learn about: 1 types of modern and traditional hand tools 2 how to safely use, sharpen and maintain hand tools 3 how to safely store and transport hand tools.
1 TYPES OF MODERN AND TRADITIONAL HAND TOOLS Most types of hand tools have not changed much over the last 100 years or more, though different materials are now used to make them. Timber, for example, was originally used in the handles for saws and chisels, but this has largely been replaced by plastic, which makes these hand tools cheaper to purchase without affecting their use. The material used for the cutting edge of a tool has progressed, resulting in better-quality modern tools that achieve and maintain a cutting edge for longer. Whether you are using old or new hand tools, the same rule applies: blunt, damaged and poorly maintained hand tools are more dangerous than sharp well-maintained hand tools. Using the correct sharp and well-maintained hand tool will allow you to work safer, faster and to a higher standard. Using hand tools can be dangerous so it is vitally important that you always follow safe practices. A culture of safety first is not an option but a legal requirement; this not only ensures the safety of yourself but others around you. Lack of time is not an excuse for poor safety practices. 54
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HEALTH AND SAFETY The following are general safety guidelines to observe when using hand tools and are covered in more detail alongside the relevant hand tools in this chapter. l Wear the correct type of PPE (personal protective equipment) for the task as outlined in the risk assessment. l Be aware of any loose clothing, jewellery or trailing earphone wires that could be caught by the tool. l Ensure the material is securely and appropriately held for the task. l Always keep your hands, arms, and legs away from the cutting edges of the tool. l Always use the correct type of tool for the task. Doing otherwise could lead to accidents. l Never try to force a tool; if it will not move or cut easily there is usually a good reason why. l Never pass a tool to another person with the cutting edge first; pass them the handle. l Keep your work area safe, clean and tidy.
There are many different types and makes of hand tools. The better-quality tools usually have brass inserts in them to help prevent wear and give an improved appearance. Hand tools are commonly grouped into the following categories: l measuring and levelling equipment l hand tools used for marking out l saws l planes l chisels and knives l drills, drill bits and screwdrivers l miscellaneous hand tools.
Measuring and levelling equipment The task you are working on will determine which measuring and levelling equipment you will require. A bench joiner would generally need slightly different types and sizes of equipment to that used by a site carpenter. Typical examples of measuring and levelling equipment that could be found in the tool kits of either trade are given below.
Measuring tape This is commonly referred to as a tape measure and is available in a range of lengths from 2 m to 10 m. The longer versions can be quite bulky and are usually used by carpenters. The end of the tape has a hook with a slight amount of movement backwards and forwards equal to the thickness of the hook. This movement allows for the measurement of both internal and external distances. The hook may have large wings for hooking onto either side, the top or the bottom of the material being measured. Some hooks have a slot in them, which is used for attaching to a nail or screw head. The hook may also be magnetic to enable measurement from steel surfaces. It is important to ensure the hook end does not become damaged or bent as this will affect the measuring tape’s accuracy.
Blade lock Blade consisting of metric and imperial measurements
Wide hook with slot
p Figure 2.1 A measuring tape
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p Figure 2.2 Using the hook of a tape measure
Figure 2.2 shows how the hook pushes in when measuring from an internal edge (left) and pulls out to the correct position when measuring from the outer edge (right).
INDUSTRY TIPS Regularly check the end hook of your tape measure to ensure it moves freely and is free from distortion. Check your tape is measuring correctly by measuring 200 mm from the end of a piece of timber using the hook and comparing this measurement to the one measured from the 100 mm mark on your tape.
Figure 2.3 shows how a nail or screw head can be used when no other surface is available. The nail or screw is driven into the material. The head of the nail or screw is then located in the slot of the hook, which allows for an accurate measurement to be made from this point.
p Figure 2.3 Using a nail or screw head with a tape measure
p Figure 2.4 Working from the 100 mm mark on the tape
When you are setting out, or when you require an accurate measurement, it is best practice to work from the 100 mm mark on the tape, as shown in Figure 2.4. Don’t forget to subtract this 100 mm from the final measurement.
Laser distance measure This type of measuring tool is used when increased distances are involved, though it has a slight fall in accuracy over longer distance.
p Figure 2.5 Laser distance measure
HEALTH AND SAFETY Never shine a laser light at anyone’s eyes: it can cause serious damage.
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Rules A steel rule is an accurate means of both measuring and drawing straight lines over shorter distances. They are available in lengths from 150 mm up to 2000 mm. Scale rules are also available and are used to take measurements from scaled drawings and to produce them. This can be an inaccurate way of taking a measurement, particularly when working with larger scales, so all drawings should have measurements on them. In the past, folding 1 m rules were commonly used to take measurements. They are available in timber and plastic but are bulky to carry and are now little used.
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A steel rule is also useful when you need to divide material into equal parts. For example, a tenon (piece of wood with a part sticking out which fits into a mortice hole) needs to be divided into three equal parts, two parts for the tenon and one part of the haunch. The total width of the tenon is 70 mm. The number 70 does not easily divide equally into three, but 75 does (75 ÷ 3 = 25). Position the rule on the edge of the tenon and angle the rule so that the 75 mm mark sits on the other edge, as shown in Figure 2.6. You can now mark the one-third position, 25 mm, for the start of the tenon and the end of the haunch. Use this principle with any easily divided measurement when you need to work out divisions.
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Haunch line
p Figure 2.6 Using a steel rule
IMPROVE YOUR MATHS A middle rail on a door measures 190 mm and needs to be divided into three equal parts for the mortice and haunch positions. What would be one of the easiest ways to divide it using the method shown in Figure 2.6?
Levels There are several types of level in a range of sizes. The level is used to check an angle, usually the horizontal or the vertical. Some are also capable of reading any angle, while others can transfer a datum line around a room by means of a laser.
Spirit level The spirit level is used to measure an angle, usually one that is horizontal or vertical. When the bubble is aligned within its marks in the siting chamber, the level will be either horizontal or vertical depending on which set of marks are being used.
KEY TERMS Horizontal: flat and level, such as water would lay. Vertical: hanging straight down, such as a weighted plumb line would hang.
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INDUSTRY TIP If spirit levels are not treated with care, they can easily become damaged and ‘out of level’, which then gives false readings. A simple way to check the accuracy of a level is to place it on a wall and mark a line along it when it is level. Then turn the level through 180° ‘end for end’ and repeat the process. The newly marked line should match the first line. If it does not match, then the level is damaged and should be replaced.
p Figure 2.7 Spirit level
Laser level
p Figure 2.8 Laser level
Laser levels are increasingly available at an affordable price and as a result are more widely used in modern construction. Better-quality laser levels are self-levelling and once set up they can transfer horizontal and vertical lines around a room and over ever-increasing distances. They have multiple uses, but are often used to mark out the fixing positions of stud partitions, kitchens and dado rails.
Inclinometers Inclinometers are like a traditional level but can read any angle. They are ideal for obtaining angles and transferring laser-accurate angles over long distances.
Water levels
p Figure 2.9 Inclinometer
Water levels were once a common site in construction but now are infrequently used. They consist of a graduated sight tube with an air vent that is attached to a length of flexible pipe tubing. The tubing is filled with water so that the water level can be read off against the graduation marks on the site tubes.
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p Figure 2.10 Water level
Hand tools used for marking out Marking-out tools are just as varied as most other types of tool and some can perform multiple tasks. The most common marking-out tools you are likely to require are set out below.
Set square and tee square The set square and tee square are usually used in conjunction with a drawing board. It is important to use squares when producing drawings or marking out material to maintain accuracy and ensure that lines remain parallel. If the drawing or rod board is inaccurate the finished job could be inaccurate too.
p Figure 2.11 Set square (top) and tee square (bottom)
Combination square, try square and mitre square Try squares allow you to mark a 90° angle and mitre squares are set at a 45° angle. They have been replaced by the combination square, which has the added benefit of an adjustable blade. It is important that if the square is supposed to measure an angle of 90° that it does so. You can easily check if your square is accurate as follows. l
Place the stock of the square against a straight edge of timber and draw a line across the timber. l Rotate the stock of the square through 180° and check the square against the first line drawn. l If the two positions line up, your square is true and produces accurate right angles.
p Figure 2.12 Mitre square
ACTIVITY Check the accuracy of your square using this method.
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p Figure 2.13 Combination square
p Figure 2.14 Try square
Roofing square A roofing square is used for larger setting out, roofing and staircase work. It can also be used in conjunction with a batten that acts as a fence, which is particularly useful when setting out stairs.
Box square p Figure 2.15 Roofing square with timber fence
KEY TERM Profiled: material which has had a decorative edge added to one or more sides.
Box squares are used to square around timber that has already been profiled (that is, timber that has had the moulding and rebate machined into it). It is difficult to accurately mark around profile material with a try square or combination square. A simple box square could be little more than two pieces of timber fixed together to form a right angle, or it could be a more complex version used to form angles, such as when forming scribed mortice and tenon joints (a mitre template).
Sliding bevel You can use the sliding bevel to measure and transfer an angle. First loosen the blade, then set it to the required angle and tighten it. It is now possible to transfer this angle to the required object without risking the angle being changed. Sliding bevels are particularly useful with roofing work as well as producing dovetails.
p Figure 2.16 Elaborate box square incorporating a 45° angle
p Figure 2.17 Sliding bevel
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Protractor Use a protractor to measure an angle or read an angle from a drawing. The larger the protractor, the easier it is to both read and measure the angle.
Compass A compass is used mainly to produce smaller curves and radiuses. Better-quality compasses have a central wheel that enables easier adjustment and the production of more accurate and stable curves.
p Figure 2.18 Protractor
Compasses and dividers can also be used to produce and bisect angles. Examples of how to do this are given on pages 62–63.
Dividers Dividers are used to accurately transfer dimensions from a drawing or setting out rod onto the work piece. They are also used to divide up distances equally or for scribing arcs onto material.
Trammel heads and beam
p Figure 2.19 Compass
p Figure 2.20 Dividers
Trammel heads are used to draw larger curves or step off multiple continuous measurements. The trammel heads are joined with a suitable piece of timber, called a beam, which is cut to the required length. Trammel heads can be fitted with either a pencil or a metal point.
Pencils The type and quality of pencil will affect the quality of the finished drawing or setting out. The ‘lead’ in the pencil is graphite, which is a form of carbon. Because carbon is soft and would easily smudge, the graphite in a pencil is hardened up. The hardness of a pencil is given a code, the most common ranging from 4H, which is extremely hard, to 4B, which is extremely soft. For general purpose setting out, a 2H pencil is suitable. Rather than being circular in shape, carpenters’ pencils are flattened to prevent the pencil rolling, which is particularly useful while working at height. These pencils have a much larger drawing surface area. Carpenters’ pencils are used mainly for marking-out carpentry tasks such as in roofing, flooring and studwork, which generally do not need the same degree of accuracy as setting out a rod board.
Producing and bisecting angles with compasses and dividers Good quality compasses and dividers are useful for producing and bisecting angles. Most angles that you will work with will be either obtuse or acute angles. The following step-by-step guides outline the stages in producing and bisecting angles.
p Figure 2.21 Trammel heads and beam
p Figure 2.22 Different grades of pencil
KEY TERMS Obtuse angle: an angle of more than 90°, but less than 180°. Acute angle: an angle of less than 90°.
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Producing a 90° angle
2a
2b
a 1a
c
b
1b 3a
3b
1 Draw a straight-line a–b and mark the position from which you would like to strike a 90° angle point, c. 2 Open the compass to draw a large circle but not so wide that it is fully open (the larger a circle that can be drawn, the more accurate the 90° angle will be). Position the point of the compass on point c. Make an arc on line a–b either side of point c, marks 1a and 1b. 3 Open the compass wider and position the point of the compass on mark 1a and draw arcs 2a and 3a. 4 Reposition the compass on mark 1b, ensuring that the compass is not adjusted, and draw arcs 2b and 3b. 5 Draw a line through the intersecting points of 2a and 2b, point c and the intersecting points of 3a and 3b. This line is 90° to line a–b.
Finding a 45° angle
p Figure 2.23 Producing a 90° angle
To find 45°, bisect the right angle in the following way. 1 Position the point of the compass on the intersecting points of 2a and 2b and draw arc 4a. 2 Position the compass point on the point of 1b and draw arc 4b. 3 Draw a line from point c through the interception points of 4a and 4b. This is 45° to line a–b. This same principle can be used to find 22½°. 2a
2b
a
IMPROVE YOUR MATHS
e
4a
Using basic drawing equipment, produce an angle of 22½° using the method outlined in this chapter.
4b 1a
c 1b
d
3a
3b
p Figure 2.24 Finding a 45° angle
IMPROVE YOUR MATHS Using your compass, produce a 75 mm radius circle and divide it into six sectors. Identify the angles of each sector.
b
Forming angles using a circle You can also form angles from a circle. 1 Form a circle as shown in Figure 2.25. The larger the circle, the easier it will be to draw and produce the different angles and they will be more accurate. 2 Keeping the compass at the same radius used to produce the circle, position the point of the compass on the edge of the circle and draw arc 1a as shown in Figure 2.26. 3 Position the point on 1a and draw arc 1b. Reposition the compass point on 1b and draw arc 1c, and so on as shown in Figure 2.26. The radius of the circle goes into the circumference exactly six times. Each arc sector is equal to 60°. 4 By bisecting an arc sector, you can obtain angles of 15°, 45°, 22½° and other angles.
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1a 6 Radius
5
90° 60° 90°
1b
45°
3
1c
p Figure 2.26 The radius of the circle goes exactly six times into the circumference
p Figure 2.27 Producing other angles
Bisecting an angle Any angle can be bisected by following this simple step-by-step guide. 1 Draw the angle to be bisected. 2 Mark an even distance down each side of the angle with a compass to mark arcs 1a and 1b. 3 Position the point of the compass on point 1a and draw arc 2a. 4 Ensuring the compass is not adjusted, position the compass point on point 1b and draw arc 2b. 5 Draw a line from the centre of the angle through the interception point of arcs 2a and 2b. This will be your bisection angle.
1a
STEP 1 Draw the angle to be bisected.
30° 15°
2 4
p Figure 2.25 Drawing a circle
1
KEY TERM Bisecting: dividing a line or angle into two equal parts geometrically.
1b
STEP 2 Using a compass, mark an even distance down both sides of the angle to be bisected.
INDUSTRY TIP 1a
1b 2a
2b
STEP 3 Use the compass to draw arcs from the first two points, taking care not to alter the compass.
STEP 4 Join the centre of the angle and the point where the arcs intersect. This is the bisection line.
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Marking gauge A marking gauge can be used to provide a relatively simple way of producing a parallel line. The marking gauge can be used for marking out joints, such as halving joints and housings, as well as hinge recesses on doors and frames. Betterquality gauges have brass inlays inserted into the stock to help prevent wear on contact surfaces. Pin
Stock
Thumbscrew
Stem
p Figure 2.28 Marking gauge
Mortice gauge
p Figure 2.29 Mortice gauge
This gauge is like the marking gauge but has two pins, one fixed and one adjustable. It is mainly used for marking mortices (and tenons) but can be used to mark any two parallel lines. Better-quality gauges are usually easier to adjust. Take care that both pins on a mortice gauge remain at the same height after they are maintained, otherwise the lines produced will not be of equal depth.
INDUSTRY TIP It is more accurate and productive to use gauges to mark out than it is to repeatedly measure with a tape or rule.
Combination gauge
p Figure 2.30 Combination gauge
The combination gauge combines a marking gauge and mortice gauge; one side has a single pin while the other side has two pins. This type of gauge eliminates the need for you to have both a marking and mortice gauge. The combination gauge shown in Figure 2.30 has a fine adjustment screw at the end of the stem for adjusting the gap between the two pins. It is important that the points of the pins always remain sharp to provide accurate marking-out lines. If the points do become blunt, sharpen them with a small needle file.
Cutting gauge
p Figure 2.31 Cutting gauge
This type of gauge has a cutting knife instead of a pin. The cutting knife is held in place with a wedge and can be changed around so that it marks either the waste side towards the stock or the other side away from the stock. This type of gauge produces clean lines across the grain of the timber. The knife severs the fibres of the timber leaving a clean cut, whereas a pin would pull and damage the fibres, leaving a poor finish. This type of gauge is particularly useful for marking out dovetails.
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2 HOW TO SAFELY USE, SHARPEN AND MAINTAIN HAND TOOLS How to use a mortice gauge to form a mortice and tenon joint The following guide outlines the process for setting up a mortice gauge to form a simple square-shouldered mortice and tenon joint. 1 Select the required size of mortice chisel. This is usually as near as possible to one-third of the thickness of the material that requires to be morticed. 2 Set the distance between the pins to the same width as the mortice chisel. 3 Adjust the stock so the mortice is in the centre of the material. To do this, first mark small pin pricks from each side; when they fall into the same holes the mortice is centralised. 4 Fully tighten the thumbscrew and recheck. The pins of any gauge should always trail the direction of travel, like a trailer following a car. If you push the gauge away from you, the pins will point towards you while in use. If you pull the gauge towards you, the pins will point away from you while you are moving the gauge. When using the gauge, in whichever direction you choose, firmly hold the stock against the timber being marked and slightly rotate the pins round and down onto the surface of the material. They should be in contact with the surface of the material. As you move the gauge either towards or away from you, the trailing pins leave slight tram lines in the material, which will be the location of the mortice or tenon. Remember to start and stop between the lines marked for the mortice or tenon, as any overshoot will leave unsightly lines that will require removing at a later stage.
p Figure 2.32 Setting the mortice gauge to the size of the mortice chisel
p Figure 2.33 Adjustting the stock so the mortice is in the centre of the material
ACTIVITY Set up and use a marking gauge to produce a 10 mm wide mortice 12 mm from the face edge.
p Figure 2.34 Starting at the mortice line gauge down the length of the mortice
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Hand-held saws Though the design of hand-held saws has changed little over the years, new materials and better production techniques have resulted in cheap, sharp saws. These have the added benefit of specially hardened saw teeth, usually seen as a black or dark blue line running along the saw teeth.
Set
These hardened saws are generally known as hardpoint saws. The hardening effect gives the saw teeth an extremely sharp and prolonged cutting life compared to traditional handsaws, which require constant maintenance, particularly when used on man-made or hard abrasive materials. On the downside, hard point saws cannot be resharpened like traditional handsaws. So, when they become blunt, they are thrown away. Kerf
p Figure 2.35 Set and kerf of a hand-held saw
Modern disposable hardpoint teeth saws are general purpose saws that are used to cut either with the grain (rip) or across the grain (crosscut) of the timber. They are also particularly good for cutting man-made materials such as plywood and MDF, which would quickly blunt a traditional rip or crosscut hand-held saw. Hand-held saws usually fall into one of the following categories: l
hardpoint saws ripsaws l crosscut saws l backed saws. l
KEY TERMS Set: a saw’s side clearance. Binding: when something is prevented from moving freely, such as a door being prevented from opening fully because it is binding against the architrave, or the side of the saw sticking and rubbing on the material during the cutting process. Kerf: the total width of the saw cut.
The cutting action of the various types of hand-held saw is different. When cutting down the grain of timber (ripsaw), the saw teeth are filed and shaped to act as a series of chisels, each cutting its own groove. When cutting across the grain of the timber (crosscut saw), the teeth are filed and shaped to act as a series of scoring knife cuts, which sever the fibres of the timber, producing a clean cut. The number of teeth in the hand-held saw also influences the way the timber is cut. A saw with fewer teeth will have larger teeth, allowing the saw to cut faster than one with more smaller teeth. Large saw teeth usually produce a poorer finish.
Tooth profiles All saws need to have teeth that are sharp to be effective at cutting. The saw also needs to have side clearance known as set, which stops the saw from binding in the cut. The total width of the saw cut is known as the kerf and is equal to the thickness of the saw blade material plus the set on both sides of the blade. Ripping: Cutting with the grain
Cut
4½ teeth per 25 mm 90° Chisel edges act as a series of chisel cuts
p Figure 2.36 Cutting action of ripsaw teeth
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Chapter 2 Carpentry and joinery hand tools Crosscutting: Cutting across the grain Cut
8 teeth per 25 mm Knife points sever fibres to produce a clean cut across grain
65°
p Figure 2.37 Cutting action of crosscut saw teeth 90°
Flame tooth profile showing kerf
60°
15°
Top fleam (bevel) is larger for softwood than for hardwood
p Figure 2.38 Fleam cut tooth design
ACTIVITY Sketch the tooth profile of saw teeth for a hand-held ripsaw and crosscut saw.
The fleam cut tooth design is a traditional design for a Japanese pull saw but is now modified slightly and used on many hardpoint handsaws.
Hardpoint handsaws There are many types and lengths of hardpoint handsaws, which are often referred to as general purpose saws and panel saws. They are used for cutting with the grain, across the grain of the timber, as well as man-made materials such as plywood and MDF. Most hardpoint handsaws have a tooth profile based on the Japanese fleam cut tooth profile; hardpoint teeth are triple-ground and have a fastcutting action. As a rule, use a saw with a high tooth count per 25 mm for finer work and thinner sheet materials, such as plywood and MDF. A handsaw with fewer teeth per 25 mm is best used on thicker materials and tanalised (treated) timber. Most hardpoint handsaws are protected by a low friction, rust-resistant PTFE coating, which makes them ideal for use when working outdoors and with tanalised timber. Only fleam cut tooth handsaws can cut on both the push and pull of the cut. They are available in 500 mm or 550 mm lengths with a tooth count of 8–10 teeth per 25 mm.
p Figure 2.39 Hardpoint saw with a plastic handle
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Ripsaw This type of handsaw is not generally used today. The task of ripping timber down its grain is usually more efficiently done by machine, either a portable powered hand-held ripsaw or a fixed bed ripsaw machine. Ripsaws are the largest type of handsaw used by carpenters and joiners. They are usually around 650–750 mm long and have very few teeth compared to other types of handsaw, around 5 teeth per 25 mm. Ripsaws cut on the downward stroke and have teeth that are filed square to the face of the sawblade. The cutting action of each tooth is like a chisel action, with each tooth removing a small channel in the timber. 60° 3–5 teeth per 25 mm 650–750 mm
p Figure 2.40 Hand-held ripsaw
Crosscut saw
INDUSTRY TIP To help prevent the saw blade from binding during cutting, a small amount of candle wax can be rubbed onto the sides of a saw.
The hand-held crosscut saw is more common than the ripsaw, but once again it has largely been replaced by power tools and the hardpoint handsaw. The teeth of a crosscut saw are smaller than the ripsaw, at about 6–8 teeth per 25 mm, and are filed to give a fine edge to the teeth, allowing them to sever the fibres of the timber. If the same tooth design were used as those used on ripsaw, the saw would jump about during cutting and would tend to rip out the fibres of the timber, giving a poor finish to the cut. 6–8 teeth per 25 mm 60° 600–650 mm
p Figure 2.41 Hand-held crosscut saw
Backed handsaws Backed handsaws have either a strip of steel (usually on cheaper versions) or brass that runs along the top edge of the saw. This metal strip keeps the blade taut and straight and adds weight to the saw. The best saws have a heavyweight brass back. Backed saws are used for fine accurate cutting such as cutting joints and can be used to cut both with and across the grain.
Tenon saw
p Figure 2.42 Hardpoint tenon saw
The tenon saw is a versatile handsaw used to cut joints such as tenons, halving joints, bridle joints and architrave. The tenon saw is available as a hardpoint saw as well as the traditional version, which requires regular sharpening and setting. The tenon saw usually has around 13 teeth per 25 mm and the teeth of non-hardpoint versions are sharpened like crosscut teeth.
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Dovetail saw The dovetail saw is a smaller version of the tenon saw and is used for finer work, typically cutting dovetail joints. The dovetail saw has more teeth per 25 mm than the tenon saw, at around 15 per 25 mm, and is generally shorter in length. Dovetail saws can be easily damaged if used on work that is too large for them because of their thin blades.
p Figure 2.43 Dovetail saw
Gents saw The gents saw is a finer version of a backed saw. It has a turned handle and often finer teeth than a dovetail saw. It should only be used with fine delicate work to prevent damaging the saw.
p Figure 2.44 Gents saw
Other types of hand-held saws There are other types of hand-held saws that do not fall easily into any of the other categories covered but are useful additions to the tool kit.
Coping saw The coping saw is a type of framed saw which consists of a narrow blade, held in tension within a steel frame. The coping saw is commonly used to remove the waste material when cutting dovetail joints and bridle joints. It is also used to cut scribed moulding profiles such as skirting board and dado rails, as well as for general curved cutting. The size of the cut is limited by the size of its frame. The tension on the blade should be released after use to prevent straining both the blade and the frame.
p Figure 2.45 Coping saw
There are two schools of thought as to which way around the blade should go when fitting a coping saw blade. Some believe that the teeth should point away from the handle, meaning that the cutting action takes place when the saw is pushed, so that any splitting will occur at the back of the timber being cut. However, cutting this way reduces the tension on the blade, increasing the chances of the blade breaking, so other people believe that it is better for the teeth to face towards the handle, ensuring the blade is in tension when cutting.
Mitre saw or frame saw The mitre saw is a variation on the coping saw in that it has a blade held in tension within a frame, but the blade is hardened and considerably deeper than the coping saw. This type of saw is held in a framework that has pre-set angles set within the base for standard angles. It can be used for cutting mitres but is of little practical use in today’s construction industry, as these types of cut are usually carried out using power tools.
p Figure 2.46 Mitre saw
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Pad saw
p Figure 2.47 Pad saw
Like a lot of traditional hand tools, the pad saw has generally fallen out of use because the tasks it was traditionally used for are now mostly carried out using power tools such as the jigsaw. The pad saw is still useful though, particularly when forming key holes in doors that are required to be ‘key shaped’ and then usually covered by an escutcheon, as well as for cutting or trimming plasterboard and where holes are required. Pad saws have a retractable blade that can be adjusted to suit the depth of the required task. These blades cut on the forward stroke and are extremely easy to bend so great care is required when using them.
Japanese handsaw The Japanese handsaw produces an exceptionally fine cut. The teeth on this handsaw are fleam cut, having little to no set. They produce a clean cut, mostly on the pull stroke, which keeps the thin blade in tension, allowing a straight cut. This handsaw is used by the bench joiner in workshops where fine, accurate cutting is required. Great care is required in both use and storage of this type of handsaw to prevent it being damaged.
p Figure 2.48 Japanese handsaw
Maintaining handsaws Very few carpenters and joiners sharpen their own saws, as this can be timeconsuming and difficult to do. When the saws become blunt, you can arrange for them to be sent to a saw doctor for sharpening on a machine. This can be an expensive process and will require that you have more than one saw of that type, which is one reason why disposable saws are so popular. A good quality saw that can be resharpened should last you for your working life if it is taken care of and well maintained.
Process to follow when sharpening a handsaw Place your saw in a suitable clamping device with the saw teeth facing upwards. Ensure that the whole of the length of the saw blade is suitably clamped. You may use lengths of timber to hold the blade, which in turn is clamped in a vice. The following stages outline what you should do when sharpening a handsaw. Not all of these processes are required every time the blade is maintained.
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Topping This process is not always required but should be carried out after several sharpening processes. The teeth of the saw are levelled using a large double cut flat mill file. The file is run along the top of the teeth until all the teeth tops are level. This process brings the high teeth into line with any lower teeth that may have been filed too much in previous sharpening.
Shaping
p Figure 2.49 Mill file
This process is only done if the topping process has been carried out. Shaping brings the teeth back to their correct shape and size using a saw file.
Setting A saw set is used to bend each tooth alternately one way then the other, which creates side clearance for the saw blade. The total width of the saw cut is called the ‘kerf’.
p Figure 2.50 Saw set
Sharpening Use a triangle file to file the teeth so they have the correct shape and angles, depending on the type of saw being sharpened. To make it easier to see which teeth have been sharpened, engineering marking blue can be used on the saw tips. This will clearly show which teeth have been sharpened and is particularly useful with smaller teeth. The teeth of a ripsaw should be filed straight across, perpendicular to the saw blade. Crosscut saw teeth should be filed at a 75° to 80° angle to the saw body. Start filing the teeth that are set to the right, looking from the handle end of the saw, and work from the left side of the saw. Then switch sides and file the teeth that are set to the left.
Using handsaws The way you use a handsaw will depend upon the type of handsaw it is and the specific task you are doing. This is a general guide for the safe use of common handsaws for everyday tasks.
p Figure 2.51 Triangular saw file
If a handsaw slips or jumps out of its cut while in use, the resulting injury to your hand or fingers could be very severe. Not only should you use the correct saw for the task, but it should also be well maintained and sharp. Blunt saws generally require more effort to use, so there is an increased risk that they will jump out of the cut. Ensure that all materials are supported or held before trying to cut them. This reduces the likelihood of the material moving in an uncontrolled manner, risking both injury to you or others and damage to the material being cut and/ or the saw. To use a handsaw correctly, hold the handsaw with your index finger pointing along the saw, while gripping the rest of your fingers firmly around the handle; this holding technique helps with the control and direction of the saw cut.
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p Figure 2.52 Correct holding technique for hand-held saws
Using panel saws HEALTH AND SAFETY After the initial few strokes to start the cut, move your non-cutting hand out of the way. The saw is most likely to jump out of its cut during the early stages of cutting and could result in severe injury if it lands on your hand or fingers.
When using hardpoint saws, ripsaws or crosscut saws, try to keep the cutting angle between the saw and material at 45° to 60°. You will find it easier to use the saw and complete the task more quickly if you apply slower full lengths of the saw rather than fast short strokes. This also produces a more accurate cut. Keep the hand that is not using the saw far away from the saw teeth once the cut has started. You can use your index finger and thumb as a guide and positioning aid when starting the cut, while taking great care and applying slower strokes of the saw, then move your hand out of the way once the saw has started to penetrate the material. As the cut progresses, you may need to give a little help in directing the saw blade. Use your finger to apply pressure along the smooth sides of the saw either before or after the cutting point, depending on which direction the saw needs to be adjusted in.
Between 45–60°
When using a vice, set timber low in vice to reduce vibration
p Figure 2.53 Maintain the correct cutting angle
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p Figure 2.54 Using a finger as a guide to deep cutting
Using backed handsaws When using a backed handsaw, such as a tenon saw to cut the tenons for a frame, different techniques are required to those used with a panel saw. The following step-by-step guide outlines the process. 1 Firmly position the material in a vice with the end requiring cutting perpendicular to the vice. Stand slightly to one side of the vice, not in front of it, holding the tenon saw with your index finger extended along the side of the saw, as shown in Figure 2.55. 2 Start the saw cut using your thumb or index finger as a guide, as shown in Figure 2.56. Ensure the saw is positioned on the waste side of the gauge line and not on the line. 3 As the saw starts to cut, move your hand away from the saw. Let the weight of the saw cut into the timber rather than forcing the cut. 4 When the cut is about 5 mm deep, remove the saw, as shown in Figure 2.57. 5 Reposition the timber in the vice at an angle of about 45° and cut a diagonal cut from corner to corner, as shown in Figure 2.58. By positioning the timber in this way, you can achieve a straight side to your tenon much more easily. 6 Turn the timber around and repeat step 5, as shown in Figure 2.59. 7 Reposition the timber perpendicular to the vice and finish the cut to the required depth, as shown in Figure 2.60. 8 The cheeks (side pieces) of the tenon can now be removed in the following way. a Position a bench hook in a vice and locate the timber up against the side support of the bench hook, shown in Figure 2.61. b Firmly hold the timber against the side support and start the cut, using your thumb as guide. Once the cut has been started, move your thumb out of the way and cut down the shoulder of the tenon until the cheek falls away, as shown in Figure 2.62. 73
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p Figure 2.55 Standing at the side of the work piece with forefinger extended
p Figure 2.56 Using your thumb as a starting guide
p Figure 2.57 Cut a depth of about 5 mm
p Figure 2.58 Cut a diagonal from corner to corner
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p Figure 2.59 Cut the other diagonal
p Figure 2.60 Reposition the timber and finish the cut
p Figure 2.61 Bench hook
p Figure 2.62 Using a tenon saw to cut down the shoulder of the tenon
Hand-held planes The hand-held plane is available in many different types and sizes. They can be used in a wide range of tasks, but they are all designed to remove material in thin shavings and to leave a smooth surface. A few planes, like the compass plane and the spokeshave, are specifically designed to produce smooth curved surfaces, while others are designed to create a smooth profile such as a groove or rebate. Well maintained sharp planes produce the best and safest finish. Planes should easily remove material provided they are correctly set up with sharp plane irons. 75
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Planes can often be referred to by their pattern number, which usually refers to the length of the plane. The number 1 plane is a small plane (no longer generally available) while the number 8 is an exceptionally long plane. The most common plane is the smoothing plane number 4 or 4½; they are the same length but the number 4½ is a wider and heavier plane, giving a wider cutting surface. Hand-held planes fall into two main categories: l l
bench planes specialist planes.
Bench planes Although these are generally referred to as bench planes, they are not limited to being used at a workbench. Even with the progress of the power plane, every tool kit should contain at least one type of hand-held bench plane. The size, type and number of planes you may need will depend on the type of work you usually do. The following are the most common types in use and should enable you to complete all the common tasks you are likely to be asked to do. As you become more skilful and specialise in an area, you may need to consider additional versions. The cutting angles and shapes of plane irons will be dealt with in more detail later in the chapter. Cam
Lateral adjustment lever
Lever cap Cap screw
Knob
INDUSTRY TIP Use the sole of your plane on its edge as a straight edge; this will allow you to see if the material is free from hollows and lumps.
Blade
Handle
Back iron Toe Adjusting screw Frog
Mouth Plane iron Sole
Heel
Frog adjustable screw
p Figure 2.63 Parts of a bench plane
45° bedding angle Iron sharpened to 25° bevel
Mouth
45°
20° clearance
Sole
p Figure 2.64 Cutting angle of a bench plane
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Try plane (number 7) and jointer (number 8) These are the longest types of hand-held planes and are seldom required nowadays because the type of tasks they were designed for is usually carried out by the more accurate surface planing machine. These long planes (550 mm and 600 mm) are used to flatten and straighten timber. The length of the sole means the plane will always sit on any high spots of the timber and reduce these before it can start to cut any hollows. These planes have the cutting iron installed with the bevel facing downwards. Smoothing plane length: 250 mm
KEY TERM Surface planing machine: an industrial fixed bed machine that uses rotating cutter blocks to produce a flat, smooth and straight length of timber.
Try plane length: 550 mm
p Figure 2.65 Short planes tend to ride up and down any hollows and bumps in the timber, while longer planes will remove any high spots, enabling the plane to produce long, flat, straight surfaces
p Figure 2.66 Try plane
Jack plane (number 5 and number 5½) This plane is used for general straightening and preparing sawn timber. While on site, it is often used to shoot doors to fit into the linings or frames. It should not be used to clean up joints, as its length will hit any high spots, preventing effective cleaning up of the joint. The blade or cutting iron is shaped differently to most other types of plane. The cutting edge of the iron has a slight convex curvature, making it difficult to achieve a completely flat finish. If these plane irons were sharpened completely straight it would be difficult to achieve a flat surface without one edge of the iron leaving a small and shallow but very noticeable stepped edge where it has met up against a previously planed pass. These planes range in length from 375 mm to 400 mm, with the number 5½ being a wider and heavier version of a number 5. Like the try plane, the iron is installed with the angle facing downwards.
p Figure 2.67 Jack plane
Smoothing plane (numbers 3, 4 and 4½) These smoothing planes are relatively short at 250 mm long. They are used to clean up joints and fine plane surfaces prior to assembly, such as removing machine pitch marks, pencil marks and other handling marks that may occur. Because of its short length, the smoothing plane is not suitable for truing or flattening long timber, as it would simply follow the timber’s original shape. The number 4½ is the wider and heavier of the range. The irons on these planes are sharpened flat across with only the corners slightly eased or rounded; this creates a flat surface without any of the unsightly stepped edges that a totally flat iron would produce. This plane is fitted with the face of the iron facing downwards. The smoothing plane is a frequently used hand plane and is an essential addition to any carpenter’s or joiner’s tool kit.
p Figure 2.68 Smoothing plane
KEY TERM Pitch marks: the marks left on the timber surface from rotary power tools, such as power planes and surface planers.
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Block plane
p Figure 2.69 Block plane
KEY TERM Interlocking grain: the grain or fibres of the timber grow at a slight incline and change direction in different years of growth. This change in grain direction can create a striped effect on the surface of the timber. Interlocked grain can be difficult to plane and may result in the timber surface tearing out, resulting in small hollows and imperfections on the surface of the timber.
The block plane is a small plane compared to the jack plane or smoothing plane. One of the main differences is the seating angle of the iron. In the block plane, the iron is installed with the bevel facing upwards, as opposed to downwards as in most bench planes. The iron seating position on block planes is much lower than other bench planes, at 20° or the ultra-low profile at 12°, compared to the 45° used on most bench planes. This relatively low angle for the iron makes the block plane particularly useful when cutting end grain and hardwoods with interlocking grain, or any timber that is known to be difficult to achieve a good smooth finish on. Another useful feature of the block plane is the easily adjustable mouth. You can reduce the gap for the mouth so it is as small as practicable when you are planing timber that is liable to break out or split down the grain, because this lessens any risks of lifting and damaging the finished surface. The mouth gap should be increased if planing damp or sawn timbers.
Iron cap or lever cap
Iron
Throat (Opening in sole is the mouth.)
Cutting depth adjustment
Lever cap screw
Front knob
Sole
Later al Body adjustment lever
Mouth adjustment
p Figure 2.70 Parts of a block plane
45° 20° bedding angle
Iron sharpened to 25° bevel Mouth
20° clearance
Sole
p Figure 2.71 Low seating angle of a block plane
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Chapter 2 Carpentry and joinery hand tools Typical uses for a block plane include: l end grain work, such as adjusting mitres and cleaning up the ends of frames l fine cleaning up of joints l working with short and cross-grained timbers such as Iroko l trimming laminate edges for worktops.
Specialist planes This group of planes tend to be mainly workshop-based planes. In most cases, these specialist planes have been replaced by power tools, such as the router or vertical spindle moulder, which produce fully accurate, quick results. The most common specialist planes are: l l l l l l l l
rebate plane plough plane bullnose plane shoulder plane side rebate plane router plane compass plane spokeshave.
INDUSTRY TIP The sole of a plane is usually made from cast iron, which is hard but brittle. Careful handling and storage are required. Dropping the plane onto hard surfaces such as concrete can break the sole, particularly across the weak edges by the plane’s mouth.
KEY TERM Vertical spindle moulder: industrial fixed bed machine used to produce decorative finishes on the edges of timber.
Rebate plane The rebate plane is designed to form a rebate down the length of the timber. This type of plane has a fence to control the width of the rebate, which is held in place with at least one arm (the better models have two arms). At the front of the plane is a depth stop, which is used to control the finished depth of the rebate and not the depth of the shavings removed by the plane. When using the rebate plane, start at the end of the timber furthest away from you and not at the end nearest you. Gradually work your way backwards until the rebate is flat and a constant depth throughout its length. This type of plane can be difficult to use and set up correctly. A common fault is for the blade to be set too proud (sticking out) of the edge of the plane, or not proud enough. In both cases, the resulting rebate will be inconsistent in profile and of a poor finish.
p Figure 2.72 Rebate plane
When setting the plane iron, ensure that the outer edge of the iron does not stick out further than the spur cutter, whose job it is to score a thin shallow groove that will form the side of the rebate. If the cutter iron sticks out past this spur, the side of the rebate will have a poor finish. If the cutter iron is not close enough to the spur cutter, a stepped rebate will be produced. The rebate plane iron is ground square and straight and is fitted with the grinding bevel facing down. It can be used in the standard central position or in the forward position when you need to work with stopped rebates.
p Figure 2.73 Start at the furthest end away and gradually work your way backwards
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Plane body Produces
Plane iron Spur cutter Fence
Plane body Produces Plane iron Spur cutter Set back here
Fence
Plane iron slightly projecting
Produces
Spur cutter Fence
p Figure 2.74 Combination plane
p Figure 2.75 Correct and incorrect ways of setting up a rebate plane
Combination plane and plough plane
p Figure 2.76 A combination shoulder and bullnose plane
The combination plane and plough plane are like the rebate plane and are used in the same way. This type of plane uses thin cutter irons that can either be square-ground or profiled and produce grooves or profiles down the length of the timber. Power tools have generally replaced this plane for the same reasons that they are replacing the rebate plane.
Bullnose plane The bullnose plane is a short plane with the iron set close to the front of the plane. It is suitable for working into corners when a rebate needs to be adjusted. The cutter iron on these planes is fitted with the grinding angle facing upwards, as with block planes.
Shoulder plane p Figure 2.77 Shoulder plane
The shoulder plane is used to finish a tenon cut by hand. Its low cutting angle allows for a good finish across the grain of the timber. Because the cutting iron sits in line with the edge of the plane, it allows for planing right up to the shoulder of the tenon. These planes can also be used to correct or increase the size of rebates.
Side rebate plane
p Figure 2.78 Side rebate plane
The side rebate plane is used to plane the side wall of a groove or rebate to increase the width of a groove or rebate, for example when fitting a tight panel into its groove.
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Router plane Router planes are available in two sizes. The smaller version is called a thumb router, which can be especially useful when letting in ironmongery, for example the faceplate of a lock. The larger version is used to level the bottom of housings to bring them to a regular depth.
Compass plane The compass plane is used for planing curved joinery items accurately to shape. The sole of this plane is flexible and can be adjusted to suit either convex or concave profiles. The compass plane is the only specialist plane that has a back iron. When planing curved timber, it is almost impossible to plane with the grain throughout the length of the curvature. To avoid tearing out of the timber, you must change the direction of planing frequently.
p Figure 2.79 Router plane
Arrow indicates planing direction to avoid lifting grain
p Figure 2.80 Compass plane in use
p Figure 2.81 Planing directions when using a compass plane
Spokeshave Spokeshaves are used to clean up curved surfaces and are available with either a flat or curved bottom. A flat bottom is used for planing convex external surfaces. A curved bottom is used for planing concave internal surfaces. As with the compass plane, the spokeshave should always follow the direction of the grain as far as possible. Spokeshaves are notoriously difficult to master at first. It is especially important that the spokeshave has a sharp cutting edge and that the cutting iron is not set with a projection that is too aggressive. In use, the spokeshave should be held at a slight angle to the timber, so the cutting iron slices across the timber fibres.
IMPROVE YOUR MATHS AND ENGLISH Your employer has offered to pay 25% of the net cost of four planes. Select four different planes which you are most likely to use and source the net cost of each. Produce an invoice showing the net cost of each plane, the percentage amount your employer will contribute and the total amount including VAT at the current rate you will be required to pay.
p Figure 2.82 Spokeshave
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Maintaining planes and cutter irons To ensure that the plane performs to the best of its functionality, the plane and its cutting iron need to be kept sharp and well maintained; small defects will affect the plane’s performance. It is just as difficult to produce a fine smooth finish using a plane iron that is sharp but poorly set as it is to produce an acceptable finish using a blunt plane iron. Follow these basic maintenance and sharpening principles.
Sole The sole or base of the plane should be kept clean and free from any nicks, which can easily occur if not stored correctly. If the sole is twisted or has any high spots, the plane will not perform well or produce a smooth flat surface. The best way to ensure your plane has a flat smooth sole is as follows. l
Place a sheet of fine emery paper or 180 or 240 grit abrasive paper on a flat surface such as MDF or glass. l Remove the cutting iron and place the plane on the abrasive paper. Holding the plane in the normal way, plane the abrasive paper. l Any high spots on the sole of the plane will be gradually removed and it is quite easy to see any hollows. When the whole of the sole is flat, the plane can be cleaned down and is ready for the next stage.
Frog The frog of a plane holds the cutting iron in place and is adjustable. This allows for the mouth gap in the sole between the cutting iron and the mouth’s front edge to be either reduced or increased to its maximum opening. As a rule, use a larger gap when planing damp timber and preparing timber, and use a small gap when fine smoothing and end grain planing are required. The frog is held in place by two screws, which should first be slackened before trying to adjust the frog by its adjuster screw. When you have obtained the required position of the frog, tighten the two clamping screws, ensuring the frog is not in twist, as this will make the cutting iron sit at an angle within the plane. Lever clamp Frog tightening screws
Back iron Cutting iron
Depth of cut adjustment screw
Mouth
Frog
Frog adjustable screw
p Figure 2.83 Frog adjustment
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Back iron You should ensure that the back iron is in good condition and correctly set. The back iron has three main purposes: l
to stiffen and add support to the cutting iron near its cutting point l to help prevent the cutting iron chattering during the cut l to break up the shaving and make it curl (both of which may cause the mouth of the plane to clog, making further planing impossible). The back iron should be flat along its length apart from the front section, which is curved to allow the lever clamp to assert pressure close to the cutting edge of the cutting iron. You should regularly check the front edge of the back iron to ensure its front edge sits flat on the cutting iron. If the back iron does not sit flush to the cutting iron at the front edge, the small gap will result in clogging between the back iron and the cutting iron, as shown in Figure 2.85.
0.5–1.5 mm Properly fitted
p Figure 2.84 Correctly fitted and positioned back iron
The back iron should be positioned square to the cutting iron and set back from its cutting edge by 0.5–1.5 mm. Use a smaller gap for fine finishing work and on end grain, while a larger gap can be used for preparation work and on damp timbers.
Adjustment lever The adjustment lever is used to ensure the cutting iron is parallel to the sole of the plane, although occasionally the cutting iron is required to be set slightly angled, such as when squaring timber that requires more material to be removed from one side than the other.
Clogged mouth
p Figure 2.85 Ill-fitting back iron resulting in clogging
In most cases, the cutting iron will need to be parallel to the sole. The cutting iron is tilted by turning the adjustment lever one way or the other. To check if the cutting iron is parallel to the sole, simply look down the sole and look at the projection of the cutting iron below the sole.
p Figure 2.86 Adjusting the lateral level for alignment of the cutting iron
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ACTIVITY Practice removing and refitting the plane iron from its back iron and reassembling the plane to achieve thin shavings.
Depth of cut adjustment screw The projection of the cutting iron will depend on how much material you want to remove in one attempt. As a rule, it is better to make two lighter cuts rather than one heavier cut. This allows for better control of the plane, a smoother planing action and a better quality finish to the surface of the timber. A projection of 0.5–1 mm for the cutting iron is a good starting point. To adjust the depth of the cutting iron, turn the adjuster wheel either clockwise or anti-clockwise, depending on whether the cutting iron needs to project either more or less from the sole of the plane. Always make the last turn of the adjuster wheel clockwise to take up any slack in the adjustment and prevent any accidental further projection of the cutting iron. Adjust cutter to project a hair’s thickness Turn adjusting nut clockwise for a thicker shaving Last movement must be clockwise to take up movements
p Figure 2.87 Adjustment for the cutting iron
Cutter positioning The grinding angle on the cutting iron is positioned with either the grinding angle up or down, depending on the type of plane being used. The following planes have the grinding angle facing downwards, as shown in Figure 2.88: l l l l l
bench plane rebate plane combination/plough plane compass plane spokeshave. Cutting iron bevel down Frog
Mouth
Sole
p Figure 2.88 Grinding angle down
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Chapter 2 Carpentry and joinery hand tools The following planes have the grinding angle facing up, as shown in Figure 2.89: block plane bullnose plane l shoulder plane l side rebate plane l router plane.
Cutting iron bevel up
l
Frog
l
Mouth
Sole
p Figure 2.89 Grinding angle up
Storage of planes When not in use for short periods, the plane should rested so that the cutting edge of the iron is not in contact with the floor or any material. With bench working, the plane is usually rested so that the front of the sole is at rest in the bottom of the bench ‘well’, while the heel of the sole sits up on the sides of the workbench; this keeps the cutting edge of the plane iron clear. Alternatively, the plane should be rested on its side in the well, which ensures that the plane cannot easily be knocked onto the floor. With site work, it is more difficult to protect the cutting edge of the plane iron when not in use, but the same effort should be made to protect the cutting edge of the plane iron. For a prolonged period of storage and when transporting the plane, the cutting irons should be wound back into the body of the plane. The plane can be wrapped in cotton rags and sprayed with a rust protection solution. Purpose-made boxes can be used to protect planes. Before reuse, clean the planes of any oil or rust protection to prevent staining of timber.
Techniques for using hand-held planes Before you begin planing, check the direction and type of grain. Wherever possible, always plane with the direction of the grain as it runs up and away from you. Planing against the grain often results in a torn and damaged surface. Interlocking or cross-grained areas such as around knots need extra care. The plane iron needs to be finely set and have a very sharp cutting edge to reduce tearing out of the timber surface around these areas. Adjusting the frog in the plane so the mouth gap in the sole of the plane is set to a small gap will also help.
p Figure 2.90 The correct direction to plane
p Figure 2.91 The incorrect direction to plane
Source: Used by permission, The Taunton Press, Copyright © 1998.
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p Figure 2.92 Torn surface around knot (branch junction) due to directional changes of the grain
Planing timber to size The availability of portable and fixed bed power tools such as a mobile planer thicknesser has almost eliminated the need to plane large amounts of timber to size using hand-held planes. On occasion, it may be necessary to reduce standardsized materials to a specific size for a task, so this is an important skill to learn.
p Figure 2.93 Using a straight edge to check surface is flat
Sawn timber is available in standard widths and thicknesses. British Standards give 3 mm per face planing allowance when preparing sawn timber. For example, sawn timber of 100 mm wide and 50 mm thick should be finished to 94 mm × 44 mm. The 3 mm planing allowance per surface allows for the removal of all the saw marks, flattening the faces and bringing the timber to square-edged parallel lengths. The following step-by-step guide outlines the general principles to use when sawn timber needs planing to thickness using hand-held planes.
p Figure 2.94 Checking for twist with winding sticks
p Figure 2.95 Face side marked
1 Examine the timber and select the largest edge that is most free from defects. Place this face up in the vice: this will become your face side. Using a jack plane, remove saw marks and produce a clean flat face. This flat surface should be free from twist, hollows and rounded ends. To check that the surface is flat along its length and width, use the edge of the sole of the plane or a straight edge, as shown in Figure 2.93. 2 Thin lightweight strips of timber called winding sticks are used to ensure that the timber surface is not twisted along its length. Place these winding strips on the timber surface, one kept nearest you while placing the other at several stages along the timber to check for twist. If the timber is in twist, part of the furthest winding strip’s top edge will either show above or below the front winding strip, indicating that it is either higher or lower, as shown in Figure 2.94. To remove any high spots, plane diagonally across the high spot area to bring it in line, followed by a few more shavings over the total length. Recheck and adjust until both winding sticks are parallel to each other along the timber’s total length. 3 Once this is complete, use a standard reference mark to show the face (this should point to the best edge and is known as the face mark), as in Figure 2.95.
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Chapter 2 Carpentry and joinery hand tools 4 The timber should now be placed in the vice with the planed edge facing out towards you and the best edge pointing up, as shown in Figure 2.96. Plane the edge until it is straight and square to the face, which is checked using a straight edge or the sole of your plane and try square or combination square. When finished this top edge is known as the face edge and is marked with the standard edge mark, as shown in Figure 2.97. 5 Mark the timber along its widest side first to the required width, using a marking gauge, as shown in Figure 2.98. Once you have marked the material from the face edge on both sides of the timber, place it in a vice with the gauge marks facing upwards. Carefully plane down to the gauge marks, regularly checking both the front and back sides to ensure that the planed edge is kept parallel and in line with the gauge lines. 6 Now mark the timber to the required thickness, as shown in Figure 2.99. Using a marking gauge and working from the face side, mark both edges. Place the timber in a vice with the waste side upwards and plane down to gauge line, ensuring you plane carefully down to the gauge marks and not beyond.
p Figure 2.97 Face side and face edge marked
p Figure 2.96 Squaring up the face edge
Required width
Required thickness
p Figure 2.98 Mark the required width from the face
p Figure 2.99 Mark to the required thickness from the face side
ACTIVITY Face and edge a length of timber 50 × 38 mm and 450 mm in length using a jack plane. Mark the finished width and thickness at 44 × 32 mm using a marking gauge and plane to thickness.
Planing end grain Planing end grain is more difficult than planing along the grain. A finer setting is usually required to the plane iron, as well as a lot more pressure in forcing the plane down into the cut, otherwise the plane may start to judder during planing, giving a poor finish. Unless the far edge of the timber is supported, breakout will occur. To prevent this breakout or spelching, adopt one of the following methods of working. l
Plane from both ends to the centre. Use a shooting board that supports the far edge of the timber, as shown in Figure 2.100. l Clamp a sacrificial piece of timber to the far edge, as shown in Figure 2.101. l
KEY TERM Spelching: the uncontrolled breakout of material, resulting in damaged and/or weakened edges.
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ACTIVITY Using a suitable material, make a shooting board that can be used to plane square the end grain of the length of timber produced in the previous activity.
Jack plane Timber
Shooting board
Fence acting as end grain support
p Figure 2.100 Shooting board used to square and smooth the end grain of timber Direction of planing
Sacrificial timber set level with the top of the material
p Figure 2.101 Sacrificial timber clamped to the end of the timber to prevent spelching
Flushing shoulders of an assembled frame
p Figure 2.102 Flushing the shoulder joints on an assembled frame
Flushing or flattening shoulders is the process of using a smoothing plane to level off the shoulders of joints. The edge of the plane is used to find any high points, which are then gradually planed down using a circular motion of the plane to produce a flat surface across the joints. Be careful not to over plane the corners of the frame, which would produce a rounded edge to the stiles of the frame. Another common fault is to allow either the back or front edge of the plane to drop inside the edge of the frame as the plane is passed backwards and forwards during the
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Chapter 2 Carpentry and joinery hand tools planing operation. This means that the sole of the plane will hit the inside edge of the frame, resulting in damage that cannot easily be repaired. When the shoulder joints of the frame are flat, take a couple of fine shavings through the rails and finally through the stiles, ensuring you are laying the grain down as far as possible when choosing your planing direction.
Chisels and knives A large range of woodworking chisels is available, some with wooden handles or plastic handles and handles with metal inserts in the handle end. Chisels with wooden and plastic handles should only be hit with a mallet, as using a metal hammer on them would damage the handle end. This leads to splitting and breakage, as well as making it uncomfortable for you to hold the chisel. Chisels that have a metal insert in the handle end can be used with metal hammers. In most cases, chisels range in size from 6 mm to 50 mm, with several different types or designs of chisel, each having a specific use. Whenever possible, always purchase the best quality chisels you can afford as these are not disposable items and should last you for most of your working life.
Parts of a chisel Traditional wooden handled chisels are made in a slightly different way to plastic handle versions, which have the plastic handle moulded around the chisel itself. The following describes the make-up of a good quality wooden handled chisel. l
Blade: the part of the chisel that is sharpened. Tang: non-cutting end of the chisel that fits into the handle. l Leather or plastic washer: fitted between the blade and the handle and used to help absorb some of the energy created when the handle is hit. l Ferrule: used to help prevent the handle splitting where it joins the tang. l Metal insert: some handles have a metal insert in the handle end so they can be used with a metal hammer; chisels with these inserts are a favourite with site operatives who tend not to have mallets. l
HEALTH AND SAFETY One important rule you should always follow when using chisels is keep both hands behind the cutting edge of the chisel for all types of work. Doing so will prevent you suffering a chisel cut. Always pass a chisel to another person handle first; this will help to reduce the possibility of accidental contact with the cutting edge.
Types of chisel
Handle
The most common types of wood chisel are: l
bevel edge chisel l firmer chisel l mortice chisel l gouges.
Ferrule Washer Tang
Bevel edge chisel Possibly the most common type of chisel in use, bevel edge chisels have some of the side edge removed, giving them a bevelled edge, which makes them quicker to sharpen. They are used for general work, for example paring and recessing. The bevel edge chisel is good for working into tight corners due to its bevelled sides and is the chisel of choice when chopping out the sockets for dovetails.
Blade
p Figure 2.103 Exploded view of a chisel
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p Figure 2.104 Bevel edge chisel
p Figure 2.105 Profile of a bevel edge chisel
Firmer chisel The firmer chisel is more robust than the bevel edge chisel, having square sides and a deeper profile near its tang. As a result, this type of chisel is better equipped for the heavier work usually found on site. The firmer chisel is losing its popularity in favour of the bevel edge chisel.
p Figure 2.106 Firmer chisel
p Figure 2.107 Profile of a firmer chisel
Mortice chisel This is a strong chisel designed to form mortices and to withstand the heavy mallet blows and levering required when chopping mortices and other heavy work. The section of this chisel is rectangular or square in shape, giving a deep profile to the chisel and increasing its strength.
p Figure 2.108 Mortice chisel
p Figure 2.109 Profile of a mortice chisel
Gouges Gouges come in a variety of sizes and radii and are usually ground on their inside face (scribing gouge). They are mostly used to cut curves such as scribes into ovolo moulded timber or when forming housings in stair strings to receive the bullnose of the stair tread. Gouges that are ground on their outer edge are typically used with the turning lathe and in carving. 90
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Blade Blade Blade ground on inside
Blade ground on outside
p Figure 2.111 Profile of a turning and carving gouge
p Figure 2.110 Scribing gouge
Knives Knives general fall into two types: l
utility knife
l
marking knife.
Utility knife The utility knife has either a retractable blade that slides back into the handle or a folding blade action that returns into the handle when not in use. This type of knife has a disposable blade that is extremely sharp so you should take great care when using it. This is an underappreciated tool, particularly for site use, and is typically used to cut packaging, plastic banding and other forms of wrappings. This hand tool can only be purchased if you are over 18 years of age.
p Figure 2.112 Utility knife
Marking knife The marking knife is usually a dedicated bench knife, although it can be used on site and is often used to mark out the positions of hinges on doors and frames. The marking knife is ground and sharpened on one side only. This allows for the knife to sit tight against the square and enables the user to mark or cut a light line across the grain of the timber. The marking knife is available as a left- or righthanded version. It is used where accurate lines are required such as when producing dovetails and for high-class joinery.
p Figure 2.113 Marking knife
Techniques for using chisels Both blunt and sharp tools are dangerous to use. If you do not use a sharp chisel correctly you may suffer a severe cut. It is surprising how often a chisel is required to do tasks during the construction process. Examples include easing joints, chopping hinge recesses, cleaning out recesses, easing clearance or removing excess material, cutting fitted packers, even using chisels as a scraper to remove pencil marks. Techniques used to safely perform common tasks with chisels are set out below; the same principles can be transferred to most tasks required of a chisel.
HEALTH AND SAFETY The most important rule to follow when using chisels is always keep both hands away from the cutting edge of the chisel.
Cutting recesses The bevel edge or firmer chisel is often used to cut a recess such as that used to house a hinge. This is a simple step-by-step guide to cutting a recess, in this case for a hinge using a bevel edge chisel. 91
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Cutting a recess using a bevel edge chisel
STEP 1 Mark out the recess to be cut using marking gauges, square and marking knife.
STEP 2 Position the chisel on the end of the marking out with the bevel towards you and start chopping out the recess using a walking method. Hold the chisel at an angle of 45° after the initial cut. This will lift the grain of the timber as it is being chiselled, making it easier to remove. For the last cut on the marking-out line, turn the chisel around so the bevel is away from you and the chisel is vertical.
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STEP 3 Carefully pare back to the gauge lines to ensure a tight fit. When paring, try to adopt a shear cut (slight angle across the recess) as this will give a better finish.
STEP 4 Check that the hinge fits in to the recess.
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Forming a mortice
STEP 1 Start at the end furthest away from you, and work towards the other end. Hold the flat side of the chisel vertically against the markingout line and strike the handle with the mallet. Turn the chisel around and repeat the process while moving to the other end of the mortice.
STEP 2 Lever the chisel forward after each mallet strike to break the grain and make it easier to remove the waste material.
STEP 3 Go just over halfway through the timber, then turn it over and repeat the process. Do not go right through the timber with your chisel, as this will split the wood. Clean out the ends of the joint.
STEP 4 Once you have morticed both sides of the joint, clean out the mortice with a blunt instrument, such as a rule or the end of a combination square.
STEP 5 Make the mortice slightly wider on the back of the joint, as this is the starting position for the wedges that will hold the joint together.
STEP 6 When the waste is clear, place the mortice on the bench and clean out any whiskers. Take care at this stage not to make the mortice any wider than it needs to be.
KEY TERM Whiskers: the small pieces of wood fibre remaining after cutting the joint. Leaving these timber fibres in place can cause an obstruction when assembling the joint.
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Forming a housing
STEP 1 Crosscut down to the gauge lines using a tenon saw. If there is a large amount of material to remove, or if there is a big knot in the middle, several other cuts can be made in the waste area to make the process of removing the waste easier.
ACTIVITY
STEP 2 Using a bevel edge chisel, cut upwards towards the middle of the joint to form a slope. Do not go right through, because the timber is liable to split. Turn the timber around and repeat the process. You will end up with a little ‘roof’ shape in the middle of the housing.
Using the length of timber from the previous activity, mark through a mortice 44 mm long and 10 mm wide, 106 mm from one end, using a mortice gauge. Chop out the mortice using a 10 mm mortice chisel. From the other end, mark out the tenon to suit the mortice and form the tenon using a tenon saw. Cut off the tenon end of the timber at 150 mm and try the fit into the mortice.
IMPROVE YOUR ENGLISH Produce a simple toolbox talk poster outlining the safe use and handling of chisels. STEP 3 Clean out the middle, again taking care not to go right through the joint with your chisel.
STEP 4 The finished housing joint.
Sharpening plane irons and chisels The following section covers the grinding and sharpening of both plane irons and chisels. Although the descriptions mainly refer to plane irons, the same principles apply to chisels. (Where any specific difference occurs between the two, these are outlined.) To cut safely and efficiently, plane irons must be kept sharp. How often they will need to be sharpened depends on several factors. l
How often is the plane used? If used infrequently it will not require regular sharpening. l What type of material is the plane being used on? If used on more abrasive materials such as oak, the plane will require more frequent sharpening. l Has the cutting iron become damaged? Hitting hard dead knots can damage the cutting edge as can hitting any foreign bodies in the timber. l Poor grinding and sharpening in previous sharpenings.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma A dull or damaged cutting edge to the cutting iron will result in: l
the need to exert greater force during planing difficulty in achieving a clean fine shaving from the plane l clogging of the mouth in the plane l small ridges on the surface of the timber, resulting from a chipped cutting edge to the cutting iron. l
The sharpening process for a plane iron can take two stages: grinding and sharpening (honing) the iron. You do not always need to grind the plane iron; you should do so only if the cutting iron has been damaged or has already been sharpened/honed to an extent that grinding is again required.
Grinding plane irons and chisels
HEALTH AND SAFETY Ensure you have been trained and authorised to use a grindstone before attempting to grind your plane iron. The safe use of the grinder is like all power tools and is covered by PUWER (Provision and Use of Work Equipment Regulations 1998), as well as the risk assessment in your workplace, which should always be followed.
p Figure 2.114 Bench grinder
Plane irons should be ground at an angle of 25°. You can do this by either dry grinding on a bench grinder or wet grinding on a water-cooled grinder. Whichever version you use, it is important that the cutting edge of the iron does not become too hot and begin to burn (bluing of the grinding edge). This is because the extensive heat generated during the burning process alters the temper of the steel, reducing the cutting iron’s facility to retain a sharp edge. When dry grinding, the plane iron is constantly dipped into water to cool the grinding edge, thereby reducing the risk of burning the grinding edge. The grindstone in the water-cooled grinding system receives a constant supply of water, either through a water trough under the grindstone or by being constantly dripped onto the grindstone. When using a grindstone, the tool rest should be set as close as practicable to the grindstone and set so the grindstone produces a 25° grinding angle. You should slowly pass the plane iron back and forth across the face of the grindstone, applying a steady constant pressure onto it. Water-cooled grindstones have a holding device attached to the framework of the grinder for improved accuracy.
p Figure 2.115 Water-cooled grinding system
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Chapter 2 Carpentry and joinery hand tools While using the grindstone, you are required to use the following PPE as a minimum: l
safety glasses even when the grinder has a safety screen l barrier cream for your hands, or protective gloves l face mask (particularly for dry grinding) l protective workwear such as an apron or overalls.
Sharpening (honing) plane irons and chisels Once the iron or chisel has been ground to 25° it can be sharpened (or honed) to an angle of 30°. This process can be carried out on several different sharpening stones – oil stone, water stone and diamond stone.
INDUSTRY TIP Before starting to do any grinding, ensure you have a supply of coolant to dip the plane iron or chisel in. This will help to keep it cool and prevent burning of the cutting edge.
Oil stone The oil stone is the most commonly used grit stone, which can be natural stone or man-made. The man-made versions are the most common and are typically manufactured from aluminium oxide grit, which is formed into a block and often referred to as an India stone. Some of the best oil stones are made from natural stone and often referred to as a Washita stone. Man-made stones are generally double-sided and are 200 mm long by 50 mm wide. In most cases, one side has a medium grade grit surface, while the other side has a fine grade grit surface. The most commonly side used is the fine grade. If you only require the fine grade, you can get all fine grade grit stones, which means you can turn the stone over as one side becomes worn.
p Figure 2.116 India oil stone
Because these stones are very fragile, they should be protected and stored in a wooden box (normally made by the owner). As the name suggests, oil stones require lubricating in use with light machine oil from an oil can.
Water stone The water stone looks virtually identical to the oil stone, but the water stone is made from a natural stone. These stones remove less metal than man-made stones and polish while sharpening, providing a very keen (sharp) cutting edge. They can be lubricated with either water or oil. If used with oil, you cannot revert to water. The disadvantage with both oil and water stones is that they wear hollow in both directions and need regular maintenance to grind them back to a flat surface.
Diamond stone The diamond stone has increased in popularity, particularly with site carpenters. They can be more expensive to buy initially, but diamond stones require little maintenance. The sharpening surface on diamond stones stays flat and is less likely to break, which are the reasons why they are particularly popular for site use. Diamond stones can be ‘fast cutting’, removing the worn cutting edge rapidly, and they are available in various grit grades. Diamond stones should be used with water, which can be applied by spray mist, and wiped clean after use.
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The sharpening (honing) process The process of honing the plane iron can at first be difficult to master, but like most tasks the finished results improve with practice. In simple terms, the plane iron is rubbed along the sharpening stone on the front edge of the grinding angle, altering the front angle from the 25° grinding angle to a 30° sharpening angle, as shown in Figure 2.117. Grinding angle 25º
First sharpening produces a 30º angle
25° Grinding angle
Excessive sharpening angle length
Second sharpening increases the sharpening angle’s length 30° Sharpening angle
p Figure 2.117 Sharpening and regrinding angles
Repeated sharpening on the sharpening stone at 30° gradually increases the length of the sharpening angle. When the length of the sharpening angle becomes excessive (about half the length of the original grinding angle) the plane iron will require regrinding and the process begins again. The process used to sharpen the iron is outlined in the following steps. 1 Lubricate the sharpening stone with a suitable lubricant (thin oil or water). 2 Place the iron on the sharpening stone point first, as shown in Figure 2.118, and slowly lower the iron until the grinding angle is flat to the stone’s surface. At first it can be difficult to tell when this happens, but usually you see the lubricant ease out at the back of the iron and you feel it sit down firmly. This is shown in Figure 2.119.
Plane iron Lower back edge of iron
Plane iron
Lower back edge of iron 25°
Sharpening stone
p Figure 2.118 Place the iron on the sharpening stone point first
Sharpening stone
p Figure 2.119 Slowly lower the iron until the grinding angle is flat to the stone’s surface
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Chapter 2 Carpentry and joinery hand tools 3 Slowly raise the back edge while keeping the point in contact with the sharpening stone, trying to achieve a 30° angle, as shown in Figure 2.120. You will lift the back edge by only a small amount. As you become more experienced, you will be able to better guess how much to lift.
Plane iron Raise back edge of iron to 30°
Area which is removed during the sharpening
Burr edge
30°
Sharpening stone
p Figure 2.120 Slowly raise the back edge while keeping the point in contact with the sharpening stone
4 You can now move the iron backward and forwards along the sharpening stone using a firm downward pressure. It can at first be difficult to maintain the required sharpening angle during this process, but again with practice it becomes easier. You should use the whole of the stone’s area to help prevent it from becoming hollow in its central area. This process can be done in a ‘figure of eight motion’, shown in Figure 2.121, or in long ‘vee’ strokes, shown in Figure 2.122. If you are not careful, the ‘figure of eight’ motion can produce a rounded effect to the sharpening edge of the iron. Several iron holding devices are available that help maintain the correct sharpening angle, such as the jig in Figure 2.123. 5 Continue the sharpening process until the grinding angle has been replaced on its front edge with the sharpening angle and produced a slight ‘burr’ (a thin wire edge, which is the result of folding back of the iron’s front edge). This is shown in Figure 2.124.
p Figure 2.121 Figure of eight motion
p Figure 2.122 Vee motion
Plane iron Thin wire burr
Grinding angle
Sharpening angle
p Figure 2.123 Jig to hold the chisel or plane iron
p Figure 2.124 Thin wire burr produced by the sharpening process
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Keep flat
p Figure 2.125 Removing the wire burr
6 Remove this wire burr by placing the back (flat) edge of the iron flat down on the stone and rubbing it up and down on the stone until the burr has been lost, as shown in Figure 2.125. Start with the burr overhanging the side of the stone and keeping the iron flat on the stone. Draw the cutting edge onto the stone and rub the iron firmly up and down the stone, ensuring that the iron is kept flat to the stone. The wire burr will gradually break away and be lost. 7 Remove any remaining wire burr by passing the sharpened edge of the iron backwards and forwards over a piece of cloth. Do not drag the cutting edge over the corner of a piece of timber, as this will trap any remaining burr in the resulting cut; then as the cutting edge of the newly sharpened iron passes over this collection of wire burrs, the cutting edge will become damaged. 8 Finally, clean and safely store the sharpening stone. Not all plane irons are sharpened square across their face. Different types of planes have different uses so they have different cutting edges. Table 2.1 shows the three most common cutting edges given to a plane. q Table 2.1 Most common cutting edges given to a plane iron Type of cutting edge
Type of plane it is used on
Square
A square cutting edge is used on try, shoulder, rebate, bullnose, plough and router planes.
Slightly convex
Slightly convex is the most popular cutting edge and is used on block planes, jack planes and spokeshaves.
ACTIVITY Grind and sharpen a jack plane iron, then correctly set and position the iron into the jack plane.
IMPROVE YOUR ENGLISH Produce a short guide on how to grind and sharpen a 25 mm bevel edge chisel. Use full sentences.
0.5 mm
Softened corners 1 mm
Softened corners are used on smoothing planes to reduce the likelihood of leaving plane marks on the finished surface after cleaning up the work piece.
Sharpening gouges Gouges are ground and sharpened differently to plane irons and chisels. The scribing gouge is ground on its inside face with a grindstone that has a suitable radius to accommodate the curvature of the gouge. The gouge is then sharpened with a slip stone that again has a suitable radius. The slip stone can either be secured in a bench vice and the gouge moved over its top edge, or the gouge can be held down to the edge of the bench and the slip stone moved over the cutting
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Chapter 2 Carpentry and joinery hand tools edge. The burr is removed in a similar way to that described for the plane iron and chisels (see page 100); the scribing gouge will also need to be rolled along its face at the same time.
p Figure 2.126 Sharpening the inside edge of a scribing gouge
p Figure 2.127 Removing the burr by rolling the scribing gouge flat on the oil stone
Drills, drill bits and screwdrivers Traditional hand-held drills are rarely used these days as they have been replaced by the more efficient portable power drill, though you may choose to use a traditional hand-held drill. There are two types of traditional hand-operated drills. l
The wheel brace drill is used to form smaller holes 1–8 mm in diameter and countersink holes. The cutting action of these drills is slow, and the hole needs to be cleaned regularly to prevent binding. To clean the drill hole, withdraw the drill bit while still rotating the hand wheel clockwise. As the drill bit is removed it helps to clear the waste from the hole. l The swing brace drill is used for boring larger holes. The turning capacity or swing of the brace enables a more efficient use of energy, which means that larger diameter drill bits may be used than with a wheel brace. Most swing braces have a ratchet facility, which allows holes to be bored close to an obstruction. The swing brace was also widely used to drive in and remove large diameter slotted screws.
p Figure 2.128 Wheel brace
p Figure 2.129 Swing brace
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Types of drill bits Portable power tools have made drilling holes much easier. With the increasing use of power tools, the types and designs of bits has changed, as many older types of bits have been adapted for use by powered means. Examples of the most frequently used types of drill bits are shown in Table 2.2. q Table 2.2 Most common types of drill bit Type of bit
Size
Uses
Type of drill to be used with
Twist
1–13 mm
Boring holes in wood, metal and plastic.
Wheel brace and power drill.
Lip and spur
1–13 mm
Modern alternative to the twist bit, produces cleaner cuts and accurate centre positioning due to its pointed centre; should only be used on timber products.
Wheel brace and power drill.
Countersink
13–20 mm
Producing a countersunk hole to receive the head of a screw.
Wheel brace, swing brace and power drill.
Masonry bit
4–25 mm
These drill bits have a TCT bit in the point, making them suitable for boring holes in masonry such as brickwork, blockwork and concrete; often used for plastic plugs used with screws.
Power drill with hammer action.
Auger
6–50 mm
Augers are used for boring deep holes in timber such as when fitting locks. The modern 5-flute cutter head in the photograph is designed to be extremely accurate and suitable for deep rapid drilling. Traditional pattern designs intended for use in swing braces included the Jennings and Irwin pattern designs, which can be sharpened.
Swing brace and power drill.
Forstner bit
9–50 mm
The short centre pin allows shallow (blind) holes to be bored within 3 mm of the back face without showing. Suitable when fitting concealed hinges.
Power drill.
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Chapter 2 Carpentry and joinery hand tools Type of bit
Size
Uses
Type of drill to be used with
Flat/spade bit
6–50 mm
Boring larger hole through softwood where a good finish is not required.
Power drill.
Drill and counter bore
Matching sizes This is a combination drill which bores to plug cutters a clearance hole for the screw and a hole for a wooden plug to be inserted following the screw.
Power drill.
Plug cutter
10, 13 and 16 mm
Produces wooden plugs which are inserted into a counterbored hole to conceal fixings.
Power drill.
Hole saw
16–152 mm
For boring large holes through generally Power drill. thin materials; useful when running services through pre-fixed kitchen units.
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Screwdrivers There are many types of screw heads, each with a screwdriver point to match. It is important that you choose the correct size and type of screwdriver to match the screw head.
Slotted
Cross slot/ Phillips
Pozidriv
Torx®
Security T
Hexagon
p Figure 2.130 Types of screwdrivers and screw heads
The most common type of head used on screws is the Pozidriv, which is an improved version of the Phillips screw head. The main difference between the Phillips and Pozidriv screw heads is that there are additional smaller ribs at 45° to the main slots in the Pozidriv.
p Figure 2.131 Yankee pump action screwdriver
KEY TERM Torque: the rotating force produced to turn an object.
INDUSTRY TIP When using spiral or pump action screwdrivers, the driver bit can easily jump out of the screw head if pumping the screwdriver quickly. These types of screwdriver are especially difficult to use when fixing slotted screws.
Pozidriv heads come in three sizes – 1, 2 and 3 – with size 3 being the largest. Size 1 is generally used for screw gauge size 3.0; size 2 is used for gauges 3.5–4.5; and size 3 is used for gauges 5 and 6. Some makers of screws produce their own driver bits specifically designed to fit their types of screws. Most screws are driven into the material with powered drivers, which usually incorporate an impact driving system. Hand-held screwdrivers have changed little over the years, apart from their head shape and the material the handle is made from, which was traditionally wooden but is now plastic; modern versions often have soft grip handles. Spiral screwdrivers or pump action screwdrivers are used less nowadays but they are still a good alternative to powered drivers. A spiral pump action screwdriver, such as the Yankee screwdriver, is available in three lengths. The larger versions are used with larger screws as this type of screwdriver can apply a high level of torque to the screw. The bits in the Yankee screwdriver can be interchanged to suit several screw head types and sizes.
HEALTH AND SAFETY You should take care when using spiral or pump action screwdrivers while working at height. If the screw head slips while you are pumping the screwdriver down, this may cause you to lose your balance.
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Using drill bits Using a powered drill fitted with a screwdriver bit and modern easy-drive screws minimises the amount of preparation work required when fitting two components together. Traditionally, three stages were required for connecting two timber components, as shown in Figure 2.132. 1 Drill the clearance hole. It is important that you choose the correct size drill bit for the gauge of screw that you are using. Selecting the correct size drill bit ensures that the top piece of timber is pulled tightly to the bottom piece of timber. A rule of thumb for drill sizes is to halve the screw gauge in millimetres for the clearance hole and halve that again for the pilot hole. 2 Form the countersink hole to suit the size of the screw head. 3 Locate the two pieces together and drill the pilot hole.
1 Clearance hole
2 Countersink hole
3 Pilot hole
p Figure 2.132 Three stages of drilling
Determine the correct size drill bit to use for pilot and clearance holes in the following ways. l
With modern metric-sized screws, use the gauge size (thickness) of the screw to equal the size of the clearance hole, and use half this size as a pilot hole. For example, metric-sized screws of 4 × 50 mm would require a clearance hole of 4 mm and a pilot hole of 2 mm. l Traditional imperial screws use a different method of sizing the gauge of the screw. For imperial screws, half the gauge size equals the size in millimetres for the clearance hole and half that size again gives you the pilot hole size. For example, imperial size screws of 8 × 2’’ would use a 4 mm clearance hole and a 2 mm pilot hole. With modern screws, the need for pilot holes and countersinking is now generally only required for hardwoods and when using large gauge screws. To use a larger auger type drill bit that passes all the way through the material, such as for a lock fitting in doors, mark the centre position of the hole on both side of the material. Using the required size drill bit, drill through the material, ensuring that the drill is kept level and square to the material. Stop when the drill point starts to penetrate the other side of the material. The point should line up with the pre-marked centre point. Withdraw the drill bit and reposition on the centre mark on the other side. This will join the two holes together, eliminating any risk of splintering on the back side.
Sharpening drill bits
Spur
Cutting edge
Most of the normal twist, lip and spur bits and some forms of auger bits are disposable items. Because of their small sharpening area, they are difficult to sharpen unless you have specialised sharpening equipment and grindstones. The low purchase price of these drill bits means that sharpening them is not a viable option. Traditional styled auger bits such as the Jennings and Irwin patterns can be sharpened using a small flat or triangular file. Sharpen these styled auger bits using the following method.
Tapered lead screw
Cutting edge Spur
p Figure 2.133 Parts of a traditional auger bit
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma 1 Cramp the auger stem in a vice, with the cutting end as low in the vice as practicable; this will reduce any vibration that may occur. 2 File the cutting edge of the bit on its top edge, not its underside edge. Maintaining its existing cutting edge, file in smooth strokes until a sharp clean cutting edge begins to form. Remove as little material as possible. 3 The spur has a rounded shape to its cutting edge. You should always file the cutting edge on its inner edge, never its outer edge, as shown in Figure 2.134, and maintain the rounded shape as far as possible. The spur should always protrude past the flat cutting edge. With repeated sharpening the spur will reduce in size. When it has been reduced to such an extent that it no longer protrudes past the flat cutting edge, replace the auger. p Figure 2.134 File the inside edge of the spur
Miscellaneous hand tools These are some important miscellaneous additions to most tool kits that would benefit both site carpenters and bench joiners.
Hammers and mallets There are three general types of hammers that you are likely to use in your work: the claw hammer, Warrington hammer and pin hammer. l
p Figure 2.135 Claw hammer
p Figure 2.136 Warrington hammer
Claw hammer: this is perhaps the most common type of hammer and is used to drive nails, pins, wedges and dowels. Claw hammers may have a straight or curved claw (a split-pein). The curved claw is used to provide leverage to remove nails from timber, while the straight claw is used to remove larger nails in timber framing. l Warrington hammer: this is a type of pein hammer and is useful for driving wedges and smaller nails and pins. Its head is shaped so that you can hold small pins and nails between your finger and thumb, and the tapered head or cross pin can be used to start nailing without knocking your hand. Once the nail is part way into the timber, the hammer is rotated so that the larger face of the hammer can be used to drive the remainder of the nail into the timber. l Pin (or pein) hammer: this is a light hammer used for driving in small pins. Pin hammers are rarely used by joiners these days, as this job is usually completed with a nail or pin gun.
INDUSTRY TIP The face of a hammer should always be clean and free of glue, otherwise it could cause the object you are striking to bend or break and cause the hammer head to slip off the nail and hit the finished surface, causing indentations. Clean the hammer head by placing some abrasive paper on a flat surface and rub the face of the hammer over it until it is clean.
HEALTH AND SAFETY Do not hit two hammer faces together. Because they are hardened, the two faces striking each other could splinter, risking injury to yourself and others around you.
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Chapter 2 Carpentry and joinery hand tools A mallet is used for assembly work and striking chisels. It is available in a variety of sizes, a medium-sized mallet being the most popular. Although a mallet is made of wood or rubber, it is heavier than a hammer and does not leave the marks of a hammer head. It is best to hold mallets and hammers at the end of the handle to provide more leverage and use less energy. Holding the handle too close to the head is known as ‘choking’ the tool and should be avoided.
p Figure 2.137 Mallet
Clamping and securing equipment An essential part of carpentry and joinery is ensuring that materials are held safely, securely and clamped while they are being manufactured, positioned or assembled. Table 2.3 outlines the main types of clamp that are available. q Table 2.3 Types of clamp Type of clamp
Description
Sash clamp
A sash clamp is used to assemble small frames up to about 1.5 m long, for example window sashes. It has a steel bar with holes to locate a pin to secure a shoe (clamping head) to the desired position. At the other end is another shoe fixed to a screw and handle to apply the pressure to the work piece. It is important to use blocks of wood to cushion the timber being clamped. You should avoid cheap clamps because they can bend when pressure is applied to the joint and they often do not clamp evenly across the entire faces of the shoes, resulting in a tight joint on the face closest to the steel bar only.
T bar clamp
T bar clamps have a heavier section bar shaped like the letter T. They are used for the assembly of large window and door frames, doors and shopfronts. The heavier section clamp is designed not to bend under the pressure applied over the larger distances. An extension bar can be attached to the clamp for bigger applications.
G clamp
A steel G clamp is so called because the open clamp including the screw shaft looks like a letter G. They are available in several sizes and depths and can be extremely useful when holding together materials under enormous amounts of pressure. Care should be taken to avoid unnecessary damage to the swivelling shoe on the end of the thread. This is always the first thing to get misplaced, resulting in possible damage to the work piece in future use.
F clamp
This clamp has an adjustable arm that can be set to accommodate any width within the distance of the main bar. It is ideal for holding materials down and clamping glue joints.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Type of clamp
Description
Quick-release clamp
These are for light temporary jobs, such as holding down work. They are available in a range of lengths and jaw depths, to suit various jobs. Smaller clamps may weaken and slip under excessive loads, so are not suited to gluing up. The quick release function allows for onehanded operations. Some clamps can be converted into a ‘spreader’, allowing the clamp to force materials apart rather than pull them together. Rubber caps are moulded to the faces of the jaws to prevent damage to the materials being held.
Vice
A bench vice is a workshop essential. It is used to hold timber as it is being cut. It is faced with plywood or timber to avoid damage to the timber being held. The plywood is held in place using screws; these can work loose over time and can create screw head shaped dents. Vices come in a range of sizes and may have features such as quick-release levers for fast adjustment. Some vices have a height-adjustable ‘front dog’, used to clamp wide material over the bench top.
Air bags Air bags, windbags or wind wedges are small fibrereinforced sealed bags that have an attached rubber pump with a bleed valve. These bags are used to level and wedge work such as when hanging doors, fitting windows or installing appliances such as fridge freezers and ovens. The air bag is inflated with air until the desired joint width or level is obtained. The air bags can expand from flat, at about 2 mm, to 50 mm. To remove the bags, deflate them by pressing the release valve button on the pump. It is recommended that you use these wind bags in pairs, so carpenters usually have at least two of them in their toolkit.
p Figure 2.138 Air bag
Abrasive paper HEALTH AND SAFETY Whenever you use abrasive paper, always ensure that you have suitable extraction fitted to take away the fine dust. Alternatively, use an appropriate dust mask.
Abrasive paper is graded by the size or number of sharp particles of grits per square 25 mm of abrasive paper: the larger the number, the finer the finish from the abrasive paper. Therefore, P60 (60 grits per 25 mm square) is coarser than P240. Coarse grade is for rougher work and finer grades for finishing. The letter P in front of the grit size stipulates that the abrasive paper has been graded to a common agreed measuring standard; thus, whichever manufacturer you use, the grading of the abrasive paper is the same. As a general guide use the grit sizes given in Table 2.4 for the various tasks outlined. q Table 2.4 Grit sizes of abrasive paper and typical uses Grit size
Typical uses
P60–P80
Rough working and heavy stock removal.
P100–P120
General use, fine finishing work and preparation work prior to applying the finishing coat.
P180–P240
Very fine finishing, typically used to finish hardwoods.
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Trestles, bearers and sawhorses It is important to support materials, either temporarily, such as for short-term storage, or while the material is being worked on. However, making suitable temporary work benches available for site working could be difficult. Strong and sturdy work trestles or sawhorses (traditional homemade supports) not only provide support for materials but can be converted into a workbench by overlaying with plywood or similar material. Solid trestles allow work, such as cutting worktops and cutting materials with power and hand tools, to be carried out safely and accurately. Modern trestles are not only extremely strong and stable but also fold flat for convenient transporting, unlike traditional sawhorses.
p Figure 2.139 Adjustable and fold-flat work trestles
p Figure 2.140 Traditional homemade sawhorse
Adhesives The table below explains the types of adhesives used in carpentry and joinery. q Table 2.5 Adhesives and foam Type of adhesive or foam Properties and use PVA (polyvinyl acetate) or white glue
This is a resin dissolved in water. As the water evaporates, the glue dries (goes off). It is available in internal and exterior grades, it has good gap-filling properties and it provides a strong permanent bond. It dries clear, but if not cleaned up properly can leave visible marks when the product is varnished or stained. It can react with some hardwoods to leave black joints or marks.
PU (polyurethane) or foam glue
A yellow-brown resin that foams when exposed to the air. It forms a strong, water-resistant bond and has excellent gap-filling properties. It can be used to join damp timbers, but timbers must be secured together while the glue dries, otherwise it could force the joint apart as it foams. The excess glue can easily be removed after it has dried by scraping it off the joint, but do not attempt to do this before it has dried, as this will result in the adhesive spreading over the work piece, your tools and potentially yourself. PU glue is normally supplied with a pair of disposable gloves, which should always be worn when using it.
UF (urea-formaldehyde) or powdered resin glue
This adhesive is mixed with water before use. A chemical reaction causes it to set after a few hours, depending on the surrounding temperature, and it forms a strong water-resistant bond. It is used for high-quality work as it does not stain the timber being joined.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Type of adhesive or foam Properties and use Synthetic resin grab adhesive
This is supplied in a tube and needs to be applied with a skeleton gun. Although not often used in the joinery workshop, it is used for site work such as fixing panels and skirting to walls. Some grab adhesives will form a skin as soon as they are exposed to the air, which prevents them bonding as well as other adhesives. Some are also very thick, which may cause the surfaces to sit slightly apart and reveal a gap in the joint.
Contact adhesive, super glue or mitre bond
This is a quick-drying adhesive used to join cornices, pelmets, plinths and skirting boards. It sets in 15 seconds. A thin layer is applied to one surface while a spray activator is applied to the other; they are then brought together and held for 15 seconds to form a permanent bond.
Polyurethane fixing foam
This is now commonly used on site to fix in all types of frames such as door and window as well as linings. It has similar adhesive properties to PU glue, but is applied using an applicator gun instead.
Expanding foam adhesive
Similar to polyurethane (PU) adhesive, this fills and bonds most surfaces and materials. Different grades of foam may have different acoustic and thermal insulation properties and fire ratings.
3 HOW TO SAFELY STORE AND TRANSPORT HAND TOOLS Hand tools are expensive to purchase and mostly will last for a long time if taken care of. Bench joiners generally do not need to transport their tools and, in the past, stored them in large wooden chests at the end of their benches. Many still do so today, although metal and plastic chests are becoming more common. Site joiners need to move their tools often and should carefully consider how best to store their tools when transporting them. Those who have their own van tend to fit it out with racking and storage boxes dedicated to specific tools, as well as installing additional lighting and power points. Any such facilities should allow for quick, easy and safe transport, storage and access. If any of these three principles are ignored, your tools will become damaged and a safety hazard during transport. Whichever storage method is chosen, silica gel packs should be used to help stop tools from rusting during storage. Tools are usually transported from the van to the work area in either tool bags or tool trolleys.
Storage totes An open reinforced lightweight tool bag may be limited in the number and size of tools it can carry, but is still very versatile.
p Figure 2.141 Storage tote
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Chapter 2 Carpentry and joinery hand tools
Toolboxes/chests Traditionally, bench joiners used wooden tool chests to store their tools, which contained trays and compartments that suited the exact size of the tools being stored. The lid was often used to store large saws. Tool safes are often used for transporting tools in vans and keeping them safe and secure; these are lockable steel strong boxes that are usually fixed permanently inside the van.
p Figure 2.142 Tool safe
Tool trolleys A wide range of portable toolboxes are available, often containing trays, drawers and compartments that can be used to separate sharp-edged tools from other equipment. This will help you to quickly find tools and prevent the sharp-edged tools from damaging other equipment or becoming blunt. Tool trolleys often have lift-off boxes, allowing the load to be split when the trolley cannot be wheeled.
p Figure 2.143 Tool trolley
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Practical task Sharpen, set up and use a jack plane Outline of task You are required to remove the iron assembly, grind and hone the plane iron, refit the iron and assemble the plane, and produce a smooth flat surface to a length of softwood. Equipment required l
Completed risk assessment for grinding and honing a jack plane iron
l
Number 5 or 5½ jack plane
l
Appropriate PPE for the task
l
Suitable grinding equipment
l
Diamond or oil stone suitable for honing a plane iron
l
450 × 50 × 50 mm length of softwood
Candidate information Before starting each task, ensure that you have been given permission by your tutor or trainer to proceed. You should be given feedback on the completed task and any retraining as required. Task
Achieved
Requires retraining
Working to a given risk assessment, select the required personal protective equipment for the outline task. Correctly set up the grinding equipment, including all guarding. Correctly grind the plane iron to the correct angle and shape without burring to the iron. Hone the plane iron on either a diamond or oil stone to the correct honing angle and shape, removing all traces of the burr. Reassemble the iron correctly onto the backing iron and assemble in the plane. Adjust the iron to the correct projection for smooth fine planing of softwood and plane a smooth flat surface. Store plane safely and correctly, retracting iron to prevent damage. All work carried out in accordance with current health and safety regulations and safe working practices.
Activity successfully achieved
Further training required detailed here
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Test your knowledge 1 A sprit level is best used to measure what? a Levels around corners
7 What is the correct grinding angle for plane irons?
b Vertical and horizontal levels
a 25°
c Pitch angle levels
b 30°
d Distance levels
c 35°
2 A water level is best used to measure what? a Distance levels
d 40° 8 What is the correct sharpening angle for a chisel?
b Vertical and horizontal levels
a 25°
c Pitch angle levels
b 30°
d Levels around corners
c 35°
3 Which of the following will a box square typically be used to do? a Mark around round timber
d 40° 9 Which abrasive paper grade produces the finest finish?
b Mark mitres
a P60
c Mark around profiled timber
b P100
d Mark out tenons
c P120
4 Trammel heads and a beam are used to do what? a Set out small circles b Set out large curves c Set out mortices d Set out tenons 5 Which of the following is used for cutting across the grain of the timber? a Crosscut saw b Ripsaw c Mitring d Scribing 6 Which plane would usually be used for fine finishing? a Smoothing plane b Compass plane c Jack plane d Rebate plane
d P180 10 Which type of drill bit would you use for masonry? a Twist bit b Auger bit c TCT bit d Lip and spur bit 11 List the sequence for planing timber to thickness from the sawn state. 12 Describe the process for grinding and sharpening a 25 mm bevel edge chisel. 13 List the process for setting up a smoothing plane iron. 14 List the basic hand tools needed for either a site carpenter or bench joiner. 15 Design and complete an order form for the purchase of the basic tool kit that you suggested in your answer to question 14.
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CHAPTER 3
POWER TOOLS
INTRODUCTION Many different power tools are available for use in carpentry and joinery. Some are used for specific tasks, such as a powered screwdriver for fixing screws, while others can be used to perform multiple tasks, for example routers. The variety and availability of power tools has made tasks easier for carpenters and joiners, enabling them to work more quickly and produce better-quality finishes; this is particularly true for site carpentry work. The choice of which power tool to use is usually a straightforward one but understanding how to correctly set up and use power tools is not always as simple. This chapter discusses the most common types of power tools available today and the tooling required for these power tools, as well as the different types of power sources they can use. Information is included on how to safely use the power tools, along with the types of tasks they are typically used for. All power tools and their tooling require maintenance and inspection, in addition to the use of appropriate personal protective equipment, and both of these topic areas are also discussed. Power tools can represent a considerable investment. Tradespeople need professional power tools, and it is usually more economical in the long term to buy good-quality power tools from leading manufacturers. Hiring portable power tools is an alternative and viable option. Like all other types of tools, power tools and any tooling they may need should be stored and transported safely to prevent damage and to ensure that the power tool is safe and ready to use when it is required. It also gives an impression of a careful and conscientious professional.
LEARNING OUTCOMES In this chapter, you will learn about: 1 power sources used with portable power tools 2 power tool safety 3 personal protective equipment (PPE) 4 types of power tools, tooling and their safe use 5 transporting, storing and maintaining power tools.
1 POWER SOURCES USED WITH PORTABLE POWER TOOLS The decision of what type and make of a power tool to purchase is important and can at times be daunting. Just as important is the need for you to consider the power source that the power tool requires to work effectively on the tasks you are likely to perform. 114
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Chapter 3 Power tools The most common power sources available are: l
electricity battery l gas l compressed air.
230 V power source
l
The advantages and disadvantages for each type of power source are set out below. A comparison of the different type of power source is given in Table 3.2 on page 118.
110 V transformer
Electricity Electricity is the most common form of power source used by carpenters and joiners for their power tools, particularly on sites. In most cases, the electricity is generated at power stations but can be generated more locally by mobile generators, particularly on new sites where the mains power has not yet been installed.
110 V extension lead
p Figure 3.1 110 V transformer sited next to the 230 V power source with 110 V extension lead from the transformer
Mains electrical power is distributed from power stations to domestic locations (residential homes) at a voltage of 230 volts (V), which can kill a person if accidental contact were to be made with the power source. To reduce the likelihood of death and serious injury from electric shock, the power supply for tools is reduced from 230 V to 115–100 V, which is more often referred to as 110 V. This reduction in voltage is achieved by using a transformer, which is yellow in colour. Any power tools that are 110 V have a special yellow plug that fits into a specific socket on the transformer. Although portable, 110 V transformers are extremely heavy. A 415 V power supply (referred to as a three-phase power supply) is usually installed within joinery workshops. This is the power source for large woodworking machines such as surface planers and vertical spindle moulders. The sockets used with 415 V power sources are red and usually hardwired. Although 115 V is preferable to 230 V when on site or in the workshop, 230 V tools are often used in conjunction with a residual current device (RCD). RCDs are designed to protect against faults that may occur in the electrical supply. When a fault is detected, the RCD cuts off the power and acts as a failsafe trip system from the fuse board. An RCD is designed to protect against the risks of electrocution, for example, if you cut through the cable when using a jigsaw.
HEALTH AND SAFETY 110 V transformers should always be installed as close as possible to the mains power source and 110 V extension leads should be used to the power tool. 230 V extension leads should not be used to the 110 V transformer.
INDUSTRY TIP 115 V transformers, extension leads and plugs are yellow or have yellow markings.
Hand-held electrical power tools have a double insulation symbol on them, which is shown in Figure 3.2. This means that the tool is designed in such a way that the electrical parts of the power tool do not contact the outer part of the power tool. Different-coloured plugs are used on power tools that have different voltages. Plugs used in the UK for portable power tools are shown in Table 3.1.
p Figure 3.2 Class II double insulation symbol
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma q Table 3.1 Plugs used for power tools in the UK Portable power tool plugs used in the UK
110 V plug (Yellow)
Standard 230 V 3-pin plug; Industrial 230 V the most common type of plug (Blue) fitted to portable power tools
415 V 3-phase plug (Red)
It is likely that you will use an extension lead at some point in you work. These are some simple guidance rules to follow when using an extension lead. l l l
l l
IMPROVE YOUR ENGLISH
Always keep and store your extension lead neatly and safely. This will reduce the likelihood of the extension lead becoming damaged. Always ensure leads do not become a trip hazard and where possible run extension leads above head height. Do not use extension leads that are still coiled up. This could lead to the extension lead overheating and becoming a fire hazard. Always fully uncoil any extension lead before use. Regularly inspect the condition of the extension lead for damage. Any damage found should be professionally repaired before using. When using an extension lead in areas where it is likely to be walked over or have traffic passing over it, use a lead protection sleeve, as shown in Figure 3.3. This will not only help prevent the lead from becoming a trip hazard, but also will help to protect the lead from damage.
Produce a health and safety leaflet outlining the main hazards of using electrical power tools and the precautions to take to avoid them. p Figure 3.3 Lead protection sleeve
Battery INDUSTRY TIP Larger amp batteries deliver power for longer periods of time.
Battery power is the power choice for most tradespeople in most circumstances. The advantages of this power source for the tradesperson usually far outweigh the disadvantages of hand-held power tools. Batteries come in a wide variety of voltages and amps. As a simple guide, the bigger the voltage, the more power the battery has; and the larger the amps the longer the battery will last before it needs recharging.
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Chapter 3 Power tools Li-ion (lithium ion) batteries are a lot lighter for the same power rating than other types of batteries, which enables manufacturers to make lighter, less bulky power tools. However, like all batteries, Li-ion batteries require charging. Owing to the time it can take large amp batteries to charge (40 minutes), at least two batteries are typically required. Another downside for battery-powered hand tools is the lack of interchangeability of the battery from one manufacturer’s power tool to another’s. This means you may need several different types of batteries along with their chargers when using power tools from different manufactures.
Gas Gas-powered tools are seldom used and are almost exclusively fixing tools, such as first and second fix nailers. Even when the primary power used is gas, a battery is used to provide the spark to ignite the gas. Gas is transferred from the canister to a small storage chamber within the power tool each time the tool is used; this gas is then ignited by a spark from the battery which delivers an instant high level of power that is used to drive a plunger and drive the fixing home. Any used gas canisters must be disposed of carefully and in accordance with the manufacturer’s instructions; under no circumstances should they be disposed of on a bonfire.
p Figure 3.4 Disposable gas canister
Compressed air Compressed air is generally reserved for workshop use where a high-pressure air storage cylinder stores the air from a compressor. Pipes and flexible hoses transfer the air to the workstations where the power tools are then connected. The main advantage of compressed air is that there is no electricity involved, other than the power needed to run the compressor. The disadvantages of using compressed air are as follows. l
Most air-powered hand tools are extremely noisy to use. Leads that deliver the compressed air to the power tool are thick and difficult to manoeuvre, making the power tools heavy and difficult to manoeuvre, compared to battery or electrically powered hand tools. l Like other forms of power, compressed air is extremely dangerous if it is not stored and used correctly. You should never use compressed air to blow on yourself or your workstation. Using compressed air to blow dust from anyone risks the possibility of introducing small air bubbles into the bloodstream, which can be fatal. Using compressed air to clean a workstation results in dust particles being introduced into the atmosphere, which may cause breathing difficulties. l Air-powered tools are limited in their scope of use as they can only be used where there is a compressed air supply. l
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p Figure 3.5 Compressor q Table 3.2 Comparison of different types of power source Type of power source
Advantages
Disadvantages
230 V
High level of constant power.
Trailing leads; usually requires an extension lead; increased electrocution risk; requires a local 230 V power source.
110 V
High level of constant power.
Trailing leads; usually requires a special 110 V extension lead; heavy transformers; requires a local 230 V power source.
Battery
Portable; flexible in use; high power; longerlasting battery life; interchangeable batteries between the same makers; does not require a local 230 V power source.
More expensive tools; requires recharging; usually requires more than one battery.
Gas
High power output.
Canisters can be flammable.
Compressed air
Constant power supply.
Limited movability; requires a large storage cylinder for the air supply; noisy; not easily transportable.
2 POWER TOOL SAFETY Before using power tools, you should be trained in how to use them safely and authorised to use them. This training should include: l
requirements for personal protective equipment (PPE) safe operation of the equipment l types of tooling that can be used with the equipment l risks associated with using the equipment. l
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Chapter 3 Power tools These safety aspects are particularly important when using power tools. Training may form part of small toolbox talks or be more formal such as, for example, delivered at a training college. Different types of power tool will require training and safety requirements specific to that power tool, the task being performed and the type of PPE requirements. Specific hazards are covered later in this chapter. Table 3.3 outlines the general types of inspection required before using any power tool, along with any actions you should take following your inspection.
KEY TERM Toolbox talk: small bitesize training sessions covering a specific area such as PPE use, safe operation of a power tool or hygiene requirements.
q Table 3.3 Types of inspection to make before using any power tool Type of inspection
Inspect for
Action
Do I have the correct type of PPE and is it in good condition?
Do the cushions on ear defenders have signs of damage? Does eye protection still offer clear vision? Do gloves have worn-out finger ends? Do I have suitable workwear and foot protection? Do I need a hard hat and a high-vis jacket? Do I need sunscreen?
Always replace worn and damaged PPE. Remember that PPE is not an option but a legal requirement.
Visual inspection of the body of the tool for damage.
Check for splits, cracks and broken components on the power tool.
Report any damaged tool and take out of use until repaired.
Visual inspection of cables.
Check for splits in the cable or poor repairs to damaged sections of cable.
Damaged cables should be reported and the tool taken out of action until repaired.
Visual inspection of plugs.
Check plug for damage and poor cable fixing into plug.
Damaged plugs should be reported and the tool taken out of action until repaired.
Visual inspection of guards.
Inspect guards for damage and adjustment. Ensure that the guard moves freely throughout its full range.
Damaged or sticking guards should be reported and the tool taken out of action until repaired. Never use a power tool with damaged or missing guards.
Visual inspection of tooling.
Is the tooling the correct type for the power tool and its intended task? Is the tooling in good condition and sharp?
Replace any damaged, blunt or inappropriate tooling with the correct sharp tooling.
Visual inspection of control components.
Are all components available and fitted for the correct operation of the power tool, such as fences, depth stops and riving knives?
Locate and use appropriate components for the safe operation of the power tool.
Check start–stop controls.
Do the start–stop controls work efficiently and responsively?
Stop using the power tool, report the fault and take out of action until repaired.
Portable appliance testing (PAT) certificate.
Does the power tool have a current up-to-date safety label?
If no PAT label is visible, do not use, report and take the power tool out of action.
HEALTH AND SAFETY Always give your power tool a visual safety inspection before use and do not use if it is found to be unsafe.
KEY TERM PAT certificate: portable appliance testing (PAT) is an examination of electrical appliances and equipment to ensure they are safe to use; a label is fixed to the power tool stating date of test.
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HEALTH AND SAFETY Always refer to the risk assessment for guidance on the type of safety precautions that need to be in place and the required PPE you should be using before starting work. Get into the habit of always wearing eye and ear protection, as well as close-fitting nonslip gloves, when using any power tool.
KEY TERM Personal protective equipment (PPE): safety equipment worn by an individual to protect themselves from workplace hazards. There are many different types of PPE including protective gloves, safety goggles and ear defenders. PPE designed to protect against respiratory hazards is referred to as RPE (respiratory protective equipment). This protects the user’s lungs and airways. Stroboscopic effect: the flickering or flashing of a light source, which can cause headaches and nausea. Stroboscopic effects can also lead to dangerous situations when using rotating tooling such as saws and routers. The flashing or flickering of the light source makes the tooling appear to be stationary or moving very slowly or even backwards.
3 PERSONAL PROTECTIVE EQUIPMENT (PPE) You will need to use various types of personal protective equipment (PPE) when using portable power tools, depending on: l l l l l l
the type of tool being used the type of material being cut where the cutting operation is taking place how long the power tool will be used for the climate conditions whether good local exhaust ventilation is available for the cutting operation.
Table 3.4 outlines some typical hazards that occur when using portable power tools and the measures you can take to help combat the hazards, including possible PPE precautions. q Table 3.4 Typical hazards that may occur when using portable power tools Type of hazard
Typical control measures
Dust from the cutting operation of the tool and/or what is already present in the atmosphere.
Always use a local exhaust ventilation system (LEV) such as a mobile dust extractor; a suitable dust mask should also be worn.
Noise from the operation of the power tool as well as the noise levels in the working environment.
Isolate the source of the noise if possible; where this is not possible use suitable ear protection.
Debris from cutting and fixing operations.
Use safety goggles or glasses. The use of safety glasses is considered a minimal requirement for all working situations.
Splinters and contaminants from timbers and solvents.
Use suitable gloves. Modern close-fitting nonslip gloves should be considered as a standard everyday item of clothing.
Visibility.
Use high-visibility jackets where traffic is likely.
Falling objects from your own work or other's.
Use hard hats and suitable footwear.
Vibration from power tools.
Hand-Arm Vibration Syndrome (HAVS) can occur from exposure to vibration including by the transfer of the vibrations from power tools. It is most commonly referred to as vibration white finger. When using vibrating tools, limit your exposure time using the tool by doing other types of work between exposures. Use heavy gloves to help absorb the impacts.
Lighting.
Ensure that you have good lighting levels and no flashing or flickering lights which could result in a stroboscopic effect. Always use good-quality mobile lighting as required.
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4 TYPES OF POWER TOOLS, TOOLING AND THEIR SAFE USE Safety guidelines when using power tools Using power tools is dangerous so it is extremely important that you always follow safe practices. Instilling a culture of safety first is not an option but a legal requirement; this not only ensures your safety but that of others around you. Lack of time is not an excuse for poor safety practices. These are general safety guidelines to observe when using power tools. l
l l l l l l l
Wear the correct type of PPE for the task as outlined in the risk assessment; this is discussed later in this chapter. Remember, PPE is not an option but a legal requirement. Be aware of any loose clothing, jewellery or trailing earphone wires that could get caught up in the power tool. Ensure that the material is securely and appropriately held for the task. Always keep your hands, arms and legs away from the cutting edges of the power tool. Always use the correct type of tool for the task; doing otherwise could lead to accidents. Never try to force a tool; if it will not move or cut easily there is usually a good reason why. Keep your work area safe, clean and tidy. Always disconnect the power source before changing any tooling for the power tool.
Portable power tools Portable power tools have advanced considerably over recent years, in ergonomics, efficiency, type, safety and cost efficiency. As a result, most types of work can now be carried out using portable power tools. Regardless of the type of power tool you use or its manufacturer, the following rule applies: blunt, damaged and poorly maintained power tools are more dangerous than sharp well-maintained ones. Using the correct type of sharp tooling in well-maintained power tools helps ensure a better-quality finish as well as a safer tool to use. The most common types of portable power tools can be grouped into the following categories: l l l l l l
drills and impact drivers mobile extraction units power saws planers routers jointers
l
powered nailers sanders l oscillating multi tools l angle grinders l scanners and detectors.
KEY TERM Ergonomics: designing equipment in a way that improves overall performance and comfort based on an understanding of human actions, such as how well it suits the body of the user or whether it is comfortable to hold.
l
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Power drills and impact drivers The drill is possibly the first type of power tool you are likely to purchase. The type of power source the drill uses will depend on the type of drill you require and where you usually work: for example, those who work at a bench most of the time may prefer a cabled drill, while those who work on site may prefer a battery version. Each type has their advantages and disadvantages (see Table 3.2 on page 118). Most drill/drivers have a 2-speed gear box. As a general guide, use the slower speed 1 when using as a screwdriver and the faster speed 2 for drilling holes. Most drill/drivers have a torque-setting feature, which allows you to adjust the power delivered to the chuck through a clutch-type system. The higher the torque setting number, the more force is delivered to the rotating chuck. When driving screws into hard materials, you usually require a slower speed and a higher torque setting. When driving screws into softwood, you are likely to need a reduced torque setting to avoid driving the screw too far into the material and risking splitting the material. Getting the combination of speed and torque right helps you to control the depth of your screwdriving without risking any damage to the material being fixed.
Differences between drills, hammer drills and impact drivers There are lots of different types of drills, but what are the differences between a drill, a hammer drill and an impact driver? Drills and hammer drills are usually used to drill holes, while an impact driver is used to fix and remove screws and bolts with a suitable type and size of screw or bolt bit. A typical drill applies a rotational force to turn the drill bit. A hammer drill incorporates a hammer action into the rotational force, which is achieved by using a spring, hammer and anvil. When the motor turns the drill shaft and you apply pressure to the end of the drill bit, a spring is compressed; this is forcefully released to drive a small hammer against the anvil. This hammering action is constant while pressure is exerted on the end of the drill bit; the hammering action enables the drill to deliver a much larger drilling force to the drill bit and is usually required when drilling masonry such as bricks, stone and concrete. It is this same hammer action that impact drivers use to fix and remove screws and bolts. Drill/drivers usually have a selection function which allows you to switch the drill between rotational drilling, screwdriving or hammer drilling. Hammer drills have a selection feature of rotational drilling, hammer drilling or just hammer only. Hammer drills tend to be heavier and bulkier machines. Drill/drivers and impact drivers are essential parts of any professional tradesperson’s tool kit.
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Chuck types
KEY TERMS
Most hand-held drills use a keyless chuck system to tighten and release the drill bit. This type of chuck uses a rotating collar at the front of the drill which is turned to tighten or loosen the drill bit. It has the advantage over keyed chucks in that it does not require a chuck key, which often become damaged and make fitting and replacing drill bits a more time-consuming process.
Chuck: the housing that the shank of the drill bit fits into. Shank: the end of the drill bit that fits into the chuck of the drill; the non-cutting part of the router cutter that is fitted into the collet of the router; the part of the nail between the nail point and the nail head.
Drill chucks in most hammer drills use a slotted drive system (SDS) chuck, which gives greater grip to the drill bit owing to the slotted grooves in the side of the drill bit. SDS chucks are also available with a standard round shank that can be fitted into a standard drill chuck, thereby converting the drill chuck into an SDS chuck.
p Figure 3.6 Keyed chuck with key
p Figure 3.7 Keyless chuck
p Figure 3.8 SDS chuck
See Table 3.5 for examples of the most common types of drills and drivers that are available. q Table 3.5 Common types of drills and drivers Type
Description
Hand-held drill/driver
Drill/drivers are the most versatile type of drill. They can be used as a screwdriver, rotational drill and hammer drill. They usually incorporate a 2-speed gearbox and a variable torque setting.
Torque setting
Reverse selector
Speed selector
Function selector
Trigger
Battery release
Battery
➜
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Description
Hammer drill SDS chuck
Depth gauge
Auxiliary handle (to be used when heavy drilling)
Trigger
Hammer drills are the heavyweight alternative to the drill/driver and are typically required when drilling larger diameter and deeper holes in masonry and concrete. Hammer drills typically have three functions: rotational drilling only; hammer drilling; and hammer only. The hammer only option converts the drill into a smaller version of a breaker, which can be used for chasing out blockwork or concrete floors and other demolitiontype activities. Hammer drills tend to use the SDS chuck system, as this slotted drive system prevents drill slippage in the chuck, which can be a problem with standard chuck systems.
Selector switch enabling drill to either rotate without hammer action, rotate with hammer action or just hammer action
SDS drill bit Slotted drive
Impact driver and hex bit
Impact drivers enable the rapid fixing of screws. The impact driver uses ¼-inch hex bits. Ensure that you select the correct size and type of bit to fit the type of screw that you are using. Most hex bits are universal at both ends.
Hex end
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Chapter 3 Power tools Type
Description
Pillar drill
A powerful workshop drill that incorporates a stand holding the drill head, and a table that can rise and fall. The drill head uses a keyed chuck, which is lowered into the material via a handle. The machine bed can have fences fixed to it, enabling constant accurate hole positioning, making these drills particularly useful for repetitive drilling of accurate holes. Pillar drills usually have multiple speed choices via pulleys and deliver extremely high rotating forces. As a rule, use slower rotation speeds for larger diameter drill bits. Speed guides for different drill diameters are detailed on the gearbox of the drill’s drive system.
Start−stop switch Drill head rise and fall
Bed rise and fall
Drill bit Connection slots for drill fence Machine bed
KEY TERM Pulley wheel: a type of wheel that a drive belt fits around; they come in different diameters to give different drive speeds for the drill bit.
Breaker or Kango
The breaker, also often referred to as the Kango (a brand name), is a drill that uses the hammering action of the smaller hammer drill but on a much larger and heavier scale. Kangos use different shaped chisels to help break up concrete, flooring and paving slabs, and undertake other types of demolition work.
HEALTH AND SAFETY When drilling small objects on pillar drills, always use a drill vice or some other type of holding device and use the drop-down drill guard. Wear safety glasses and keep clothing and hair away from rotating tooling.
INDUSTRY TIP For speed, safety and accuracy, it is best to use fences and stops on pillar drills.
p Figure 3.9 Using a pillar drill with drill vice
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Using drills and drivers Common problems that you may encounter when drilling timber with hand-held drills or using impact drivers are outlined in Table 3.6, along with information on how to remedy them. q Table 3.6 Common problems encountered when drilling timber with hand-held drills or when using impact drivers Problem or fault
Remedy
Drill bit slipping in chuck while drilling timber.
Keep withdrawing drill bit to clear debris from hole. Adjust drilling speed. Consider using SDS drill or SDS conversion chuck.
Spelching out on the back side of material.
✘
Clamp a sacrificial piece of timber to the back side of the material being drilled, as shown opposite. Mark out and drill from both sides if possible.
✔
Battery keeps stalling during drilling.
Switch to drill setting. Increase torque setting. Recharge battery.
Screwdriver bit keeps jumping out of screw head.
Use correct type and size of screwdriver bit. Reduce rotation speed to slow. Ensure screwdriver bit is correctly lined up with screw head. Replace damaged head.
Screw keeps splitting timber.
Drill clearance hole suitable for screw gauge. Reduce torque setting.
Screw penetrates too deeply into timber.
Reduce torque setting.
Screw does not fully drive home.
Increase torque setting.
IMPROVE YOUR MATHS Your employer has asked you to source one type of drill that you require for your type of work. Source the best price for it, outlining the net cost, the VAT at the current rate and delivery costs to your home. Display this information on an invoice that could be given to an employer.
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IMPROVE YOUR ENGLISH Write a paragraph outlining the main differences between an SDS drill chuck and a standard drill chuck, as well as the advantages and disadvantages of each.
Mobile extraction units A mobile extraction unit is one of the most important power tools to include in your tool kit, whether you intend to use portable power tools or hand tools only. Most portable power tools come with some form of dust collection facility; this is usually a cloth bag, which is poor at collecting the dust particles, has a small capacity and relies on the power tool’s cutting motion to throw the dust particles into the bag. The mobile extraction system or local exhaust ventilation (LEV) is a specialist vacuum that uses a powerful suction to help suck dust and debris into the collection bag within the extraction unit. Mobile extraction units not only help to keep dust and debris to a minimum while using power tools, but they also help to keep the atmosphere free from fine dust particles. Fine filters within the extraction unit filter the expelled air, trapping the fine dust particles so further helping to control hazardous dust particles. Mobile extraction systems create healthy working conditions, but they also save time in cleaning the work area, as there is little dust and debris to clear up compared to when working without one. They allow the power tool to produce a clean smooth finish to the cut that may otherwise be affected by a build-up of dust and other debris. Using mobile extraction systems shows you are a careful and safe worker, and their use is also very often a requirement of a risk assessment.
HEALTH AND SAFETY Always vacuum up dust particles whenever possible, as sweeping up results in more hazardous dust particles being thrown into the atmosphere.
Mobile extraction systems are produced in several sizes and are extremely transportable. Attachments are also available that enable you to use the unit for vacuuming the floor instead of sweeping up, which allows for dust-free collection. Sweeping up usually leaves a dust cloud, which then settles and requires further cleaning, whereas vacuuming reduces dust in the atmosphere, improves safety and saves time.
p Figure 3.10 Mobile extraction system
p Figure 3.11 Mobile extraction unit being used as a traditional vacuum to clean the floor
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Power saws Hand-held power saws are another must-have power tool for the professional tradesperson. Not only do they save time when cutting material, they also produce accurate and neat cuts. Portable powered handsaws generally fall into one of the following two categories. l
Saws that use circular saw blades, which revolve at speed to cut the material, such as plunge type saws, sliding mitre/chop saws, rail/track saws and table saws. l Saws that use a flat cutting blade, which cuts the material in repeated push/pull type stroke, such as jigsaws, multi-tools and reciprocating saws.
Types of circular saw blades
KEY TERMS Tungsten carbide tip (TCT): a tip made of hard-wearing metal used to form the cutting edges of tooling such as saw blade teeth. Angle of hook or rake: the angle at which the face of the saw tooth slopes from the tooth tip, either down and forwards from the tip, as in the case of negative tooth profiles for cross cutting, or down and backwards from the tooth tip, as in the case of positive tooth profiles for ripping.
HEALTH AND SAFETY Do not use a sawblade with a positive angle of hook or rake for crosscutting. This type of tooth design sawblade will snatch in the cut (the sawblade will move uncontrollably), particularly on deep cuts, and you may injure yourself or damage the material you are working with.
All saw blades have saw teeth topped with tungsten carbide tips (TCT). Tungsten carbide is an extremely hard-wearing material that is particularly good at cutting man-made and hard abrasive materials such as plywood, medium-density fibreboard (MDF) and oak. As a rule of thumb, the more teeth the saw blade has, the finer will be the finish of the cut, but it is the shape of the teeth more than their number that determines the type of work the saw blade should be used for. To determine which type of angle of hook or rake the blade has and, in turn, what type of cutting operations it is suitable for, follow the step-by-guide given below. 1 Take a line down the face of the saw tooth from the tooth tip. Compare this line to a line taken from the tooth tip to the centre of the saw blade. 2 If the saw centre line is in front of the face line of the tooth tip, the saw blade has a positive angle of hook or rake and is suitable for ripping activities. This is shown in Figure 3.12. 3 If the centre line is behind the face line of the tooth face the saw blade has a negative angle of hook or rake and is suitable for crosscutting activities. This is shown in Figure 3.13. 4 If both lines are in the same position, the saw blade has a zero angle of hook or rake and is classed as a natural cutting action blade. This type of blade is particularly suitable as a general-purpose blade used in plunge saws and is shown in Figure 3.14. This means that three basic types of circular saw blade are available. l
Ripsaw blade: this has a positive angle of hook or rake and is used to cut timber along its grain. See Figure 3.12. l Crosscut saw blade: this has a negative tooth design and is used for cutting across the grain of the timber in power tools such as sliding mitre saws and chop saws. See Figure 3.13. l General-purpose or neutral angle saw blade: this has a zero angle of hook or rake and is the most common type of blade used in plunge saws due to their finer cutting action and facility for use with multiple types of tasks. See Figure 3.14.
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Chapter 3 Power tools Gullet
Clearance angle
TCT tips
Kerf Point
Pitch Face of tooth
Sharpness angle
Tangential side clearance
Positive angle To centre of hook or rake of saw
p Figure 3.12 Parts of a TCT ripsaw blade with a positive angle of hook Kerf
Point
Clearance Face of angle tooth
Pitch
Sharpness angle
INDUSTRY TIP The number of teeth the sawblade has is a good indication of the quality of finish the saw will give. As a rule, a sawblade with more teeth will give a smoother finer finish, while those with fewer teeth are more suitable for deep fast cutting of timber.
IMPROVE YOUR ENGLISH
Gullet To centre Negative angle of saw of hook
p Figure 3.13 Parts of TCT crosscut saw blade with a negative angle of hook
Produce a safety poster outlining the features that makes circular saw blades different and why they should only be used for the tasks for which they are designed.
Kerf
Point
Clearance Face of angle tooth
Pitch
Sharpness angle
Gullet To centre of saw
p Figure 3.14 Parts of a TCT general-purpose or neutral angle of hook sawblade
Plunge saw The plunge saw is a hand-held circular saw that is easy to use and adjust. It cuts multiple materials, such as timber, plywood, MDF and laminate-faced materials. Modern plunge saws can be used for a variety of cutting operations, including: l l l l l l l
HEALTH AND SAFETY TCTs are hard-wearing, but they are also brittle and liable to chip and break. Take care when using the saw and when changing the blade to ensure that the cutting edges do not come into contact with any nails, screws or similar metal items, which may damage the blade tips and will result in a poor finish to the cutting edge.
straight cutting along the entire length of the material starting and stopping part way along the material using the plunge cut action of the saw angled cuts compound angle cuts (see page 135) precise depth of cuts for grooves close cutting to walls splinter-free cutting of face materials when using the guide rails. 129
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Newer models use a safer plunge cut system, where the saw blade is started within the machine casing and then steadily plunged down to the pre-set depth of cut. The saw can then be steadily moved into the material. To position and guide the saw cut, a specially designed guide system is used with guide rails that incorporate a semi-rigid splinter guard. The splinter guard helps to ensure that the top face of the material does not chip out (break away). This is particularly useful when cutting face materials used with kitchen fittings, such as veneer-faced sheet materials and kitchen worktops. Plunge saws use a circular saw blade to form the saw cut. The number of teeth the saw blade requires is usually determined by the type of cutting the saw is used for. As a general guide, a blade diameter in the region of 160 mm with lots of teeth (48) is suitable for cutting material where a fine finish is required, while a saw blade with fewer teeth (18) can be used for deep cutting of timber.
ACTIVITY Select a circular saw blade. Using the information given in this chapter, determine what type of activity the blade is suitable for.
HEALTH AND SAFETY Hand-held circular saws can be extremely dangerous if not used correctly. You should only use a power saw if you have been trained and authorised to use it.
These are some of the main advantages of using the plunge saw and guide rail systems, compared with older versions of hand-held circular saws. l
l
l
l l
l
l
The saw blade is always fully enclosed by the power tool’s body and only becomes exposed when the saw blade is plunged to the required cutting depth; this is a big safety improvement on the older versions. The plunge action allows for safe starting and stopping part way along the material that requires cutting, whereas older versions risked kickback of the saw, which is extremely hazardous. This operation should not be attempted unless you are using a plunge saw. The depth of the saw cut can be easily and quickly adjusted with a fine adjustment screw to produce fully accurate adjustments for precise cut depths. Older saws are more difficult to set up precisely and usually require you to make several attempts to produce an accurate depth of cut. The saw blade is electronically braked for faster and safer stopping of the saw blade, unlike many older versions. Most good-quality plunge saws can quickly and accurately produce angled cuts from −1° to +45°, whereas older versions usually required several practice cuts to achieve an accurate angle. Most good-quality plunge saws now incorporate a rail system that enables accurate and neat splinter-free cuts. Older saws relied on small side fences or clamping a straight edge to the material and running the saw against the straight edge; this often resulted in the saw running away from the straight edge and producing a wandering cut. Guide rails are particularly useful when cutting faced materials, such as those used as decorative panels in kitchen fittings, as well as for fast and neat removal from door sides and bottoms and other sheet materials, such as MDF and plywood.
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Chapter 3 Power tools l
Guide rails ensure the saw does not wander while cutting straight lines, as often happens when using the small side fences provided with older type saws. l The design of the modern hand-held circular saw allows for close cutting against walls, usually within 15 mm; on older versions this distance is considerably increased due to the design of the saw’s base. l The way the saw blade is changed is a safer and more efficient process. Dust extraction Start–stop trigger outlet
Plunge release trigger Casing guard Saw depth gauge
Rails Riving knife Saw blade Outer edge chip breaker Anti-splinter guard fitted to outer edge of rail to line up with side of teeth
p Figure 3.15 Modern plunge saw with anti-splinter guide rail system
INDUSTRY TIP Have at least two of each type of saw blade. This ensures that one is always available, while the other can be sent away for sharpening.
p Figure 3.16 Non-plunge hand-held circular saw using a standard small side fence
When selecting a circular saw blade, always ensure that the size of the blade is compatible with your plunge saw. Using a blade that is too small results in a slower peripheral blade speed, which can result in injury.
HEALTH AND SAFETY Always ensure the power supply is disconnected before you start to fit or remove any saw blade.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Fitting circular saw blades into hand-held circular saws Circular saw blades must be fitted into the plunge saw with the arrow on the saw blade pointing in the direction of rotation of the plunge saw, which is around and up towards the machine base at its front edge. The teeth on the saw blade cut in an upwards motion, pulling the hand-held power saw down onto the material being cut.
Saw base
Rotational direction arrow Riving knife
TCT on the saw tooth
Gap as small as practicable
Saw teeth should rotate up towards the front part of the machine’s base
p Figure 3.17 Saw blade and riving knife
Riving knife The circular saw must be fitted with a riving knife, which sits just behind the saw blade, and its shape follows the circular profile of the saw blade. The riving knife should be positioned as close as practicable to the back of the saw teeth and no more than 8 mm away. The riving knife has two purposes, which are to: l
act as a rear guard to the saw blade l help prevent any material binding on the saw blade during cutting operations that may result in possible binding of the saw blade. To help prevent the saw blade binding in the saw cut, the riving knife is slightly thicker than the material used to form the saw blade, but thinner than the kerf of the saw cut. Dust extraction outlet The dust extraction outlet is sited at the rear of the machine casing. It is important to use a dust collection system. In most cases, the plunge saw is provided with a dust collection bag, but this has a limited facility to collect the dust particles and relies on the saw blade throwing the particles into the dust bag. A mobile dust extraction unit is a far better option.
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Chapter 3 Power tools Using plunge saws safely Selecting and adjusting the cutting depth of the modern plunge saw is a simple and quick process. When you need to make a full-depth saw cut, always set the cutting depth of the blade so that it projects through the material by only 3 mm or 4 mm. It is important to limit the distance the saw teeth project below the material as much as possible. This helps to reduce the risks of accidental contact with the saw teeth.
Riving knife
Saw teeth only just projecting through the material
p Figure 3.18 Correct saw blade cutting depth
Jig, multi and reciprocating saw blades Jigsaw blades The blades used in jigsaws fall into two categories: the up-cutting and downcutting tooth profiles. The up-cutting tooth profile blade cuts on the upwards stoke of the jigsaw and as a result it can tend to splinter the top surface of the material being cut. It is typically used for cutting timber. p Figure 3.19 General purpose up-cutting jigsaw blade
The down-cutting tooth profile blade cuts on the downward stroke of the jigsaw; this leaves the top surface of the material clean and splinter-free and is particularly useful when cutting laminated surfaces such as those used in kitchen fitting.
p Figure 3.20 Down cutting jigsaw blade
Jigsaw blades can efficiently cut several different types of materials, such as wood, plastics and metals. 133
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Multi-tool blades There are several different types of multi-tool blade. Depending on the type of blade used, they can cut timber, plastic and metal. They can range in shape from straight cutting edges to semi-circular cutting edges. Multi-tool blades have fine teeth and are particularly useful for cutting in tight areas, such as the bottom of door lining when fitting laminate flooring. p Figure 3.21 Multi-tool blade for cutting timber
INDUSTRY TIP When cutting laminate-faced materials, such as decorative mouldings used in kitchen fitting, use a saw blade with a high tooth count. Always try to ensure that any decorative face is the face that the teeth cut into first.
Reciprocating sawblade These sawblades are like those used with jigsaws except that they are usually stronger and longer. Like jigsaw blades, they are available for cutting multiple different materials.
Sliding mitre saws/chop saws Like the hand-held circular saw, these types of machines use circular saw blades to cut the material. As with saw blades for hand-held circular saws, the higher the number of teeth the saw blade has, the finer the finish of the cut will be. Sliding mitre saws differ slightly to the chop saw: a chop saw can only cut in a downward action, while the design of the sliding mitre saw allows for the saw blade to slide forward as well as downwards, enabling a much larger cutting area than a chop saw. As a result, the sliding mitre saw is the preferred option for the professional tradesperson. These saws can produce the following cuts: l
KEY TERM Compound cut: a type of angled cut that incorporates two angles simultaneously cut, one from the mitre angle of the saw and one from the bevel or canted angle of the saw.
square edge cuts, such as when cutting materials to length mitred cuts, such as those used for skirting board and architrave cutting bevelled cuts l compound cuts, such as those used for roof rafter cutting. l
Duel action safety start trigger
Dust extraction hose
Clear Perspex guard
Saw head sliding arms
Portable timber support table
Mitre adjustment lock
Saw blade
Bevel adjustment
p Figure 3.22 Sliding mitre saw on a saw stand incorporating long timber support beds
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Chapter 3 Power tools The sliding mitre saw is a widely used power tool, particularly on site, allowing for fast accurate cutting of: l
square cuts: 0˚ mitre angle and 0˚ bevelled direction
Direction of saw cut
Timber being cut
HEALTH AND SAFETY A sliding mitre/chop saw should have a 300 mm hands-free zone marked in front of the cutting area. Remember, when producing mitres or compound cuts, the hands-free zone will be in line with the new cutting direction.
300 mm hands free zone
p Figure 3.23 Plan view of square cut l
mitres: usually between 0˚ and 50˚ in both directions
Direction of saw cut
p Figure 3.24 Plan view of mitre cut l
bevelled cuts: usually between 0˚ and 50˚ in both directions
Timber being cut
p Figure 3.25 Edge elevation view for bevelled cut l
compound cuts: any angle between 0˚ and 50˚ in the mitre and bevelled directions.
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HEALTH AND SAFETY When cutting long lengths of material, always ensure that the ends of the material are fully supported.
The sliding mitre/chop saw has an adjustable back fence used to support the material during cutting operations; this back fence should always be kept as close as practicable to the saw cut. During standard square edge cuts and mitre cuts, the back fences are pushed close together, providing support to the material during cutting operations. When a bevelled or compound cut is required, the back fence will need to be moved away from the new cutting line of the saw to prevent the saw blade hitting the fence. Sliding mitre saws/chop saws should always use a crosscut (negative) tooth saw blade and never a ripsaw (positive) tooth saw blade. The positive cutting action of this type of tooth design would tend to snatch at the material; this would result in a poor finish and more importantly could result in injury to you or damage to the tool.
Table ripsaw The table ripsaw is a smaller version of the larger industrial circular saw found in workshops. The smaller table ripsaw is intended to be portable, allowing for quick and easy installation on site. The health and safety measures involved in the safe use of these machines are the same as those required for the larger industrial circular saws. This type of saw bench is not to be used by an inexperienced worker due to the high level of risks involved in their use. You must be trained in the saw’s safe operation and authorised to use the machine before doing so. Crown guard
Extraction hose Cross-cut fence
Rip fence
Start/stop switch
p Figure 3.26 Parts of a table ripsaw
Table ripsaws are mainly intended for ripping down the grain of timber, although some machines can be fitted with small sliding crosscut fences. Always ensure that any materials being cut are fully supported at both the infeed end as well as the outfeed end, as these machines can easily be tipped over when using them to cut heavy materials.
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Chapter 3 Power tools Circular ripsaws are used for the following three types of basic operation:
KEY TERM
l
flatting, where the timber is ripped down its length through its thinnest section (thickness) to the required width (as shown in Figure 3.27) l deeping, where the timber is ripped down its length through its thickest section (width) to the required thickness (as shown in Figure 3.28) l angled cutting, where the material is placed on a jig or saddle that holds it stable at the required angle during the cutting operation (as shown in Figure 3.29). This ensures that an accurate angle is produced but, more importantly, aids the safe delivery of the material and safe control of the offcut.
Saddle: a type of jig used to support the timber during the cutting process.
Angle ripping Extension piece
Saddle
Work piece
p Figure 3.27 Flatting
p Figure 3.28 Deeping
End cleat
p Figure 3.29 Angled cuts using a saddle
Cutting material The way in which timber is presented and fed through the saw bench is vital to its safe operation. Timber can shrink and twist in several different ways because of seasoning or atmospheric changes during storage. This movement can take several forms, the most common being: l
cupping, where the timber curves upwards at either edge to form a cup shape over the face of the board; wide boards that are cut tangentially will usually cup over time l bowing, which is a curvature along the board’s face (its widest section) from one end to the other l springing, which is a curvature along the board’s edge from one end to the other l twisting, which is a curvature along both edges of the board’s length, producing a propeller-shaped twist.
Cupping
Bowing
Springing
KEY TERM Tangential: timber boards that have been converted so that the end grain is at an angle of less than 45°.
Twisting
p Figure 3.30 Types of timber movement
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma When using circular sawing machines, it is important that the material being cut is positioned correctly on the machine before cutting. The following drawings outline the correct positioning for materials that have common seasoning problems or timber that is not flat and straight.
Crown guard Fence
Saw blade
Fence
Crown guard Cupped side against fence
Saw blade
Cupped positioning when flatting: cupped side uppermost
p Figure 3.31 Correct positioning for ripping cupped timber through its thinnest section
Points of contact
Cupped positioning when deeping
p Figure 3.32 Correct positioning for ripping cupped timber through its thickest section
INDUSTRY TIP Always position the cupped side facing upwards so that the outer edges fall away from the saw blade.
Riving knife
Riving knife
Convex side to fence
Concave side up The timber needs to be in contact with the machine bed at the point of cutting with the large blue arrow
p Figure 3.33 Correct positioning for cutting timber that is bowed down its length
Concave edge
p Figure 3.34 Correct positioning for ripping timber that is sprung down its length
INDUSTRY TIP A simple straight batten can be tacked on its face and used against the fence for safer and accurate cutting. 138
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Chapter 3 Power tools You may experience problems when sawing twisted timber. Use your best judgement when following the above guidance. In the case of excessive twisting or when in doubt, do not use the material. During the cutting operation, timber can sometimes pinch in onto the sides of the saw blade, causing friction; this is usually a result of case hardening in the timber. If this happens, the timber may be forcefully pushed back at the person operating the saw; in severe cases, this could result in injury. To help prevent the timber pinching in onto the saw blade, drive a wedge into the saw cut behind the riving knife; this action will help to stop the timber closing in any further. Safety measures for setting up and using table ripsaws When setting up and using table ripsaws, you should always: l l l l l l
position the crown guard as close as possible to the top of the material being cut ensure that the riving knife is correctly positioned at the rear of the saw blade and not more than 8 mm away from the saw teeth ensure that the material is fully supported by the machine bed and, when required, an extension table and support rollers use an extraction system to collect the sawdust ensure that you have a suitable push stick available and always use it to feed the last 300 mm of the material through the saw cut ensure that, when someone is removing material at the rear of the saw bench, they are not positioned closer than 1200 mm from the centre of the saw blade.
KEY TERMS Case hardening: a defect caused by the timber being dried too rapidly, leaving the outside dry but the centre still wet. It typically causes the material to bend and twist during cutting, resulting in binding on the saw blade and kickback. Push stick: a length of timber used to help feed and control the material being cut.
m
00 m
ea ld b
imu
min
hou
ce s
tan s dis
f3 mo
Thi
450
85°
mm
End of push stick
Timber
Table Spike – for controlling thin offcuts
p Figure 3.35 Push stick and spike used to help control the timber through the table saw
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma 1200 mm minimum
ACTIVITY List the advantages and disadvantages of using a hand-held plunge saw and guide rail system compared with using a table ripsaw for cutting sheet materials such as MDF.
p Figure 3.36 Outfeed table used to ensure outfeed operative is kept at least 1200 mm away from the centre of the saw blade
Jigsaws The jigsaw is a versatile tool, mainly used for curved and irregular shaped cuts. The blades used in jigsaws are narrow, which in turn allows the jigsaw to preform tight turns. It is important to ensure that the blade is moving before it comes into contact with the material to be cut. This prevents there being a sudden and uncontrolled movement of the blade, which usually results in the blade being bent and can be potentially dangerous. When using the jigsaw to cut out an aperture in material such as a worktop, always drill a hole large enough for the blade to fit in first.
Trigger
Blade release
Pendulum setting. The higher the setting, the faster the cut Bed
Blade
p Figure 3.37 Pendulum action jigsaw
Jigsaws incorporate a quick-release tool-free blade change system, which is usually located behind the front transparent guard. The blade of the jigsaw cuts in an up and down motion. Most jigsaws have an adjustable pendulum or orbital action cutting feature. The pendulum action gives a slight swinging motion to the cutting action of the blade, with the forwards swing taking place on the upwards stroke of the cut, while the backwards action allows for faster and better cleaning of the sawdust from the cut. The higher the pendulum action setting, the more swing the blade has, which usually allows for faster cutting. The pendulum action is typically used when cutting timber; a higher setting (with more swing) is used for deeper cuts. A disadvantage of a high pendulum action is that more swing usually means that it is less easy to produce an accurate cut. When tight accurate curves or neat 140
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Chapter 3 Power tools finishes are required, use a zero-pendulum setting, as this allows for a steadier controlled cut. Care is needed to prevent friction on the side of the blade as this will produce a burnt finish to the finished cut.
Straight up and down cutting action
Pendulum cutting action
p Figure 3.38 Cutting actions of a jigsaw
One of the most common problems you may experience when using a jigsaw is when the blade bends during cutting, as shown in Figure 3.39, particularly when making deep cuts using a high pendulum setting. Any bending of the blade can produce an undercut edge, which affects the required size and shape of the cut. Using a blunt or dull blade increases the likelihood of the blade bending, so you should always discard a blunt or dull blade and replace it with a new sharp blade.
p Figure 3.39 Bending of the blade during cutting produces an undercut edge
Reciprocating saw The reciprocating saw has become an increasingly popular power tool due to its versatility and, with the correct type of blade, its facility to cut through almost any type of material. The reciprocating saw is commonly used by window and door installers for removing windows and doors. When using the correct type of blade, the saw blade can be run down the side of the brickwork to cut through the fixings holding the frame in place, enabling quicker and easier frame removal. The reciprocating saw uses a push and pull cutting action like that of a jigsaw and uses a similar type of blade, but they are longer and stronger.
p Figure 3.40 Reciprocating saw
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Planers The power planer is used to form a smooth flat surface or to reduce materials to a given thickness, much like the hand versions. The power planer produces the flat surface by passing revolving cutters (usually two) along the material. The front of the planer has an adjustable bed, which limits the amount of material removed in each pass. At the rear of the cutters there is a fixed bed, which sits on the completed planed surface and supports the planer during the cutting operation. Depth of cut scale
Start–stop control
Depth of cut adjustment knob for infeed bed Dust extraction port which can be fitted to either side
Outfeed bed Infeed bed Side fence, used to form rebates
p Figure 3.41 Portable power planer
Planer knives The cutters of the planer are usually referred to as planer knives and in most new models they are disposable. Each knife has two cutting sides. When one side of the knife becomes blunt or damaged, it can be turned around and the new cutting side can be used before replacing the knife. A step-by-step guide to removing and replacing the planer knives is set out below. 1 Disconnect the planer from the power source. 2 Loosen the bolts securing the planer knives and slide out the old knife and wedge bar. 3 Clean away the resin and dust that has built up around the seating area of the knife, as well as on the wedge bar. When turning around old cutter knives to their new cutting edge, thoroughly clean the cutter knife as well. 4 Fit the new cutter knife onto the wedge bar. The two small holes in the cutter knife sit over the pins in the wedge bar, enabling fast and accurate positioning of the cutter knives. 5 Slide the wedge bar and cutter knife assembly into the housing in the circular cutter block and fully tighten the bolts.
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Chapter 3 Power tools
Wedge bar
Cutter knife
Infeed bed
Outfeed bed
p Figure 3.42 Cutter knife and wedge bar assembly being replaced
Using the power planer The power planer can be used to remove a lot of material very quickly; sometimes too much may be removed if you do not use the power planer carefully. To prevent a poor finish and to limit any risk of removing too much material in one pass, it is good practice to limit the depth of cut to a maximum of 2 mm. If you need to remove more material, then it is best to use several smaller cutting depths instead of one deep cut. Using deep heavy cuts above 2 mm can result in ‘chatter marks’ on the finished surface, caused by the power planer slightly jumping from the material during use. A further cause of a poor finish is unsightly ‘pitch marks’, which are a consequence of passing the power planer over the material at too high a speed. Passing the power planer too fast over the material surface can also lead to tearing out of the material’s surface. Pitch marks appear as a series of raised bumps and hollows on the timber surface. All rotating cutters leave pitch marks as the material is passed over the cutters or the cutters are passed over the material (as in the case of the hand-held power planer). Small pitch marks are difficult to see and appear as a smooth flat surface. Large pitch marks are easily visible and usually a result of high-speed travel of the hand-held power planer over the material.
Large pitch marks are a result of high-speed planing and show as raised bumps on the material
Tear out on the surface is a result of high-speed planing
p Figure 3.43 Large pitch marks and tear out on the surface of the timber caused by too fast a feed speed
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Feed direction
ACTIVITY Fit a hand-held power planer with a new set of cutter knives and set the planer to a cutting depth of 2 mm. Slowly plane a piece of timber. Using the same setting, repeat the process using a faster feed speed and compare the quality of finish. Now set the hand-held power planer to 0.5 mm and repeat the process. Notice the difference when you can control the planer and the quality of finish.
Pitch
p Figure 3.44 Small pitch marks resulting from a slower feed speed of the power planer Feed direction
Pitch
p Figure 3.45 Large pitch marks resulting from a fast feed speed of the power planer
The hand-held power planer can produce splits or spelching (see Chapter 2, page 87) to the outfeed end when planing end grain. For example, when planing the bottom rail of a door, as you pass over the door stile you will cut end grain. The same principle applies to any other task involving planing end grain.
INDUSTRY TIPS Small raised tram lines following the line of the planed cut are clear signs of damaged planer knives. Further signs are torn grain and a fluffy appearance to the timber surface. Portable planer knives are usually made from tungsten carbide, which is very brittle. Avoid planing metal objects such as staples, which are often found on the edge and bottoms of doors, as these will chip the cutting edge, leaving small raised lines down the planed cut.
The following guide will help you to reduce the likelihood of splitting out any end grain during planing operations. 1 Start by planing a small cut at your intended finishing end first, as shown in Figure 3.46. This cut does not need to be more than 20 mm long but must be the same depth as will be used for the rest of the cut. Intended cutting depth
Start with a small cut here about 20 mm long
Intended finishing end
Grain direction
p Figure 3.46 First stage of preventing splitting of end grain when planing
2 Next, move to your starting end and plane the complete length of the material and out past your first cut as normal, as shown in Figure 3.47. Your planing line should line through with your first cut, thereby eliminating the risk of splitting the end grain.
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Chapter 3 Power tools Continuation of second cut to line through with first cut First cut
Second cut
Grain direction
p Figure 3.47 Second stage of preventing splitting of end grain when planing
Variations of cuts The power planer is not only used to produce smooth flat surfaces on tasks such as reducing doors to size. It can also be used to produce shaped flat surfaces such as: l bevels, which run completely across the surface of the material from one edge to the other, incorporating two corner edges l chamfers, which run part way across the surface of the material, incorporating just one corner edge l rebates, which are right-angled recesses cut into one corner edge of the material and require the use of the fence provided with the power planer. The depth of the rebate may be greater than the cutting depth of the planer; in these cases, several cuts will be required to achieve the required finish depth of cut.
p Figure 3.48 Bevel
p Figure 3.49 Chamfer
p Figure 3.50 Rebate
ACTIVITY Set up the hand-held power planer to cut a 30 mm wide rebate, where the finished required depth of the rebate is 12 mm. Using several smaller cuts, produce a 30 mm × 12 mm rebate in a length of timber.
Routers Portable routers are among the most versatile portable power tool available to the carpenter and joiner. They can be used to perform a large range of operations including making grooves, rebates, housings, circles and profiles. Essentially, a router is a cutter directly attached to a big motor via a collet, as shown in Figure 3.51. Fences, guide bushes and stops are used to control and adjust the depth and width of cut.
KEY TERMS Grooves: narrow cuts or channels along the grain of the timber. Housings: joints consisting of a groove usually cut across the grain, into which the end of another member is housed or fitted to form a joint. Profiles: decorative shapes formed along the edge of materials, such as rebates, ovolo, ogee, bullnose, lamb’s tongue and scotia.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Speed setting. This is reduced when using large diameter cutters
Trigger and safety switch Handle Handle
Body Fine depth adjustment
Fine adjustment for fence
Chuck and collet Depth stop
Adjustable turret or castellation
Base
Fence
p Figure 3.51 Hand-held portable router
These are the component parts of a router. l
l
l l l l l
l
Speed setting: most routers have electronic speed controls which allow for increased or decreased cutter rotations by the router motor as well as helping maintain rpm (revolution per minute) while under load. A larger cutter will require a slower rotational speed for safety reasons. Most routers operate between 10,000 and 22,000 rpm. Another big advantage of variable speed is the soft start feature; this is where the router gradually builds up speed, eliminating the sudden jolting of the machine that can happen with fixed speed machines. Switch: this is used to operate the machine. It is important not to start the machine if the cutter is in contact with the material being cut. Most machines now have a slow start, meaning there is no initial ‘kick’, and all new machines are fitted with a braking system to make sure the cutter stops within a few seconds of the switch being turned off. Handles: these are used to firmly grip the tool. In some smaller models, twisting them acts as a depth lock. Body (motor): this is the casing that holds the motor. Collet: this is a chuck that holds the router cutter. Base: this is the bottom of the tool that is in contact with the work. Depth stop: this is used to control how far the router will plunge or the depth of cut. A castellation/turret (multi-position depth stop) enables several depth adjustments to be set at the same time. The castellation is turned to obtain each setting. When the desired depth is set, the depth lock will lock the bed into position, maintaining an accurate depth of cut. Fence: this is used to adjust the width of cut. It is adjusted by loosening and tightening the nuts. Fine adjustment can be achieved by using the knob.
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Chapter 3 Power tools The router is usually supplied with a few basic accessories, including a guide fence, guide bush and a selection of collets, but lots of accessories and jigs are available to use in conjunction with the router, as shown in Figure 3.52.
A
E D
B
F
C
p Figure 3.52 Some of the basic accessories available for the portable router A Roller fence/bearing guide: used for trimming and curved work. B Spanner: always use the one supplied with the machine to prevent overtightening. C Guide bush: used with jigs and templates; available with different diameters. D Trammel: used for producing radius shapes. E Straight fence: for straight working running against the material. F Fine adjustment to fence.
Router cutters Most router cutters are designed to produce specific profiles or for use with different types of jigs. One of the most frequently used types is the straight flute cutter. This type of cutter is used for a wide range of applications, from cutting grooves to forming rebates. It may be used in conjunction with templates and jigs, for trimming and cleaning up edges of timber and manufactured boards. The materials that router cutters are used for are varied, but they fall into two main categories: l
hard and abrasive materials, such as oak, ash, beech, iroko and mahogany, and man-made materials like plywood, MDF, chipboard and laminated materials l softwood such as European redwood, spruce and cedar. Router cutters for the hand-held portable router are available in three types of cutting material. 1 TCT cutters are the most suitable for hand-held routers; they are reasonably cheap, readily available and exceptionally good for cutting hard abrasive materials and softer materials. The smaller diameter cutters are made from solid tungsten carbide, while the larger diameters cutters have TCTs. More commonly available now are router cutters that use disposable rotating TCT cutters. As the cutting edge becomes blunt, the cutter is simply turned around until all its cutting edges have been used. The cutting edge is replaced, instead of replacing the whole cutter as with other types of router cutters. 147
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma 2 Polycrystalline diamond (PCD) cutters are suitable for cutting softwoods, hardwoods and man-made materials. However, they are extremely expensive and are used mainly on high-volume production computer numerically controlled (CNC) routers. 3 High-speed steel (HSS) cutters are only suitable for cutting softwoods. If they are used to cut the harder, more abrasive types of material, they will burn out the cutting edge very quickly, resulting in an extremely poor finish and a ruined cutter. These types of cutter are seldom used. Some of the types of cutter profiles used with portable routers are shown in Figure 3.53. The name associated with each type of cutter usually describes the type of profile the cutter produces. Ovolo cutter Finished profile
Cutting edge
Bearing-guided rebate cutter
Bearing-guided chamfer cutter
Astragal cutter
Dovetail cutter
Trimming cutter
Bearing-guided ogee cutter
Bearing-guided scotia/cove/ cavetto cutter
Straight flute cutter used to form a rebate when used in conjunction with the router fence
Shank
Bearing guide
V cutter
Straight flute cutter used to form a groove in conjunction with the router fence
p Figure 3.53 Common types of router cutter
Router cutters are available in several different ‘shank’ sizes. The most common sizes of router shank are 6 mm, ¼ inch, 12 mm and ½ inch diameter. Larger diameter shank cutters are typically used with larger sized cutters and larger, more powerful routers.
INDUSTRY TIP The roller guide bearing on router cutters can be changed to a different size, allowing for slightly different profiles to be produced from the same cutter.
Large-diameter router cutters should not be used in hand-held portable routers. Always refer to the manufacturer’s information on the appropriate cutting speed and type of router cutter that can be used in your router. Larger hand-held portable routers are more capable of using larger diameter cutters than smaller versions. Router cutters of more than 50 mm diameter should not be used in portable hand-held routers but only in fixed bed router tables. If the motor in the router shows signs of slowing down or the router becomes difficult to feed, reduce the size of the cut and produce the correct finished size of the moulding in multiple passes until the required size is achieved.
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Chapter 3 Power tools Cutter speed settings Using the correct peripheral speed or rotation speed of the router cutter edge is vital for the safe operation of the router, as well as the production of an acceptable surface finish to the material. If the peripheral speed of the cutter is too low it can result in a poor finish, while too high a peripheral speed can result in a difficult-tocontrol and dangerous machine.
KEY TERM Peripheral speed: the distance the rotating cutting edge travels, expressed as metres per second (m/s).
The peripheral speed of a router cutter is affected by several factors including: l l l
l l
the type of material being cut – hard abrasive materials will slow the router cutter down more than softwoods the size of the cut – larger cuts will slow the cutter down and put more strain on the router motor the feed speed at which the router travels through the cut – the faster the router is fed along the material during the cutting process, the more strain is put on the motor, resulting in a reduced peripheral speed cutter sharpness – using a sharp router cutter revolving at the correct peripheral speed will ensure a good quality finish the power rating of the router – the power of a router is measured in watts, with most routers ranging from 700 watts for a small lightweight DIY router up to 2200 watts for a heavy duty professional router. Larger watt machines can use larger diameter cutters, take larger cuts and work for longer periods of time without risking damaging the router motor.
Use the following formula to work out the peripheral speed of the cutter: (Diameter of cutter in mm × π × router speed)/100 = peripheral speed in m/s
(Note: π = 3.142)
Example: Cutter diameter: 20 mm Router speed: 18,000 rpm
Peripheral speed of the cutting edge = 20 × 3.142 × 18,000 = 1131.12 m/s 1000
Router cutters have an optimum peripheral cutting speed, which is generally accepted at about 1520 rpm. Maintaining the rpm is dependent on many factors previously discussed. The formula for working out the speed setting of the router is as follows.
IMPROVE YOUR MATHS The optimum peripheral speed of the cutter can be worked out using the following formula: (Optimum peripheral speed × 1000 )/(π × diameter of cutter)
Example:
Optimum speed of cutter = 1520 rpm π = 3.142
Cutter diameter = 30 mm (1520 × 1000)/(3.142 × 30) = 16,125 rpm
Therefore, the optimum speed setting of the router would be approximately 16,000 rpm. Using the above formula, work out the optimum speed for a 20 mm diameter cutter.
IMPROVE YOUR MATHS Calculate the peripheral speed of a cutter that has a 25 mm diameter.
INDUSTRY TIP As a rule, the smaller the cutter diameter, the faster the router should revolve; and the bigger the cutter diameter, the slower the router should go round. Never use cutters with a diameter over 35 mm in hand-held routers as they can become difficult and dangerous to control. 149
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Types of work produced using hand-held portable routers The list of work that can be done with a router is extensive and, with the use of proprietary (shop bought) and custom-made jigs, many more items can be added to this list. Types of work you can produce using hand-held portable routers include: l l l l l l l l
edged profile work using fences and bearing guided cutters profiles and grooves using guide rails worktop jointing door hinge recesses lock and letterbox cutting openings in worktops (apertures) producing circles and ellipses forming dovetails.
Work along the edge of the material, using either a fence or the bearing of the cutter running along the material.
Dust extraction hose to vacuum
Router guide fence
p Figure 3.54 Straight cutting using the router fence
Figure 3.55 shows someone using a template or jig in conjunction with the guide bush. With this type of working, an appropriately sized guide bush is inserted into the base plate of the router. The guide bush then follows the predetermined shape of the template or jig.
p Figure 3.55 Using a temple and guide bush
p Figure 3.56 Router guide bush
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Chapter 3 Power tools Bearing guided router cutters are designed to be used in direct contact with the material, eliminating the need for a jig or template.
Router base plate
Router cutter
Bearing to router cutter
p Figure 3.57 Using a bearing guided router cutter to run along the outer edge of the material
Figure 3.58 shows someone using a guide rail system. The same guide rail system used with circular saws can also be used with routers, providing that the router/ guide rail attachment is available. The guide rail is positioned at the required position (allowing for the offset of the router) on the material. The guide rail attachment, which has been fixed to the router, is then located onto the guide rail. Using guide rails allows for accurate and stable working anywhere on the material, and is not limited to the outer edges or the restricted distance allowed by the router fence.
p Figure 3.58 Router and guide rail system
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma q Table 3.7 Jigs and templates for use with hand-held portable routers Jig or template
Example
Worktop jig
Hinge recessing jig
Dovetail jig
Trammel being used to form circular cuts
Portable routers can also be used in conjunction with a router table. This is where the portable router has been inverted into a specially designed table. This type of working is mainly reserved for workshop working since most router tables are not easily transported. When using a portable router in a router table, the router acts very much like a vertical spindle moulder (a large professional machine used for profiling timber components) and requires all the appropriate safety features and rules that apply for the vertical spindle moulders.
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Chapter 3 Power tools Rear guard and extraction hose port located behind fence
HEALTH AND SAFETY
Router table fence Adjustable guard to sit above router cutter Router table bed
When using router tables, always use the guards and use a push stick for feeding the last 300 mm of the material. This will reduce the risk of your hands and fingers making accidental contact with the cutter.
Aperture for router cutter Router mounted below bed of table
p Figure 3.59 Router table
Direction of travel for the hand-held portable router For safety and control, feed the hand-held portable router in the correct direction of travel in relation to the rotation of the cutter. The correct direction of travel for the router can be determined in the following way. Looking down from the top of the router towards the cutter, you will notice that the cutter rotates in a clockwise direction. The forward-facing or forward-rotating edge of the cutter should always do the cutting; this is called push cutting. In Figure 3.60, the router should be positioned on the right-hand side of the material and pushed away from you or positioned on the left of the material and pulled towards you. In both cases, the cutter is cutting on its forward-facing edge. If you feed the router in the opposite direction, which is called ‘climb cutting’, the cutter will dig into the material, resulting in the cutter pulling the router along in a self-feeding or climbing motion along the material. This can result in loss of control and a poor-quality or lumpy surface finish to the material, as well as possible injury to the operator. Clockwise rotation of cutter
Climb-cut direction Push-cut direction
✔ p Figure 3.60 The correct direction of travel when viewed from the top of the router looking down towards cutter
Cutter digs into the material
p Figure 3.61 The incorrect direction of travel, with the cutter digging into the material
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Forming a rebate using a guide fence
INDUSTRY TIP If during the cutting process you find the router is hard to control, has excessive vibration and excessively high noise levels, it is likely that you are trying to remove too much material in one pass.
When forming a profile such as a rebate, the cutting edge may splinter or spelch, probably owing to the cutter working beyond its centre point. To prevent any spelching or splintering along the cutting edge of the material while forming a rebate, it is important that you do not cut beyond the centre of the router cutter in one go. If the finished size of the rebate is wider than the radius of the cutter, form the rebate in multiple passes. The maximum cutting depth in one pass for a router cutter should be limited to a cut equal to the cutter’s radius. For example: a cutter with a diameter of 6 mm should be limited to a maximum 3 mm depth of cut for one cutting pass; a 10 mm diameter cutter should be limited to 5 mm maximum cutting depth in one pass; a 12 mm diameter cutter should be limited to 6 mm maximum cutting depth in one pass; and so on. This applies to softwoods; when machining hardwoods, you should further reduce this maximum cutting depth in one pass. When a rebate is required that is greater in its width than the radius of the cutter, use the following procedure.
18 mm
First cut shown in green set at 9 mm
STEP 1 In this example, the required width of the rebate is 18 mm, while using a 25 mm diameter cutter.
STEP 2 The maximum amount in one cut that the cutter should produce.
The maximum amount in one cut that a 25 mm cutter should produce is 12.5 mm, which is equal to the radius of the cutter. To achieve the required rebate size of 18 mm, two passes of 9 mm each are needed.
Second cut shown in green equal to 9 mm but totalling an 18 mm wide rebate
STEP 3 The second cut of 9 mm will now achieve the total width of 18 mm without the cutter having to cut beyond its centre line in one pass.
Do not cut in one pass beyond the centre line of the cutter
STEP 4 The incorrect way to form a rebate is to try to cut beyond the centre of the cutter in one go.
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Chapter 3 Power tools If these guideline measurements are exceeded there is a risk of breaking the cutter, particularly when using smaller diameter cutters. Although these are guidelines for the maximum cutting depths in one pass in relation to the cutter’s diameter, it is the material being cut and its quality that will determine the maximum cutting depth of each pass of the cutter. Push stick
Router cutter
Work piece
tion
irec
dd Fee
Table fence
Direction of cutter movement
Table bed, router fixed to underside
INDUSTRY TIP Feeding the router too slowly along the material can produce burn marks (or dwell marks, as they can be called) on the finished surface of the material.
HEALTH AND SAFETY Be aware of dead or loose knots on the edge of the material that the router cutter will pass along, as these can be dislodged, resulting in potential injury.
Note: Guards and pressures missing for clarity
p Figure 3.62 Feed direction for the router table
When using a router table, always feed the material into the direction of the revolving router cutter and, as with using a hand-held router, never cut beyond the centre line of the cutter in one pass.
Jointers Jointers are used to join material together, such as forming joints when constructing frames, joining kitchen worktops, lengthening materials and making furniture. Jointers fall into two general types: l l
biscuit jointer domino jointer.
Biscuit jointers and domino jointers can generally be used for the same type of work. However, it is widely accepted that domino jointers produce stronger and more accurate joints. They are becoming a highly valued and versatile workshop power tool, particularly in environments that do not have access to the larger and more expensive industrial workshop machinery, such as a mortice and tenon machine.
Biscuit jointer The more traditional biscuit jointer uses oval shaped discs, referred to as biscuits, which fit into matching circular grooves in each piece of material to be jointed. The groove is cut by a small grooving saw contained within the biscuit jointer, as shown in Figure 3.65.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma
p Figure 3.63 Biscuit jointer
p Figure 3.64 Biscuit jointer blade
p Figure 3.65 Biscuit recesses cut in a rail ready for assembly
KEY TERM Loose tenon: a length of timber or plywood used to form the joint of a mortice and tenon joint that is separate from (loose) both pieces of timber that are to be jointed. This contrasts with the traditional tenon that is a part of one of the pieces being jointed together.
Domino jointer Domino jointers allow you to undertake a wider range of work. They enable you to produce larger items of joinery that require stronger joints, more quickly and cheaply than would otherwise be possible. The domino cutter uses a specially designed drill bit that cuts a round-ended slot, called a mortice, into which fits a flat round-ended loose tenon, called the domino, as shown in Figure 3.67. Domino joints are widely used in the manufacture of frames and furniture and in general jointing practices. Domino joints are considered a stronger, more accurate type of jointing system than biscuit joints and are widely used in workshops, but they can also be used for work on site, such as worktop jointing.
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Chapter 3 Power tools Domino cutters are available in five different sizes – 4 mm, 5 mm, 6 mm, 8 mm and 10 mm – to suit the required size of mortice for the application and the corresponding domino thickness. Width of mortice adjustment
Start–stop switch
Dust extraction hose Plunge depth of cut adjustment Fence height stops
Dominos
Domino cutters
Adjustable fence for producing angles from 0˚ to 90˚ adjustment
p Figure 3.66 Domino jointer and dominos
Domino mortice slot
INDUSTRY TIP Domino inserted
The mortice should be approximately one-third of the thickness of the material.
p Figure 3.67 Rail and stile prepared for joining with dominos
Comparison of jointing techniques The biscuit jointer uses thin compressed material like fine-grade oriented strand board (OSB) made from compressed beech pulp to form its biscuits. Due to their manufacturing process, biscuits can be weak and prone to splitting across their width. All biscuits are 4 mm thick and are available in the sizes shown in Table 3.8.
KEY TERM Oriented strand board (OSB): board comprising wood fibres that lie in opposing directions to each other, in a similar way to plywood.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma q Table 3.8 Biscuit sizes Size of biscuit
Dimensions (mm)
Required depth of groove (mm)
0
47 × 15
8
10
53 × 19
10
20
56 × 23
12
Biscuit groove
Biscuit
p Figure 3.68 A biscuit and the two lengths of timber that it will joint
The domino jointer cuts its mortice in a downward oscillating motion. Special drill bits have been designed that not only cut on the downward stroke, as with other drill bits, but also on its side. This oscillating motion to the cutting process allows for mortices of varied width and thickness to be selected, such as 4–14 mm-thick dominos and 20–140 mm-wide domino mortices, with a maximum depth of 70 mm.
Using jointers Before using any jointer, always ensure the cutter is in good, sharp condition. Dull or damaged cutters will give a poor-quality finish and could result in movement of the jointer, particularly with biscuit jointers. Before forming any joints in the material, always secure the workpiece so that it cannot move during the cutting operation. Always ensure that you hold the jointer with both hands at the intended points: place one hand on the motor housing close to the start–stop switch and the other hand on the additional handle towards the front of the machine.
HEALTH AND SAFETY Whichever type of jointer you use, always follow the specific instructions on use provided by the manufacturer.
With both types of jointer, the cutting action is achieved by applying a steady but firm push motion into the material being cut. This ensures the jointer does not move during the cut and helps to produce an accurate and neat finish. Ensure that the cutter of the jointer has stopped and retracted into its housing before removing the jointer from the material. This ensures the safety of the operator and prevents accidental contact being made to the material by the cutter. Table 3.9 outlines the main differences between a biscuit jointer and a domino jointer, together with advantages and disadvantages of each.
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Chapter 3 Power tools q Table 3.9 A comparison of a domino jointer and a biscuit jointer, showing their main differences, advantages and disadvantages Criteria
Domino jointer Description
Biscuit jointer Advantages
Disadvantages
Type of cutter
Drill type cutter in Different thickness Requires changing of several sizes dominos can be used for increased cutter strength
Jointing material
Solid beech loose tenons with rounded ends available in multiple sizes
Description Small grooving saw of one thickness
Advantages
Disadvantages
Cutter only requires changing when needs to be sharpened
Only one thickness of biscuit can be used, limiting the strength of the joint
Capable of producing joints of multiple sizes, both in length and thickness
Requires multiple Small oval different-sized shaped discs only dominos available in three sizes and made from compressed materials
Few sizes available, reducing stock requirements
Limited strength of joint due to smaller size of the jointing area and strength of jointing material
Attachments Several
Multi-use tool for producing joints in frames, doors, worktops and furniture and in other types of jointing situations
None
None
None
Relies on accurate marking out and positioning of the jointer for the accuracy of the joint
Strength of joint
Solid beech timber dominos in multiple sizes, allowing for deep, wide and thick mortice joints where required
Strong joints can be produced with deep and wide mortices, allowing for more surface contact and a large glue area
None
Limited strength due to limited surface contact area
Limited
Limited strength of joint; mainly used to align joints
Speed of use
Plunge cutting process
Fast and clean None cutting of mortices
Plunge cutting process
Fast-cut circular recesses
None
Ease of use
Easy pre-set stops for different domino sizes and positions
Allows for easy positioning
Can be timeconsuming when changing cutter for different-sized dominos
Easy to locate with clear saw centre lines for positioning
Quick to position
Can move during use
Types of work
Any type of jointing work requiring strong joints
Useful for almost any type of joining work; particularly suitable where strong joints are required, such as in frames or furniture
None
Useful for joining material not requiring a strong jointing method. Often used to help with correct location of two pieces
Quick and easy to use
Joint has limited strength, limiting the type of work it is suitable for
attachments available to enhance precision and positioning of the joint and to allow for more varied joint positions
ACTIVITY Describe the main requirements when jointing timber and list the advantages and disadvantages of using a domino jointer compared to a biscuit jointer. Which type of jointer would be most suitable for the type of work you usually undertake?
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HEALTH AND SAFETY Always wear suitable eye and ear protection when using powered nailers.
Powered nailers Powered nailers are often referred to as nail guns and come in three sizes. Small nailers are designed to fire small fixings such as pins or staples into thin plywood or beads and are often used in furniture manufacturing. The most frequently used types of nailers in construction are referred to as first fix and second fix nailers. l
The first fix or framing nailer can fire the largest heavy gauge nails, from 51–90 mm in length, into timber. It is used for roofing, stud partitions and other types of heavy joinery work. l The second fix nailer uses lighter gauge nails, ranging from 16–63 mm in length (the smaller lengths are usually referred to as brads). It is used to fix trims such as architrave and skirting board or other lightweight work. Powered nailers may be powered by electricity, battery, gas or compressed air and are available in either a square or angled design. Second fix nailers are usually square in design, while first fix nailers are angled. One advantage of an angled nailer is that it allows easier access into tight corners, such as when fixing studwork to sole plates or when fixing roof rafters. When carrying out maintenance or clearing jammed fixings, always remove the power source first. It is usually considered safe to reload the nailer with the power source still connected, but always refer to the manufacturer’s advice. Air filter
Gas cell chamber
Hook
44 nail magazine 7.2 V Liion battery LED light service indicator
Contact nose
p Figure 3.69 Parts of an angled nailer
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Chapter 3 Power tools
Fixings used with powered nails Powered nailers use strips of collated nails. These can be galvanised, passivated or bright steel, making them suitable for external use. The nails are available as either smooth shank or ring shank and in several thicknesses of shank, which is referred to as the gauge of the nail. Brad nails are small thin gauge finishing nails that have no heads or have small narrow heads, which allows them to be firmly embedded into the material, eliminating the need to use nail punches. Small ridges around nail shank
p Figure 3.70 Collated nails
p Figure 3.71 Ring shank nails
Collated: assembled in the correct order and held together in strips usually with glue, plastic or paper. Galvanised: a protective zinc coating that is applied to steel and iron to help prevent rusting. Passivated: a protective coating, usually zinc. Ring shank: a nail with small ridges around the shank, which increases the nail’s resistance against pulling loose.
HEALTH AND SAFETY
Using powered nailers Powered nailers drive a single nail at great speed and power into the material. To prevent firing the nailer accidentally, ensure that the contact nose of the nailer is fully depressed. When fully depressed, the contact nose releases the safety tip, allowing power to the trigger. When the trigger is then pressed, the nailer fires the nail. To fire another nail, the contact nose must be reset. To do this, lift the nailer and reset the contact nose. If the contact nose is not fully depressed, the nailer will not fire a nail, regardless of how many times the trigger is pulled. When using nailers, you should take particular care when working near knots. The fast driving speed of the nail can dislodge knots, especially dead arris knots (see Chapter 4, page 188). Nails can also deflect from the intended course, causing ricocheting of debris from the nail.
Good positioning of free hand
KEY TERMS
Always keep your free hand away from the location of the nailer and do not drive a nail towards any hands that may be supporting the material.
IMPROVE YOUR ENGLISH Produce a safety poster listing the dos and don’ts of using powered nailers that can be used as a toolbox talk.
Free hand too close to intended path of nail
✔
p Figure 3.72 Correct positioning of free hand, well away from risk of deflection of the nail
p Figure 3.73 Incorrect positioning of free hand
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Sanders Sanders are used to provide a high-quality smooth finish to the surface of material. The quality or smoothness required for the finish depends on the type of surface finish being applied. Polished surface finishes usually require a smoother finer finish than a painted surface finish. In all cases, sanders use differing grades of abrasive paper to cut the top surface of the material. Differing grades of abrasive paper are used to produce an increasingly finer finish. There are four main types of portable sander: l
INDUSTRY TIP Belt sanders can easily remove large amounts of material but should be used with great care to prevent excessive material removal.
KEY TERM Tracking: adjusting the front roller so the abrasive paper will run central to the pulley rollers.
HEALTH AND SAFETY Ensure that no loose clothing or other loose material can be caught around the rotating belt.
belt sander l random orbital sander l orbital sander l detail sander.
Belt sander Belt sanders are the largest and heaviest of the hand-held sanders and usually require both hands to control them. They use a continuous belt of abrasive paper that runs around two pulley wheels and over a flat metal bed, which is used to apply pressure to the surface of the material. The sanding belt is kept in place by spring tension of the front roller, to help ensure that the belt does not slip and runs central on the pulley rollers. To further ensure that the abrasive belt runs central on the pulley rollers, the front roller is used to align the abrasive belt. This involves slightly twisting the front pulley roller which, in turn, makes the abrasive belt run towards the higher point of the front pulley. When the correct amount of adjustment is achieved, the abrasive belt has a slight sideways wandering movement to it but will run central over the pullies. The alignment process is called tracking. Belt sanders are usually associated with fast large surface removal using coarse grit abrasive belts. This type of sander is very efficient at removing unwanted material, but can produce unwanted dips in the surface of the material as well as easily rounding any corner edges if you do not take sufficient care. It is important to keep this type of sander moving quite quickly to both improve surface finish and help prevent surface dips and rounded corners. Dust bag Start switch
Speed control Rear driven pulley
Abrasive paper tensloning lever
p Figure 3.74 Belt sander sanding sheets
Front free-running pulley used to ‘track’ the abrasive paper
p Figure 3.75 Belt sander
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Random orbital sander The random orbital sander is smaller and lighter than the belt sander and is easily controlled with one hand. It is primarily used in finishing the surface material. The round pad on the random orbit sander moves in eccentric circles as well as spinning in circles. This dual action method of sanding achieves a high-quality finish with no signs of small circles or swirls scratched into the surface, which might be caused by a traditional orbital sander. Start /stop switch
Flexible sanding pad
KEY TERM Eccentric circles: where one smaller circle is offset within a larger circle.
Power cable
Dust extraction port
p Figure 3.76 Random orbital sander Centre point of rotation for smaller circle
Rotation of circles
Centre point of rotation for larger circle
p Figure 3.77 Eccentric circles
The sander has a speed selection control, which adjusts the rotation speed of the sander. Higher rotational speeds generally increase the cutting power of the abrasive pad and, as a result, remove material faster. A slow rotational speed setting can at times be the best option, giving benefits such as: l
less vibration through the sander, making it easier to control minimising any heat generated by friction from the sanding pad l better pad flexibility, which allows the pad to flex and better follow any contours of a shaped product l less risk of damaging the sanding pad itself. l
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HEALTH AND SAFETY All sanders produce fine dust particles, which can cause serious breathing problems. Always use a dust collection system, even if only using the sander for a short time, and where necessary a dust mask.
The sanding pad used to hold the abrasive paper has holes through the pad, which are used to help draw up the dust produced during operation. The sanding pad has a slight flexibility to its outer edges and uses a hook-and-loop method of attaching the abrasive paper. This attachment method relies on small semi-flexible hooks attached to the underside of the abrasive paper hooking onto the small loops on the sander pad. Any abrasive sheets used with the random orbital sander should be of the same diameter as the sander pad, as well as having puncture holes through them. The holes in the abrasive paper and the sander pad should be lined up, so that the sander can draw up the sanding dust to the extraction port of the sander, where it is removed by a portable extraction system. When used in this way, the random orbital sander leaves little surface or atmospheric dust, making it one of the safest sanding methods available. This type of sander is intended for use in slow movements along the material, with little downward pressure. This allows the sander to do the work and helps it to produce a mark-free surface. Always try to keep the sander flat as this will help to produce flat surfaces without any dips.
p Figure 3.78 Random orbital sander abrasive disc with puncture holes for improved dust extraction
Orbital sander
INDUSTRY TIP Connect your power tool to a portable dust extractor when possible; these extraction units are preferable to dust bags.
The orbital sander has a square or rectangular sanding area and is similar in size to the random orbital sander. The difference in how they work is in the way the sanding pad moves. On the orbital sander, the pad only vibrates in an eccentric manner and does not rotate; this can leave fine circular swirl marks on the surface finish. The abrasive paper is held in place by spring loaded clips to the front and rear of the sander. Front knob
Speed control Trigger
Dust bag Spring loaded clip
Abrasive paper
p Figure 3.79 Orbital sander
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Detail sander Detail sanders are ideal for getting into tight, hard-to-reach areas and are suitable for fine sanding. They usually have a small triangular or delta-shaped pad which incorporates the hook-and-loop method of fixing the abrasive paper. This type of sander uses an oscillating action of the sanding pad. p Figure 3.80 Detail sander
Abrasive paper The abrasive grit used with sanders is mainly aluminium oxide, a relatively cheap and hard-wearing cutting agent which is graded by its size, from very fine particles to larger coarse particles. The number of grits or particles is measured per square 25 mm. For example, P60 has 60 grit particles in every 25 mm square and P120 has 120 grit particles per 25 mm square. Therefore, P60 grade abrasive paper has fewer particles and produces a coarser finish than P120 grade abrasive paper. Coarsegrade abrasive paper is usually used for rapid surface removal in rough work, while fine grades of abrasive paper are used for finishing.
KEY TERM Oscillating: move back and forth in a consistent repeated movement.
The letter ‘P’ in front of the grit size, such as P120, indicates that the abrasive paper is manufactured according to an international standard. This means that the grades of grit are the same even if the paper comes from different manufacturers. Abrasive paper grades and the work for which they are typically used are given in Table 3.10. q Table 3.10 Abrasive paper grades and typical uses Paper grade
Uses
P60–P80
Rough working and stock removal
P100–P120
General fine working and finishing
P180–P240
Very fine finishing, generally on hardwood or materials requiring a polished finish
Abrasive papers can become clogged with the dust and resin produced through the sanding operation, particularly when sanding softwoods. This build-up on the surface of the abrasive paper may prevent effective further sanding but it does not necessarily mean that the abrasive paper needs replacing. To extend the working life of clogged abrasive papers, remove any build-up on its surface by rubbing the surface with an eraser; this cheap and effective method pulls out the dust and resin from the small gaps between the pieces of grit glued to the surface of the abrasive paper. Abrasive papers for random orbital sanders and detail sanders are pre-cut to size and shape with pre-punched holes at the required spacings for dust removal. The abrasive papers are held in place with a hook-and-loop system of fixing, allowing for quick and easy changing. Belt sanders use pre-made continuous belts of differing lengths to suit differing sander sizes. Abrasive paper for orbital sanders is available in large rollers that are cut to the required lengths for your size of sander.
KEY TERM Resin: a thick, sticky fluid contained within timber.
ACTIVITY Compare the surface finish of different grades of abrasive paper on softwood and hardwood surfaces.
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Using sanders These are some tips for producing a good surface finish using a powered sander. l l l l l
p Figure 3.81 Random orbital sanding disc with the hook-and-loop method of fixing
l l l
Keep the sander moving. Ensure that you move belt sanders quickly and move random orbital sanders slowly. Use progressively finer grades of abrasive papers to achieve the required finish. Cleaning your abrasive papers regularly can prolong their life and save you money and time. Always use suitable exhaust ventilation to collect the sanding dust and when necessary also use a suitable dust mask. Keep the sanding pad flat. Let the sander do the work. You need to apply little downward pressure to the sander. Always try to work with the grain of the material. Remember that the sander is intended to produce a fine surface finish. Larger amounts of material should be removed by a powered or hand plane.
Oscillating multi-tools The oscillating multi-tool is a versatile power tool, which uses a variety of cutting and sanding blades of differing shapes and sizes. Multi-tools work by vibrating the saw head thousands of times per minute to create a sawing motion to the blade. The versatility of the blades and the compact size of the multi-tool allows you to cut and sand different materials with just one tool. It can be used to perform accurate cuts in tight spaces that are difficult to access with traditional saws. The disadvantage of multi-tools is that the blades become blunt quite quickly, which results in a poor finish with a high degree of burnt edges to the materials. Most models incorporate a tool-free quick-change blade system. Depending on the type of accessory used, you can perform the following tasks: l l l l l l
sawing timber cutting plasterboard cutting metal plunge cuts sanding scrapping.
The multi-tool is considered by some as a ‘must-have’ tool, especially for site carpenters undertaking restoration work and installing laminate flooring and tiles. However, it can be just as valuable for new build work and general maintenance work.
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p Figure 3.82 Oscillating multi-tool with semi-circular wood cutting blade
Multi-tool Storage box
Shaped abrasive paper Half-moon saws used for cutting straight lines in timber Different-sized cutting blades suitable for plunge cuts
Sanding pad attachment
p Figure 3.83 Multi-tool and accessories
The cutting action of the multi-tool works on an oscillating action of the blade or other attachment. This oscillation produces a small sideways back and forth motion, which produces a narrow cutting stroke in the form of an arc at up to 21,000 strokes per minute.
Blades The blades are easily changed by a quick release lever. The design of the tool and blade housing allows for easy location of the blade in a 360˚ circle around the multi-tool. This versatility of blade positioning allows you to use the multi-tool to easily cut or sand in almost any working position on almost any material.
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INDUSTRY TIP Worn blades can easily generate enough smoke to activate smoke alarms.
By selecting the correct type of blade, you can use the multi-tool to cut different materials such as timber and timber-based products, plastics and metals. Abrasive blades are also available that can be used to clean out grout joints in tiling, as well as differing grades of abrasive paper for the sanding attachment. The blades are available in several different widths. Worn and blunt blades can easily burn the finished cut, produce lots of smoke and have high noise levels, so it is important that they are replaced regularly.
HEALTH AND SAFETY Worn blades produce extremely high noise levels, particularly when working in confined spaces.
Cutting edge
Multi-point location holes
p Figure 3.84 Plunge cut multi-tool blade
Typical uses for oscillating multi-tools Some of the different tasks suited to a multi-tool with the appropriate type of blade are: l l
undercutting door frames and linings cutting the bottom of door jambs to accept the flooring when laying tiles or laminate flooring around the framework, as this is the neatest and most professional method.
Blade suitable for cutting timber Use offcut of flooring to achieve an accurate cut line
p Figure 3.85 Cutting door frames and architrave to accept laminate flooring
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Chapter 3 Power tools Plunge cuts The multi-tool is designed in such a way that plunge cuts can be easily made if the correct blade is used. Plunge cuts are used in plasterboard for service requirements, in timber for notching, or for cutting through skirting boards. Figure 3.85 shows a plunge cut being made. Flush cuts in wood Using a half-moon blade enables you to make easy longer cuts in timber and timber-based products. The increased surface area of the half-moon blade helps you to maintain a straight line while cutting. Figure 3.82 shows a half-moon blade being used. Other tasks suitable for the multi-tool Other types of tasks suitable for the multi-tool include: l l l l l l l l
repairs to doors and windows sanding down timber and metal removing old ceramic tiles removing glued carpets forming notches cutting metal such as the ends of nails removing rotted wood trimming plastic piping.
Angle grinders Large heavy-duty angle grinders are not often used by carpenters and joiners, but the smaller single-handed versions are useful. Angle grinders use rotating discs to cut or grind away material and when used with the correct type of disc they can cut almost any material, including: l l l l l l
stone brickwork and masonry concrete steel plastic timber.
When fitted with a ‘flap disc’, the angle grinder becomes an aggressive type of sander. The flap discs are available in different grades of abrasion, just like the abrasive papers used with sanders. Small strong abrasive sheets are layered around a disc in a partially overlapping sequence. This construction method gives the flap disc a strong flexible cutting action, making it easy to manoeuvre and suitable for any type of sanding operation. Flap discs are particularly useful for sanding back shaped profile work, such as is needed with skirting board scribing.
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p Figure 3.86 Flap disc fitted in an angle grinder
When the angle grinder is fitted with a flap disc, it can easily be used to grind or sand back the waste material of the scribe on skirting board to the required profile finished edge. This type of cutting back was traditionally carried out using a coping saw, which can be time-consuming, particularly with complex profile edges. This type of work can now be carried out using an angle grinder fitted with a flap disc in a fraction of the time that it would take with a coping saw.
Flap disc
p Figure 3.87 Using a flap disc to undercut the scribed joint on cornice
Scanners and detectors Hand-held scanners or detectors are used to detect hidden services such as gas and water pipework, electric cabling and data and phone cables. They can also be used to detect metal and timber studwork used to construct walls and panels that are hidden from view, usually behind plasterboard. Two main types of scanners and detectors are used: l l
surface scanners to detect hidden services voltage indicator pens to check for power running through electrical cables.
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Scanners These types of detectors are generally simple to use. In some cases, the detection mode can be changed to help with identifying the type of structure discovered. The scanner is then passed over the surface of the wall and when it detects any hidden services, metal or solid timber structures it generates a warning buzzing sound.
Voltage indicator pen Voltage indicator pens are similar in size and design to pens. The voltage indicator pen is used to detect whether cables, switches and sockets are live and have power flowing through them by holding it against them. When power is present, the detector will light up and, in some cases, also give out an audible buzz. This type of detector should only be used to give information on where power is located and not be used to adjust any electrical work.
p Figure 3.88 Surface scanning for hidden services
HEALTH AND SAFETY
p Figure 3.89 Voltage pen being used to check if power is present at the socket
Do not make any adjustment or interfere with any electrical work. Always use a qualified person to make the required adjustments.
Avoiding service runs Any wiring should run vertically from sockets and switches behind the face covering such as plasterwork. This helps with locating the cabling and ensures that fixings do not accidently contact the wiring. Wiring may often be found in a ring for sockets, particularly in kitchens, so you should always check for this, particularly in older properties. Pipework for water or gas should also run in vertical and horizontal directions. Always try to avoid drilling or positioning fixings near any service runs. Where this is unavoidable, or if you are in any doubt, carefully break away a small amount of the surface covering in the intended location until the substructure, such as the brickwork or blockwork, is visible. If there is no sign of any services, it is a good indication that it is safe to drill. Where services are visible, it may be possible to move them out of the way slightly to allow for drilling. When this is not possible, you will need to find an alternative location for the fixing. When you need to locate studwork, for example to use as a secure fixing point, using a surface scanner is a simple and accurate way of finding the stud’s location.
INDUSTRY TIP Whenever possible, always try to position your fixing into a solid background such as studwork or masonry, which give superior fixing backgrounds, rather than directly fixing into plasterboard. 171
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5 TRANSPORTING, STORING AND MAINTAINING POWER TOOLS Power tools are most likely to be damaged when they are being transported. You must take care to ensure that your power tools are securely stored in transit to avoid damage from other tools, equipment or materials. Most power tools are now supplied in purpose-made storage boxes, which in most cases can be easily connected to storage containers from the same manufacturer. Several types of wheeled tool trolleys and chests are available to further help with transporting power tools. Some owners of work vans prefer to have dedicated shelving and storage slots for their tools. This allows for quick and easy access to the power tools but can leave them open to damage, particularly if they include any trailing leads, guards and cutting edges such as saw blades. This type of storage system also makes it difficult to transport the power tool to and from the location that it is required. Correctly cleaning, maintaining and storing your power tools in their correct storage boxes as well as storing them securely, whether in vans or workshops, will save money and time in the long term. Correct safe storage also ensures that when required the power tool is in good condition and ready to use. Power tools require little maintenance other than visual safety inspection before each use and regular PAT tests. Always follow the manufacturer’s advice on the type of maintenance required and its frequency to prolong the power tool’s life and to ensure that it remains safe to use and is readily available when required.
HEALTH AND SAFETY Remember that a blunt, or damaged power tool is a dangerous power tool.
Tooling used by the power tools will require regular maintenance, such as sharpening dull and blunt saw blades and drill bits. Where disposable cutters are used, as with most planers and router cutters, this tooling should be replaced as soon as it shows signs of damage or difficulty in cutting the material easily, such as if the tool causes burning, generates large amounts of smoke, produces poor finishes or is generally difficult to control safely.
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Practical task Cut out and mould a table top You are required to cut out a section of 18 mm MDF to finish 400 mm × 300 mm and form a moulding around its edge, using a portable router and a bearing guided router cutter. Candidate information Before starting each task, ensure that you have been given permission by your tutor or trainer to proceed. As each task is completed, you should be given feedback on the completed task and any retraining as required. Always work according to a risk assessment and environmental and health and safety regulations. Task instructions You are required to: l
mark out a rectangle of 400 mm × 300 m on a sheet of 18 mm MDF
l
set up and use a plunge saw and guide rail system to cut the MDF to the specified sizes
l
fit the supplied router cutter into the router and set the router up to form a moulding around the top outer edge of the MDF
l
form the moulding around the top edge of the table top.
Equipment required l
Completed risk assessment for fitting butt hinges
l
Selection of appropriate and inappropriate PPE for the task
l
1 piece of 18 mm MDF large enough to safely cut out the required size table top
l
Mobile dust extraction system
l
Plunge saw and guide rail system
l
Bearing guided router cutter to form moulding around table top
l
Router with a selection of different-sized collets
l Clamps
Task
Achieved
Requires retraining
Work to a given risk assessment and select the required PPE for the outlined task. Correctly mark out MDF to given sizes. Correctly set up guide rails. Correct use of plunge saw to cut MDF to required sizes without burning during the cut. Correct fitting of router cutter and setting up of router to produce required moulding. Correct profiling of MDF without burn marks or undue bumpy surface.
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Achieved
Requires retraining
Correct use of PPE and mobile dust extraction. All work carried out in accordance with current health and safety regulations and safe working practices. Work area left clean and tidy with all tools and equipment correctly stored away safely.
Activity successfully achieved
Further training required detailed here
Practical task Produce a shelf with decorative moulding You are required to produce a shelf that has a decorative moulding along both ends and the front edge. Equipment required l
Completed risk assessment for using required portable power tools
l
Selection of appropriate and inappropriate PPE for the task
l
Sliding mitre saw and saw stand
l
Plunge saw and guide rails
l
Portable router and a selection of profile cutters
l
Portable sander and a selection of graded abrasive sanding sheets
l
A length of planed softwood 20 mm thick × 194 mm wide × 1000 mm long
l
Selection of suitable clamps to be used to hold the material as required
Candidate information Before starting each task, ensure that you have been given permission by your tutor or trainer to proceed. As each task is completed, you should be given feedback on the completed task and any retraining as required. You are required to trim the given length of planed timber using a sliding mitre saw to a finished length of 950 mm. Using a plunge saw and guide rail system, you are required to rip the timber to finish 180 mm wide. You are required to set up a portable router with a suitable bearing guided profile cutter to produce a decorative profile along one edge and both ends. 174
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Chapter 3 Power tools Using an orbital sander, you are to produce a suitable finish to accept a clear varnish finish. Task
Achieved
Requires retraining
Safely work to a given risk assessment. Correct selection of suitable and appropriate PPE for the outlined tasks. Correct set up and use of the sliding mitre saw to trim both ends of the material square and to finish 950 mm long. Correct set up and use of the plunge saw and guide rails to produce a parallel cut and a finished width of 180 mm. Correct set up and use of portable router to produce a suitable decorative finish along one edge and both ends. Correct use of orbital sander and selection of abrasive paper to produce required surface finish to material. All work carried out in accordance with current health and safety regulations and safe working practices. Work area left clean and tidy with all tools and equipment correctly and safely stored away.
Activity successfully achieved
Further training required detailed here
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Test your knowledge 1 On what type of power tool would you find an SDS chuck?
7 Which type of saw is most suitable for cutting material to length?
a Impact driver
a Jigsaw
b Pillar drill
b Plunge saw
c Hammer drill
c Sliding mitre saw
d Oscillating drill
d Table ripsaw
2 TCT are used for saw tips because they are: a hard-wearing
8 On which type of power tool would you find a collet?
b cheap and easy to install
a Router
c easy to sharpen by hand
b Plunge saw
d hard and indestructible.
c Sliding compound saw
3 A PAT test label gives what information on a power tool? a Type of use that it is suitable for
d Sander 9 On which type of saw would you use a negative tooth profile saw blade?
b Type of power supply required
a Plunge saw
c Date of purchase
b Oscillating multi-tool
d Date of inspection
c Sliding compound saw
4 Which of the following power sources is the recommended voltage for use on site? a 10 V
d Jigsaw 10 Which of the following grades of abrasive paper produces the finer results?
b 110 V
a P60
c 240 V
b P80
d 415 V
c P100
5 Which of these do mobile LEV or extraction units help to reduce? a Noise b Offcuts c Small dust particles d Manual handling 6 On which type of power tool would you find a riving knife? a Router b Plunge saw c Jigsaw d Domino jointer
d P120 11 Describe the main differences between a plunge saw and a sliding mitre saw. 12 List the main differences between a domino jointer and a biscuit jointer. 13 List the five most important portable power tools you would require in your tool kit and why. 14 Research purchase prices for the power tools selected in your answer to question 13 and produce an invoice, detailing the purchase price before VAT and including VAT, that could be forwarded to your employer or included in your self-assessment claim for tax relief. 15 Design a toolbox safety poster that can be used for hammer drill training.
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CHAPTER 4
PRODUCE WOODWORKING JOINTS
INTRODUCTION Carpenters and joiners form woodworking joints as part of their work every day. Whether building a roof or constructing a staircase, you must have the knowledge and skills required to design and form strong joints to suit the task in hand. The continued development of new power tools and machinery mean that some of the processes used to form woodworking joints have evolved to make them more efficient; however, you still need to have the basic knowledge of how to form woodworking joints. This chapter looks at the selection of suitable timber for use, setting out, marking out and forming woodworking joints for a frame and loft hatch. You will also learn how to mark out, cut and fix architraves and skirtings.
LEARNING OUTCOMES In this chapter, you will learn how to: 1 select and store materials used to produce woodworking joints 2 select and use hand tools to produce woodworking joints 3 identify the resources required to mark out woodworking joints 4 mark out woodworking joints
5 select and use hand tools and materials to produce basic woodworking joints 6 understand how to manufacture a frame using woodworking joints 7 form a frame using woodworking joints 8 construct and fix hatch linings 9 cut and fix skirtings and architraves.
1 SELECT AND STORE MATERIALS USED TO PRODUCE WOODWORKING JOINTS Timber is a natural resource used for many construction purposes. The shape, size and species of each tree determines many features of the resource, including the colour of the wood, the pattern of the grain and its workability. Timbers that are used for structural purposes, such as roof rafters and floor joists, need to have relatively straight grain to maintain their shape and strength under the loads imposed on them. When using timber for joinery purposes, you may select it for its decorative qualities and its durability. No two pieces of timber are the same, so your ability to select the right materials can be the difference between a good job that will last for many years and substandard work. Timbers that are less durable should be treated with preservatives to prevent them from rotting. Your timber merchant can advise you on the most suitable timbers
KEY TERMS Workability: how easy or difficult the timber is to plane, saw, machine and finish. Durability: how hard and resistant something is. Some timbers are more resistant to the weather than others because of their natural oils and resins and are therefore more suitable for exterior work.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma for internal and external joinery and construction work. Timber suppliers classify the durability of timber according to how long it will last when fully exposed to the elements before it starts to decay, as shown in Table 4.1. q Table 4.1 Durability of timber
KEY TERMS Converted: sawing along the grain of a tree trunk to produce sawn boards of timber. Felling: cutting down a tree. Softwood: a category of timber that comes from coniferous trees, such as pine. Hardwood: a category of timber that comes from deciduous trees, such as oak.
ACTIVITY Use the internet to research the methods used to convert timber in a sawmill. There may be videos of the process.
Number of years left exposed to elements before the decay is obvious
Classification for durability of timber
0–5 years
Perishable
5–10 years
Non-durable
10–15 years
Moderately durable
15–25 years
Durable
25+ years
Exceptionally durable
Methods of timber conversion When you purchase materials from a timber supplier or a builder’s merchant, timber has usually been sawn and sometimes machined into a range of standard sections. Before the timber reaches the supplier, it is converted and dried to a suitable moisture content. This process begins with felling the trees in the forests where they have grown, using motorised machines known as harvesters. The trees are cut down when they are established enough to convert them into usable planks or beams. Mature trees are usually selected when they are between 40 and 150 years old, depending on the type of tree. Softwoods like spruce, fir and pine are fast-growing trees. They are frequently used in the construction industry, compared with more expensive and less sustainable slow-grown hardwoods. The branches of trees are usually stripped by the harvesters, leaving the trunks to be cut to length and transported to the sawmill. At the sawmill, the bark is stripped from the trunks (this is called debarking) and used for other purposes, such as making timber-based sheet materials, for example orientated strand board (OSB). The trunks are then sawn into sections along their length. When the cut sections are moved through the processing mill, they are assessed visually for quality and condition and then scanned by machine for size and strength. Softwood timbers are awarded one of the following commercial grades depending on their country of origin; firsts or grade 1 are the premium (best quality) grade. l
Russian softwoods: l unsorted grade (a mixture of grades 1 to 3) l fourth grade (standard grade) l fifth grade (contract grade). l Scandinavian softwoods: l unsorted grade (grades 1 to 4) l fifth grade (standard grade) l sixth grade (contract grade). Sixth grade timber is the lowest quality. The grain of sixth grade timber is not always straight and is usually full of large knots and other defects. This grade of timber may be used for cladding and some furniture manufacturing. It is also used for disposable pallets and packaging material. 178
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Chapter 4 Produce woodworking joints The way that a trunk is converted in a sawmill determines the angle of the growth rings on the ends of the timber and the direction of the grain on the faces. It is also an important factor with regards to its strength and stability. Figure 4.1 shows how a piece of timber shrinks as it dries and distorts after it has been cut from the trunk. Shrinkage greatest along the growth rings
Shrinkage least across the growth rings
Diamonding
A B Little shrinkage along length
Cupping
p Figure 4.1 A section through a tree trunk
The pieces of timber with grain at an angle of 45° or less tend to shrink away from the centre of the tree, resulting in cupping of the boards. This type of cut is referred to as tangential. Timber that has been sawn with grain above 45° is known as radial cut or quarter sawn. When the moist timber is cut from the trunk, it will naturally start to dry until an equilibrium moisture content is reached.
Strengths and weaknesses of timber conversion methods The simplest and most cost-effective way to convert timber is to use a method known as through and through (also known as ‘slab’ or ‘flat’ sawing). Although there is no waste with this method of conversion, the boards on either side of the centre of the trunk are prone to shrinkage and distortion.
KEY TERMS Growth (or annular) rings: produced every year that a tree grows, therefore increasing its size. Trees generally grow more in spring and summer than they do in the colder winter months. The amount of growth that has taken place during these seasons can be seen on the end grain: the lighter rings are produced in the summer and the darker rings in the autumn and winter. Cupping: the curling (distortion) of timber away from the centre of the tree. Equilibrium moisture content: the point at which the moisture contained within the timber is equal to the environment it is in. Timber with a high moisture content in a dry setting, for example a heated room, will rapidly dry out and shrink to reveal gaps in the joints of connecting timbers.
Quarter sawn timber is the best quality because it produces mostly radial cut boards, but a lot of waste material is created to achieve this. This method of conversion is also the most expensive, not only because of the wasted material, but also owing to the additional production time it takes to rotate the trunk to make radial cuts. Radial cut timber is less likely to distort than tangential cut timber and is therefore ideally suited to using for superior joinery purposes. Although radial cut boards are not as strong as tangential boards, they are harder wearing, making them ideal for flooring.
p Figure 4.2 Through and through sawn
p Figure 4.3 Quarter sawn
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Tangential cut timber is the strongest and is preferred for load-bearing joists and structural beams. The low angle of the grain on the ends of the boards produces an attractive ‘flame figuring’ grain on the faces, as shown in Figure 4.7.
INDUSTRY TIP
p Figure 4.4 Tangential sawn
You should always alternate the pattern of the end grain on tangential boards when you are joining them together. Doing so will even out any cupping that occurs and result in a more stable board.
Figure 4.6 A section through the end of multiple timber boards being jointed together p Figure 4.5 Boxed heart sawn
If a tree has a rotten core or is badly split (referred to as ‘shaken’), then the trunk is still used by cutting around the damaged timber to produce radial cut boards. This method of timber conversion is referred to as boxed heart.
p Figure 4.7 Flame figuring
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ACTIVITY Which one of the following timbers is radial cut and which one is tangential?
a
b
Methods of seasoning timber Trees naturally take in carbon dioxide and produce oxygen. Sunlight and water are also needed to produce food for them to grow through a process known as ‘photosynthesis’. After the trunk has been converted, it needs to be seasoned to reduce the moisture content to below 20%, otherwise dry rot is likely to occur if the moisture content is above this threshold. Timber that has not been dried is referred to as green and it can be easier to work with in some situations. A good example of this is green oak, a timber commonly used to build timber-framed houses. The higher moisture content in the wood makes it softer and easier to cut the joints in the frame. As the oak dries out and becomes harder, it shrinks; this can lead to surface shakes, a character that is often considered attractive. Timber that has been converted for external construction work does not need to be seasoned, because it is exposed to the elements and will naturally acclimatise. Timber used for internal carpentry and joinery purposes is dried to make it lighter and easier to machine and to reduce the amount of shrinkage after it has been installed. Seasoned timber also provides a much better surface for finishes to adhere (stick) to, such as paints and stains. Table 4.2 gives the range of moisture contents of timber used for different purposes. q Table 4.2 Moisture content of timber used for different purposes Timber uses
Moisture content
Timbers used for structural applications, such as studwork for partition walls, floor joists and roof battens
20% moisture content or less; in line with Building Regulations
External joinery, such as windows and doors
15–18% moisture content
Most timbers used for internal work
10–15% moisture content
Timber that is to be used close to a heat source or in situations that are continuously centrally heated
8–10% moisture content
KEY TERMS Seasoning: a process of drying timber to reduce its moisture content. Dry rot: a type of fungus found in timber that causes it to decay. Shakes: natural splits that occur in timber.
INDUSTRY TIP The moisture content of wood can be checked with a moisture meter. The two metal electrodes on the device are simply pressed into the face of the timber to measure the resistance between them. The more moisture that is present in the timber, the easier it will be for electricity to flow between the electrodes and therefore a higher reading will be registered on the meter.
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KEY TERM Piling sticks: lengths of thin batten used to create a space between stored timber layers to allow air to flow between the boards. Stacking timber for a long period without the use of piling sticks may result in an increase in the moisture content in the centre of a pack.
Timber can be seasoned in one of three ways: l
air dried kiln dried l microwave vacuum seasoning. l
Air-dried timber is usually stacked up in open-sided sheds like the one shown in Figure 4.9, with piling sticks placed between each board to allow air to flow between the timbers so that they can dry naturally. Timber dried using this method is more stable and less likely to develop seasoning defects such as shakes, splitting and twisting. The disadvantage of this method of seasoning is that it can take months and sometimes years to achieve the desired moisture content, depending on the thickness of the material and the species of wood. Covered roof
Piling sticks Large boards at bottom of stack
Joists
Brick piers
p Figure 4.8 Moisture meter
p Figure 4.9 Air drying timber with the use of piling sticks
The quickest and most efficient method of seasoning timber is to use a temperature-controlled kiln, which is a large oven. The timber is wheeled into the kiln on trolleys. Heat is then introduced into the kiln to dry the timber, which creates moist hot air that circulates out through a ventilation system. Timber can be seasoned in a kiln within a couple of days, depending on the sections and type of timber. The disadvantage of using this method to dry timber is that it may cause seasoning defects such as case hardening. This occurs when timber is dried too quickly, leading to the surfaces of the wood drying to encase the high moisture content in the centre of the timber. This produces timber that can be difficult to work with and cut.
IMPROVE YOUR MATHS A piece of timber has a moisture content of 48% before seasoning and it needs to be reduced to 15% to use for some internal joinery work. It takes 3 days to season the timber in a kiln. On average, how much moisture will be lost per day?
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KEY TERMS
p Figure 4.10 Kiln seasoning
Microwave vacuum seasoning is a relatively new technique used to dry timber in hydraulic pressure-drying tanks within hours, rather than days or weeks. The system works in a similar way to a domestic microwave, by heating the inside and outside of the timber at the same time to evaporate the moisture in the timber, unlike air and kiln seasoning, which dry from the outside inwards. Seasoning defects are less likely to occur using this method compared to others because of the rapid drying process.
Storing and protecting woodworking materials When natural timber gets wet it absorbs moisture and swells, whereas in a dry environment it loses moisture and shrinks. The amount of movement in timber will depend on several factors, such as the species of timber and the environment it is in. If the moisture content of the timber being used is not equal to the humidity in the air, it will either shrink and cause gaps between any joints or swell and distort the wood. Whenever possible, timber that is to be used for internal work should be unwrapped and stored flat on bearers with piling sticks in between in the room that it is to be used in for several weeks prior to fixing. This allows the timber to achieve an equilibrium moisture content (referred to as second seasoning) and minimises the amount of movement in the wood after it has been installed. Timber or timber-based sheet materials delivered for use in a joinery workshop should be stored in a designated rack, under cover and not exposed to the weather or any damage that could occur on a construction site. Timber that is to be used for structural applications on a construction site may have to be stored outdoors. It should also be adequately supported with bearers and placed under a waterproof cover or shelter to protect it from the weather. Timber that has not been stored correctly could become saturated with (full of) water, which means it becomes stained, heavy and difficult to cut. Care should be taken to protect decorative timbers and sheet materials from the direct sunlight, as this can cause bleaching of the timber. A well-planned construction site will have a designated storage area for timber that is close to where it will be needed and is secure to prevent theft.
Bearers: lengths of timber positioned on the ground at equal spacings so that timber can be stored on them off the ground. They are used to prevent the timber absorbing moisture from the ground, which may cause warping, twisting and other defects. Bleaching: a change in the natural colour in a solid timber or timberbased material caused by the exposure to UV light, such as in sunlight.
p Figure 4.11 Timber with ‘blue staining’ as a result of poor storage and fungus growth
p Figure 4.12 Bleaching
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Characteristics of different woodworking materials Hardwood and softwood trees are vastly different in the way they grow and look. Hardwood comes from deciduous trees, which have broad leaves that drop in the winter months. Softwood comes from coniferous trees, also known as evergreen trees, which have needle-like leaves that remain on the trees all year round. The cell structure of hardwoods and softwoods is also different, which helps to determine the properties of the timber.
Spruce: softwood (coniferous)
Oak: hardwood (deciduous)
p Figure 4.13 Examples of hardwood and softwood trees
See Table 4.3 for examples of commonly used softwoods and Table 4.4 for examples of commonly used hardwoods. q Table 4.3 Examples of some commonly used softwoods Softwood
Origin
Description
Cedar
Canada, Algeria, Morocco, Middle East, Northern India and the UK
Light brown in colour, with a soft grain which makes it exceptionally durable and easy to work. Natural oils in the timber make it resistant to weather. Used for cladding, shingles and weather boarding.
Douglas fir
North America, Europe and the UK
Reddish brown in colour with prominent growth rings. A moderately durable and strong timber, used for general joinery, such as windows and doors. Also used for structural timbers when it is still green (unseasoned).
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Chapter 4 Produce woodworking joints Softwood
Origin
Description
European redwood
Sweden, Finland and Russia
Cream with light brown grain. Slow-grown timber, ideal for machining and joinery. Suitable for both internal and external uses.
Yellow pine
The USA and Canada
Yellow/orange in colour, with open grain. A moderately durable and strong timber, used for general joinery, such as window boards and stairs.
Whitewood
Norway, the UK, Ireland, the USA and Canada
Cream white in colour. A fast-grown softwood. Often used for studwork, joists and rafters. Also used for some joinery purposes, such as stairs. Non-durable (internal use only).
q Table 4.4 Examples of some commonly used hardwoods Hardwood
Origin
Description
Ash
The USA, Europe, North Africa and Western Asia
Creamy white to light brown heartwood, with lighter sapwood. Straight-grained with a medium texture. Non-durable. Good for bending. Used for high-class internal joinery, cabinet making and sports equipment.
Beech (steamed)
Europe and the UK
Available either steamed or unsteamed. It is white to biscuit brown when unsteamed, or slightly pinker when steamed. Both have straight grain with a fine even texture. Used for furniture, internal joinery and musical instruments. Non-durable.
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Origin
Description
Maple
Canada and the eastern USA
Creamy to off-white in colour. Hard, heavy and strong. Uniformed texture with a close grain. Used for flooring, furniture, shop fitting and worktops.
Oak
The USA, Europe, the UK, Asia and North Africa
Tan to biscuit brown in colour. Moderately durable and machines and glues well. Quarter sawn boards are the most desirable due to their unique grain. Used for flooring, skirtings and architraves, high-class internal and external joinery.
Sapele
Ivory Coast, Ghana, Nigeria, Cameroon, Uganda and Tanzania
Reddish brown in colour, straight grain with a fine texture. Moderately durable. Used for internal and external joinery and boat building.
KEY TERM Steamed: a process timber goes through after it has been converted but before it is seasoned that changes its colour.
ACTIVITY Use the following link for further information on a range of different woods: www.trada.co.uk/woodspecies/ Make a list of six hardwoods and softwoods, then indicate which ones are suitable for external carpentry and joinery work.
INDUSTRY TIP Although some timbers are suitable for exterior use, they may still need to be treated with preservative to prevent them from rotting. Preservative can be applied with a brush, sprayed on or dipped. Pressure treating is the best method to use. Most timber suppliers have a stock of carcassing timber that has already been pressure treated; such timbers are referred to as tanalised. Figure 4.14 shows a section through a tree and its different layers, which consist of: ● ● ● ● ● ●
pith: the centre of the tree heartwood: the mature part of the tree that no longer grows sapwood: the living part of the tree that transports water and minerals up from the roots to the crown (top) of the tree annular or growth rings: the part of the tree that has grown in the colder months cambium: the layer of the trunk that produces new bark and wood each year phloem (bast): the inner bark of the trunk that transports sugars and nutrients from the leaves to other parts of the tree.
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Chapter 4 Produce woodworking joints Cambium Annular rings
Cork
Phloem (bast)
Outer bark Pith Cork cambium
Inner bark Sap wood
Secondary phloem Vascular cambium
Bark Secondary xylem Heartwood
p Figure 4.14 A section through the trunk of a tree
p Figure 4.15 Cell structure of a trunk
Timber sizes The most common sizes of sawn hardwoods range from 100 to 550 mm wide and between 2 metres and 4.9 metres in length, depending on the species of timber. They come in a range of thicknesses including 26, 32, 38, 51, 65, 76 and 100 mm. Softwoods range from 100 to 275 mm in width and from 1.8 to 7.2 metres in length in increments of 300 mm. They also come in a range of thicknesses including 19, 25, 38, 50, 63, 75 and 100 mm. When sawn timber is machined flat, square and smooth, it is usually reduced in size by 5 to 6 mm in thickness and width. Timber that has been planed with a face side and edge is referred to as PSE (planed square edged), although this term has also been adopted for timber that has been planed on all four sides. Timber that has been planed on all four sides should be referred to as PAR (planned all round). Most timbers used for structural and carcassing work are planed smooth on all four sides and have rounded corners, so they are uniform in thickness and better to handle. This timber is referred to CLS (Canadian Lumber Stock, because of the country it originated in). However, it is now widely produced in Europe and the UK. CLS sizes widely used in the UK are: ●
●
●
38 × 63 mm 38 × 89 mm ● 38 × 140 mm
●
38 × 184 mm 38 × 235 mm ● 38 × 285 mm.
Stress grading Floor joists, rafters and partition walls are examples of structural timbers that support loads in a building. The timber used for these tasks must be structural grade quality, without large spits, knots or other defects. Timber can either be graded visually by a trained inspector or more efficiently by a machine. 187
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Hardwoods are graded with a ‘D’ followed by a number to determine the strength of the timber; a higher number denotes stronger wood. Softwoods are graded with ‘C’ marks. The most used grades are C16 and C32.
Common defects found in timber Table 4.5 illustrates the most common defects in timber, which may be naturally occurring, seasoning or handling defects, and their causes. q Table 4.5 Most common defects in timber and their causes Natural defects
Cause
Live knots (splayed, arris and face knots)
Naturally occurring points of the trunk, where the branches would have grown before conversion.
Dead knots
Branches of the tree that become damaged or removed during the tree’s growth still draw sap to that area before it dries out, causing dead knots. The dry sap around the dead knots can cause them to become loose and fall out after the timber has been converted.
Cup shakes
The annular rings can become separated by excessive bending of the tree in high winds and develop defects known as cup shakes.
Grain lifted
Sap ducts/pockets
These are growth defects that usually develop in timbers with high resin content, such as pine. Once the timber has been converted, the sticky resin bleeds (leaks) from the sap ducts.
Waney edge
The edges of a timber board still containing bark that show the naturally occurring shape of the trunk.
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Chapter 4 Produce woodworking joints Natural defects
Cause
Heart shake
A heart shake is a single split or crack that passes through the pith and the heartwood of a tree. It can be caused by poor seasoning or decay.
Star shake
Star shakes are three or more heart shakes that radiate from the centre of the tree. They are also caused by poor seasoning or using a tree past its maturity.
Sapwood
Sapwood is the newly formed outer layers of tree growth that carry the enriched sap to the crown.
KEY TERM Sapwood
Blue stain
Crown: the top section of a tree containing the branches. Blue stain is a fungus that causes a bluish grey discolouration to the sapwood of timber. Although it is a type of fungi, it does not decay the timber or weaken it.
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Cause
Pith
The pith is the very centre of the tree. It is sometimes slightly softer than the heartwood and darker in colour.
Sloping grain
Timber that contains a grain that runs towards the edges of a board is caused either by the way that the trunk has been converted or by the natural shape of the tree. Timber containing sloping grain can be more difficult to plane with hand tools and is weaker than timber with straight grain.
Insect infestation (woodworm)
Woodworm is a term used to describe any wood-boring larva. There are four main types of woodworm: • common furniture beetle • death watch beetle (pictured) • house longhorn beetle • powder post beetle. The female adult beetles lay their eggs on the surface of the timber, which hatch larvae (grubs) that burrow into the wood. The larvae pupate and the adult beetle emerges from the timber, leaving exit holes on the surface.
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Chapter 4 Produce woodworking joints Seasoning defects
Cause
Twisting
Poor stacking of the timber during seasoning can cause the timber to wind or twist. Once the board has developed this defect, it cannot be corrected.
Cupping
The timber has curled away from the centre of the trunk along its length due to tangential cutting during conversion. (See page 180.)
Springing
A curve along the length of a piece of timber, while the face of the board remains straight/flat.
Bowing
Bowing is similar to springing; however, in bowing, the defect is on the face of the board and not the edge.
Case hardening
Poor seasoning can result in the outer surfaces of the timber drying too quickly and causing moisture to get trapped in the core.
Dry outside
Wet inside
Splits/checks
These can sometimes develop in the ends of timber boards when they have lost moisture.
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Cause
Fungal attack
Dry rot is a fungus that attacks the timber when the moisture content is above 20%. Dry rot can also spread to other timbers via strands and particles that become airborne to continue the decay. Timber that contains dry rot often has a mushroom-like fungus and white strands that grow on it; it also has a distinct musty smell.
Collapse
Also referred to as wash boarding, this occurs when the timber is kiln-dried too quickly during seasoning.
Handling defects
Cause
Thunder shake
A hairline fracture of the timber, across the grain that is sometimes referred to as ‘upset’. This is caused when a tree has been poorly felled. The impact of the trunk hitting the ground first, end on, causes the grain to distort.
Damage caused in transit
Materials and finished timber products that are not properly supported and tied down during transit can be damaged.
Defects occurring during manufacturing
Many types of defects may occur during the manufacturing process, some of which may be caused by inaccurate machining or be the result of a poor selection of quality timber.
Foreign bodies
Large metal staples are sometimes knocked into the ends of timber boards to bridge any splits and prevent them from opening further. Timber suppliers also attach labels to the surface of timber with staples, so that it can easily be identified. It is also possible that grit and small stones can be embedded into the surface of timber if it is placed directly on the ground when delivered. Most foreign bodies can be found and removed when they are visually checked before use. It is advisable to use a metal detector to check recycled timber for old nails and screws. Foreign bodies can cause damage to your tools and equipment. They also have the potential to be hazardous if they become dislodged when the timber is machined.
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2 SELECT AND USE HAND TOOLS TO PRODUCE WOODWORKING JOINTS Hand tools used to set out, mark out and produce woodworking joints are identified throughout this chapter at the relevant stages. Further information on carpentry and joinery hand tools and holding devices is given in Chapter 2.
Common faults with woodworking hand tools Woodworking hand tools must be regularly inspected and maintained to keep them in good condition and to reduce the likelihood of an accident occurring when you are using them. Employers have a legal responsibility to make sure that all tools provided are in good condition and do not deteriorate. (See Chapter 6.) Employees are responsible for reporting any defective tools and equipment they find to their supervisors. If any faults are identified with a tool that cannot be put right, then it must be clearly labelled ‘out of action’ and not used. Carpenters and joiners must be trained to check the condition of hand tools and do this each time before using them, so they can identify and possibly repair any minor faults found. Tools and equipment that cut or plane timber will lose their sharp cutting edges over time, so this type of maintenance is routine. Employers should keep up-to-date records of all the maintenance carried out to the tools and equipment they provide. If an accident occurs in the workplace that must be reported under the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations (RIDDOR), the Health and Safety Executive (HSE) will investigate the cause and may look at these records. Further information about the role of the HSE and RIDDOR regulations is provided in more detail in Chapter 6. Common faults found in hand tools and how to fix them are given in Table 4.6.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma q Table 4.6 Common faults found in hand tools and how to rectify them Hand tools
Fault
Remedy
Chisels
Blunt
Resharpen the chisel.
Chipped edge
Remove the damaged edge with a bench grinder. The chisel will also have to be resharpened. (Remember to always wear impact-resistant goggles while using a bench grinder.)
Over sharpened
Remove the damaged edge with a bench grinder. The chisel will also have to be resharpened.
The handle is split (common fault with wooden handles)
Wooden handles often split if they are struck with a hammer, rather than a mallet. Take the chisel out of action and replace it.
Bent along its length
If a chisel is bent, it is likely to have a weakness in its neck (the joint between the blade and handle). Any attempt to straighten the chisel will most likely weaken the chisel further, so it should be replaced.
Split head on a timber mallet
Replace the head of the mallet or the entire tool.
Damage to the face of the head though overuse, making it difficult to strike things squarely
Recut the face of the mallet so that it is flat again. If the strength is compromised by reducing the size of the head, then the mallet should be replaced.
The set has been lost on the teeth, causing the blade to jam in the saw cut (kerf).
The saw should be reset and sharpened if possible. It the saw has hardpoint teeth it should be disposed of and replaced.
The teeth have lost their sharpness, making it difficult to cut.
Resharpen the saw if possible; if not it should be disposed of and replaced.
The face of the hammer is dirty, making it difficult to strike nails cleanly without bending them.
Rub the face of the hammer flat on a piece of abrasive paper to sand it flat and remove the dirt.
The head of the hammer is loose.
This is a common fault with hammers that have wooden shafts (handles). There is a risk of the head of the hammer coming completely off the shaft while in use, so it should either be disposed of and replaced or have a new handle fitted and secured with a wedge.
The plane iron is blunt.
Resharpen the plane iron.
The plane keeps clogging up with shavings.
The cap iron is either set too far back from the front edge of the plane iron or it is not sitting flat on the plane iron. Adjust the cap iron so that it is 0.5–1.5 mm back from the front edge of the plane iron. If that does not work, then the underside of the cap iron may have to be filed flat so there are no gaps between the two components when they are screwed together.
There is a chip in the plane iron, resulting in a poor finish to the work piece.
The plane iron must be reground at 25° (the grinding angle) and sharpened on a sharpening stone at 30° (the honing angle).
The plane is removing more materials on one side of the timber than the other.
The plane iron must be adjusted with the lever on the plane, so that it projects evenly below the sole of the plane.
There are gouge lines in the surface of the timber where the plane has been used.
This can be the result of the plane removing too much material when in use or the cutting edge of the plane iron not being shaped correctly. Wind the plane iron back to reduce the amount of material being removed and reshape the sharpening stone.
Mallets
Handsaws
Hammers
Planes
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Chapter 4 Produce woodworking joints Hand tools
Fault
Remedy
The plane does not remove any shavings when in use.
Wind the plane iron out using the depth adjustment wheel until a fine shaving is being removed from the surface of the timber when in use.
There is surface rust on the body of the plane.
Remove the surface rust with some fine wire wool or abrasive paper. Wipe over the body of the plane with a lightly oiled rag.
The cutting edge has lost its sharpness, making it difficult to use and resulting in a poorquality finish.
Twist drill bits can be resharpened on a bench grinder. Auger bits can also be resharpened, but you need to use a small triangular file to sharpen the cutting edges.
The drill bit is wobbling when turning.
The drill bit may not be positioned centrally in the chuck of the power drill, so it should be removed and reinserted in the correct position. The drill bit could also be bent; if so, then it should be disposed of and a replacement used.
Break out (spelching) on the back face.
Clamp a piece of waste timber to the back of the workpiece before boring a hole through the timber. Alternatively, bore a hole to the centre of the workpiece or until the point starts to protrude through the back face (depending on the type of drill bit being used), then complete the hole by drilling from the opposite side.
Squares
The square has been damaged and it is no longer 90°.
Some squares can be trued (recalibrated) back to 90°. If this is not possible then the square should be replaced.
Screwdrivers
The screwdriver is bent along its length.
Dispose of the screwdriver and replace it.
The handle is beginning to split.
Do not use the screwdriver when in this condition as the handle is likely to break off the main shaft and this may result in an accident. Dispose of the screwdriver and replace it.
The head of the screwdriver is damaged and no longer fits properly into the screw heads.
Slotted screwdrivers can be repaired in a bench grinder; any other types should be replaced.
The pin(s) on the mortice, marking or combination gauge no longer have a sharp point on them.
Use a small needle file to resharpen the pins to a point.
The pins on the mortice gauge are different heights.
File the top of the highest pin until they are both the same height, then resharpen the pin.
The cutting gauge is ripping up the grain of the timber.
Remove the brass wedge holding the cutter in position. Resharpen the cutter and replace it in its original position, with the wedge holding it securely.
The stock of the gauge wobbles on the stem when locked into position.
The stem may have worn through use. Remove the old stem and replace with a new one. If a replacement cannot be found, then the whole gauge should be replaced because you will no longer be able to use it accurately.
The figures on the tape measure are difficult to read, especially the first metre where it has been mostly used.
Once the markings on the tape become difficult to read, it should be replaced, otherwise it could lead to mistakes.
The ‘hook’ on the end of the tape moves more than its thickness.
This can be caused by the tape being quickly retracted into the body of the tape measure, allowing the hook to stop abruptly against the casing. This fault will result in inaccurate readings being taken from the tape measure; therefore, it should be replaced.
The ‘hook’ is bent.
The hook can be straightened out by placing it over a metal worker’s vice, or something similar, and lightly striking it with a hammer back to its original position.
The tape measure has bent, leaving a crease.
The crease would create a weakness in the tape that could break if it continues to be used. It will also prevent accurate readings from being taken from the tape measure, therefore it should be disposed of and replaced.
The tape does not recoil properly when fully extended.
The spring mechanism has most likely broken. If the spring can’t be repaired or replaced, the whole tape measure will have to be disposed of and replaced with a new one.
Wood-boring tools (such as drill bits)
Gauges
Tape measures
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IMPROVE YOUR ENGLISH Write a sentence relating to carpentry or joinery with the word ‘abruptly’ in it. You can refer to a dictionary for the definition of the word if you need support. Can you think of another word that is also an adverb (often -ly words) with the same meaning as ‘abruptly’?
ACTIVITY Carry out an inspection of a range of hammers that you use at your training centre and clean the face of the hammers as described in Table 4.6. Ask your tutor or teacher to observe you while you complete the task to make sure that you do so correctly.
3 IDENTIFY THE RESOURCES REQUIRED TO MARK OUT WOODWORKING JOINTS
INDUSTRY TIP Joinery that is square and contains standard sections is referred to a routine joinery. This type of work does not always require a rod to be reproduced for each item. Instead, the positions of the joints and mouldings, for example, can be marked out directly onto the prepared square timber sections.
This section begins to look at the sequence of producing woodworking joints, from setting them out, through marking them out and finally to making them. This same process is commonly used in the construction industry to make joinery items, which is also included later in this chapter.
Using working drawings and setting out rods Sometimes, the information on working drawings does not provide enough detail to manufacture joinery items. Therefore, full-sized drawings of plans, elevations and sections are usually produced by joiners; these are known as ‘setting out rods’, which may contain the following specific information: l
sections of the components l joint details l profiles and mouldings (such as rebates and grooves) l glazing and panel details. Once a setting out rod has been prepared, it should be double-checked by your supervisor for accuracy. A mistake identified at this stage can easily be rectified. Once the timber has been cut, it can be costly to replace it and this may cause delays.
KEY TERM Ironmongery: hardware, such as locks, handles and hinges.
Information about the materials to be used for the task will be found in a document known as a specification. This is the written document that contains additional information that may not be found on the working drawings, such as the type of timber and ironmongery to use and the finish (for example, painted or stained).
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Chapter 4 Produce woodworking joints The length, width and thickness of each component drawn on the setting out rod will need to be measured and recorded on a cutting list, along with the quantities needed. Table 4.7 is an example of a cutting list. The cutting list is passed on to the wood machinist who will cut the timber to size and plane it straight, square and smooth. Columns on the cutting list contain the nominal sizes. These are the dimensions given to the machinist to rough saw the timber to size, before reducing them to the finished sizes with the planing machines. The nominal size is usually 5–6 mm bigger than the finished size. Setting out rods are used as a reference to mark out all the joints and profiles on the components needed to make joinery. If more than one item of joinery of a given size is needed, referring to the rod to mark them out will help to ensure that they are all reproduced to the same size and will save time.
INDUSTRY TIP It is more accurate to produce a setting out rod on a smooth piece of timber-based sheet material, painted with white undercoat/primer or emulsion, than it is to use a piece of paper. Using the sheet material for your setting out will avoid the need to join pieces of paper together for your rod and avoids the shrinkage and expansion that can sometimes occur with paper owing to changes in humidity.
KEY TERMS Cutting list: a detailed list of the components, types of materials, dimensions and the quantities needed for a task. Cutting lists are used by the wood machinists to prepare timber to manufacture joinery products. Profile: the shape of a section of timber, for example, a rebate, pencil round and ovolo are profiles that can be found on timber.
q Table 4.7 Cutting list Component
Species
Number
Length
Nominal width
Nominal thickness
Finished width
Finished thickness
Stiles
R/wood
2
2050
100
50
95
45
Top rail
R/wood
1
800
200
50
195
45
Mid and bottom rail
R/wood
2
800
200
50
195
45
Comments
p Figure 4.16 Setting out rod
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma The following tools are used to produce a setting out rod: l l l l l l l l l l l l l
tape measure or ruler tee square to mark vertical lines pencil gauge and thumb rule to mark horizontal lines eraser 2H pencil 45° set square to set out 45° and 90° lines 60°/30° set square to set out 60°, 30° and 90° lines straight edge to set out accurate straight lines on a rod sliding bevel to transfer angles protractor to set out angles compass to draw circles and arcs dividers to divide spaces equally trammel heads and beam to draw large circles and arcs when the compass can no longer be used.
(Further information on hand tools is given in Chapter 2.)
INDUSTRY TIP 2H pencils are preferred for setting out because they will produce a clearer line than softer pencils, such as HB. p Figure 4.17 Trammel heads and beam
4 MARK OUT WOODWORKING JOINTS This section looks at the process of marking out the joints on timber components for a basic frame using a setting out rod. The explanation of good practice for this job can be applied to a range of more advanced joinery tasks to form woodworking joints, which include: l l l l l l
windows door frames doors stairs cupboards and cupboard framing roof framing.
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Chapter 4 Produce woodworking joints
Using a setting out rod when marking out woodworking joints to form a frame Here is a step-by-step guide to using a setting out rod when marking out woodworking joints to form a frame. 1 Inspect your pieces of timber for any defects or slight imperfections. You should always try to keep these faces to the side where they are least likely to be visible. Mark the best edge and adjacent face with face edge and face side marks using a 2H pencil, as shown in Figure 4.18. Any defects found can sometimes be removed from the timber when rebates, mouldings and grooves are machined. Therefore, you should always consider the choice of face side and face edge at this stage.
p Figure 4.18 Mark out the face side and face edge marks on a piece of timber
2 Place all four parts of the frame on the setting out rod with the face sides facing upwards and the face edges towards the middle of the setting out rod, as shown in Figure 4.19. This is the final arrangement of the components for the assembled frame and must not be changed.
p Figure 4.19 Arranging the frame components on the rod
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma 3 The two sections of timber used for the side of the frame are referred to as the stiles if the rails are jointed between the top and bottom rails. Line up one of the jambs perfectly with the setting out marks before transferring the position of the mortices from the setting out rod onto the edge of the timber, as shown in Figure 4.20.
p Figure 4.20 Mortice positions being transferred onto a jamb
INDUSTRY TIP When using marking out tools to mark out the components of a frame, make sure that you use them from the face sides and face edges of the timber every time, otherwise the marking out may be inaccurate and the joints may not fit together properly.
4 Place the two jambs together as a pair with the face edge marks pointing towards each other. Use a try square and a 2H pencil to mark the positions of the mortices from the first jamb to the second. These positions can now be transferred around the jambs to the other side. This is achieved by making sure that the stock (the handle) of the try square is placed firmly against either the face side or edge to mark each line, as shown in Figure 4.21. This will ensure that the lines meet up when they are transferred around the timber.
KEY TERM Shoulders: the surface area square to the edge or face (cheeks) of a woodworking joint member, which exposes the end grain. Shoulders are used to increase the strength of joints.
p Figure 4.21 Transferring the marking out lines around a piece of timber with a try square
5 Place either the top or bottom rail on the rod and align it with the setting out marks. Transfer the positions of the shoulders from the rod onto the rail. Place the top and bottom rails together as a pair with the face edges facing upwards, then transfer the position of the tenons across both components using a try square and a pencil. Mark the positions of the shoulders squarely all the way around the ends of the timber.
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Chapter 4 Produce woodworking joints Shoulders
Cheeks
p Figure 4.22 Shoulders and cheeks on a tenon
6 Reposition all the parts of the frame on the rod to double-check that they have been marked out correctly, as shown in Figure 4.23. The position of the mortice and tenons can now be marked between the marking out lines to indicate where to cut to form the joints. An explanation of how to do this is given later in this chapter.
p Figure 4.23 All the frame components laid out on the setting out rod
Using marking out tools to produce woodworking joints to form a frame Some tasks may require the use of additional tools to mark out. Some of the marking out tools that you may use as a carpenter or joiner include: l l l l
l l l l l
tape measure and rule, used to accurately measure lengths, widths and thicknesses compass dividers gauges: l marking gauge for marking single lines along the grain of the wood l mortice gauge for marking parallel lines along the grain of the wood l cutting gauge for scoring single lines across the grain l pencil gauge for marking single lines parallel to the timber without leaving a permanent mark pencils (2H hardness pencils are recommended for marking out joinery) trammels set square try square for marking out square lines across the grain of the timber combination square for marking out 90° and 45° lines on materials; the adjustable rule can also be used as a pencil gauge
INDUSTRY TIPS A marking gauge can also be used as a pencil gauge by simply drilling a pencilwidth hole towards the end of the beam (also known as the stem). A pencil should be wedged into the hole tightly and the stock part of the marking gauge adjusted according. A micro-adjust wheel gauge is an alternative marking out tool to a traditional marking gauge. The wheel gauge is easier to use and improves the accuracy of marking out, and the sharp steel cutter prevents tearing out the grain. 201
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KEY TERM Stock: the handle of a square or the sliding heads on a mortice gauge, marking gauge and cutting gauge.
IMPROVE YOUR MATHS Carpenters and joiners use the metric units of measurement, metres (m) and millimetres (mm), rather than centimetres. Practise finding the following measurements using your tape measure: l 15 mm l 63 mm l 269 mm l 0.5 m l 1.681 m.
ACTIVITY Make a list of all the hazards you could be exposed to in the place where you work or train when marking out woodworking joints. Consider what preventative measures are already in place to protect you from harm and any recommendations you would like to make to your tutor or employer. Discuss your ideas with your tutor or employer and add to your list any hazards you may have missed.
l
marking knife for accurately marking out across the grain by cutting the fibres of the timber l scribers: l engineers’ scribers are occasionally used by carpenters and joiners to mark clear lines on metals l combination squares usually have a scriber stored in the stock l box square/over square for accurately transferring lines around timber when it has a profile moulded on it.
ACTIVITY Make a simple setting out and marking out trammel, with guidance from your tutor or teacher. There are lots of video tutorials online that explain how to do this. Remember, only use the tools and equipment that you have been trained and authorised to use.
Current regulations for marking out woodworking joints Although the process of marking out timber may only involve a small number of low-risk hand tools, your employer still has a responsibility to protect their workers under the Provision and Use of Work Equipment Regulations (PUWER). They also have a duty to risk assess all hazardous activities, which may identify that the use of personal protective equipment (PPE) is needed for some tasks; this will fall under the Personal Protective Equipment at Work Regulations. Both regulations are covered in more detail in Chapter 6. A safe working environment must always be maintained in the workplace to protect people’s health, safety and wellbeing, regardless of what task you are completing. When you are marking out joints, the area in which you work should be free from trip hazards and noise pollution from any woodworking machinery that is being used, and the air should be free from any fumes or dust. Both you and your employer must also consider the disposal of waste materials and products to avoid polluting and harming the natural environment. People who dispose of their waste irresponsibly could be penalised for breaching environmental regulations.
5 SELECT AND USE HAND TOOLS AND MATERIALS TO PRODUCE BASIC WOODWORKING JOINTS This section looks at some of the most commonly used timber-based manufactured boards, the reasons why they are used and some of their applications. It also refers to relevant environmental and health and safety regulations for using hand tools.
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Selecting woodworking materials to produce woodworking joints In addition to the solid timbers considered earlier in this chapter, carpenters and joiners frequently use timber-based manufactured boards for some tasks. Sheet materials range in thicknesses and overall size. The most commonly used size is 2440 mm long by 1220 mm wide. Timber-based sheet materials are a cheaper alternative to solid wood. They are also more stable and easier to cut and fix using the right tools. Some sheet materials can be used both internally and externally, while others are for internal use only. If the wrong materials are used for a task they can quickly rot, delaminate and cause staining. They may also not meet Building Regulations and could therefore be condemned by a building control officer. Details of the correct materials to use should be given in a document known as a specification or shown on the working drawings. The abbreviations given in Table 4.8 are used to identify different types of sheet materials. q Table 4.8 Abbreviations used to identify different types of sheet materials Abbreviation
Type of sheet of material
MR
Moisture-resistant (red/pink coloured boards); these are suitable for areas with high humidity, such as kitchens and bathrooms
FR
Fire-resistant (green coloured boards); these boards are commonly used in high-risk areas, such as shops
WBP
Weather- and boil-proof (a type of plywood suitable for external use)
MDF
Medium density fibreboard
OSB
Oriented strand board
KEY TERMS Delaminate: when layers of materials split apart. Specification: a written document that an architect produces. It contains additional information about a project that cannot be fitted onto the working drawings. Veneer: a thin layer of timber.
The most commonly used timber-based manufactured boards are listed in Table 4.9. q Table 4.9 Commonly used timber-based manufactured boards Manufactured board
Description
Chipboard
There are several different grades of chipboard. High-density is used for worktops, flooring and fire doors. Medium and normal grade chipboard is used to make kitchens and furniture. The boards are made by bonding wood particles together with heat and pressure to make a smooth and rigid sheet. Standard chipboard will swell and break if it gets wet, so MR chipboard must be used in moist conditions.
Plywood
Plywood is made up of an odd number of wood veneers, each one glued at a right angle to the one below. The more veneers in the plywood, the thicker and stronger it becomes. WBP plywood can be used in wet areas providing it is painted or stained. Marine plywood can be completely submerged in water and still not delaminate, so it is often used for boat building.
➜ 203
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Manufactured board
Description
Flexi ply
Flexi ply is made from two thick laminates of wood veneers on the outside of the sheet with the grain facing in the same direction. Between the two outer sheets there is a thin laminate bonded at 90°. This forms a flexible sheet that is suitable for making curved work.
Medium density fibreboard (MDF)
MDF is made from wood fibres bonded together with a synthetic resin adhesive to provide a smooth and stiff board suitable for making kitchens, furniture, staircases, skirting and architraves. There are MR and FR versions of MDF; it is also available with a range of different wood veneers bonded to the faces.
Flexible MDF
Flexible MDF is MDF sheets with grooves cut out on one side to provide a flexible board, suitable for making curved units.
Hardboard
Standard grade hardboard is for internal use only. It is a lightweight, non-structural board commonly used for back panels and drawer bottoms in kitchens and flat-pack furniture.
Laminated/engineered panels
Laminated panels are made from solid pieces of narrow timber glued together to make a wide board that can be up to 600 mm in width. They are suitable for making furniture, kitchens and internal joinery. They can be cut, planed, moulded and sanded like normal timber.
➜
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Chapter 4 Produce woodworking joints Manufactured board
Description
Oriented strand board (OSB)
OSB is a cheap timber-based sheet material used for roofing, flooring and cladding. it must be sealed to protect it from the elements. The board is manufactured from wood strands bonded together with water-resistant resin to form a random pattern.
Current regulations for using woodworking hand tools Relevant health and safety controls that apply to the use of woodworking hand and power tools are covered in detail in Chapter 6. Those areas of particular interest for this chapter are: l l l l l
l l l
the Health and Safety at Work Act (HASAWA) the use of work equipment (Provision and Use of Work Equipment Regulations PUWER) personal protective equipment (PPE at Work Regulations) working with hazardous materials and substances, such as wood adhesives (Control of Substances Hazardous to Health Regulations, or COSHH) maintaining tools, such as planes and chisels (Safety in the use of abrasive wheels). Further information and guidance on the safe use of abrasive wheels can be found at www.hse.gov.uk/pubns/books/hsg17.htm power tools that cause vibration, such as sanders (Control of Vibration at Work Regulations) control of noise (Control of Noise at Work Regulations) environmental regulations.
6 UNDERSTAND HOW TO MANUFACTURE A FRAME USING WOODWORKING JOINTS As you progress through your training, it is likely that you will undertake various tasks involving different types of woodworking joints. This section analyses the most frequently used joints and considers why they are used.
Different uses for woodworking joints In simple terms, a woodworking joint can be defined as the connection of two pieces of timber. Many joints rely on adhesive to hold them together, while others need mechanical fixings such as nails, screws and bolts. The types of joints used for a task depend on a several factors, such as their strength, toughness, flexibility and 205
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma appearance. You may also have to consider what a joint is being used for and the materials used; for example, solid woodworking joints are often different to those used to connect man-made timber-based sheet materials such as medium density fibreboard (MDF) and chipboard. Some joints are more complex than others and take longer to make, whether by hand or machines, and may result in a project costing more. Woodworking joints are broadly divided into three different classifications: l
INDUSTRY TIP The quality of a widening butt joint can be improved if both parts are rubbed together after the glue has been applied. This technique makes sure that the wood adhesive is pushed into the grain of the timber to achieve a strong bond. It also ensures that the adhesive is evenly spread over the whole surface of the joint.
widening joints
l
lengthening joints
l
framing joints.
Widening joints Often, timber needs to be joined in its width (side by side, longest sides together) to make wider boards, such as for panels and worktops. Thin wide boards are less stable than thick narrow ones, especially if they are tangential cut, which can lead to distortion and cupping of the wood. This type of joint is known as a ‘widening joint’. To keep the panels flat, you should use narrower boards for thin panels. The annual growth rings should also be arranged so that they alternate in direction. The simplest widening joints are not always the best. For example, using a plain butt can make it difficult to keep the faces flush while it is being glued and clamped together, though it is the quickest method. Alternatively, the edges of the timber can be machined with a tongue and groove (often referred to as T&G); this will improve the strength of the joint and help to align it. The disadvantage of using T&G to form widening joints is that the boards will be reduced when the tongue is profiled on one side of the boards. A more cost-effective method is to use a loose tongue and groove, where a thin piece of timber or plywood is glued in a groove on each edge of the board to form the joint, as shown in Figure 4.24. There are several jigs and power tools that are designed to joint timber together in width, which include: l
drill and jig or dowelling jointer, used to make a dowel joint (Figure 4.25) l domino jointer, used to make a domino joint (Figure 4.26) l biscuit jointer, used to make a biscuit joint (Figure 4.27).
p Figure 4.24 Loose tongue joint
p Figure 4.25 Dowel joint
p Figure 4.26 Domino joint
p Figure 4.27 Biscuit joint
IMPROVE YOUR ENGLISH Write a review for a fictional woodworking magazine on the following power tools: l dowelling jointer l domino jointer l biscuit jointer. Speak to your tutor or teacher about the review you have written and explain the judgements you have made about each tool.
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ACTIVITY The domino jointer is a tool used to create widening joints and framing joints. Find and watch a video demonstration on how to set up and use a domino jointer.
Lengthening joints There are lots of situations where timbers need to be jointed in their length, such as the handrails on a staircase, skirting and flooring. These types of lengthening joints are considered non-structural because they do not support any loads; the most common are known as heading joints (see Figure 4.28). Butt, splayed and tongue and groove joints are the main types of heading joints for lengthening non-structural timber. Structural timbers that carry loads, such as ridge boards and the purlins in a roof, need stronger scarf joints to support the weight of the other roof members (see Figures 4.29 and 4.30). There are different types of structural scarf joints designed to suit each situation and the amount of weight they must bear, some of which will require strengthening further with bolts and metal plates.
p Figure 4.28 Heading joints in floorboards support by structural joists
p Figure 4.29 Structural scarf joints in a purlin
p Figure 4.30 Scarf joint in a ridge board in a roof
Framing joints Woodworking joints used to make frames such as windows, doors and cabinets are referred to a framing joints. There are seven main classifications for this type of joint: l l l l l l l
butt joints bridle joints dovetail joints halving joints housing joints mitred joints mortice and tenon joints.
Within most of these classifications of joints, there are several variations on the basic joint. The next section looks at some of these joints, what they are used for and why they are used.
Butt joint A basic butt joint varies little, other than the angle in which the two parts of the joint come together. In most cases, the joint will be formed at 90°. However, when used to build roofs, most of the butt joints will be angled to suit the pitch of the roof. Carpenters on construction sites use butt joints extensively to build
KEY TERMS Ridge board: a structural beam, usually found at the top of a traditional roof. Purlins: large timber beams used to support the rafters in a traditional roof. Mortice: a rectangular hole, often created with mortice chisels or a mortice machine. Pitch: something that is angled (for example, a pitched roof has sloping rafters so that the rainwater can run off).
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma walls, roofs and floors because they are simple and quick to cut. Because of their simplicity, butt joints must be strengthened with nails, screws or metal brackets.
INDUSTRY TIP When strengthening a butt joint with nails in joinery, you should angle it slightly in a dovetail formation to improve its resistance to pulling apart. A similar principle is used in carpentry to fix larger sections of timber together for partition walls and rafters in roofs; in this case, the method is referred to as skew nailing.
Figure 4.31 Dovetail nailing a butt joint together
Figure 4.32 Skew nailing a butt joint together
Bridle joints Bridle joints are like mortice and tenon joints, especially when they are used to form a corner of a frame, but they are open-ended, not enclosed. There are several different types of bridle joints, including tee bridles, corner bridles and mitred bridles. Although the corner-mitre joint is more challenging to make, it has the benefit of concealing most of the unsightly end grain when the joint is put together. Bridle joints are used to make door frames, furniture and cupboards.
INDUSTRY TIP Dovetail joints should be put together twice only, once to make sure that the joint fits and then again when it is ready to glue together. The greater the number of times a joint is assembled and taken apart, the slacker and weaker it will become.
Dovetail joints Dovetail joints are used to construct high-quality drawers for kitchens, units and furniture. The joints are attractive and extremely strong when they are glued together. Through dovetails and lapped dovetails are two main types of dovetail joints (see Figure 4.33). Through dovetails are commonly used for the joints in the back of a drawer box, where the end grain of the timber is least visible. Lapped dovetail joints are used in the front of a drawer, so that the end grain of the joint is hidden from view. The angles of the dovetail joints in softwood are usually a ratio of 1:6 and in hardwoods they are 1:8. Some joiners prefer to use 1:7 for both softwoods and hardwoods.
Through
Lapped
p Figure 4.33 Through and lapped dovetail joints (including pitches for hard and softwood)
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Chapter 4 Produce woodworking joints
IMPROVE YOUR MATHS Draw to scale the ratios for dovetail joints in softwoods and hardwoods. Using a protractor, calculate how many degrees each joint is to the nearest whole number.
Halving joints Halving joints are also referred to as lap joints because one part of the joint overlaps the other. They are used by carpenters as lengthening joints, as well as framing joints for partition walls and wall plates for roofs and floors to be built on. There are several different versions of halving joints: l l l l l l
corner halving joint angled halving joint tee halving joint cross halving joint dovetail halving joint (for improved strength) raked halving joint.
Raked halving
Tee halving
Corner halving
Cross halving Dovetail halving
p Figure 4.34 Halving joints
Housing joints Housing joints are used to construct door linings, hatches, shelving, staircases and sliding sash windows. They are formed by creating a shallow trench or housing across the width of one part of the joint, usually either one-third or half of the thickness of the timber in depth, depending on the thickness of the timber. The other part of the joint should fit directly into the housing at a right angle. It is then secured with wood adhesive and nails, if they are needed. A basic through housing joint runs across the full width of the timber; a stopped housing joint has a trench that stops short of the full width so that the joint is hidden for a high-quality finish (see Figure 4.36). A housing joint can also be created with a ‘shoulder’ on one side, known as a shoulder housing joint or tongued housing. This is particularly useful if the joint is used to form a corner, because the tongue prevents the joint from coming apart.
KEY TERM Trench: a groove cut across the grain of a piece of timber.
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Through
Stopped
Tongued
p Figure 4.35 Through housing joint, stopped housing joint, shoulder/tongued housing joint
Mitre joints
p Figure 4.36 Mitre box
KEY TERMS
Carpenters and joiners often cut mitre joints to continue a moulding or trim around a corner or to form a 90° bend. They are also used to fit beading to hold glazing in doors and windows. Mitre joints are used to avoid the end grain of the timber being exposed and so that any profile on the timber continues neatly around the joint. It is difficult to cut a perfect mitre with a handsaw without the use of a mitre box, mitre saw or chop saw. Most mitred joints rely on adhesive to hold them together. However, they can be strengthened with nails, biscuits or wooden dowels. Later in this chapter, we will look at how mitres are used to install skirtings and architraves.
Beading: a small section of timber, often shaped with a decorative profile. Architrave: a timber trim or moulding often used to cover the joint between a door lining and a wall.
α90°
p Figure 4.37 Mitre saw
90°
p Figure 4.38 Mitred skirting and architrave
INDUSTRY TIP Sometimes, mitres need to be trimmed with a plane so they fit perfectly. The most accurate way to do this is by using a shooting board. This tool looks like a bench hook, apart from the back stop being set at 45° rather than 90° to suit the angle of the mitre.
Mortice and tenon joints These are used in joinery to construct doors, frames, windows and staircases because they are extremely strong joints. There are two parts to the joint: the tenon, which is referred to as the ‘male’, and the ‘female’ mortice. A basic mortice and tenon joint is sometimes wedged and dowelled to increase its strength. The joint becomes more complicated when the shoulders of the joint need to be
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Chapter 4 Produce woodworking joints shaped or scribed over profiles and rebates that may be on the edge of the timber. A third of the tenon is usually removed from corner joints so that they can still be wedged together; this type of joint is known as a haunched mortice and tenon. Where wider timbers may be used to join the rails in doors, double tenons are used to avoid weakening the timber and to reduce the weakening effect of a wide tenon shrinking. The tenon on some joints may be kept short to prevent it going through the timber and exposing the end grain of the joint; this is referred to as a stub (or blind) mortice and tenon joint. Haunched mortice and tenon
1/3
1/3 2/3
Double tenon 1/3 1/3 1/3
Double haunched mortice and tenon 1/4 1/4
KEY TERMS Scribed: a shape that has been replicated, marked out and cut on a piece of timber to fit over another surface. Haunch: a portion of a tenon that has been removed to strengthen the joint. A haunch also creates a space where wedges can be driven down the sides of the tenon to strengthen it further.
Haunched mortice and tenon joint showing tenon thickness and ratio Wedges glued and driven in with a hammer either side of each tenon to strengthen the joints.
1/4 1/4
1–2 times tenon thickness
p Figure 4.39 Mortice and tenon joints
7 FORM A FRAME USING WOODWORKING JOINTS This section includes step-by-step guidance to some of the techniques used to cut woodworking joints using carpentry and joinery hand tools.
Producing and assembling woodworking joints to form a frame You will carry out two actions when cutting woodworking joints: rip sawing along the length of the grain and crosscutting across the grain. It is always more difficult to cut along the length of the grain with a saw, so you should always make sure that you are cutting within the waste area of your joints. You may always reduce the thickness of your joint to make it fit but cannot add it on to the timber. When you crosscut the timber to make joints you will be forming the shoulders. Some examples of joint shoulders can be seen in Figure 4.41.
HEALTH AND SAFETY You should always use sharp tools when producing woodwork. You are more likely to have an accident with blunt or damaged tools because you will have to force them to cut.
KEY TERM Waste area: the part of the timber removed to create the joint.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma
Part of lap joint or rebate
Part of lap joint or r
Dovetail
Dovetail
Tenon
of halving joint or housing Part of halving joint or housing
p Figure 4.40 Joint shoulders
KEY TERM Hatching: evenly spaced parallel lines, running in the same direction, at 45° from each other.
Whenever you are cutting joints, you must ensure that the timber is secured to prevent it from moving around and causing potential accidents. Depending on the task, you can use a vice, a bench hook or a clamp. Before making any cuts, double-check your marking out and make sure that the waste area of your joint is clearly indicated with hatching or crosses.
p Figure 4.41 Starting to rip along the grain of a joint
p Figure 4.42 Finishing ripping along the grain of a joint
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Chapter 4 Produce woodworking joints
Ripsawing to form woodworking joints Here is a step guide to ripsawing to form woodworking joints (sawing along the grain to form the cheeks). 1 Secure the timber in a vice at a slight angle. 2 Bend your thumb and place the side of a tenon saw against it. Use this as a guide to start your first cut in the waste area of your joint. 3 Continue sawing down to the shoulder lines you have marked out, making sure that you slow down as you near the end of your cut for better control. 4 Take the timber out of the vice, turn it around and repeat the process on the opposite side. 5 Adjust the position of the timber in the vice so that it is vertical, place the saw in the cut that has been made and continue sawing down to the shoulder lines. Keep checking on both sides of the timber to make sure that you are not sawing below the shoulder lines.
INDUSTRY TIPS Stand at the end of your bench when you are ripping down the grain to cut joints. This will avoid you having to lean over the bench from the other side and will help you to make vertical cuts. When you are cutting tenons, look directly along the top (the spine) of the saw. You should be able to see both sides of the blade if you are cutting square.
Crosscutting Here is a step-by-step guide to crosscutting (sawing across the grain of timber to form the shoulders). 1 Place the timber firmly against the bench hook and hold it in position with one hand. Alternatively, secure it in a vice. 2 Using your thumb as a guide, hold a tenon saw at a slight angle on the edge of the timber against the bench hook and begin making light saw cuts in the timber, as shown in Figure 4.44. 3 When the cut is deep enough to prevent your saw slipping away from your marking out line, move your hand safely out of the way to complete the cut down to your gauge lines, as shown in Figure 4.45. Keep checking both sides of the timber while you are cutting, to make sure that you are not sawing below your marking out lines.
p Figure 4.43 Starting to crosscut
HEALTH AND SAFETY Always keep your hand behind the cutting edges of sharp tools when they are in use.
p Figure 4.44 Finishing a crosscut
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma
INDUSTRY TIPS Rub a pencil along the blade of a try square, turn it over and rub the edge in a housing joint to check if it is flat. Any high points of the housing will have a pencil mark on them that can be flattened out with a chisel. When making multiple housing joints, it is more productive to use an electric router and a jig.
ACTIVITY Mark out and cut a tee halving joint following this step-by-step guidance.
INDUSTRY TIP When cutting a haunched mortice and tenon joint, you may cut the wedges from the waste area of the tenon. This will save time making accurate wedges.
ACTIVITY Mark out and cut a through mortice and tenon joint using this step-by-step guidance.
Housing The technique used for making housings can also be used for several joints, including tee halving joints, bridle joints and housing joints. Here is a step-by-step guide to making a housing joint. 1 Secure the workpiece in a vice. 2 Use a tenon saw to cut along the marking out lines, down to the gauge line. Keep checking both sides of the timber while you are sawing to make sure you do not cut below the gauge line, as doing so could weaken the joint. 3 Make several more saw cuts between the marking out lines in the waste area. This will make it easier to remove the waste wood at the next stage. 4 Select a bevel edge chisel, slightly smaller than the width of the housing. Hold the chisel at a slight angle and start to remove the waste material by striking the chisel with a mallet. Start chiselling at the top of the joint and remove small sections at a time until you reach the gauge line. 5 Remove the timber from the vice, turn it around and repeat the process on the opposite side of the joint 6 You should be left with a high point in the centre of the housing at this stage, which can now be chiselled flat from both sides of the joint. Alternatively, a hand router can be used to clean up the bottom of a housing to provide an accurate finish to the joint.
Morticing A joiner will rarely cut mortice joints by hand these days unless it is easier to do so than using a woodworking machine, known as a morticer. Regardless of whether the joint is cut by hand or machine, the marking out process is the same, and some of the manual skills are transferable to other tasks. You must use a mortice chisel to cut the joint, because it has square edges that help to produce accurate mortices. It is also important to make sure that your workpiece is held securely on your workbench while you are cutting the mortices with a mallet and chisel. The following step-by-step guide explains how to cut an accurate mortice. 1 Secure your timber to a workbench. 2 Stand at the end of the bench, holding the mortice chisel upright just inside of your marking out line at one end of the mortice. 3 Begin to chip out the waste material in the mortice by striking the chisel with a mallet 10–12 mm into the edge of the timber. Remove the chisel and repeat the process further along the mortice, until the end is reached. 4 Repeat step 3 to the centre of the timber. 5 Unclamp the timber, turn it over and repeat steps 3 and 4 until a through mortice has been made. 6 Make the mortice slightly longer at each end on the back edge to allow room for wedges, if required.
Dovetails Creating neatly fitting interlocking dovetail joints is not as complicated as it may seem at first. The following is a step-by-step guide to creating dovetail joints. 214
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Chapter 4 Produce woodworking joints Marking out 1 Set up a sliding bevel to the correct angle for the dovetails. Alternatively, you could use a dovetail template that is already shaped to either 1:6 for softwoods or 1:8 for hardwoods. 2 Mark the thickness of the timber on one end of the joint. This will become the shoulder line. 3 Mark out the dovetails on one piece of the joint in an alternating pattern. 4 Use a pencil to indicate the waste parts of the joint. Cutting 1 Place the piece of timber marked out with the dovetails in a vice, so that one side of the dovetail is vertical. 2 Use a fine-toothed dovetail saw to cut the cheeks on one side of the dovetails. Adjust the timber in the vice to repeat this process on the other side. 3 Use a coping saw to remove the waste between the dovetails in the middle. 4 Cut along the shoulder lines either side of the joint with a dovetail saw. 5 Remove the timber from the vice and place it on a waste piece of material to protect the bench below. Use a bevel edge chisel to pare along the shoulder line to make it neat. 6 Use the dovetails made as a template to mark out the ‘pins’ on the end grain of the other part of the joint with a marking knife. 7 Mark the depth of the pins and the shoulder line around the end of the joint, then cut out the sockets using the same method used to make the dovetails. 8 Assemble the joint using a mallet and a block of wood to protect the joint from damage. Assembling the frame 1 Once all the joints have been cut for a frame, each joint should be individually dry fitted, then the frame put together without any glue to check the all-over dimensions against the original setting out rod. 2 Disassemble the frame and clean up the inside edges of the timber using 80 grit sandpaper for softwoods or 120 grit paper for hardwoods. 3 Glue the frame together with a suitable wood adhesive.
Adhesives used to bond wood together Several different types of adhesives are used for bonding wood together and each one has different qualities. For example, when you are constructing frames for exterior work, the adhesive must be moisture-resistant. You may also need to consider the drying times of the adhesive. If it starts to dry too quickly while assembling a frame, it can cause problems and weaken the bond between the joints. The following list comprises the most common adhesives used for producing frames. l
PVA (polyvinyl acetate): this is probably the most commonly used adhesive because it does not need to be mixed and can be used straight from a bottle or dispenser. The adhesive is white, but turns clear as it dries. There are both interior and exterior grades of this adhesive. PVA generally dries hard within 12 hours; however, some glues dry quicker. Any excess glue can be removed from the joints with a damp cloth to prevent it staining the wood.
INDUSTRY TIP Whenever possible, you should leave the rails (which hold the mortices) longer than they need to be, so that the joints can be assembled and wedged without breaking out. The extra length on the joints is referred to as the horn. Horns are usually removed with a handsaw or rail saw just before fitting the frame.
KEY TERM Dry fitting: a stage in the process of manufacturing joinery, when each joint is fitted individually before assembling the frame without glue to make the final checks. After the checks have been made, the joinery can be taken apart and the internal faces sanded (also referred to as papered-up) before being reassembled with a wood adhesive for the final time.
HEALTH AND SAFETY Always follow the manufacturer’s safety instructions for the use, storage and disposal of wood adhesives, such as always wearing the disposable gloves provided when using PU adhesive.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma PU (polyurethane): this adhesive has become extremely popular with carpenters and joiners. As the brown resin cures, it turns yellow, produces a foam to fill any gaps in the joints and forms a very strong bond within 5 minutes. Any excess glue on the frame should be allowed to cure before removing it with a chisel to prevent staining the timber. PU adhesive is suitable for both interior and exterior use. l UF (urea-formaldehyde): this is a powdered resin wood adhesive that should be mixed with water before use. Once it has been mixed in a pot, it will start to dry within 1–2 hours, depending on the temperature, and is fully cured within 6 hours. Joiners use this adhesive for laminating curved work together, because it is extremely strong and does not flex like other glues. Excess glue can simply be removed with a damp cloth while it is still wet. UF adhesive is suitable for interior and exterior use. l
ACTIVITY Research different types of wood adhesives and make a list of carpentry and joinery tasks that each adhesive could be used for.
Gluing-up
KEY TERMS Curing: the chemical process adhesives go through before they achieve their full strength. Squaring rod: a thin piece of batten with either a point or a nail on the end of it. It is used to measure the diagonal distances in a frame to check that it is square. Horns: portions of waste material left on a frame to strengthen the joints before they are later removed after final assembly and finishing.
The following is a step-by-step guide to gluing-up. 1 Prepare the work area by placing two bench bearers on your bench and checking them to make sure they are not twisted, as shown in Figure 4.46. If they are twisted, place thin packers under them to make sure they are level. 2 Spread wood adhesive over the joints and assemble the frame with a mallet. 3 Use a sash clamp to pull the joints together. 4 Check the frame is square by marking the lengths of both diagonals on a squaring rod (Figure 4.46). Adjust the frame, if necessary, until the diagonals are equal. 5 Make sure the frame is not twisted before driving the wedges and knocking them into the mortice with a hammer. 6 Trim any excess length off the wedges. 7 Remove the clamps and plane the joints flat with a smoothing plane. 8 Cut off the horns with a tenon saw. 9 Make sure you are wearing the correct PPE for using an orbital sander. Make the surfaces of the frame smooth and remove any marks. 10 Remove the sharp edges (the arris) with abrasive paper to complete the task.
p Figure 4.45 Bench bearers
p Figure 4.46 Squaring rod
INDUSTRY TIP Removing the arris from your completed work allows any paint that is applied to stick to the corners: it is also more comfortable to handle and provides a professional finish. 216
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Current regulations for using woodworking joints Information on current environmental and relevant health and safety regulations is given in Chapter 6. The following guidance is especially relevant when using woodworking joints. l
You should always clear away any surplus materials and dispose of debris in accordance with your college’s or company’s procedures at the end of each task. This avoids unnecessary accidents. l Some pieces of timber may go back into the stores to be reused, while smaller sections will be recycled. Materials that cannot be recycled must go into the general waste bins. l Clean any tools you have used for the task and check them for damage, before storing them away in preparation for the next job. l Remove from use any equipment that is damaged and report this damage to your tutor, line manager or supervisor.
HEALTH AND SAFETY Make a list of all the hazards that you could be exposed to while making woodworking joints to produce a frame.
8 CONSTRUCT AND FIX HATCH LININGS A hatch is similar in many ways to a door lining. Both are made with housing joints and trimmed with architraves. Hatches are most frequently used to line the openings created between ceiling joists to gain access into loft spaces. These types of hatches either have a loose panel that can be removed to gain access or a door that is hinged to open into the loft or to drop below it. Loft hatches that open downwards are usually hung with butt hinges to prevent them falling out of the lining; they also have either a push latch or rim lock fitted to secure them in their closed position. This section looks at how to make a basic loft hatch. You should refer to Building Regulations for the exact specification with regards to sound and thermal insulation and fire resistance rating. There are no restrictions on the size of a loft hatch in these regulations. However, a minimum opening size of 530 mm × 530 mm is recommended for personal access.
Producing and assembling woodworking joints to construct and fix a hatch lining Before a loft hatch is made by the joiner, the opening that it is going to be fitted into on site is measured and checked to make sure that is square. A tolerance of a least 15 mm must be made between the size of the opening and the dimensions of the hatch. This gap will allow the carpenter to make any slight adjustments needed to the positioning of the hatch when it is being fitted. An experienced joiner may not produce a setting out rod for a simple task such as making a loft hatch. This would initially be drawn so that the dimensions of the materials can be taken and recorded on a cutting list. Many different species of timber could be used to make a loft hatch, such as European redwood or American 217
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma whitewood, providing that they have the correct moisture content to use internally. Once the materials have been cut to size, planed smooth and straightened, the following process of marking out the timber and cutting the joints can be followed. To make and fit a hatch, you will need: l l l l l l l
2H pencil try square and combination square tape measure and rule marking gauge tenon saw bevel edge chisel mallet
l l l l l l l
smoothing plane and block plane squaring rod Warrington hammer and nail punch cordless drill/driver spirit level bench hook, G clamp and sash clamp PPE.
Marking out a hatch The following is a step-by-step guide to marking out a hatch.
INDUSTRY TIP Place small blocks of timber between the sash clamp and the timber workpiece while clamping together. This will prevent the pressure applied by the clamp from damaging the timber.
1 Mark the face side and edge on all the components, ensuring that you keep any defects facing towards the outside of the hatch when it is completed. 2 Place one side and end piece on the setting out rod in turn to transfer the positions of the housing joints onto the timber. (Note: through housing joints can be used, but tongued housings will provide stronger joints.) 3 Pair the side and end pieces (a left hand and a right hand) and clamp them together with a G clamp. 4 Use a try square to transfer the pencil marks from the first pieces marked out to the others. 5 Remove the G clamp and use a try square to mark the positions of the joints across the grain of the timber, while keeping the stock (adjustable block) of the square against the face side and edges for accuracy. 6 Set up a marking gauge to the depth of the housing joints with a ruler. Then mark out the depth onto the two side components, either side of each joint. 7 If the hatch is being constructed with through housing joints then no further marking out needs to be done at this stage. If tongued housing joints are being used, then the thickness of the tongue can be marked on the two end pieces.
Manufacturing a hatch The following is a step-by-step guide to manufacturing a hatch.
KEY TERM Break-out: the damage caused when a tool, such as a chisel or drill bit, is used from one face of a piece of timber and exits the opposite side. Break-out can be reduced if a clamp is used to hold a scrap piece of timber behind the area being worked on.
1 Use a tenon saw to cut across the grain of the timber on both side pieces until the gauge lines have been reached between the marking out. Make sure the cuts are within the waste area of the joints. This will help to ensure that both parts of the joint fit together well. Make several additional saw cuts between the marking out lines so that the waste can easily be removed with a wooden mallet and chisel. 2 Use a bevel edge chisel, slightly smaller than the width of the housing joints, to chisel from both sides of the timber upwards towards the centre of the joint. Once the gauge lines have been reached, the high point in the middle of the joint can be removed by carefully chiselling from both sides of the joint to prevent break-out.
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Chapter 4 Produce woodworking joints 3 If tongued housing joints are being used to make the hatch, the tongues can be cut with a tenon saw and cleaned up with a bevel edge chisel at this stage. There is no need for any further work on the joints if through housings are being used. It is recommended that the hatch is dry fitted prior to finishing to make sure that all the joints fit and to check the overall dimensions against the setting out details. 4 Remove any pencil or machining marks from all timber components with a sander before the wood adhesive is applied. 5 Spread adhesive over each joint and reassemble the hatch. A pair of sash clamps can be used to help clamp the joints together. The joints should be secured with counter sunk wood screws, so a suitable pilot hole must be drilled and countersunk before they can be fixed together. Remove any excess glue with a clean damp cloth. 6 Use a squaring rod to check that the hatch is square and then secure it with a temporary brace. 7 Look through the frame to check that it is not twisted by comparing one edge against the other end on the opposite side of the hatch. If it is flat, both edges will be parallel to each other. If the frame is twisted, you may need to apply pressure to untwist it. If this does not work, the joints may have to be adjusted. 8 Use a smoothing plane to make sure that each joint is flush, before sanding the edges of the hatch on both sides. 9 Measure, then mark out and cut some timber stops to go around the inside faces of the hatch. The joints can be simply butted together unless moulded beads are used, in which case they should be mitred. Mark a parallel line around the hatch to determine the height of the panel or door to be fitted. Secure the beading in position with oval nails and use a nail punch to drive them below the surface of the timber. Alternatively, a nail gun could be used to fix the beads. 10 The panel or door can now be fitted. Check to make sure there is an equal gap of 2 mm clearance between its edge and the hatch. 11 A pair of butt hinges and a latch or lock can finally be fitted if the hatch has a door that opens downwards. 12 Adjust the rule on a combination square to the margin to be used between the architraves and the edge of the hatch. Mark the margin on the edges of the face side of the hatch. Mark out the mitre joints and cut the architraves ready for installation by the site carpenter.
KEY TERMS Counter sunk: shaped so that the head of the screw sits below the surface of the timber when it is fixed. (Further information on screws is given in Chapter 5. Pilot holes: small holes drilled (or bored) into timber to prevent it from splitting when the fixing screws are inserted.
INDUSTRY TIP Clearance holes may be used when fixing two materials together. These holes should be drilled into the top material and should be large enough for the screw to pass through it, therefore preventing the two materials pulling apart when the screw is tightened. (See Chapter 5, page 233)
INDUSTRY TIP All the arrises should be removed from your hatch before completion to provide a professional finish and to allow the paint applied to stick better to the slightly rounded edges.
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HEALTH AND SAFETY Installing a loft hatch can be very hazardous because you are likely to work at height from suitable access equipment. You will also use tools and equipment above head height, which could result in debris, such as wood dust, falling into your eyes. Your employer should have a risk assessment for this task informing you of the best way to protect against the hazards identified. In addition to your safety boots, high visibility jacket and hard hat, you should also wear safety goggles to reduce the risk of an injury to the lowest possible level.
Installing a hatch After the joiner has finished constructing the loft hatch, it will usually be delivered to the construction site for installation by a carpenter. The following is a step-by-step guide to installing a hatch. 1 Double check the width and the length of the hatch. Compare these dimensions against the size of the opening in the ceiling to make sure that it will fit. 2 A timber loft hatch is normally secured in position with countersunk screws above the stops that the loft panel sits on. Alternatively, the beading can be temporarily removed and the fixings can be hidden underneath. 3 Drill and counter-sink holes into the hatch before lifting it into position. It is also useful if the fixings are partially screwed into the hatch. As it is quite difficult to install a loft hatch unaided or without temporary supports, having additional help is recommended for this stage. 4 Position the hatch so that the backs of the architraves are fitted flush to the ceiling surface, providing that the ceiling has been previously plastered. If the ceiling has not been plastered, then the hatch lining will need to project below the surface of the plasterboard ceiling by 2 mm. Partly screw the fixings in each corner of the hatch into the ceiling joists to hold the hatch in position while it is checked with a spirit level to make sure that it is not in twist. Pack out any gaps behind the hatch fixing points with plastic frame packers or timber wedges, before finally inserting the fixing screws fully. 5 Check the diagonal measurements of the hatch to make sure that it is square before inserting the remaining fixing screws and removing the temporary brace. 6 Fix the architraves to the edge of the lining after the ceiling has been plastered.
9 CUT AND FIX SKIRTINGS AND ARCHITRAVES Skirtings and architraves are lengths of timber trims that are fitted by site carpenters at the second fixing stage of building work, after plastering has been completed. Architraves are fixed to the outside edges of door linings. They are used to hide the joint between the wall and the frame. They may also be fitted around the outside edges of a loft hatch, or similar opening, to cover any gaps between the frame and the plasterboard ceiling. p Figure 4.47 Architrave and skirting
Architraves should be fitted after a door has been hung. This allows the site carpenter to make further adjustments, if needed, at the back of the lining when they are fitting the door, before the gaps are finally covered with the trims.
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Chapter 4 Produce woodworking joints Skirting is positioned at the bottom of walls to protect them from damage around the perimeter of rooms and hallways. They are also used to conceal any expansion gaps left by the carpenters at ground level and provide a neat finish between the floor and the finished wall. This section looks at the process of marking out, cutting and fixing sets of architraves and skirtings. Some of the most common profiles used on these mouldings are also identified.
Marking out, cutting and fixing architraves and skirting Architraves are usually fitted before skirting boards because they extend along the jambs of the door lining to the floor. This allows the skirting to butt neatly against it. The edge of the architrave should be set back from the face of the door lining to create an equal parallel gap all the way around the frame; this gap is referred to as the margin. Margins are usually 6–9 mm wide, but this usually depends on the width of the architrave. Bigger architraves may have a wider gap. Margins enable door hinges and other ironmongery needed to hang a door to be recessed into the lining without interfering with the architraves. They also prevent the door from binding when hung and avoid an unsightly joint that would result if the architraves were flush with the face of the lining. The profiled edge of the architrave should always face towards the door opening in the centre of the lining. It is then mitred at 45° in the top corners to allow the profile to return continuously around the frame at 90°. The sequence shown below illustrates how to mark the margin on a door lining and fit a set of architraves. You should either fix the head architrave first or one of the legs (the long lengths of architrave). This will make the task easier by avoiding the need to fit two mitres at the same time. The tools that you will need to mark out, cut and fix architraves are: l l l l l l l l l
2H pencil combination square rule and tape measure sliding bevel (needed to set out and mark out when the corners are not square) tenon saw mitre box, mitre saw or powered chop saw (also referred to as a mitre saw) block plane claw hammer and a fine nail punch or second fix nail gun PPE.
KEY TERMS Expansion gaps: spaces left between materials to allow them to move freely if they shrink or expand. If gaps are not left and the materials expand, they are likely to buckle and distort. The joint between floorboards and a wall is a good example of where an expansion gap should be left. Joiners also use expansion gaps between tongue and grooved boards when they are making matchboarded doors. Jambs: the long lengths of timber used to form the vertical sides of a door lining or frame. Binding: when something is prevented from moving freely, such as a door being prevented from opening fully because it is binding against the architrave, or the side of the saw sticking and rubbing on the material during the cutting process. Head: the top component in a frame.
INDUSTRY TIP It is best to use nail guns and power mitre saws to cut and fix architraves and skirtings because they enable you to complete the tasks more quickly and more accurately than when using hand tools.
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Fixing architraves Corner check line
Margin
STEP 1 Set up a combination square so that the adjustable rule extends the same distance as the margin. Place a pencil against the end of the combination square and mark a line all the way around the edge of the door lining.
STEP 4 Hold one of the leg architraves against the door lining and mark the top of the fixed head architrave on the back of the leg architrave. The position of the mitre can now be marked properly on the face of the architrave. Repeat this step for the other side of the frame.
STEP 2 Cut a 45° mitre on one end of the head architrave, making sure that the moulding will face towards the margin when fitted. Place the architrave onto the edge of the door lining, so that the bottom edge lines up with the margin line marked out. Adjust the position of the architrave so that the corner of the mitre lines up with the vertical margin line marked out on the jamb, then mark the position of the mitre of the opposite end.
STEP 5 Cut the mitres you have just marked out on the architraves and check that they fit against the door lining.
STEP 3 Cut the mitre marked out on the head architrave and fix it in position. If you are cutting the joints and fixing the architrave by hand, then the oval nails used to hold it in position should be left sticking out at this stage. If the joints have been cut with a power mitre saw, then a bead of grab adhesive should be applied to the back of the architrave and it should be permanently fixed with a nail gun. You should always hide the fixings used to secure the architraves by nailing through either the fillet or the quirk. These are the lower parts of the profile that cast a shadow, so they are more likely to disguise the nail holes.
STEP 6 If necessary, you can plane the mitres to achieve a perfect fit; this is referred to as dressing the timber. When you are satisfied with the result, you can glue and nail both architraves in position. It is common practice to space the fixings 200–300 mm apart.
STEP 7 If you have temporarily fixed the architraves and left the nails raised, you can now drive them below the surface with a claw hammer and nail punch. If a nail gun was used to secure the architraves, the brads will have already been fired below the surface of the timber, ready for filling by the decorator.
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KEY TERMS
INDUSTRY TIPS You should avoid nailing too close to the ends of the architraves when you are fixing them by hand because this may cause the timber to split. When fixing the mitres together, either drill a small pilot hole first or blunt the point of the nail with a hammer. Avoid nailing the mitres together if the architraves are made from MDF because nailing causes the fibres to part, splitting the joint. Fix the mitred joints on architraves together with quick-setting mitre adhesive and nail them together through the head; this will provide a strong joint and hide the fixing. There will be times when you need to fit architraves around corners that are not square, such as under a staircase or where the ceilings are angled in a loft room. To do this, you should bisect the angles needed for the mitres. This simply means dividing the angles equally by two and is not as difficult a task as it may seem (see Figure 4.49). Hold a length of timber trim on the lining head and mark its width onto the face of the wall with a pencil, then repeat the process for the leg architraves. From the point where both lines cross over (intersect), you can mark a line to the inside corner of the door lining to bisect the angle. At this stage, you should adjust and set up a sliding bevel to the bisected angle. You can then transfer the angle onto the architrave to mark out your mitre joints. A similar process can be used to mark out and cut skirting boards to fit around obtuse angled walls.
Adjustable bevel set up to mitre line
Width of trim
? 2
Grab adhesive: a strong glue used to bond timber and timber-based materials like MDF to different surfaces, such as plaster, bricks and concrete blocks. Fillet: a sunk or raised flat surface on a timber moulding, such as skirting and architrave. Quirk: a narrow, deep indentation forming part of a moulding. Dressing: planing the surface of a piece of timber with a hand plane, such as a block plane.
Mitre Intersecting mitre line
?
Width of trim
p Figure 4.48 Bisecting angles for architraves
Bisecting angles for skirting
STEP 1 Draw the thickness of the skirting on the floor.
STEP 2 Bisect the angle on the floor.
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STEP 3 Transfer the setting out lines from the floor to the skirting.
STEP 4 Cut and fix the mitred skirting together.
The tools that you will need to mark out, cut and fix skirting are:
Moulded section mitred
l l l l l l
Waste removed Return moulded section
p Figure 4.49 A splayed heading joint (skirting)
INDUSTRY TIPS It is bad practice to scribe an internal joint of skirting that has a bullnose profile because the scribe produces a weak top edge that could easily break. This problem can be overcome by using a false mitre joint. This type of joint is a combination of a mitred top edge for strength and a scribed lower portion. Always cut the longest lengths of skirting required first. Any offcuts of timber can be used for the shorter walls. This method helps to reduce the amount of time it takes to fit the skirting by minimising the number of lengthening joints needed.
l l l l
2H pencil combination square tape measure sliding bevel handsaw coping saw mitre box, mitre saw or chop saw block plane claw hammer and a fine nail punch or second fix nail gun power drills (cordless screwdriver and SDS hammer drill).
Once the architraves have been installed, the skirting can be fitted. Where the skirting changes direction at the internal and external corners it must be jointed; it may also have to be joined in its length. All the external corners must be mitred at 45° so that the profile of the skirting continues around the corner; this also prevents the unsightly end grain from being visible. This can be done with a chop saw or a mitre saw or marked out with a combination square and cut with a handsaw. Using a chop saw is the preferred method because it is quick and extremely accurate. Any mitres that do not come together perfectly may have to be dressed (planed) with a sharp block plane until there are no visible gaps in the joint. Mitres are not suitable for internal corners because they will reveal large gaps between the skirtings if they shrink, so these joints must be scribed. A scribed joint has the profile of the skirting shaped on the end grain on one part of the joint, to fit neatly over the other section against the wall. The scribed joint is usually undercut slightly so that the visible front edge remains tight fitting and the back of the joint that fits against the wall has a slight gap. Undercutting the joint makes an allowance for the corner of the wall being slightly out of square (not square), which is often the case. Sometimes, the skirting you have will not be long enough for a wall in one length and another piece will be needed to extend it. The best joint to use in this situation is a splayed heading joint rather than a butt joint (see Figure 4.50). The joint should be glued together, nailed securely and sanded to make sure it is perfectly flush. The method used to fix skirting to a wall is determined by the materials used to construct it. If the wall is made of timber and covered with plasterboard, then the
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Chapter 4 Produce woodworking joints skirting can be bonded with grab adhesive and secured with nails, either using a nail gun or oval nails and a claw hammer. If the skirting needs to be fixed to a brick or concrete block wall, you will need to use an SDS hammer drill to bore holes into the masonry to accept plastic plugs and screws or another suitable fixing, such as a hammer-in fixing. If the skirting is to be painted, the heads of the screws should be countersunk below the surface of the wood so that they can be filled. Fixings should be counter-bored (see Chapter 5) on skirting that is to be stained or will have a clear finish applied so that a timber pellet with matching grain can be glued and inserted into the fixing hole to hide the head of the screws.
HEALTH AND SAFETY You should not use a nail gun to secure skirting to masonry walls because doing so could damage the power tool and cause it to misfire. A hazard could also be created if nails hit the masonry wall because they could bounce off the wall and towards the operator or people nearby.
KEY TERM
p Figure 4.50 Timber pellets
ACTIVITY
Misfire: a nail gun failing to operate properly, causing the nail or fixing to get jammed in the chamber of the tool. Always follow the manufacturer’s instructions to avoid this happening.
Research and list a range of suitable fixings that could be used to secure hardwood skirting to a masonry wall. Write a short sentence to explain the benefits of using each of the fixings you have found, such as cost and speed of use.
Skirting/architrave mouldings The detailing on the profile of skirtings and architraves usually suits the style of the property or building in which it is fixed. In new build house construction, the profiles are often extremely simple, so it is easier to cut the internal scribes, quicker to install and cost-effective. Traditional buildings had deeper and more elaborate mouldings to reflect the grandeur of the property. The following illustrations are some of the most used profiles for both skirtings and architraves.
p Figure 4.51 Bull nose, splayed, torus, ogee and grooved mouldings
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Practical task Drawing a setting out rod Outline of task You are required to draw a setting out rod for a frame incorporating six different types of woodworking joints discussed in this chapter. Mark out the components to make the frame from the setting out rod. Produce the joints marked out and assemble the frame. Candidate information Before starting each task, ensure that you have been given permission by your tutor or teacher to proceed. You should be given feedback on the completed task and any retraining as required. Task
Achieved
Requires retraining
Used a range of setting out tools to produce an accurate setting out rod Used face side and face edge marks Used a range of marking out tools to mark out the components from the setting out rod Safely used a range of hand tools to produce a variety of woodworking joints, free from gaps of more than 0.5 mm Assembled a frame and checked to make sure it is flat and square Made sure all the joints are flush and that the frame has been sanded Removed the sharp edges
Activity
Further training required detailed here
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Chapter 4 Produce woodworking joints
Test your knowledge 1 Name the two methods used to season timber. 2 Explain how timber or timber-based sheet materials should be stored. 3 Label the following profiles:
a
b
c
d
e
4 What kind of joints are used on skirting for external and internal corners? 5 What is a squaring rod used for? 6 What ratios are used to make dovetail joints? 7 Draw face side and face edge marks in the boxes below: Face side
Face edge
8 What type of handsaw is commonly used to cut the shoulders of woodworking joints? 9 What is the correct term for the sharp corners on a piece of timber, usually removed with abrasive paper? 10 Name the three classifications of woodworking joints.
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CHAPTER 5
TYPES OF FIXINGS AND IRONMONGERY
INTRODUCTION The terms fixings and ironmongery are used to describe the different types of hardware used in the carpentry and joinery industry. This chapter outlines the most common types of fixings and ironmongery used today. It includes a discussion of where to place different types of fixings and ironmongery, their specific uses, how to select appropriate types and fixing techniques. Your choice of fixings and ironmongery impacts not only on the finished look of the project, but also the effectiveness of the hardware when used for its required task.
KEY TERMS Fixings: types of screws, nails, adhesives and sealants used within carpentry and joinery and the construction industry as a whole. Ironmongery: hardware, such as locks, handles and hinges.
LEARNING OUTCOMES In this chapter, you will learn about: 1 materials used in the manufacture of fixings and ironmongery 2 fixings used in carpentry and joinery 3 types of ironmongery 4 installing ironmongery.
1 MATERIALS USED IN THE MANUFACTURE OF FIXINGS AND IRONMONGERY A wide range of fixings and ironmongery is available for use within carpentry and joinery in many different types of materials, designs, and colours.
INDUSTRY TIPS Ferrous metals contain iron while non-ferrous metals do not. Metals containing iron and steel are prone to rusting. Do not use iron and steel with acidic timbers such as oak, which can cause unsightly staining to the joinery.
Ironmongery and fixings are usually made from either ferrous or non-ferrous metal. The type of materials the fixings and ironmongery are made from will determine their most suitable location, along with their suitability for specific tasks.
Ferrous metal Ferrous metal contains iron and unless it is protected in some way it is liable to rust if exposed to damp conditions or used in external environments. Ferrous metal is the most widely used material in the production of ironmongery and fixings, usually in the form of mild steel. This is often the cheapest material. The appearance of mild steel can be enhanced by a process called electro-brass or zinc plating, which also adds protection to the mild steel, enabling it to be used in external situations.
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Chapter 5 Types of fixings and ironmongery Heavy-duty iron or cast-iron ironmongery is suitable for heavyweight doors but cast iron can be brittle. Although stainless steel contains iron, the manufacturing process for this type of steel makes it very resistant to rusting or staining. It is frequently used in damp or external situations.
Non-ferrous metal Non-ferrous metal does not contain iron and includes metals such as aluminium and brass, which are used in some fixings and ironmongery, as well as other metals such as copper, lead, gold and silver. These metals are extremely resistant to rusting and staining and are suitable for both internal and external use. Brass and aluminium are often used in the production of screws and ironmongery, but they are soft metals that can easily be damaged. If you do not take great care when using brass screws, they may break when being screwed into hard materials such as beech and oak.
2 FIXINGS USED IN CARPENTRY AND JOINERY Fixings used within carpentry and joinery usually fall into one of the following categories: ● ● ● ● ●
nails screws coach screws and bolts wall plugs and cavity fixings adhesives.
Nails Loose nails are not used nowadays in carpentry and joinery as often as they were in the past. Most carpenters and joiners use powered nailers and collated nail strips when fixing materials, though several types of loose nails are still available and in common use, as shown in Table 5.1. q Table 5.1 Types of nail and their uses Type of nail
Description
Uses
Cut clasp nails
These nails are known as floor brads and are sheared or punch cut by machine from steel plate, producing a nail with a distinctive wedge shape that ends in a blunt point. This helps to reduce the risk of splitting the ends of the timber.
Traditionally used to fix wooden floorboards and door and window frames.
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Description
Uses
Lost head nail (oval nail)
These are manufactured in varying lengths and gauges, each having a small oval head shape that is easily driven below the surface of the material.
Used when the head of the nail needs to be hidden or lost in the surface of the material; has limited holding abilities.
Bright steel round head nails
These are manufactured with large flat round heads.
Used for multi-purpose fixing situations and available in a variety of different lengths and gauges. This type of nail head gives the nail better holding properties than an oval nail and is used in situations where seeing the nail head is not a problem.
Annular ring shank nails
These are manufactured with large flat heads and a series of raised ridges around the shank of the nail.
The raised ridges give this nail increased pulling resistance compared to other types of nail.
Galvanised clout nails
These nails have extra-large heads and a galvanised coating.
Used in external fixing of items such as tile lath and roofing felt.
Collated nails (also known as brads)
These are manufactured from galvanised coated steel and glued in place as strips of nails. Available as either ring shank nails or smooth shank nails.
Used with power fasteners and available as either straight or angled collated versions. Used in internal and external fixing, such as fixing roof members and studwork with heavier longer nails and skirting and architraves for shorter lightgauge versions.
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Chapter 5 Types of fixings and ironmongery Type of nail
Description
Uses
Masonry nails
Masonry nails look similar to lost head nails but have slightly larger heads. They are made of hardened zinc for added strength.
Used for direct fixing into masonry such as brickwork.
PVCu covered nail heads
This type of nail is manufactured from stainless steel with small annular rings around its shank. The nail head has a covering of PVCu.
Used with the installation of PVCu materials such as fascia and soffit. The annular ring shank has high pulling resistance once fitted.
KEY TERMS
INDUSTRY TIP As a rule, the nail should be roughly 2½ times greater in length than the thickness of the material being nailed through. For example, 20 mm wide material being fixed would require a nail that is 50 mm long.
IMPROVE YOUR MATHS Jan has been asked to select the correct nail lengths for fixing softwood timber in place. Which of the following nail lengths would be most suitable for the different standard finished thicknesses of timber? Nail lengths available: 40 mm, 65 mm, 75 mm and 100 mm. Timber thicknesses requiring fixing: 15 mm, 30 mm and 44 mm.
Screws Screws are available in different sizes, materials and head shapes and require a wide range of drivers to fix them.
Tile lath: length of treated timber used to help hold roof tiles in place. PVCu: polyvinyl chloride unplasticised. This is often referred to as uPVC, but the abbreviation was changed in the 1980s to PVCu, so that British manufacturers now use the same term as their European counterparts.
Metric diameter (mm) Type of driving bit required
Length (mm)
Many screws are designed to suit specific types and styles of ironmongery so will vary in style and material. Wood screw sizes are defined by two different numbers, as shown in Figure 5.1. ●
In imperial screw sizes, the first number given is the gauge of the screw, which refers to the screw’s thickness or gauge, but it is not the screw’s diameter in inches. ● In metric screws, the first number refers to the screw’s diameter in millimetres.
Pack size
Imperial gauge
Length (inches)
p Figure 5.1 Example wood screw sizing chart
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For both imperial and metric screws, the larger the number, the larger the diameter of the screw.
Shank
The length of the screw is given in the second number, which is always the depth that the screw penetrates the timber, or other material being fixed, and does not include the length of any raised or pan-headed screws.
Parts of a screw There are 4 distinct parts to a wood screw, as shown in Figure 5.2. Thread
Head The shape of the screw head determines the suitability of the screw for different types of tasks. The most common types of screw heads are as follows.
Tip
p Figure 5.2 Parts of a screw
A countersunk head has a flat surface along the top of the screw and a straight taper from its underside down to the start of the shank. This design allows the head of the screw to finish flush (just below the surface of the timber). Some screws offer an improved double countersunk design, which gives the screw head additional head strength and makes the countersinking process easier. A raised head or pan head has a countersunk underside to the screw head but is combined with a raised head. The head protrudes above the finished surface as a decorative feature. It is a common type of screw head used with ironmongery such as lever handles on door locks. Raised oval head
Flat top Tapered underside
Tapered underside
Shank Shank
p Figure 5.3 Countersunk screw head
KEY TERM Japanned: a black lacquer applied to the surface of the screw or ironmongery and then baked hard.
ACTIVITY Compare a flat head screw and a countersunk screw in a pocket screw hole and consider the capability of the different screws to form a strong tight joint.
p Figure 5.4 Raised oval head screw
A washer head screw has a large flat underside to the screw head that appears to incorporate a washer. The screw head has a wide flat surface area and is used in situations where a countersunk head may cause splitting. This type of screw head is commonly used with a pocket screw jig. A round head has a large flat base with a rounded or domed shape to the top of the screw head. It is available as either a coarse (spread out) thread, such as with wood screws, or a fine machine thread like those used on bolts with nuts and washers. This type of head provides a larger surface area for the screw head to grip and stop and is typically used on black japanned screws with traditional black ironmongery and also with pocket screws. A bulge head is a variation of the countersunk screw head, but the bulge head design has a curve to the slope of the countersink. This screw is typically used on drywall wall screws for plasterboard, because the bulge design helps to reduce any tearing of the paper surface of the plasterboard.
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Chapter 5 Types of fixings and ironmongery
Curved underside
p Figure 5.5 Pocket screw and drill
p Figure 5.6 Bulge head used on a drywall screw
Shank and thread
KEY TERM
The thread of a screw wraps around the screw’s shank and is the part of the screw that drives or pulls the screw into the material. Some screws have a full thread; in others, the thread stops before it gets to the head and approximately a quarter of the shank is not threaded.
Clearance hole: a hole that is slightly drilled through only the upper component being fixed. This hole should be slightly wider in diameter than the gauge or diameter of the screw. This enables the screw to pass cleanly through the material without binding.
Traditional screws usually have partial threads. The lack of a full thread allows for a higher level of security between the connected materials. For example, the threads at the bottom of the screw drive into the lower material, pulling the upper material down and forming a secure connection. If fully threaded screws are used without a clearance hole, they can sometimes allow the upper material to have limited or even no contact with the lower material, although the screw is fully driven home. This problem has largely been eliminated by the introduction of impact drivers and modern screws. When using fully threaded screws, particularly with hardwoods, you should drill the correct-sized clearance hole through the upper material. Screws are available as single thread or twin-threaded screws. A twin-threaded screw has two threads running along the shank, while a single thread screw has just one. Screws incorporating twin threads are usually faster driving screws, which means they can be inserted and removed twice as fast as a single thread. Twinthreaded screws hold the material more securely than a single thread screw but are usually more expensive. Some screw designs have a serrated thread, allowing the screw thread to cut its way through the material being screwed more easily, thereby requiring less force and potentially saving time if driving home the screw.
INDUSTRY TIP When using part-threaded screws, always use a suitable sized clearance hole.
Tip of the screw Cut-away
The tip or point of the screw is designed to help start the process of fixing it. section of self-cutting Modern screws incorporate a self-cutting tip, as shown in Figure 5.7. This type of design has the screw tip partly cut away to form a cutting edge. The screw tip cuts screw tip the material as it is being driven in, allowing for reduced strain on the material and screw. In turn, the screw can be inserted more easily and this reduces the risk of the screw splitting the material, which can be a problem when fixing near the ends p Figure 5.7 Self-cutting screw tip of timber. 233
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ACTIVITY On a spare piece of timber, compare different types of screw thread and screw tips for their capability to penetrate timber without splitting it when the screw is positioned within 30 mm of the timber end grain.
Types of screw Carbon steel, brass and stainless steel are the most common materials used to manufacture screws, but other materials such as nickel alloys and aluminium alloys are also used. The more usual types of screw and their uses are given in Table 5.2. q Table 5.2 Types of screw and their typical uses Type of screw
Typical uses
Yellow passivated wood screw
These are general purpose wood screws with a high resistance to corrosion, suitable for all exterior and interior use. These screws have been dipped in zinc and treated with a coat of yellow dye to help resist rusting.
Quicksilver wood screw
These are carbon steel screws that have been electroplated with a zinc alloy coating. They are economical general-purpose interior wood screws that are resistant to corrosion, suitable for all types of interior work.
Stainless steel wood screw
In appearance this looks like the quicksilver screw. It has a high corrosion tolerance and superior strength compared to brass screws. These screws are suitable for external and internal uses, particularly in areas where conditions are generally damp. They do not react with acidic materials such as oak so do not stain the material or corrode away.
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Chapter 5 Types of fixings and ironmongery Type of screw
Typical uses
Countersunk screws with a round head
Countersunk and raised head screws are used to fix fittings such as door handles. They are often used in conjunction with screw cups.
Screw cups These are available in either a brass or silver finish and are used to add a decorative finish to the fixing, often with furniture. They also provide a wide fixing surface area, which is particularly useful when using small screw heads that provide limited surface fixing areas.
Black japanned screw
These are round headed screws with black japanned finish. They are used with traditional black ironmongery, commonly used in restoration projects, period homes, with some types of latches and hinges and with any type of japanned ironmongery. The black japanned finish is a black lacquer applied to the surface of the screw or ironmongery and then baked hard.
Concrete screw
Concrete screws have been developed as a more efficient and modern alternative to the traditional wood screw and wall plugs. Concrete screws were developed to overcome the difficulties associated with lining up the screw with the wall plug through hollow materials such as PVCu windows and doors. Concrete screws do not require wall plugs but they do require a pilot hole of the correct size, which is stated on the screw’s box. When using concrete screws, the correct size pilot hole is drilled through the frame and into the masonry beneath. The thread of the screw has a special cutting design that cuts into the pre-drilled masonry hole, giving a firm and secure grip.
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INDUSTRY TIP When using brass screws, first use a steel screw of the same size and then replace it with the brass screw. Using a small amount of lubrication such as beeswax, petroleum jelly, furniture wax or candle wax on the screw thread will help to drive brass screws home and reduce the likelihood of stripping the screw head or breaking the screw.
Brass is an exceptionally soft material but is particularly good at resisting corrosion. Brass screws are ideal for use with brass ironmongery and furniture where the screw head will be on display. They are also suitable for external use, but because of their softness they tend not to be used apart from with brass door hinges and other forms of ironmongery. Brass screws are weak and can easily break, particularly when being fixed in hard materials such as oak. It is essential that you always use suitable sized pilot and clearance holes when using brass screws to avoid breaking the screw.
Screwdriver bits Many different screwdriver bit designs are available that correspond with the shape of the recess (sunken area) cut into the head of the screw. You should select the correct design bit to match the type used on the head of the screw, because using a different bit design to that intended for the screw head can result in damaged screw heads. This can make it difficult to either fully drive the screw home or remove it. It also leaves an unsightly damaged screw head which gives a poor impression of the quality of your work. The most common types of screw heads are Pozidriv (PZ), Phillips (PH), slotted, Torx®, square recess and hex, as shown in Table 5.3.
q Table 5.3 Types of screwdriver bit and screw head designs Screw head design and type of screwdriver bit Slotted
Description This is a traditional screw head design consisting of a single slot, used mainly with imperial screw sizes and some forms of ironmongery. This type of screwdriver bit can easily slip out of the screw head in use, resulting in damage to both the screw head and the surrounding material. The slot in the screw head should always be finished with the slot running vertical (upwards).
Phillips (PH)
This screw head design is an improvement on the slotted head. The single crossshaped recess gives better contact with the screwdriver bit and better resistance to the screwdriver head, preventing it from slipping in the screw head.
Pozidriv (PZ)
This is the most common form of screw head. It has two sets of cross recesses in the head, one smaller shallower set cross at 45˚ to the larger and deeper set cross. The screw heads require screwdriver bits ranging from the smallest, size 0, to the largest, size 3, with size 2 being the most frequently used.
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Chapter 5 Types of fixings and ironmongery Screw head design and type of screwdriver bit
Description
Torx®
The Torx® screw head has a six-pointed star design and allows for higher torque, better grip and improved driving angles than the Pozidriv head. It is ideal for use with combi drills and impact drivers for fast driving of the fixing.
Square recess
This type of screw is also known as a Robertson screw. It has a square-shaped socket in the screw head and a square protrusion on the driving bit, with both the screw head and bit having a slight taper. It is often used in furniture manufacturing and pocket screw jigs.
Hex
This type of screw head has a six-sided recess in the head of the screw and can be driven in with hexagonal driver bits or Allen keys. This type of screw is like a hex bolt. It is commonly used with a corresponding nut and washer, as well as being a type of fixing found on kitchen appliances such as fridge doors, where it is often necessary to change the hanging side of the door.
It is important that you use the correct shape and size of screwdriver bit to prevent slippage and for ease of use. Typical screwdriver sizes needed for varying screw sizes are as follows. ●
3.0 mm and smaller screws require screwdriver size 0. 3.5 mm screws require screwdriver size 1. ● 4.0–4.5 mm screws require screwdriver size 2. ● 5.0 mm and larger screws require screwdriver size 3. ●
IMPROVE YOUR ENGLISH Outline the main differences between ferrous, non-ferrous and zinc-coated screws. Identify which types are the most suitable for external uses and present your recommendations in a simple information leaflet that could be placed in your ironmongery stores.
ACTIVITY Compare how the appropriate type of screwdriver bit locates in the screw head and resists slippage for the: ● slotted screw head ● Pozidriv screw head ● Torx ® screw head.
INDUSTRY TIP Ironmongery should be fitted in accordance with Building Regulations approved documents.
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Timber pellets
Timber pellet
p Figure 5.8 Timber pellet covering a screw head
In some cases, it is not acceptable for a screw head, even a countersunk screw, to be on display. Better-quality work requires that screw heads are hidden. One solution, if the screw head is driven deep enough, is to cover the screw head with filler and paint over it. In other cases, the fixing can be hidden beneath a door stop such as with door linings. However, on particularly high-quality work, such as hardwood joinery or timber frames and linings requiring a clear finish, a more effective finish is needed. The type and quality of finish will determine the way a fixing is used and hidden. One of the best methods of hiding screw heads is to use timber pellets to conceal fixings. Timber pellets are cut in such a way that the grain direction of the pellet follows the grain direction of the material it is being inserted into. Timber pellets are available in a wide variety of timbers and manufactured to fit specific sized bored holes; alternatively, they can be home made with special plug cutters.
Fitting timber pellets After determining the location of the screws, make a counter-bored hole of a suitable diameter to match the size of the pellet and drill to a depth that will allow the screw head to be driven fully home (fully tightened) while leaving enough room above the screw head to insert the timber pellet to a depth of at least 6 mm.
ACTIVITY Practice forming, fitting, and cleaning up timber pellets manufactured from different materials such as softwood and oak.
After fully driving home the screws and when you are satisfied with the location of your work, glue the timber pellets in place. When positioning the matching timber pellet, it is important to position it with its grain direction matching that of the material being fixed. When the glue has fully set, clean the pellet flush with the timber surface. A chisel and block plane are usually used to cut back the protruding section of the pellet. The pellet is then further finished with abrasive paper to finish flush with the timber surface.
Coach screws and bolts Coach screws are heavy-duty fasteners consisting of a part-threaded shank and a large hexagonal head. These types of screws are specially designed for fastening heavy timbers and metalwork to timber. A suitable size clearance hole should always be used with this type of fixing.
Pilot hole size no greater than this measurement
p Figure 5.9 Coach screw
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Chapter 5 Types of fixings and ironmongery Coach bolts tend to have a rounded or domed head with an anti-slip square section beneath. The shank is only part-threaded with a much finer thread that accepts a nut and washer. This type of fixing requires a clearance hole and is used to firmly clamp two pieces of material together. The coach bolt is typically used in conjunction with ‘dog tooth’ connector plates, which are placed on the coach bolt between the two pieces of material being clamped. When fully clamped together the teeth of the dog penetrate (dig into) the timbers, gripping them and helping to prevent the two connected pieces of timber from slipping and twisting, thereby helping to form a strong connection.
Squared section just beneath head
p Figure 5.10 Coach bolt and nut
p Figure 5.11 Dog tooth connector
Wall plugs and cavity fixings Masonry walls tend to be porous and brittle. As standard thread wood screws do not have sufficient grip to hold fast and support a weight on a masonry wall, they are used in combination with wall plugs. Wall plugs enable wood screws to be driven into them to hold the fixing to the masonry wall, such as for kitchen cabinets. Wall plugs are now almost exclusively made from nylon, although originally timber and fibre would have been used.
KEY TERM Nylon: a type of plastic.
Wall plugs Wall plugs need to be inserted into the correct size of clearance hole. It is important that you choose the size of drill bit that corresponds to the diameter of the wall plugs you intend to use. Wall plugs are colour coded to help with the sizing of suitable screws and clearance hole diameters. Slight variations on clearance hole sizes will depend on how porous and brittle the masonry is. As a rule, use a slightly smaller sized clearance hole for porous and brittle masonry. Table 5.4 gives guidance on suitable size comparisons.
p Figure 5.12 Standard type nylon wall plug
For example, when drilling into a firm masonry background, a 7 mm masonry drill bit should be used to form the clearance hole for a brown plug using 5 mm gauge screws. q Table 5.4 Wall plug size comparisons Plug colour
Clearance size
Screw gauge
Yellow
4.5 or 5 mm
3 mm
Red
5.5 or 6 mm
3.5 to 4 mm
Brown
6.5 or 7 mm
4.5 or 5 mm
Blue
7 or 8 mm
5 or 6 mm
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Cavity fixings Where you need to fix into a cavity (such as those found in plasterboarded stud partitions) a different type of fixing is required, as the standard type of nylon wall plug cannot provide sufficient holding power. A cavity fixing (often called a drywall fixing or cavity anchor) that increases the surface area grip of the fixing is required. Various types have been developed specifically for hollow cavity walls, the most common of which are listed in Table 5.5. q Table 5.5 Fixings for hollow cavity walls Type of fixing
Description
Advantages
Disadvantages
Nylon expanding anchor
This is a plastic fixing that expands as the screw is tightened into the anchor. The back edges of the fixing expand (get bigger), making it harder for the anchors to be pulled out.
Cheap and easy to install.
Limited ability to hold heavy weights.
Metal expanding anchor
This is a metal version of the nylon anchor that requires a special leveroperated setting tool. As the lever is pumped, the anchor’s inner section expands and tightens against the plasterboard.
Able to hold heavier weights.
More expensive and difficult to use.
Self-drilling plasterboard anchors
This is an easy-to-use self-drilling plug, available in either a plastic or a metal construction. The cutting end forms its own starting point, while the wide course threads drive into the plasterboard to provide a firm fixing. These should only be screwed in by hand, as power drivers can easily strip out the plasterboard.
Can be screwed straight into plasterboard without predrilling. Supplied with relevant size screws.
Can easily strip plasterboard.
Gripit® plasterboard fixings
This is a relatively new addition to plasterboard anchors. It has anti-rotational fins on the back side, which provide a firm fixing.
Available in four different sizes to suit different weight categories and different thicknesses of plasterboard. Provides a firm stable fixing suitable for heavy use. Supplied with relevant size screws.
Expensive to purchase.
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IMPROVE YOUR MATHS Use different types of cavity fixings to attach a coat hook onto a plasterboard surface. When the coat hook is securely attached using each type of cavity fixing, pull the coat hook from the surface. Rank the fixings in order of resistance to pulling, where 5 is extremely difficult to remove and 1 is easily removed. Present your findings in a suitable bar chart.
Types of adhesives and their uses Several types of adhesives are commonly used in carpentry and joinery. Although site carpenters and bench joiners tend to use different adhesives, both trades can use any type of adhesive. Site carpenters mostly use faster acting adhesives, such as foam adhesive, grab adhesive and contact adhesive, while bench joiners use more slowly acting adhesives that usually set under pressure from clamps. Table 5.6 outlines the most commonly used adhesives within the carpentry and joinery industry. q Table 5.6 Most commonly used adhesives within carpentry and joinery Adhesive type
Description and uses
PVA
This adhesive is a resin dissolved in water; it usually comes mixed and ready for immediate use. As the water evaporates and is absorbed by the timber, the adhesive dries (goes off).
Polyvinyl acetate (Also known as white glue)
PVA is available in internal grades and also exterior grades, which can be used where damp and wet conditions are likely to be met. It has good gap-filling properties and provides a strong permanent bond (grip) between surfaces. This type of adhesive dries clear, but if not cleaned up properly can leave visible marks when the product is varnished or stained. It can react with some hardwoods to leave black joint lines or marks.
PU Polyurethane (Also known as foam glue)
This is a yellow-brown resin that foams when exposed to the air. It forms a strong, water-resistant bond and has excellent gap-filling properties. It can be used to join damp timbers. The glued joint must be secured together while the glue dries, otherwise the foaming action of the adhesive could force the joint apart. The excess glue can easily be removed after it has dried by scraping it off the joint, but not before it has dried, as this will result in the adhesive spreading over the work piece, tools and potentially yourself. PU glue is normally supplied with a pair of disposable gloves, which should always be worn when using it.
Urea-formaldehyde
This adhesive is mixed with water before use. A chemical reaction causes the adhesive to set after a few hours, depending on the surrounding temperature.
(Also known as powdered resin glue)
This type of adhesive forms a strong water-resistant bond. It is used for high-quality work as it does not stain the timber being joined.
Synthetic resin
This is supplied in a tube or cartridge and applied using a skeleton gun, either to the back of the moulding or direct to the wall and frame prior to final positioning. Some grab adhesives form a skin as soon as they are exposed to the air, which prevents them bonding as well as other adhesives. Some are also very thick, which may cause the surfaces to sit slightly apart and reveal a gap in the joint.
UF
(Also known as grab adhesive)
Although it is not often used in the joinery workshop, it is used for site work such as bonding timber to walls. Modern grab adhesives are popular for providing an additional method of securing moulding such as architraves and skirting to the lining and wall. They also allow for any imperfections in the wall surface and help to prevent any gaps caused by shrinkage. Contact adhesive
This type of adhesive is used for bonding plastic laminates to manufactured board, such as kitchen edging strips. A thin layer is applied to each surface, left until touch dry, and then the two surfaces are brought together for an instant permanent bond.
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Description and uses
Mitre adhesive (also known as super glue)
This is a clean and quick-drying adhesive and activator used for fixing architrave corner mitres on skirting boards, cornices, pelmets and plinths. Mitre adhesives consist of a two-part system of a cyanoacrylate bonding adhesive and a spray-applied activator. The adhesive is applied to one surface and the activator sprayed onto the other. As soon as the activator has evaporated, the two surfaces are brought together to form a bond that is solid in approximately 10–15 seconds. Extreme care is needed to prevent contact with skin, which can quickly and easily be stuck together.
Polyurethane fixing foam
Polyurethane fixing foam is now commonly used when fixing all types of frames and linings and is applied using an applicator gun. It is a bit like polyurethane (PU) adhesive. It fills gaps and bonds most products to all surfaces and materials. Different grades of foam may have different properties, such as accoustic insulation (resistance to the passage of sound), thermal insulation (ability to retain heat or reduce the transfer of heat) and fire ratings (ability to act as a fire barrier). It is particularly useful in fixing and sealing door frames and window frames when used in conjunction with mechanical fixings.
HEALTH AND SAFETY
IMPROVE YOUR ENGLISH
When using adhesives, always follow the manufacturer’s instructions and use suitable hand protection to prevent skin contamination.
Download the health and safety data sheets for mitre adhesive (super glue) and produce a simple fact sheet for using it safely.
3 TYPES OF IRONMONGERY Traditional ironmongery was made from iron, but modern manufacturing techniques now enable the use of an almost unlimited choice of materials, designs and colours. Ironmongery is sometimes referred to by its location, such as door, window, gate and kitchen furniture, as well as by its type, such as: ●
hinges ● locks and latches ● handles and knobs
KEY TERMS Ironmongery schedule: a document used to list repeated ironmongery that is used throughout a project such as new build housing. Butt hinge: a type of hinge consisting of two flat leaves revolving around a pin (hinge), the knuckle of which pivots. Commonly used to support internal and external timber doors.
●
bolts and security devices ● door closers ● cabinet hardware.
On larger building projects, the ironmongery may be listed on an ironmongery schedule, identifying the specific type of ironmongery to be used in specific locations. For example: door A should use 1½ pair of 100 mm high-performance ball-bearing stainless steel hinges, a cylinder night latch and a security viewer. The schedule will also give further details on the positions of the ironmongery on the door.
Hinges Hinges are frequently used to hang doors. They are available in a wide range of sizes, materials and designs to suit different applications. When selecting a size and style of hinge, you need to consider the size and type of screw to use with the hinge. When fitting butt hinges to doors, use the following lengths of screw as a guide. ●
For a door that is 35 mm thick, use 25 to 32 mm screws. ● For a door that is 44 mm or 54 mm thick, use 32 to 40 mm screws. Whatever length of screw you use, it is important to ensure that the countersunk head of the screw matches the countersunk recess in the hinge. This is to prevent the screw
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Chapter 5 Types of fixings and ironmongery head from either protruding above the hinge, which can cause the door to ‘bounce’ open, or having too small a screw head that fails to properly hold the hinge in place. One of the most common types of hinge you are likely to fix is the butt hinge (see Figure 5.13). Butt hinges consist of two leaves joined by a fixed pin that passes through the knuckles formed on the inner edges of both leaves. There are several variations: some have washers between the knuckles while others contain small ball bearings. Butt hinges should be fitted so that both leaves are recessed equally into the door and frame, leaving a small gap between them when the door is closed to help the door to operate without binding. The knuckle is usually positioned to project just past the face of the door to give increased clearance for the door to swing open when it is being used. There is normally an odd number of knuckles on butt hinges. The leaf with the most knuckles is usually fitted to the door frame and the leaf with the least knuckles is fitted to the door. Pin through centre of knuckles
INDUSTRY TIP There is a helpful rhyme to help you remember how to fit butt hinges: ‘the most to the post’, which means that the leaf with the most knuckles is fixed to the door frame.
Hinge knuckles Countersunk screw recess holes
Hinge leaf Most knuckles on this leaf
p Figure 5.13 Parts of a standard butt hinge
Butt hinges are available in a range of sizes, from 25 mm up to 100 mm. Brass butt hinges are susceptible to wear on the knuckles, so stainless steel or phosphorbronze washers are fitted between the knuckles to prevent this. The washers also reduce squeaking. Table 5.7 outlines some of the common types of hinges in general use. q Table 5.7 Types of hinges in general use Type of hinge
Description and typical uses
Ball race butt hinge
High-performance ball bearing or ball race hinges give a much smoother action. They are durable and particularly good for use with heavy doors. They are available in sizes from 75 mm to 150 mm.
Ball bearings
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Description and typical uses
Loose pin butt hinge Loose pin lifts
Loose pin butt hinges enable easy removal of the door by removing the pin from the hinge knuckle. This enables the door to be removed without having to remove the hinge from either the door or the door jamb. The pin can be tapped upwards out of the hinge to allow the door to be lifted away with little effort. This type of hinge should not be used on outward swinging exterior doors. A variation on the loose pin hinge is the lift off butt hinge, which enables the door to be lifted off when it is in the open position. The hinges are handed for doors that are opening either from the right or the left and incorporate one long pin hinge and one short pin hinge. The long pin hinge is positioned at the bottom of the door and the short pin hinge is the upper hinge.
KEY TERM Door jamb: the part of the door frame running vertical on either side of the door opening Rising butt hinge
Rising butt hinges have a spiral-shaped knuckle, allowing the door to rise as it opens. They are particularly useful in clearing uneven floors or mats and rugs. The shape of the knuckle also gives the door a self-closing action. The top of the door requires a taper on the hinge side known as a leading edge. This allows the door to move past and clear the head of the door frame as it opens and closes. These hinges are handed, meaning that you need to choose different hinges depending on whether they will be fitted to a right-hand opening door or left-hand opening door.
Parliament hinge
Parliament hinges have wide leaves that allow the knuckles of the hinge to protrude away from the edge of the door. This type of hinge allows the door to swing open and away from the hanging side of the wall. It is particularly useful when the door needs to be folded back close to the wall.
Flush hinge
Flush hinges are only suitable for lightweight doors such as those used for encasing services (such as pipes and waste traps) for easy access, for furniture and for hatches.
Fit this part to the door
These hinges are quick and easy to install as they sit on the surface edge of the door and frame, eliminating the need for the timeconsuming process of cutting recesses into the door and frame.
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Chapter 5 Types of fixings and ironmongery Type of hinge
Description and typical uses
Spring hinge
Adjustable spring hinges are designed to make a door selfclosing. They have large cylindrical (tube-like) knuckles that can be tensioned to the required closing action. Single-action spring hinges have two leaves and are used to open and self-close to one side of the opening. Double-action spring hinges are designed to make a door self-closing. They have large cylindrical knuckles that can be tensioned to the required closing action. They have three leaves and open 360°.
Fitted double-action spring hinge Jamb Batten 90°
Door
Door open
90°
Door closed
Tee hinge
To correctly install double-action spring hinges, fit a planed strip of timber that is the same thickness as the door to the hanging edge of the frame. This allows free movement of the cylindrical knuckles. Double-action spring hinges are often used in corridors of public buildings such as schools and hospitals, and between kitchen and dining areas in restaurants and pubs.
Door open
Tee hinges are made from thin-gauge steel and are usually black japanned or galvanised. They are mainly used with matchboard doors and gates.
KEY TERM Matchboard: a term given to tongue and grooved timber boarding, often used on doors and gates.
Hook and band hinge
Heavy-duty hook and band hinges are made from stronger galvanised or stainless steel. They are used for heavier industrial or garage doors and farm gates. They are also used for framed, ledged and braced doors, which consist of vertical boards strengthened with horizontal boards on one side. Hook and band hinges can be straight or cranked (bent) and can have a means of adjusting the hinge, usually through a threaded bolt adjustment.
Concealed cupboard hinge
This is commonly used to hang kitchen unit doors. Kitchen cabinets are usually made with artificial boards, such as chipboard and MDF, which do not hold screws well on their edges. To overcome this problem, a ‘blind’ circular recess is bored into the inside face of the doors to accept the hinge. The recess has a diameter equal to the diameter of the concealed hinge; this is usually a standard 35 mm diameter, but smaller versions are available at 26 mm diameter. The concealed hinge is inserted into the blind recess and secured with 3.5 × 16 mm screws. This type of hinge ranges from a basic design with limited adjustment to a soft-close (smooth and silent closing) fully adjustable version.
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Description and typical uses
Invisible closers/hinges
This type of concealed hinge is intended not to be seen when fitted unless the door is open. It is suitable for flush doors with timber, steel and aluminium frames. One of the most common types is the Soss hinge, which is available is several sizes suitable for full-height doors down to small furniture doors. Soss hinges are suitable for both internal and external use and can be used for heavy-duty doors and fire doors.
Soss hinge
Selecting hinges for use It is essential that you select the correct type and number of hinges required for hanging a door to ensure that it works properly. If it is not hanging perfectly within the frame, the door may sag and drop over time. This means that the lock or latch may fail to locate correctly and the door will not shut and lock correctly. 150 mm
Equal
Equal
225 mm
p Figure 5.14 Standard door hinge positions
●
Lightweight internal doors, such as hollow core doors, usually require only one pair of 75 mm hinges per door. However, a manufacturer’s information may specify that bathroom and en-suite doors should be hung on one and a half pairs of 75 mm hinges (three hinges). ● Install 35 mm-thick timber doors, such as panelled and glazed internal doors, using one and a half pairs of 75 mm hinges. ● Install all 44 mm-thick doors, whether internal or external, with one and a half pairs of 100 mm hinges. ● Fire doors should be installed using one and a half pairs of fire-rated 100 mm hinges. The specified hinge positions for some fire doors may be different because of their size, construction method and fire certification. It is not uncommon to see the middle hinge moved to 200 mm below the top hinge or for there to be 4 hinges used on heavier doors. Hinge positions for doors have regional variations, but the standard positions are 150 mm down from the top of the door and 225 mm up from the bottom, while the centre hinge is positioned an equal distance between the top and bottom hinges. On heavier doors, the middle hinge is often moved up to 200 mm below the top hinge.
Locks and latches Locks and latches are mostly made from steel, with a variety of finishes that can be matched to the finish of other door furniture. They are usually supplied with fitting instructions. Most locks and latches are morticed (recessed) into the closing edge of the door, although a few, like rim locks, sit on the face of the door. An increasingly wide variety of locks and latches is available, but most fall into the following three main categories: ●
mortice latch/lock mortice latches ● rim locks and latches. ●
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Chapter 5 Types of fixings and ironmongery The main difference between a mortice latch and a mortice lock is that a door fitted with a mortice lock can be locked as well as just latched shut, while a door fitted with a mortice latch can only be latched shut and not locked. The lock is controlled by levers and activated by a key: the more levers the lock has, the more secure it is because it is more difficult to pick. A lock works when the correct key lifts the levers within the lock to the correct height, allowing the bolt to move either forwards or backwards as the key turns. Three-lever and five-lever locks are the most frequently used types. A mortice latch/lock is also known as a sash mortice lock and is a combination of a mortice latch and mortice lock. This type of latch/lock is available in vertical or horizontal versions. Vertical versions are suitable for fitting in most types of doors. Horizontal types are only suitable for fitting in doors with wide stiles or when positioned in the middle of the lock rail and these are typically used with doorknobs. Both types are available with different lengths of back set (see Figure 5.15) so that the handle or knob can be positioned closer or further away from the edge of the door. This type of lock also has reversible latches to enable it to be used with lefthand (LH) and right-hand (RH) opening doors.
Back set
Latch
KEY TERMS Stiles: the vertical sections on the outer edges of a door. Back set: the distance between the face of the lock and the centre of the handle, knob spindle or key hole.
Removable faceplate Strike plate
Spindle hole for handle Case depth Keyhole
Lock bolt
p Figure 5.15 Parts of a mortice latch/lock
Variations on mortice locks include the following. Mortice dead locks: this type of lock only has the locking bolt part of the mechanism, meaning that the door will only remain shut when the door is locked as there is no latch part to the lock. It is usually used on doors that are used as a security measure and need to remain locked and opened only by those with keys, or as an additional lock to a door fitted with a standard mortice lock/latch. ● Privacy locks: these are used to lock bathroom or toilet doors from the inside. Privacy locks must be fitted with bathroom lever handles to enable the door to be unlocked from the outside in the event of an emergency, by turning the release slot on the outside handle with a flat-head screwdriver or coin. ●
Table 5.8 outlines other types of locks and latches in general use.
Latch Lock activation lever
Lock release slot
Lock bolt
p Figure 5.16 Privacy lock
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma q Table 5.8 Other types of locks and latches in general use Name of ironmongery
Description
Mortice latch
Mortice latches are used mainly for internal doors that do not need to be locked. The most common type is the tubular mortice latch. The latch engages into a striking plate on the lining or frame, which keeps it shut. It is operated from either side of the door by a pair of lever handles or doorknobs.
Spindle hole Back set
Latch
They are available in different lengths and backset depths to suit different applications.
Case depth
Striking plate
Faceplate
Cylinder night latch Keep or staple Night latch
Connecting tail bar
Cylinder
Cylinder night latches are used mainly on entrance doors, typically in domestic properties. The door is opened by a key from the outside and by turning a handle from the inside. The latch bolt engages with a keep that is fixed to the door jamb. Better-quality night latches have a double-locking facility, which improves their security: when double-turned from the inside, they prevent the lock from being opened from the outside, even with a key. They are available with different back sets to fit narrow door stiles. The cylinder night latch is fitted so that the cylinder part of the lock is inserted into a hole bored through the door and screwed in place through its backplate. The night latch part of the lock is then fixed to the inside of the door via a backplate and inserted onto the connecting tail bar from the cylinder, which allows the lock to function from the outside.
Cylinder washer
Rim lock
Rim lock/latches are fixed on the surface face of the door unlike mortice lock/latches which fit into a mortice. Rim lock/latches are traditionally operated by a pair of doorknobs.
Latch
This type of lock is often used on ledged and braced doors, as these are not thick enough to receive mortice locks. Rim lock/latches are more commonly used in period properties or where an authentic appearance is required. Keep or staple
This type of lock is handed and will need to be purchased either as a left or right rim lock, depending on which side of the door the lock is being fitted in relation to its hanging side.
Lock
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Chapter 5 Types of fixings and ironmongery Name of ironmongery
Description
Euro pattern lock
Mortice latch/locks are available with European (Euro) pattern cylinder lock sections. With this type of lock, the key-operated mechanism can be easily replaced without taking out the whole mortice lock.
Euro lock location hole
Euro pattern lock inserts
Digital code-operated locks
Digital keypads and code-operated locks are used in conjunction with deadlocking mortice latches or cylinder night latches to provide keyless entry. This type of lock requires a number and/or alphabet code to release the lock. Entry is then made by simply turning a knob or a handle on the body of the lock. This type of entry is often used by hotels which usually use a card-operated version of the locking mechanism.
Thumb latch
Thumb latches are used on matchboard ledged and braced doors. Traditionally, they were made by a blacksmith from mild steel. A variety of designs are available, usually with a black japanned finished. The most widely known are the Suffolk latch (with two parts, one either side of the door) and Norfolk latches.
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ACTIVITY Produce a list of the benefits of fitting Euro pattern locks in public buildings compared to fitting standard mortice locks. Present your conclusions to the rest of your group.
Fixing positions for locks and latches There may be regional variations to the fixing positions for latches and locks. You should always refer to your employer or to specified fitting instructions when selecting the exact location for the ironmongery Figure 5.17 outlines the standard locations for mortice latch/locks and cylinder night locks.
Mortice latch/lock spindle at 990 mm from floor
Cylinder night latch between 1200−1500 mm from floor
p Figure 5.17 Standard fixing positions for mortice latch/locks and cylinder night latches
INDUSTRY TIPS Insurance companies usually require that entrance doors to private dwellings are fitted with locks that meet British Standard (BS) 3621. When replacing doors, you may have to fit locks and latches at the same heights as on doors adjoining the room, so that they match.
Door furniture Door furniture usually refers to items of ironmongery that are fixed to the face of the door, such as handles, knobs, bolts and door closers. Like most types of ironmongery, these items are available in multiple different types, colours and materials. In most cases, the choice of ironmongery is determined by factors such as security and practicality first and then by preferences of colour and style. Examples of types of door furniture are given in Table 5.9. 250
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Chapter 5 Types of fixings and ironmongery q Table 5.9 Type of door furniture Type of door furniture
Description
Lever handle furniture
Door handles are used to operate the latch part of the latch/lock to enable the door to open. During assembly, the handle is inserted onto the spindle from the mortice latch/lock and then screwed onto the face of the door. The lever furniture, as it is known, is available in multiple varieties of designs and finishes.
Euro pattern lock handle for a mortice latch/lock
Round handle to operate the latch and a separate matching round lock escutcheon
Ornate black japanned mortice latch/lock handle Knobs
These were traditionally only used with rim latch/locks, but now they are often used on mortice latch/locks as well. Knobs should not be used with mortice latch/locks that have a small backset. This is because the knob will need to be fitted too close to the edge of the door, which may cause your hand to catch the door frame or lining as the door is opened and closed.
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Description
Espagnolette bolt
Espagnolette bolts are a latch and locking system fitted into the lock stiles of doors. They provide multi-point locking down the door stile, providing higher security. Traditionally, these bolts were only used with PVCu entrance doors but are now available for timber doors as well.
Panic bolt
Panic bolts and latches are usually used on the inside of emergency exit doors. This type of locking system means the door remains bolted shut but allows for easy opening in an emergency by simply pushing the panic bar, which disengages the bolts at the top and bottom of the door from the keeps that are recessed in the frame.
Barrel bolts and tower bolts
Barrel bolts are generally used on doors and gates, while the larger and longer versions, called tower bolts, are used to secure larger doors and gates, such as those used on industrial unit doors and garages. These types of bolts are sometimes referred to as monkey tail bolts due to their long handles which allow for easy reach. Bolts are also available as cranked or necked for doors and gates that open outwards.
Flush bolts
Flush bolts finish flush with the door. They are fixed on the edge of the door stile and are used primarily to secure one half of a pair of doors. One bolt is positioned at the top of the door and another at the bottom of the door. This type of bolt is unobtrusive and can only be seen when the door is open.
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Chapter 5 Types of fixings and ironmongery Type of door furniture
Description
Rack or ratchet bolt
The rack or ratchet bolt is a type of deadbolt that is fitted into a bored hole on the edge of the door. The bolt is operated by a key that is inserted through the escutcheon fitted on the inside face of the door to engage in the rack of the bolt. The rack is shaped to match the key. As the key is rotated, the rack drives the bolt out into the door frame or withdraws it from the door frame into the door, allowing the door to open.
Keep
Ratchet bolt
Escutcheon Key
Escutcheon
An escutcheon provides a neat finish to any open keyhole and is typically used in conjunction with rim locks and deadlocks. In most cases, the keyhole is covered by the lever furniture. Where it is not, an escutcheon is required to protect the door face as well as providing a neat finish to the lock key hole.
Security viewer
Door viewers enable occupants of a room to see who is on the other side of the door without having to open the door. Security viewers are fitted into a hole that passes through the door at a suitable height and gives the occupier a wide-angled view of what is on the other side of the door.
Security chains
Security chains permit the door to be opened by only a small amount but without risk of the door being snatched fully open. This enables conversation to take place with anyone on the other side of the door while still maintaining a high level of security.
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Description
Letter plate
Letter plates are usually positioned centrally in the middle of the door but can be fitted in the bottom rail of the door if no middle rail is available. Smaller vertical letter plates can be fitted into the door stile. Traditionally, letter plates were fitted by drilling a series of holes and cutting out the shape with a padsaw. This is now done with the aid of a jigsaw or with a router and a jig to suit the size of the letter plate.
Proprietary threshold
Most purchased thresholds form a weather-proof seal between the bottom of a door and the door frame cill. They are usually made of aluminium with nitrite seals and can easily be cut to length with a hacksaw to suit the door width. Thresholds are usually supplied with fitting instructions. However, they are normally laid on a generous bead of silicone sealant and secured to the cill. Some aluminium thresholds are designed to be fitted with a compatible rain deflector at the foot of the door to direct water away.
44 mm Outside
Inside
20 mm Clearance min 12 mm max 16 mm
Drainage holes
13 mm
48 mm
Trickle vents
Trickle vents are used in door and window frames to provide a means to ventilate a building. Most vents have panels on the inside face that can be opened or closed to control the amount of ventilation being supplied through them. In some circumstances, trickle vents are required by the Building Regulations.
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Chapter 5 Types of fixings and ironmongery Type of door furniture
Description
Weather seals
There are many different examples of weather seals. Each is designed to suit the position in which it is intended to be used, usually in a door or window frame. Weather seals are designed to prevent draughts, water ingress and heat loss. They are available in a basic range of colours to match natural wood or painted joinery finishes. A continuous groove is usually machined around the rebated frame and the weather seal is pushed into this groove to hold it firmly in place.
Door closer
Door closers are used to ensure that doors close on their own and are used to prevent the spread of fire, draughts and sound or to ensure privacy throughout a building. Overhead door closers are fitted to the top of the door or the door frame above. They work by means of either a coiled spring mechanism or hydraulic system enclosed within the casing, with an arm to either pull or push the door shut.
Drawer runners
Drawer runners are available in a range of different finishes and lengths to suit the unit that they will be fitted into. Standard drawer runners usually only allow the drawer to extend midway out from the face of the unit. However, ‘full extension’ examples are also available for better access to the drawer. The runners can either be fitted to the underside of the drawer or to the sides. Good-quality runners will have ball bearings fitted for smooth operation; they may also have a soft-close action to prevent the drawer from slamming closed and possibly damaging the unit.
Plinth feet
Plinth feet are commonly fixed to the bottom of kitchen units. They are simply turned at the bottom to adjust the height of the unit and level it. The plinth fixings (clips) attach to the plinth feet for quick and easy installation and removal of the plinth.
INDUSTRY TIP Building Regulations usually require that fire doors have some form of door closer. However, some types of closer can spoil the look of the door set, so you could fit a concealed door closer in the door edge and door frame. Alternatively, you could install fire-rated butt hinges with a concealed spring in the knuckle that provide the self-closing action needed to meet current regulations.
IMPROVE YOUR ENGLISH Identify the types and quantities of ironmongery you would consider necessary for use on a typical solid timber front door. Present your selections in a suitable format that could be used to order the required ironmongery from your supplier.
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IMPROVE YOUR MATHS List the different types and quantities for each type of hinge, latch and lock used to hang all the doors in your home.
Hinge bolt
Barrel or rack bolt
Hinge bolt
Signage 1500 mm 1
Letter plate 760–1450 mm
Hinge bolt
2
height security chain
Hinge bolt
Cylinder rim latch 1200– 1500 mm
Barrel or rack bolt
p Figure 5.18 Standard ironmongery heights for doors
4 INSTALLING IRONMONGERY This section outlines standard fitting procedures for installing ironmongery to standard doors using basic hand tools. Some ironmongery manufacturers provide fitting instructions along with paper templates to aid fitting, which may be used where necessary. Doors are hung and finished with ironmongery in three distinct stages. It is important to follow each stage carefully to ensure that both the door and the ironmongery can function correctly. These stages are described in Table 5.10. q Table 5.10 Stages of hanging a door and installing ironmongery Stage
Description
Stage 1: Fitting the door
This involves trimming the door to the required size for the opening. It is unusual for a door not to require some form of fitting, even if it is only giving the door a leading edge to its closing side (a slight taper on the closing edge). Internal doors usually have a 2 mm clearance gap around each side and along the top of the door, with a slightly increased gap of 4 mm along the bottom edge of the door. External doors have increased clearance gaps of 3 mm along each side and the top.
Stage 2: Swinging the door
This stage involves fitting the hinges and ensuring that the door swings or opens and closes correctly without the door binding or sticking.
Stage 3: Installing the ironmongery
This stage involves fitting any latches/locks and other required ironmongery.
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Installation and fitting guides These items of ironmongery are covered in the following general fitting guides. ● ● ● ● ● ●
Butt hinge Mortice latch/lock Cylinder night latch Letter plate Escutcheon Rack bolt
Fitting butt hinges to standard doors Butt hinges can be installed using traditional hand tools or with power tools and jigs, as is typically the case when installing doors into new build frames and linings. The following step-by-step guide outlines a method used to mark, cut and fit a standard butt hinge to an internal door using basic hand tools. 1 Using a suitable door stand, securely hold the door with the hinge stile facing upwards. 2 Mark the starting position of the hinge, either 150 mm down from the top or 225 mm from the bottom, ensuring that the hinge is on the correct face edge of the door. Carefully and accurately score along each side of the hinge using a marking knife.
3 Set up a marking gauge to the width of the butt hinge leaf. Transfer this to the face edge of the door and mark out the width of the hinge recesses between the score lines only. This distance
4 Adjust a second marking gauge to the thickness of one butt hinge leaf. Transfer this to the face of the door, only marking between the score lines. This is the finished depth of the hinge recesses. Hinges that have large or wide knuckles will need to finish slightly below the surface of the door and frame to maintain the correct door clearance (2 or 3 mm) within the frame; adjust the marking gauge as necessary to allow for this increased depth. 257
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5 Using a bevel edge chisel and mallet (or hammer if the chisel has a metal insert to allow it), accurately cut down on each marked end of the hinge recess. Ensure that the flat edge of the chisel is always to the outside of the recess and the chisel is kept vertical, so that the result is a square cut.
6 Turn the chisel around so that the flat edge is facing upwards. Holding the chisel at an angle of about 45˚, start cutting at the end of the hinge recess that is furthest away from you and work your way along the recess using a walking action of the chisel. Holding the chisel at an angle of 45° helps to lift the grain of the timber as it is being chiselled, making the cuts easier to remove in the next steps.
7 Keeping your chisel flat, carefully pare back the recess to the required depth, as marked by the marking gauge. Slightly angling your chisel and cutting in a slicing action can help to achieve a neater flat bottom to the recess.
HEALTH AND SAFETY Always keep both hands behind the cutting edge of the chisel. Do not be tempted to hold the back of the door behind the recess while cleaning out the hinge recess with a chisel.
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Chapter 5 Types of fixings and ironmongery 8 Clean out the back edge of the recess and trial fit the hinge.
INDUSTRY TIP For a deep hinge recess, several shallower cuts may produce a neater finish.
9 When you are satisfied that the hinge fits correctly within the recess, drill a pilot hole for the screws with a hinge drill bit. Using this type of drill bit means that the screws will automatically be centralised within the hinge holes so the screw heads sit central and flush within the countersunk holes of the hinge. Fix the hinge in place, remembering ‘most to the post’, to fit the hinge to the door by the leaf containing the fewest moving parts to the knuckle.
p Figure 5.19 Finished hinge recess
p Figure 5.20 Trial fit the hinge for fit
KEY TERM Pilot hole: a small hole drilled (or bored) into timber to prevent it from splitting when the fixing screws are inserted.
p Figure 5.21 Using a hinge drill bit to form the pilot holes
Installing a mortice latch/lock The procedures required to install a mortice latch and a mortice latch/lock are similar, though installing a mortice latch is an easier task and can be completed more quickly. Mortice latch/locks require a longer mortice recess to accept the latch/lock’s case and an extra hole in the door’s face to receive the key for the lock. A simple procedure that can be used to fit either a mortice latch or a mortice latch/lock is outlined in the following step-by-step guide. Use Figure 5.22 to help you. 1 The standard height for a mortice lock/latch spindle is 990 mm from the bottom of the door. Measure up from the bottom of the door to the required height of the spindle hole on the lock stile of the door. From this measurement all the following measurements can be marked on the door: ●
the lock’s backset for the spindle and key holes (B in Figure 5.22) ● the case height of the lock (C) plus an extra 3 mm above and below ● a centre line on the edge of the door for the latch/lock case, running between lines marked for (C); this will be the centre of the mortice recess to accept the mortice latch/lock.
ACTIVITY Cut and fit a 100 mm butt hinge onto a suitable section of timber using hand tools. Show your finished project to your tutor and outline how you may improve the task or how you would do things differently next time.
INDUSTRY TIP When fitting a replacement door, the spindle height will usually need to correspond with the heights of the spindles on any adjacent doors unless specified.
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B
A
E D
A = Case depth B = Backset C = Case height Spindle hole
Lock hole
p Figure 5.23 Spindle and lock holes
p Figure 5.24 Keyhole formed with two holes
900 mm spindle height from bottom of door
C
D = Centres E = Forend length F = Forend width
B
p Figure 5.22 Fitting a mortice latch or mortice latch/lock
2 Drill the spindle and keyholes from each side of the door using a suitably sized drill bit. Plenty of clearance should be given for the spindle to turn within the hole; a 20 mm drill bit is usually sufficient. When selecting a suitable size drill bit for the lock hole, it is common practice to use the same-sized drill bit as that used for the spindle hole, or a slightly smaller 18 mm drill bit. Drilling this larger hole saves a considerable amount of time forming the lock keyhole compared to forming a traditional keyhole shape, but this larger keyhole can at times make it more difficult for you to locate the key into the mortice case lock hole. Drilling a large keyhole is considered poor practice by most traditionalists, but pressure from many employers to install doors quickly has led to the single larger keyhole becoming more standard practice in modern door installation. 3 When the preferred key shaped lock hole is to be used, two holes are used to form the basic shape of the keyhole: a larger 10 mm hole with a 6 mm hole centre lining just below. The finished shape of the keyhole is formed using a padsaw and file. Considerable accuracy is required when forming the keyhole shape as only a slight misalignment will result in difficult key location in the lock case. 4 Form the lock case mortice by drilling a series of overlapping holes that are slightly larger than the lock case width, to the required depth. Drill the two outermost holes first and then work your way in towards the centre. Mark the drill bit with tape at the required depth or set up the drill's depth stops if available. When fitting a mortice latch, you need a single hole with a diameter just big enough to accept the latch.
INDUSTRY TIP Drilling the spindle and lock holes before the mortice recess prevents the side of the mortice recess splintering and spelching inward when the spindle and lock holes are drilled through. This limits damage to the door and possible weaknesses to the door’s face and means that there is no need to further clean out the mortice recess.
+5 mm
p Figure 5.25 Drill a series of holes to help form the mortice recess for the case of the latch/lock
5 Mark down each side of the mortice recess with a mortice gauge, as shown in Figure 5.26. This gives a clean straight line to use as a guide for the chisel when you clean the mortice recess out.
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INDUSTRY TIP Most locks/latches are accompanied by paper templates that can be used to mark out the lock on the door.
p Figure 5.26 Using a mortice gauge to mark the sides of the mortice recess
p Figure 5.27 The steps for installing a mortice latch/lock
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma 6 Clean out the mortice recess with suitable sized chisels. 7 Insert the latch/lock into the mortice recess and check for size. Mark around the forend (front face) of the latch/lock with a marking knife, then remove the latch/lock and form the recess for the forend with a suitable sized chisel. Fit the latch/lock into the door.
p Figure 5.28 Fitting and marking forend and forming recess in door frame
8 Fit the lever door handles on either side of the door. If the lever furniture has straight sides, fit it vertically. For round furniture, ensure that the handle is horizontal.
ACTIVITY Cut and fit a mortice latch/lock into a suitable section of timber.
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Installing a cylinder night latch Cylinder night latches are mostly fitted on doors that need to limit entry to a room or building, allowing only some people to gain access but allowing anyone to exit. When the door is shut, a key is needed to gain entry, but it is easy to open the door from the inside and exit. Cylinder night latches are usually only fitted to doors that open inwards, such as front doors in domestic properties or doors to rooms opening in from a corridor. Most cylinder night latches are provided with a paper template and fitting instructions to make the installation a simple and straightforward operation. The following step-by-step guide outlines a procedure that can be used to fit a cylinder night latch. 1 Mark the top of the cylinder night latch on both sides of the door, usually 1200–1500 mm from the bottom of the door. 2 Mark the required backset of the night latch from the edge of the door. This is the centre of the hole for the cylinder, usually 40 mm or 60 mm from the edge of the door. 3 Drill a 32 mm hole through the door, working from each side.
4 Insert the cylinder into the hole from the outside and mark the end of the connecter bar as it passes through the door. Remove the cylinder and cut the connecter bar 8–10 mm longer than where marked.
5 Refit the cylinder and tighten to the back plate, ensuring that the key will be vertical when placed in the lock. 6 Locate the night latch onto the back plate and screw home. 263
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ACTIVITY Cut and fit a cylinder night latch into a suitable section of timber using hand tools.
p Figure 5.29 Fitting sequence for night latch
Installing a rack bolt Rack bolts are used as a replacement to barrel bolts, in circumstances when a barrel bolt would look unsightly and out of place on the door’s surface. The following step-by-step guide outlines a simple method to follow when installing a rack bolt.
INDUSTRY TIP Always ensure that the door has the correct amount of clearance before fixing the rack bolt.
1 Mark the centre position of the rack bolt on both sides of the door and the centre of the door edge. When selecting the rack bolt’s location, ensure that you allow sufficient fixing depth for the faceplate screws and that the rack bolt does not destroy or weaken the integrity of the door’s jointing system. 2 Using a drill bit, allow a suitable amount of clearance and drill a hole from both sides of the door to form the hole for the rack bolt key. 3 Drill a hole for the rack bolt in the edge of the door, ensuring that it is in the centre of the door’s thickness. 4 Insert the rack bolt and, ensuring that the faceplate is square to the door edge, mark around the rack bolt faceplate with a marking knife. Use a mortice gauge to mark the sides of the recess. 5 Form the recess for the faceplate using a suitable sized chisel. 6 Fit the rack bolt and screw home. 7 Insert the key through the key escutcheon and locate it in the rack bolt, then align the escutcheon and fix in place. 8 When the door is shut, turn the rack bolt key so that the rack bolt’s point locates the centre position for the rack bolt’s keep. Position the keep so that the marked point is in its centre and mark out the position of the keep. Cut the recess and fix the keep.
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Practical task Fit a butt hinge You are required to fit a 100 mm butt hinge in a section of softwood timber that represents a section of door stile. Candidate information Before starting each task, ensure that you have been given permission by your tutor or trainer to proceed. As each task is completed, you should be given feedback on the completed task and any retraining that may be required. Always work according to a risk assessment and environmental and health and safety regulations. Task instructions You are required to: ●
mark out the correct position of the butt hinge
●
set up marking gauges to the required sizes from the butt hinge
●
mark the location of the hinge using the marking gauges
●
chop out the hinge recess using the correct size chisel and mallet
●
fit the hinge using the correct size pilot holes, screws and screwdriver.
Equipment required ●
Completed risk assessment for fitting butt hinges
●
Selection of PPE
●
1 length of softwood timber measuring 450 mm × 44 mm × 94 mm
●
Vice or clamps
●
100 mm butt hinge
●
Marking knife
●
Two marking gauges
●
Selection of bevel edge chisels
● Mallet ●
Selection of drill bits
●
Selection of screws
●
Selection of screwdrivers
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Achieved
Requires retraining
Work to a given risk assessment and select the required personal protective equipment for the outlined task. Correctly mark out location of hinge 150 mm from one end using marking knife. Correctly set up marking gauges to match hinge sizes. Correctly mark out hinge position with marking gauges on timber without extending beyond marked lines. Safely cut out hinge recess with suitable size chisel to correct size and depth using a mallet. Select suitable screws and drill the correct size pilot holes. Securely screw home the butt hinge, ensuring the hinge’s correct location, correctly fitting the screws using the correct size screwdriver. All work is carried out in accordance with current health and safety regulations and safe working practices. Work area is left clean and tidy with all tools and equipment correctly stored away safely.
Activity successfully achieved
Further training required detailed here
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Test your knowledge 1 Which of the following is classed as a nonferrous metal?
7 When installing butt hinges, which phrase is used as a reminder for positioning?
a Mild steel
a Least to the post
b Iron
b Down to the door
c Brass
c Most to the post
d Cast iron
d More to the door
2 Which type of nail has small raised ridges around its shank? a Cut nails
8 Which type of hinge is purchased in pairs, depending on the opening side of the door, and acts as a self-closing hinge?
b Lost head nails
a Rising butt hinge
c Bright steel round head nails
b Parliament hinge
d Annular ring shank nails
c Flush hinge
3 Which type of nail is most suitable for driving into brickwork? a Clout nails
d Double-action spring hinge 9 Which type of lock has easily replaceable lock sections?
b Masonry nails
a Cylinder night latch
c Brad nails
b Digital code lock
d Cut nails
c Euro pattern lock
4 Which type of screwdriver bit has a head shaped like a six-pointed star?
d Escutcheon 10 Where would you find an escutcheon?
a Pozidriv
a On the end of a cylinder night latch
b Phillips
b Operating mortice lock spindles
c Slotted
c As an insert with Euro pattern locks
d Torx®
d Covering a keyhole
5 Which of the following is a fast-acting adhesive considered suitable for joining mouldings, such as architraves and cornices, at joints? a Mitre bond adhesive b Polyvinyl acetate c Synthetic resin grab adhesive d Contact adhesive 6 Which type of screw has a black lacquered finish applied to it? a Brass wood screws b Black japanned screws c Zinc-plated wood screws d Yellow passivated wood screws
11 Describe the main differences between a mortice lock and a cylinder night latch. 12 List the main differences between ironmongery made from non-ferrous metal and ironmongery made from ferrous metal. 13 List the tools you would require and the process involved in cutting a butt hinge recess. 14 Acquire purchase prices for three sets of ironmongery typically used on a domestic front door. Produce an invoice detailing the purchase price before VAT and including VAT. 15 Design a toolbox safety poster that could be used with a training session on cutting out recesses and installing butt hinges on a timber entrance door.
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CHAPTER 6
HEALTH, SAFETY AND WELFARE IN CONSTRUCTION
INTRODUCTION Construction sites and workshops can be extremely hazardous working environments for everyone working in them or visiting them or for anyone nearby. Reducing the risks to people’s safety and long-term health and welfare to the lowest possible level must be a priority for all those who plan and manage work. The law places legal responsibilities, referred to as duties, on people involved in the construction process. Everyone has a responsibility for the health, safety and welfare of themselves and others at work, including young people, apprentices, trainees and those on work experience placements. This chapter discusses the legal responsibilities for duty holders and how everyone can manage and monitor the workplace to make it a safer environment for all.
LEARNING OUTCOMES In this chapter, you will learn about: 1 health and safety regulations, roles and responsibilities 2 accident and emergency procedures and documentation 3 hazards in the workplace 4 health and welfare in the workplace
5 handling materials and equipment safety 6 access equipment and working at height 7 working with electrical equipment in the workplace 8 using personal protective equipment (PPE) 9 causes of fire and fire emergency procedures.
1 HEALTH AND SAFETY REGULATIONS, ROLES AND RESPONSIBILITIES Health and safety legislation There are many risks associated with working in the construction industry, a large number of which may be reduced or removed altogether to protect people at work. Sadly, there are still many accidents (including some which are fatal) in the construction industry. Some of these may be because people with moral or legal responsibilities have failed to fulfil their duties.
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Chapter 6 Health, safety and welfare in construction Working in the construction industry nowadays is far safer than it used to be and standards continue to improve. Many of these standards are enforced through health and safety regulations. In 1974, a new piece of primary legislation was introduced to protect people at work and those affected by work activities, known as the Health and Safety at Work Act (abbreviated to HASAWA, HASWA or HSWA). The HASAWA was introduced because of the poor working conditions and the disproportionately high number of fatalities (deaths) across many industries for many decades prior to 1974. The HASAWA imposes many ‘general’ duties on employers, as well as on other duty holders. Many regulations control the way we act and work, so it is important to understand how they affect you and what your duties are under each of them. In some cases, regulations are updated to reflect the changes in industry standards and practices, as well as new technology.
KEY TERM Legislation: a law or legal regulation. For example, the Health and Safety at Work Act 1974 is a piece of legislation.
There are many regulations governing the construction industry. Table 6.1 outlines the main regulations that carpenters, joiners and their employers regularly have a duty to follow. Further details of some of these regulations will be given later in this chapter to put them into context. q Table 6.1 Health and safety regulations that carpenters, joiners and their employers have a duty to follow Regulations
Abbreviation Introduced Overview
Health and Safety at Work Act
HASAWA
1974
A piece of legislation used to protect all people at work and from work activities. The general objective of the HASAWA: ‘It shall be the duty of every employer to ensure, so far as is reasonably practicable, the health, safety and welfare at work of all their employees’. An employer's duties are: ● ● ●
● ●
to provide and maintain plant and systems of work so that they are safe and do not cause risks to health to make arrangements for the safe use, handling, storage and transportation of articles and substances, such as wood glue to provide information, instruction, training and supervision as necessary to ensure, so far as is reasonably practicable, the health and safety at work of their employees to ensure safe access to and egress (exit) from any place of work under the employer’s control and without risks to provide and maintain a working environment for their employees that is, so far as is reasonably practicable, safe, without risks to health and adequate as regards facilities and arrangements for employees’ welfare at work.
Employees also have duties that are explained later in this chapter. Further information about the Health and Safety at Work Act 1974 can be found on the Health and Safety Executive (HSE) website: www.hse.gov.uk/ legislation/hswa.htm
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Abbreviation Introduced Overview
Construction, Design and Management Regulations
CDM
2015
These are the main regulations that cover the management of health, safety and welfare on all construction projects, regardless of size. They say that: ● ● ● ● ● ●
work should be sensibly planned so that any risks involved are designed or managed out from the start to the end of the project the right people should be employed for the right jobs at the correct time any work carried out should be done with the co-operation and co-ordination of others people should have access to the right information about the risks and how they are managed information about the risks should be communicated effectively with those that need to know workers need to be consulted and engaged with about the risks and how they are being managed.
The key duty holders under CDM regulations are: ● client ● designer ●
principal designer
● contractor ● worker.
On a construction project, you would be regarded as a ‘worker’ and would have to comply with the following duties. ●
Only carry out construction work for which you have the relevant skills, training, knowledge and experience, unless you are being trained with supervision to enable you to complete the job safely. ● Always follow the procedures and site rules. ● Make yourself aware of the health and safety risks on every site and how they are being managed. This is usually done at a ‘site induction’. ● Report any risks you discover to your supervisor, regardless of whether it affects your health and safety or not. Control of Asbestos No common at Work Regulations abbreviation used
2012
There are several different types of asbestos, some more hazardous to remove than others. The Control of Asbestos at Work Regulations defines the different types of asbestos and the type of work that can be carried out by different suitably qualified and competent people. The types of work fall broadly into the following categories. ●
Licensed work: high-risk work that should only be completed by a licensed contractor. ● Notifiable non-licensed work: minor work/repairs with asbestos-containing materials (ACM) where the exposure is sporadic and of low intensity. Work may be carried out by a competent non-licensed contractor providing they fulfil certain conditions. ● Non-licensed work: non-continuous, short-duration work on lower risk ACMs, such as drilling into a textured coating containing asbestos to secure a shelf. All work with asbestos must be risk-assessed by a competent person. If you suspect that you have discovered asbestos at work, stop and report it to your supervisor immediately.
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Chapter 6 Health, safety and welfare in construction Regulations
Abbreviation Introduced Overview
Control of Substances Hazardous to Health
COSHH
2002
This regulation requires employers to control the use and handling of substances that are hazardous to health. The law states that workers’ exposure to hazardous substances (such as hardwood dust) can be reduced or prevented by: ● ● ● ● ● ●
Manual Handling Operations Regulations
MHOR
1992
assessing the risks to health deciding how to prevent harm, such as the use of PPE implementing control measures to reduce harm to health and making sure that they are used providing training, instruction and information to employees and others providing health surveillance and monitoring when appropriate making adequate plans for emergencies.
Many carpenters and joiners suffer long-term health effects from the incorrect handling of materials and equipment. The MHOR sets out the following measures to deal with the risks of manual handling. ●
Avoid manual handling so far as is ‘reasonably practicable’, such as using a forklift truck to unload a delivery of timber rather than lifting by hand wherever possible. ● Assess the hazards if they cannot be avoided. ● Reduce the risks of injury so far as reasonably practicable, such as spliting the load into smaller loads. Provision and Use of Work Equipment Regulations
PUWER
1998
PUWER places legal duties on people who own, operate or have control over work equipment and organisations whose employees use the equipment. This law says that equipment should be: ●
suitable for its intended use safe, maintained and inspected ● only used by people who are trained, instructed and informed ● provided with health and safety measures, such as controls and devices, like an emergency stop button on a table saw ● used in accordance with specific requirements. ●
Reporting Injuries, Diseases and Dangerous Occurrences Regulations
RIDDOR
2013
These regulations place legal duties on employers, the self-employed and those in control of premises to report specified dangerous occurrences (referred to as near misses), occupational diseases and serious accidents in the workplace.
Personal Protective Equipment Regulations
PPE
2018
This law says that PPE should be used as a last resort if the risks cannot be suitably controlled by other measures. This includes taking reasonable steps to protect workers and others from coronavirus (COVID-19). The regulations also require: ● an assessment to be made to ensure that PPE is fit for its intended purpose ● employees to be provided with instructions on how to use PPE safely ● that PPE is used correctly by employees ● that PPE and RPE (respiratory protective equipment) must be stored properly and well maintained.
Work at Height Regulations
WAHR
2005
These regulations apply to employers and people who are responsible for work at height, such as a maintenance manager. All work at height must be adequately planned for, including an assessment of the risks and the right type of access equipment for the work. ● Employees also have the following duties under WAHRs. ● Take reasonable care of themselves and others who may be affected by their actions. ● Co-operate with their employer to enable them to fulfil their health and safety duties.
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Abbreviation Introduced Overview
Control of Noise at Work Regulations
No abbreviation used
2005
The aim of these regulations is to protect the hearing of people at work from excessive noise (such as that produced by woodworking tools and machinery), which could lead to hearing loss or damage, such as tinnitus. This must be done by assessing the risks to workers’ health and identifying measures to eliminate or reduce their exposure to the noise. Employers have a duty to: ● ● ● ● ●
assess the risks to workers’ health and provide information and training at 80 decibels provide personal hearing protection at 85 decibels use control measures, such as safety signs or hearing protection zones provide health surveillance for workers regularly exposed to noise above 85 decibels not expose workers to the ‘upper action value’ of 87 decibels or above. This takes into account any reduction in noise provided by hearing protection.
Control of Vibration No at Work Regulations abbreviation used
2005
Employers have a duty under these regulations to assess the risks and measure the amount of vibration that their employees are exposed to in a working day. The regulations introduce action and limit values for handarm and whole-body vibration to protect people from the risk of hand-arm vibration syndrome (HAVS). For example, a small random orbital sander produces vibration above the action level specified in the regulations, so an employer requiring its use should reduce the risk of harm to their employees by introducing control measures, such as limiting the time spent using the tool without a break.
Electricity at Work Regulations
No abbreviation used
1989
These regulations are concerned with electrical installations and both employers and employees have duties under them. The regulations are technical. However, they clearly state that only trained and competent contractors should carry out electrical work.
Lifting Operations and Lifting Equipment Regulations
LOLER
1998
Any organisation or business that undertakes lifting operations or provides lifting equipment for others to use must control and manage the risks to avoid damage or personal injury. Lifting operations must be: ●
properly planned supervised appropriately ● undertaken by competent people ● carried out in a safe manner. ●
KEY TERMS
ACTIVITY
Tinnitus: a permanent ringing in the ears. This is often caused to carpenters and joiners by long exposure to noise produced by routers and woodcutting machinery, when adequate protective measures have not been taken. Decibels: a unit used to measure the intensity of sound levels. It is often abbreviated to dB.
Besides employers and employees, there are additional duty holders under the Health and Safety at Work Act, who are: ● self-employed persons ● people in control of premises for persons other than their employees ● manufacturers. Use the internet to research the legal responsibilities of these duty holders and make a list giving an overview of each.
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Chapter 6 Health, safety and welfare in construction
ACTIVITY Imagine that you are a self-employed carpenter/joiner and have a project to complete. You could base the project on the replacement of a kitchen for a member of your family or a friend. Under the CDM Regulations, you are required to consider all the risks on the project before starting work and plan for welfare facilities. Use the CDM Wizard or other CDM app to complete details of the project. Once completed, reflect on the points that you would not have considered planning for if you hadn’t used the app, and the importance of these areas with regards to the health and safety of yourself and others.
Employer and employee responsibilities Employer responsibilities For a young person or someone new to the industry, the regulations may seem overwhelming; however, broadly speaking they are very straightforward. When you arrive at work you will have expectations that your employer will provide a safe working environment and they will provide you will all the information, adequate training and equipment that you need to work safely. (Workplace inductions and toolbox talks are covered on page 277–278 later in this chapter). It can take time to learn how to do new tasks and become competent; until then, your employer must provide supervision while you are at work to protect you from harm.
INDUSTRY TIP Under the CDM Regulations, every project must be correctly planned and organised with regards to health, safety and welfare, regardless of its size. Free apps are available to do this, such as CDM Wizard produced by CITB ConstructionSkills, which can be used to help support employers to manage this process for small construction projects.
Anything likely to cause harm is referred to as a hazard. Your employer has a duty to assess all the significant hazards in your workplace on a document known as a risk assessment. If your employer has five or more employees, the law says that risk assessments must be written and kept in case there is an inspection or for insurance purposes. Figure 6.2 is an example of a risk assessment.
KEY TERM Hazard: something that has the potential to cause harm. For example, a nail gun has the potential to cause harm to your eyes or body from the nails it fires. The noise that it creates could also cause damage to your hearing over a period of time. Remember, your employer has a legal responsibility to protect you from all potential hazards in the workplace.
p Figure 6.1 Examples of hazards
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Risk Assessment Activity / Workplace assessed: Return to work after accident Persons consulted / involved in risk assessment Date: Reviewed on: Significant People at risk and what is Existing control measure hazard the risk What is currently in place Describe the harm that is likely to control the risk? to result from the hazard (e.g. cut, broken leg, chemical burn etc.) and who could be harmed (e.g. employees, contractors, visitors, etc.).
Location: Risk assessment reference number: Review date: Review by: Further action required What is required to bring the risk down to an acceptable level? Use hierarchy of control described in guidance note when considering the Multiply (L) * (S) to produce risk rating (RR) controls needed. Risk rating Use matrix identified in guidance note. Likelihood (L) Severity (S)
Actioned to: Who will complete the action?
Due date: When will the action be completed by?
Completion date: Initial and date once the action has been completed.
Uneven floors
Operatives
Verbal warning and supervision
L 2
S 1
RR 2
L/M/H M
None applicable
Site supervisor
Active now
Ongoing
Steps
Operatives
Verbal warning
2
1
2
M
None applicable
Site supervisor
Active now
Ongoing
Staircases
Operatives
Verbal warning
2
2
4
M
None applicable
Site supervisor
Active now
Ongoing
Severity
Likelihood 1 Unlikely
2 Possible
3 Very likely
1 Slight/minor injuries/minor damage
1
2
3
2 Medium injuries/significant damage
2
4
6
3 Major injury/extensive damage
3
6
9
1 – Low risk: action should be taken to reduce the risk if reasonably practicable. 2, 3, 4 – Medium risk: is a significant risk and would require an appropriate level of resource. 6 & 9 – High risk: may require considerable resourced to mitigate. Control should focus on elimination of risk, if not possible control should be obtained by following the hierarchy of control.
p Figure 6.2 Risk assessment
ACTIVITY Think of a hazard that you are likely to encounter at work. Now list all the practical measures that could be taken to protect you from the risk of injury. Discuss your answers with your trainer or employer. Could more be done to reduce the risk as low as possible?
The risk assessment may identify a particular hazard associated with completing a task such as cutting a piece of timber to length on a mitre saw. The noise level produced by the saw can cause hearing damage, so it is recommended that hearing protection is worn. Your employer must supply you with any personal protective equipment (PPE) necessary, free of charge. This will include items that you routinely wear, such as safety footwear, a high-vis vest or jacket or a hard hat. If the PPE becomes worn or damaged, your employer must replace it when requested, but you have a responsibility to look after it. The poster Health and Safety Law: What you need to know (HSE 2009, ISBN 9780717663149) is one of many sources of written health and safety information that you will see displayed in your workplace. The Health and Safety Information Regulations require all employers to display this poster or provide workers, including yourself, with an HSE-approved equivalent leaflet. The poster contains three important headings, with the main points of the law: ●
what employers must do for you ● what you must do ● if there is a problem. 274
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Chapter 6 Health, safety and welfare in construction Employers have a responsibility to protect their workers from injuries and ill heath at work. Reflect for a moment on what you would do if you had an accident that prevented you from working. An accident can be life-changing not only for the injured person, but also for their families. If, following an accident, you considered your employer had been negligent, you may seek to claim financial compensation. The Employer’s Liability (Compulsory Insurance) Act places a duty on businesses that have employees to make sure they have adequate liability insurance (at least £5 million cover). If the employer is found to have been at fault by a court, the insurance will help to pay any compensation due to their employees. If your employer does not display a valid certificate of liability insurance or they cannot provide one when requested by a HSE inspector, they can be fined up to £1000. In addition, employers can be fined up to £2500 for every day that they do not have suitable insurance. Carpenters often work at various locations and occasionally joiners will also fit items they have made on site, especially if they are in component form, such as a staircase with a change of direction. In these situations, workers may not have access to the information contained on the HSE approved law poster in the vehicle they travel in, or at a domestic client’s property. For this reason, employers can now fulfil their legal responsibility by issuing their employees with handy ‘pocket cards’ that outline what they need to know with regards to staying safe and healthy at work.
Employee responsibilities So far, this chapter has considered the employer’s responsibilities under the main health and safety regulations. As an employee, you also have duties under the regulations. They are not difficult to understand and should be easy for you to follow. If there is anything you are unsure about, you must always ask your supervisor. Health and safety at work is common sense. Unfortunately, accidents still occur because people do not follow some simple rules. The Health and Safety at Work Act says you must do the following things. ●
Take reasonable care for the health and safety of yourself, and others who may be affected by the things you do or do not do. Work safely and act responsibly, follow your employer’s rules and report any hazards, near misses or accidents that you see to your supervisor. Remember, your behaviour not only affects you; it can also have an impact on others. ● Co-operate with your employer to enable their duty or requirement to be performed or complied with. For example, if you removed your PPE at work because you preferred not to wear it or did not use the dust extraction provided on a power tool, you would be breaking the law. These are examples of control measures that your employer has put in place to protect you. You must follow the training and instructions that your employer has provided. ● Do not intentionally or recklessly interfere with or misuse anything provided in the interests of health, safety or welfare. For example, if you were to remove or alter any components on a scaffold or a guard on a woodworking machine without it being agreed with your supervisor, you would be failing to comply with the HASAWA.
KEY TERM Negligent: a term often referred to in health and safety law when someone does not fulfil their responsibilities.
INDUSTRY TIP The health and safety pocket cards are published free by the HSE. Use the following link to download a copy for yourself as a reference of key information, such as what to do if there is a problem at work and what your responsibilities are: www. hse.gov.uk/pubns/books/ lawposter.htm
KEY TERMS Near miss: an incident that occurred that could have caused harm to someone but did not. It is important to report near-miss incidents to prevent them from happening again. Control measures: a system used to protect people from harm, such as the use of PPE, guards on machinery, safety signs and fire extinguishers.
p Figure 6.3 A near miss to be reported
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KEY TERM Improvement notice: a formal document issued by the HSE to employers when they have fallen short of their health and safety responsibilities, usually in non-lifethreatening ways that can be easily corrected.
ACTIVITY 1 Use the internet to find out how much the Health and Safety Executive currently charge (per hour) for their time. 2 The HSE have other powers to enforce the HASAWA. Have a look at their website to see what else they can do: www.hse.gov.uk/ enforce/enforcement.htm
Roles and responsibilities of the Health and Safety Executive The Health and Safety Executive (HSE) is a government organisation responsible for enforcing health and safety law in the workplace. It has many powers to enforce the law, which include being able to enter a workplace at any reasonable time without notice. It may carry out inspections and investigations to help with an enquiry, especially if a serious accident or incident has occurred. If the HSE inspectors suspect that a machine or process is dangerous and could lead to an accident, they can stop the work from continuing immediately by issuing a prohibition notice. For example, if your employer has erected a scaffold to construct a new roof, and during a visit the HSE identify parts of the scaffolding that are missing and there is a serious risk of it collapsing, the prohibition notice they issue would prevent anyone from using it. If hazardous equipment and machinery cannot be made safe, the HSE has the power to seize and destroy it. If the HSE visit your workplace, you should carry on doing your job until you are instructed to do otherwise, either by your employer or by the HSE inspector. During their visit they may want to speak to you and ask for you to provide a statement as part of their investigation. A visit from the HSE does not necessarily mean that your employer has broken the law. It may just be a routine call to offer advice and guidance on best practices. However, if during their visit they find that your employer has failed to comply with health and safety law, they could issue an improvement notice or in some cases fine them in a court of law. If during the time an HSE inspector is at a workplace, they discover breaches of health and safety law, they can charge the employer for their time. This will include any time investigating, helping to put things right and taking any enforcement action.
Sources of relevant health and safety information As you progress through your training as a carpenter and joiner, you will work for various qualifications. A fundamental part of your training will be about health and safety at various levels depending on your experience. Employers also must have an up-to-date knowledge of health and safety law, to make sure that they are fulfilling their duties to provide a safe working environment.
p Figure 6.4 An example of a source of information provided by the HSE
There are many sources of health and safety information for you to refer to while training and working. If you had to set up and use a new power tool that you were unfamiliar with, it is most likely that you would look at the manufacturer’s manual or instructions. It is a legal duty for manufacturers to provide all the information needed on the safe use of their products under the Health and Safety at Work Act.
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Chapter 6 Health, safety and welfare in construction
ACTIVITY The following table contains a list of organisations that are further sources of health and safety information. Follow the links given in the column opposite the names of the organisations to discover what they do and how they can support you. Write a brief overview of each organisation. Organisation
Website
British Safety Council
www.britsafe.org
British Standards Institution (BSI)
www.bsigroup.com/en-GB
Construction Industry Training Board (CITB)
www.citb.co.uk
Health and Safety Executive (HSE)
www.hse.gov.uk
Institute of Occupational Safety and Health
https://iosh.com
Royal Society for Public Health (RSPH)
www.rsph.org.uk
Royal Society for the Prevention of Accidents (RoSPA)
www.rospa.com
Site inductions and toolbox talks Employers have a duty to provide you with information and instructions under the Health and Safety at Work Act 1974. Before entering your place of work, you will be told the rules and procedures to follow. In a joiner’s workshop, this may be given to you by your employer in the form of an induction when you initially start work. The hazards in a workshop or factory are usually consistent. On a construction site, the environment can change from day to day as the work progresses or as you visit new sites. For each new workplace (site and workshop) that you attend, you will be given a site induction by the construction site manager or another senior manager. The content of a site induction will vary depending on the size of the site, the stage the building work has progressed to and the nature of the work undertaken. The following points are some of the topics that may be covered during a site induction. ●
Welfare facilities, such as toilets, drinking water and washing facilities. ● First aid provision, who the first aiders are at work and who to report an accident to. ● Pedestrian routes and traffic plans for site vehicles. ● Site rules, such as no spitting on site. ● Alcohol and drugs policy. ● Areas where smoking and vaping are allowed. ● Personal protective equipment (PPE). ● Emergency procedures, such as escape routes, assembly points, fire alarm and fire-fighting equipment. ● Environmental issues, such as lighting, noise, dust, pollution of water ways and the disposal of waste. ● Site security. Under the Construction (Design and Management) Regulations (CDM), members of the public should be protected from all construction work activities. This is usually done with physical barriers or fencing around the perimeter of the site, and a signing-in and -out system, using a book, a card reader or even a fingerprint scanner. ● Card schemes. Some employers will not allow workers or visitors on their construction sites without a valid CSCS card or similar card. These cards identify the holder, their levels of health and safety competence and any relevant industry-recognised qualifications.
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KEY TERM CSCS card: a card confirming your level of training depending on your role.
INDUSTRY TIP The Construction Skills Certification Scheme (CSCS) was developed by the CITB as a way of training, testing and awarding construction workers with an identification card to show employers that they can be safe on the job. There are various types of cards to suit the role and level at which people will be working on site. The CITB supports the construction industry with the development of training, qualifications, careers and standards. You may recognise the CITB as it is a training provider for many apprentices across the country. 277
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p Figure 6.5 Personal protective equipment (PPE)
p Figure 6.6 A site office where toolbox talks can take place
p Figure 6.7 An example of a CSCS card
p Figure 6.8 An operative (worker) with a portable power tool
HEALTH AND SAFETY Statistically, you are most likely to have an accident on a new construction site or joinery workshop when you first start work because it will be unfamiliar to you and you may not be aware of all the hazards. To reduce the likelihood of an accident, you must have an induction.
As changes take place in the workplace and work progresses, the risks that are present will also evolve, so your employer has a legal responsibility to make you aware of these changes. Updates and advice on matters of health, safety and the environment are communicated to workers through a brief training session known as a toolbox talk. This training is usually undertaken on site, in a setting that enables everyone to clearly understand the information given on the topic, without any disturbances. You could be asked to attend a toolbox talk on a number of subjects, such as a new piece of equipment or using ladders because of a reported near miss.
2 ACCIDENT AND EMERGENCY PROCEDURES AND DOCUMENTATION Legislation used for reporting accidents Working in the construction industry is hazardous by its nature. All accidents and near misses must be reported to your supervisor and recorded. This is important because employers have a legal responsibility to keep records of all accidents in
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Chapter 6 Health, safety and welfare in construction the workplace and to investigate their causes to prevent a reoccurrence. They also have an obligation to their insurance company to keep accident records, which are referred to if a claim for compensation is made against them. Serious accidents, illnesses and dangerous occurrences must be reported to the HSE under the key legislation, Reporting of Injuries, Diseases and Dangerous Occurrences Regulations. (RIDDOR0). It is important to be able to distinguish between an injury, a disease and a dangerous occurrence. A minor injury in the workplace, such as a small cut to a finger, is usually treated by a first aider and recorded in the first aid book. Even small cuts should be properly treated and covered to prevent infections being contracted and spread. RIDDOR states that the types of incidents outlined in Table 6.2 are more serious and should, therefore, be reported to the HSE. q Table 6.2 Types of serious incidents that should be reported to the HSE Type of incident Report Injuries
The death of any person. Specified injuries to workers, such as: ●
fractures, other than fingers, thumbs and toes
● amputations ● ● ● ● ● ●
any injury that could lead to permanent loss of sight any crush injury to the head or body serious burns any removal of skin from the head requiring hospital treatment any loss of consciousness caused by a head injury or similar any other injury caused by working in an enclosed space, such as hypothermia.
If a worker is unable to perform their job or is away from work for more than seven consecutive days because of an injury at work. Non-fatal accidents to non-workers (such as members of the public) that resulted in them receiving hospital treatment. Occupational diseases
Diseases caused because of work, such as asthma, dermatitis or cancer.
Dangerous occurrences
The collapse, overturning or failure of lifting equipment. Construction vehicles or equipment coming into contact with overhead powerlines. The accidental release of a substance which could cause injury to any person, such as a major chemical spill. Fire or explosion.
Gas incidents
The accidental leakage of gas. Incidents where someone has died, lost consciousness or been taken to hospital for treatment in connection with the gas.
Source: www.hse.gov.uk/riddor/reportable-incidents.htm
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Accidents resulting in the death of a person at work, a specified injury or hospital treatment to a non-worker and other dangerous occurrences must be reported to the HSE without delay. If an accident results in a person being unable to work for seven days or more, then the HSE must be informed within 15 days.
Major types of incidents that could occur in the workplace Some of the hazards that a carpenter will face on a construction site will be hugely different from those faced by a joiner in a workshop. Your employer has a duty to consider all the significant hazards in their workplace and take steps to safeguard workers from them. Poor housekeeping and untidiness can cause trip hazards and result in waste materials building up around the site or workshop, which is a major cause of fires. In 2017, there were over 400 fires on construction sites, 170 of which were started deliberately (arson). A good security system in the workplace will reduce the likelihood of unauthorised people entering the site during working hours and other times. Your employer should have considered the best security methods; as a minimum, perimeter fencing or hoarding should be used to restrict access. Figure 6.9 illustrates the most common causes of fatal accidents in the construction industry. As the graph shows, falls from height are still the biggest causes of accidents in the workplace. This is looked at in more detail later in this chapter. 47%
Fall from a height Trapped by something collapsing/overturning
16%
Struck by moving object, including flying/falling object
12%
Struck by moving vehicle Contact with electricity or electrical discharge
10% 4%
40 fatal injuries to workers in 2019/20 This is similar to the annual average number of 37 fatalities for 2015/16–2019/20 p Figure 6.9 Key accident trends in the construction industry in the UK
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p Figure 6.10 Construction work at height
During a building project, you are likely to see many construction vehicles on site delivering goods, moving materials or excavating the ground for the foundations of buildings to be laid. A well-planned construction site will have safe pedestrian walkways to keep people clear of moving vehicles and to prevent accidents. Digging or drilling the ground on a site can be very hazardous and must be properly controlled by restricting this type of work to competent people who have been authorised by the site manager. For example, if you had to drill a hole in a wall, would you be confident that you would not be about to come into contact with a water or gas pipe or an electrical cable? Drilling and excavating the ground is not too dissimilar, because you could also make contact with buried service pipes and cables if the correct precautions are not taken. In addition to these risks, in certain areas of the UK there is also the potential to unearth unexploded bombs or military ammunition from the Second World War.
ACTIVITY Watch Your Step is a short toolbox talk on the importance of good housekeeping: www.hse.gov.uk/ construction/campaigns/ watchyourstep/video/ index.htm
Deep trenches, holes and wells in the ground have the potential to collapse if they are not adequately supported, and they may also flood. Such spaces are referred to as confined spaces. You should avoid working in them if possible.
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p Figure 6.11 Construction plant clearing a site
p Figure 6.12 Pedestrian walkways on a construction site
ACTIVITY Draw three columns with the following headings: ‘injury’, ‘disease or ill health’ and ‘dangerous occurrence’. Place the following examples of emergencies and illnesses in the correct columns. If you are unfamiliar with some of the terms below, research them on the internet. ● The sides of a trench collapsing ● Occupational asthma (lung condition) ● A fall from a ladder that resulted in a bruised elbow ● Stress tendonitis ● A cut arm ● A twisted ankle ● Sawdust in an eye ● Vibration white finger ● A wall collapsing ● Cancer ● Electrocution ● Hearing loss ● A burnt leg ● Gas leak ● A broken finger ● Fire ● A pulled muscle ● Discovery of an unexploded bomb ● Dermatitis (skin inflammation) ● Fuel leaking from a site vehicle
Actions to take when discovering an accident At work, there will be trained first aiders who can treat a casualty when called for in an emergency. It is unlikely that a first aider will be the first person to discover an accident, so everybody in the workplace needs to know how to react in this situation. Employees have a legal duty to report unsafe conditions and accidents to their employer whenever they witness or experience them. If you discover an accident in the workplace, it is important to stay calm and make a quick assessment of the situation. Things you may consider include the following. ●
How serious is the accident? ● Are there any other witnesses who could help?
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Chapter 6 Health, safety and welfare in construction ●
How did the accident happen? It may be obvious at this stage. ● Are you and others safe from danger? For example, if a person was electrocuted, you may be able to isolate the power supply to avoid further injuries? ● Are you likely to get injured by helping the casualty? ● If something has fallen from height, are further materials likely to fall? You should always act quickly, calling for help and first aiders as soon as possible after witnessing an accident. You should never attempt first aid on a casualty unless you are a trained first aider or the emergency services direct you to do so. Your employer will appoint a person to be responsible for notifying the emergency services as quickly as possible, with details of the accident and the location of the workplace, among other details. Employers should be well-prepared for an emergency and will have company procedures that everyone should follow when necessary. It is important that you understand the role that you will play in an emergency; if you do not know what you would do then you should talk to your supervisor as soon as possible.
First aid and first aid kits The role of a first aider is to preserve life, prevent the casualty’s condition from worsening and promote recovery until the emergency services arrive. First aiders are not doctors and cannot issue medicines from the first aid box. Employers should assess their first aid needs to reflect the hazards and risks of their workplace. The nature of the work being carried out, the number of workers and the spread of the workforce will indicate what provision is needed. If people are mobile or work in remote locations, then more first aid kits and first aiders may be needed. Employers should also ensure that there is adequate cover if first aiders are absent from work due to holidays or sickness. Your site induction should tell you who the first aiders are in your workplace and how to contact them in an emergency. You should also be told where the first aid kits are located. Your employer will nominate a worker to be responsible for taking care of the first aid kits by making sure that they are fully stocked and remain in their designated position. Eye wash
Burn dressing Foil blanket Sling Microporous tape Cleaning wipes Plasters
Bandages Resuscitation face shield Nitrile gloves Safety pins Scissors
p Figure 6.13 Contents of a basic first aid kit
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ACTIVITY Make a list of all the details you think will be needed to complete an accident report. Once you have finished, ask your employer or tutor if you can compare your suggestions with the details given in the accident book at your place of work or training centre.
Reporting and recording accidents (the accident book) The accident book (BI 510) is an essential document for employers and employees; it is used to report and record all accidents that cause injury in the workplace. It is normally kept with the first aid kit so that it can easily be found and completed by the first aider, the injured person or a witness as soon as possible after an accident. Once a report has been completed in the accident book, there is a legal requirement that it should be removed and stored safely for a minimum of three years. Over a period of time, a picture can emerge of the types of accidents that recur. Your employer will address this issue and rectify the problem with further training, if needed, for those workers likely to be affected.
Authorised personnel involved in dealing with accident and emergency situations When an accident first occurs, several people may be involved in dealing with the injured person as a priority; these could include: ●
first aiders emergency responders (ambulance, fire brigade and police) ● managers and supervisors. ●
Many serious accidents and dangerous occurrences must be reported under RIDDOR. It is likely that once the report has been completed, either online or over the phone, the Health and Safety Executive (HSE) will visit the scene of the accident to investigate the cause. If a major accident has occurred in the workplace, it will inevitably have an impact on production and work may be stopped. During an investigation, the HSE will talk to the employer and their health and safety officer, managers and employees/witnesses. If necessary, the HSE could isolate an area of the site or workshop; in extreme cases, they could close the entire site. An employer may also want to conduct their own investigation into the cause of an accident. The investigatory process described above may have a negative impact on production time and could result in missed deadlines and possibly financial penalties. These cases could be reported in the news and on the HSE’s website. An employer with a reputation for having poor health and safety standards could have a poor company image, lose future contracts and have difficulties recruiting and retaining staff.
3 HAZARDS IN THE WORKPLACE Risk assessments and method statements Risk assessing is something that you do every day in normal life. Before crossing a road, you assess whether it is safe to do so by looking and listening for any signs of traffic before stepping out. There are lots of hazards present on construction sites,
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Chapter 6 Health, safety and welfare in construction such as plant and equipment and working at height. As building work progresses, these risks will evolve. Other changing circumstances that should be considered are periods of extreme weather, such as flooding, intense heat, wind and snow. These can seriously affect the ground conditions, workers’ wellbeing, the stability of scaffolding and so on. It is a legal requirement for employees not to be made to work in extremely hot or cold conditions. The current HSE recommendations are that indoor temperatures should be ‘reasonable’: at least 16°C for workrooms and 13°C if much of the work involves rigorous effort. Further guidance can be found on the HSE’s website: www.hse.gov.uk/temperature
ACTIVITY
identify the potential hazards in the workplace identify who could be harmed and how evaluate the risks and decide how likely it is that harm will occur make a record of all the significant hazards, how people might be harmed and what measures are already in place to control the risk 5 regularly review the risk assessments and decide if improvements can be made, such as new equipment to reduce the risk.
Consider some of the hazards at your place of work or training centre. These could be a piece of woodworking machinery, a process or a substance that is used. Choose one of these hazards and try to complete a risk assessment using the template provided on the HSE’s website: www. hse.gov.uk/simple-healthsafety/risk/risk-assessmenttemplate-and-examples. htm Talk to your employer or tutor if you feel that more could be done to protect you from the hazard you have identified.
It is important to remember that even though your employer may already be doing everything practically possible to protect people at work from any hazards, they still legally must complete risk assessments.
KEY TERMS
Your employer has a duty to assess and record all significant hazards in the workplace on a document known as a risk assessment. There are five key steps to completing a risk assessment, which are to: 1 2 3 4
Although not a legal requirement, many employers produce written documents referred to as method statements. These documents outline the process of completing a practical task, while addressing the hazards identified in the risk assessments. Many of the larger construction sites in the UK insist on contractors having both risk assessments and method statements for the work they are completing. The term used for both documents together is RAMS.
Types of hazards in the workplace To complete a risk assessment, you must first identify the things that could cause harm (the hazards). If you look at a table saw in a joiner’s workshop as an example, you may say straight away that the saw blade is the hazard, because it could cut you. However, there are other risks that you may not have thought of immediately, such as the hazardous dust created when you are sawing that can cause lung damage or the risk of dermatitis from handling hazardous substances. If you can recognise the potential to cause harm, you can usually do something to prevent it from happening in the first place. This chapter looks at the following workplace hazards in more detail:
Method statement: a document used to detail how to carry out a job safely to control the hazards identified in the risk assessment. RAMS: an abbreviation often used in the construction industry for ‘risk assessments and method statements’.
●
fire hazards ● electrical hazards ● manual handling hazards.
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p Figure 6.14 A worker manual handling
Slips, trips and falls from height are some of the main causes of accidents on site, but some health hazards may cause ill health progressively over a long duration and can often go undetected until they have caused damage that cannot be undone. Have you ever heard somebody say that they will do a task quickly without taking the correct precautions, such as wearing PPE? It does not matter how long each task takes or whether anyone notices: hazards may still cause harm to your health. Dust that is created from concrete, stone, rock and some timbers while they are being cut or worked with can cause lung damage and diseases. There are several ways to reduce the risk of harm from dust. The safest method is to avoid creating dust altogether by using a different process to complete the task that is less dangerous or that does not create any dust. Alternatively, you could use a dust extraction system, known as a local exhaust ventilation (LEV) system, or an extraction plant for fixed wood machines. This collects the dust at its source and protects everyone from the hazard. PPE should only be used when all the other methods have been considered first, because PPE only protects the user, not anyone else nearby. Hearing loss can affect young people just as much as older adults. Damage is often caused over a prolonged period and can often go undetected until it is too late.
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Chapter 6 Health, safety and welfare in construction Primary school classroom Quiet office
Conversation
Loud radio
60 TV and sound studio
Quiet library
40 20
Faintest audible sounds 0
Arc Tractor welding cab Power drill
Bar or nightclub
80
Road drill Chainsaw Punch press
100
Riveting boiler shop 120 Jet aircraft taking 140 off 25 m away
p Figure 6.15 A chart illustrating a range of sounds
Asbestos is a naturally occurring mineral mined from the ground that used to be mixed with other materials, such as cement, to make building products. It was used because it was fire-resistant, strong and would not rot. Since the use of asbestos began many years ago, it has been discovered that breathing in asbestos fibres can lead to lung diseases and types of cancer. Asbestos was banned from use in the UK in 2000; however, it can still be found in many buildings constructed before this date. The Control of Asbestos Regulations places duties on your employer and people in control of premises to protect people who work with asbestos. If you suspect that you have found asbestos in a building, you should stop work and report it to your supervisor immediately. Asbestos should only be removed by trained and competent workers under special conditions. If you are likely to be working with it, your employer must provide you with the proper training on how to identify asbestos and what to do if you discover it. Lead is a construction material that has been used for hundreds of years in roofing, plumbing and paint. However, it can cause serious health risks such as kidney damage, nerve damage and brain damage if the correct safety precautions are not taken. The Control of Lead at Work (CLAW) Regulations places a duty on employers to prevent or control employees’ exposure to lead. Though the use of lead is not banned in the UK, its high cost and the development of alternative materials mean that it is no longer used as much as it once was in the construction industry. Although you may not be working directly with some of the hazardous materials mentioned, carpenters and joiners could still work in an environment where they are exposed to the same risks.
ACTIVITY Use the HSE website to discover the materials and areas of a building that could contain asbestos: www.hse.gov.uk/ asbestos/building.htm
p Figure 6.16 Lead flashing joining a roof to an adjacent wall
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Some materials and substances can contaminate people’s bodies to cause harm to their health in the following ways: ● ● ● ● ● ●
inhalation (breathing in a substance) absorption (a substance passing through the skin) exposure to the hazard (for example a loud noise or the Sun’s harmful rays) ingestion (swallowing a substance) cross-contamination (a substance unintentionally transferring from one object or substance to another) injection (a substance entering through broken skin, such as cuts and grazes).
If you understand the way that materials and substances may cause harm, you can then take precautions to prevent it from happening. Once you have identified the hazards in the workplace, you must understand how they cause harm to people so that you can put precautions in place to avoid or minimise the risk to health and safety.
Precautions required KEY TERMS Housekeeping: keeping a space clean, tidy and organised. Leptospirosis or Weil’s disease: a rare infection that can be passed from infected animals, such as rats, to humans through contaminated water or urine.
Your employer should inform you of the precautions that must be taken at your place of work to reduce the likelihood of an accident or illness. Simple precautions can be taken, such as housekeeping, to prevent trip hazards and avoid blocking emergency escape routes. Waste materials should not be allowed to build up in the workplace and must be disposed of responsibly.
p Figure 6.17 An example of good housekeeping on a construction site
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Washing your hands regularly before you eat, drink or smoke and after using the toilet will prevent the spread of germs and harmful bacteria. This is particularly important if you are working near animals or water (streams and rivers) or on waterlogged sites. In these areas, there is potential for the spread of a disease known as leptospirosis (Weil’s disease). You can catch the disease if you come into contact with soil or water containing the urine of infected mice, rats, cows, pigs and dogs. Although the chances of infection are low in the UK, you should still take the necessary precautions, such as wearing gloves and washing your hands before eating, drinking or smoking.
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p Figure 6.18 A construction worker washing their hands
When working outdoors in the warm weather, you may feel tempted to wear shorts and a tee shirt; however, the harmful UV rays from sunlight can cause sunburn and potentially skin cancer if you do not protect yourself properly. Some construction sites may have a policy that prevents you from wearing shorts or exposing too much skin. If you work outdoors in the heat, your employer should provide you with a high-factor sun cream (SPF 30 or above with a UVA protection rating of 4 or 5, as recommended by the British Association of Dermatologists) and keep you hydrated with a supply of fresh drinking water.
KEY TERMS SPF: an abbreviation of ‘sun protection factor’. UVA: an abbreviation of ‘ultraviolet A’, the harmful long-wave rays from sunlight that can cause skin damage.
Some of the materials that you work with, such as wood dust and resins, can remove the natural oils from the skin in your hands. If your skin loses its natural oils it can dry out and become cracked and sore: it could also lead to conditions such as dermatitis. You should wear barrier cream to protect your hands during work when you are unable to wear gloves. The Control of Substances Hazardous to Health (COSHH) Regulations require manufacturers of materials containing hazardous chemicals to provide health and safety information about their products on a document known as a safety data sheet. This is a source of information that employers refer to when completing risk assessments; safety data sheets are sometimes referred to as COSHH assessments. If there is a chemical spill in transit or the workplace, it is important to understand how to deal with it without causing further hazards. A COSHH assessment explains what the risks are and how you should avoid them. Some products that could be used to clean up a spill can react badly with hazardous chemicals, so employers should provide spill kits designed for use with a specific chemical in an emergency. COSHH Regulations control the use, transportation, handling, storage and disposal of substances that are hazardous to health by preventing or reducing workers’ exposure to them. Asbestos is not covered by these regulations as it has its own regulations, the Control of Asbestos Regulations.
p Figure 6.19 Nail gun gas canisters are a hazardous substance covered by COSHH Regulations
ACTIVITY Research hazardous solvents that are used in your trade. Find the safety data sheet for one of those products from an online retailer. You will find lots of technical information about the product, but most importantly you need to find out how you should use the product safely. Are there any precautions that you should take that you are not taking currently?
KEY TERM Solvent: a substance that can dissolve other substances.
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KEY TERM Raze: to destroy or demolish to the ground.
Many different activities are undertaken by construction workers, besides building new housing developments. The demolition of old buildings and existing homes to make way for new developments is also technically construction. If it is safe to do so, explosives are sometimes used by demolition companies as a quick way to raze a building or structure. Only suitably trained and qualified workers are permitted to use explosives, following the strict guidelines set out in the Explosives Regulations 2014. As part of your initial training as a carpenter and joiner, you will be taught how to use portable power tools (see Chapter 3). You may already be aware of some of the hazards associated with using these tools, such as sharp blades and cutters. Some tools may have other risks. Tools that are connected to a mains power supply can cause electrocution and serious burns if they are not properly maintained and used as instructed. Sanders, jigsaws and multi-tools are examples of power tools that produce vibration as they operate, which can cause muscular, ligament and nerve damage to your hands, your arms and even your whole body in extreme cases. It can also a lead to a condition known as hand/arm vibration syndrome (HAVS) or vibration white finger. Early signs of the damage caused by vibration are tingling, numbness and a loss of sensitivity in your fingers and a loss of strength in your hands. Poor blood circulation caused by the vibration can also result in a loss of colour in your fingers. Taking regular breaks from using these tools and wearing anti-vibration gloves will help to reduce the risk of injuries. You should also try to avoid using the tools in cold and damp conditions, because these conditions can worsen the effects. The Control of Vibration at Work Regulations set clear guidelines that employers must follow to protect their workers from the risks of vibration. These include calculating the level of vibration produced by tools and restricting the duration of time for which they are used. New tools and equipment are designed to minimise the amount of vibration they produce. Failure to regularly service tools can cause an increased amount of vibration to be produced.
p Figure 6.20 A random orbit sander is a power tool that produces p Figure 6.21 Ground workers using concrete breakers (power tools) vibration
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Chapter 6 Health, safety and welfare in construction Later in this chapter, different types of PPE are discussed, along with how to wear it correctly and why it is important. Most construction sites have rules stating that a minimum amount of PPE must be worn by everyone. This usually includes the following five points of PPE: ● ● ● ● ●
a hard hat to protect against head injuries, such as cuts, bumps and falling objects a high-visibility vest so that you can be seen by moving vehicles on site or on public roads steel toe-capped footwear to protect your toes and feet from crushing and sharp objects safety glasses or goggles to protect your eyes from flying objects, dust and chemicals gloves to protect your hands and skin from hazardous materials and infections.
Storage of materials including combustibles and chemicals on site Employers normally have a system of ordering materials for jobs ‘just in time’. This means that the materials are purchased and delivered by the suppliers just before they are needed. If materials are ordered too early, there may not be anywhere to store them and they may get in the way. They could get damaged by moving plant and equipment on site and by the weather. It is also not uncommon for materials to be stolen from construction sites, because these sites are difficult to secure. Building materials such as timber, bricks and sand are usually stored in a designated compound with easy access for vehicles and segregated walkways for pedestrians. To prevent construction plant coming into contact with people in this compound, the walkways will have physical barriers and clear safety signs to control the movement of traffic and reduce the risk of accidents. Valuable items such as windows, doors and ironmongery are secured in lockable containers with racks and shelving. Materials such as adhesives and fillers have an expiry date, referred to as a shelf life, after which they start to dry up and may not work as well as they were intended to. It is important that any materials with a shelf life are rotated, so that the oldest materials are the first to be used; this system is referred to as stock rotation. Materials such as timber that are not stored in the correct environment may be damaged by rain, wind and sunlight, for example, while other materials may cause a fire risk or explosion. Employers have a duty to ensure that combustibles and chemicals are stored safely and securely in a well-ventilated designated space to minimise the risk to others. Hazardous substances should always be stored in accordance with the manufacturer’s instructions and kept to a minimum. Further guidance is available from the HSE. Small quantities of hazardous substances can be stored in a robust storage cabinet with a removable tray to contain any leaks and spillages that occur. This is sometimes referred to as the COSHH cupboard (see Figure 6.23). Any spillages from the cupboard should be cleaned up immediately with a spill kit. Substances that could react with one another must be kept in separate storage containers.
INDUSTRY TIP It is unlikely that your employer will have a minimum PPE policy while working in a joiner’s workshop, because the hazards are different from those on a construction site. If you work with woodworking machinery, there may be items that are mandatory for you to wear, such as ear defenders and eye protection.
KEY TERMS Segregate: to divide, isolate or keep apart. Shelf life: the expiry date of a material. Stock rotation: using the oldest products first to maximise shelf life and avoid wasting materials.
p Figure 6.22 Timber sheets stored off the ground on bearers to prevent damage
p Figure 6.23 COSHH cupboard
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Waste control procedures Manufacturing industries are responsible for producing excessive levels of carbon emissions during the production of building materials, which are harmful to the environment. Careful consideration should therefore be given to the use of alternative materials, such as sustainably sourced timber, that have less of an impact on the environment. Some of the issues surrounding waste control and their solutions are outlined in Table 6.3. q Table 6.3 Waste control issues and solutions Waste disposal
Issue
Solution
Burning materials on open fires on construction sites
Can be extremely dangerous if not properly controlled
Avoid if possible
Can cause air pollution and a nuisance to neighbours
If not possible to avoid, seek permission from the local authority
Materials sent to landfill sites
Can take hundreds of years to break down and can produce dangerous gases, such as methane and carbon dioxide, as this process takes place
Avoid sending waste to landfill
Can cause ground and water pollution Harmful to wildlife and their natural habitat
Dispose of waste responsibly and in designated bins or skips
Transporting waste away from the site creates carbon emissions, which is dangerous to the atmosphere
Reuse or recycle the waste materials on site
Careless disposal of waste on site Sawdust and shavings from joinery manufacturing
Reduce waste materials Reuse and recycle materials
General waste skips may be used on small construction projects, but they can be expensive. The most cost-effective and considerate way to dispose of waste materials is to segregate them into different bins or skips; the materials can then be either reused or recycled. You should never allow large quantities of waste to build up, as this may cause a fire risk and invalidate any insurance.
Signs and safety notices used in the workplace In the workplace, you will notice many different signs, notices and posters displayed in various locations. Many of these sources of information relate to the health, safety and welfare of people or to warn others of work activities. Employers must display safety signs when all other relevant measures have been taken but a significant risk remains. The purpose of the signs is to communicate health and safety information quickly and clearly so that everyone understands what actions need to be taken.
p Figure 6.24 A safety sign showing the minimum PPE requirement for entering the workplace
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Chapter 6 Health, safety and welfare in construction The Health and Safety (Safety Signs and Signals) Regulations 1996 set out standardised categories of safety signs that must be used under UK law. These are illustrated in Table 6.4. q Table 6.4 Categories of safety signs that must be used in the UK Category of sign
Meaning
Action to take
Prohibition signs
You must not do …
Stop what you are doing as a matter of emergency
(For example, no smoking)
Mandatory signs
You must do ... (For example, ear protection must be worn)
Warning signs
A warning of a hazardous material, object or environment
Follow the actions or behaviour shown on the sign
Take precautions and be careful
(For example, beware of the laser beam)
Safe conditions signs
Emergency escape or first-aid signs (For example, a fire assembly point)
Firefighting signs
Location of firefighting equipment and facilities
Locate/take note of the fire doors, escape routes, safety equipment and facilities that are signed
Identify the fire hose, fire extinguishers and fire alarms that are signed
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Each safety sign is identified by its shape, its colour and the symbol or pictogram (picture) contained on it. Employers should avoid displaying too many safety signs in the workplace, because they may become confusing and be ignored. The safety signs listed above may also be supported with ‘supplementary’ signs, such as a directional arrow along an emergency escape route to exit a building.
p Figure 6.25 Supplementary sign
INDUSTRY TIP Since the last revision of the Health and Safety (Safety Signs and Signals) Regulations, the warning sign for harmful or irritant material (a black cross on a yellow triangle) has been removed and should not be used anymore. The law says that where this sign would have been used, employers should now use one of the most relevant remaining safety signs.
The safety signs illustrated in Figure 6.26 are not covered by the regulations already mentioned, but they do form part of the COSHH Regulations. You will probably recognise many of these signs from the packaging of some of the hazardous cleaning products that you have at home. Toxic
Gas under pressure
Caution
Flammable
Explosive
Dangerous to the environment
Oxidising
Longer term health hazards
Corrosive
p Figure 6.26 COSHH warning signs used in chemical labelling and packaging
ACTIVITY Create a list of the products you have at home that display one or more of the COSHH safety signs. Now reflect on the use of these products by asking yourself the following questions. ● Are they stored correctly (for example, away from heat sources and young children)? ● Are they always used safely? ● Are they disposed of responsibly (as some can be hazardous to the environment)? ● How are spillages dealt with? ● Is there anything more you could do to protect the people at home from harm?
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4 HEALTH AND WELFARE IN THE WORKPLACE Welfare facilities in the workplace At work, your employer will provide you with basic facilities for your welfare. Facilities provided for joiners are usually located at the company premises and are easier to control and maintain than those provided for carpenters and other workers on construction sites. Joinery workshops are usually equipped with toilets, washing facilities and an area to have your break; they are also dry and relatively warm. The workforce on a construction site can be spread over a large area and can frequently change as different tradespeople come and go at different stages of a project. The Construction (Design and Management) Regulations (CDM) place a duty on employers to provide the welfare facilities given in Table 6.5 as a minimum for construction sites under their control. q Table 6.5 Minimum welfare facilities to be provided by employers on construction sites under their control Facility
Requirements
Toilets
These should be well-lit, ventilated, clean and well-maintained. A ratio of 1 toilet for every 7 people is recommended. There should be a good supply of toilet paper, and for women’s toilets, a method of disposing of sanitary waste. Separate lockable rooms should be provided for men and women who share facilities.
Drinking water
A fresh supply of drinking water must be made available in suitable locations on the construction site. The water must be clearly labelled as ‘drinking water’ with an appropriate sign and positioned so that it cannot become contaminated with other substances. Adequate cups should be provided for use unless the water comes from a fountain that enables a person to drink from it comfortably.
Washing facilities
Basins for washing hands, forearms and face must be supplied. The facilities should include clean hot and cold running water (if possible) and soap with towels or another suitable method of washing and drying. These should be in the vicinity of the toilets (and changing rooms if these are required). Showers must also be provided, with separate rooms for men and women, if the nature of the building work is particularly dirty.
Changing rooms with lockers
These must be made available for workers who have to wear specialist clothing for their construction work or are unable to change elsewhere.
Facilities to rest
These must include an adequate number of seats with backs and tables for the number of workers likely to use them at one time.
Separate changing rooms must be provided for men and women, with seating and a method of drying their clothing. Lockers must be provided for specialist clothing that has to be stored on site, for personal clothing that is not worn during working hours and for personal items.
Workers should also have access to facilities to boil water and prepare and eat meals. The rest rooms or rest areas should have a method of maintaining a comfortable temperature at different times of the year. Employers must provide facilities for any women at work who are pregnant or for a nursing mother to rest lying down.
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p Figure 6.27 Rest facilities
p Figure 6.28 Changing room with lockers
p Figure 6.29 Clean drinking water
The number of welfare facilities needed at work will depend on several factors and must be calculated by your employer. It is recommended that 1 toilet and basin is provided for every 1–15 men only, and 1 to 5 for women only or for mixed use.
Health effects of noise Noise at work is a hazard that can cause harm to your health. An employer’s responsibilities under the Control of Noise at Work Regulations are outlined on page 272. It is important to understand what health effects can be caused by noise and the reasonable precautions that can be taken to reduce or control the risks. In the workplace, it is unrealistic to expect to remove the sources of all sounds, but ‘noise’ is an unwanted or nuisance sound. p Figure 6.30 Ear defenders
p Figure 6.31 Ear plugs
Tradespeople are regularly exposed to the noise caused by machinery and powered tools. Explosive noises from cartridge-operated nail guns and impact noises from hammering, for example, can also cause damage to the inner parts of your ears. Hearing loss can be either temporary, from working in a noisy environment, or permanent, from extremely loud or sudden explosive sounds. Regularly suffering with temporary hearing loss can lead to more serious conditions and should never be ignored. Working in a noisy environment may cause a distraction or loss of concentration and even balance problems, which are equally as dangerous, especially when working at height or with tools and equipment. Legislation requires that, where possible, employers should eliminate or reduce people’s exposure to noise by: 1 removing the source of the noise 2 replacing the tool or equipment with something less noisy to reduce the sound to an acceptable safe level 3 isolating the noise with physical barriers, preventing unauthorised access with warning signs and limiting the amount of time that people are exposed to the noise
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Chapter 6 Health, safety and welfare in construction 4 providing information and training to employees on the dangers of working in a noisy environment and the control measures to be used 5 providing PPE, such as ear defenders or ear plugs. PPE is the least effective way of preventing harm to your hearing and should only be used when all the other measures have been considered first.
Risks associated with drugs, alcohol and medication in the workplace The Health and Safety at Work Act 1974 Section 7 states that every employee must take reasonable care for the health and safety of themself and of other persons who may be affected by their acts or omissions. The use of recreational drugs and alcohol in society is a health and safety concern for employers at work. Drugs and alcohol in a person’s system can affect the way that they perform, which can be extremely dangerous, especially when they are working with machinery and equipment. The effects of drugs and alcohol can last anywhere between 15 and 30 minutes to 12 hours and these substances can remain in your system for several days after they have been taken. They are less productive (get less work done)
They have slow reaction times
They appear lethargic They are absent more often and/or have poor punctuality They seem anxious and paranoid
Key indicators that a worker may have taken drugs or alcohol They become worse at spotting risks
They develop low self-esteem They have short highs of overconfidence and happiness
They become withdrawn (quieter and interact less with others)
p Figure 6.32 Key indicators that a worker may have taken drugs or alcohol
Most employers will have a written health and safety policy that prevents the use of recreational drugs and alcohol or excludes people under the influence of them from the workplace. Employers may also have a policy to allow random drug and alcohol tests at work. This is particularly important for employees who are in control of high-risk plant and lifting equipment, where the consequence of losing control is more dangerous.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma The production, supply and possession of illegal drugs are criminal offences, regardless of whether you are at home or work. Therefore, if you are caught breaking your employer’s rules, you could not only be removed from site and potentially lose your job but you could also be arrested. If you were under the influence of drugs or alcohol at work and responsible for an accident involving others, you could also be prosecuted (taken to court). While it is not illegal to use drugs at work if they are prescribed by a doctor, you must still inform your employer in case of an emergency and so that they can consider the effect that the medication may have on your ability to drive or operate machinery safely.
5 HANDLING MATERIALS AND EQUIPMENT SAFELY Legislation for safe handling of materials and equipment KEY TERMS Musculoskeletal system: the parts of the human body that provide its shape, movement and stability. This includes the skeleton (bones), muscles and joints. Lifting aid: an item or piece of equipment used to reduce the risks involved in manual handling, such as a wheelbarrow or a sack truck. Centre of gravity: the point of an object where the weight is evenly distributed.
Manual handling is a term used to describe the physical act of pushing, pulling, lifting, carrying or lowering objects. These actions have resulted in a lot of workplace injuries. Repetitive strain injuries (RSIs) and injuries that occur to the arms, legs and joints, for example, are referred to as musculoskeletal disorders or MSDs for short. Whenever manual handling is required, there is always an element of risk, although there are lots of things that you can do to reduce this risk to an acceptable level. The Manual Handling at Work Regulations provides the legislation that employers must follow to protect their workers from harm. The regulations state that if the manual handling task cannot be avoided, then a suitable risk assessment must be carried out to reduce the risk of injury. A manual handling assessment should consider the following points. ●
Task: Can the task be avoided by using mechanical lifting equipment or machinery, such as a forklift? What needs to be done? How long will the task take? Will it have to be repeated? Can a lifting aid be used? (These are discussed on pages 300–301.) ● Individual: Is the task within the person’s capacity (are they able to do it)? Have they received the necessary training, instructions and information? Can the item(s) be lifted by a team rather than an individual? ● Load: Consider the weight, shape and size of the object. Is it hot or cold? Does it have sharp edges? Is it stable? Where is its centre of gravity? Will PPE be needed? Can the load be broken up into smaller and more manageable loads? ● Environment: Are the ground conditions suitable? What are the weather conditions (is it windy, raining or icy)? How far will the load need to be carried? Is the route clear?
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Chapter 6 Health, safety and welfare in construction Lifting equipment such as forklifts and loader cranes (a type of crane, often mounted on a delivery lorry, sometimes referred to as HIABs) are controlled by the Lifting Operations and Lifting Equipment Regulations (LOLER). People in control of lifting equipment must make sure that it is fit for its intended purpose and appropriate for the task. All equipment used for lifting must be regularly examined by a competent person. Any defects found must be recorded and reported to the person responsible for the equipment. Operations involving lifting equipment must be carefully planned and supervised and should only be carried out by competent people to ensure that they are completed in a safe way. Lifting aids and machinery are work equipment so their use is also covered by the Provision and Use of Work Equipment Regulations (PUWER).
Safe lifting and manual handling procedures Using your body to complete a manual handling task is referred to as kinetic lifting. Unfortunately, this is the cause of most musculoskeletal disorders, particularly back pain, in the construction industry. It is a common mistake to only consider using a lifting aid when something cannot physically be moved manually: we should consider using a lifting aid whenever possible. Before lifting a load by yourself, take the following steps. 1 Plan your route: Make sure there are no obstacles on the floor. Consider a rest point midway for long lifts. 2 Prepare before you lift: Assess the load and think before lifting. Is it safe? Could it move? Is the weight evenly distributed? Is the weight of the load indicated on the box? 3 Position yourself: Crouch down with your knees bent. Lift one corner of the load to put your hands underneath it, making sure that you have a good grip. Face the direction in which you intend to carry the load with your head up. Stand close to the load, with your feet shoulder-width apart and only slightly in front to maintain your balance. 4 Perform the lift: Stand up slowly in a smooth motion, while keeping your back straight, as shown in Figure 6.34. Keep the load as close to your chest as possible and try not to lean forwards. Never lift more than you can easily manage. 5 Complete the lift: Place the load down and then adjust its position. Try to avoid any sudden movements or twisting.
p Figure 6.33 A cherry picker
ACTIVITY Watch this HSE presentation about workrelated musculoskeletal disorders and safe lifting techniques: www.youtube.com/ watch?v=KIMSsJunXB4
KEY TERM Kinetic lifting: the action of using the human body to move, lift, lower, pull and carry objects.
p Figure 6.34 The sequence of safe kinetic lifting
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ACTIVITY Now that you are aware of how to lift safely, you should assess the tools and equipment that you lift regularly at work. Design a chart listing ten different types of tools and equipment like the template given below and add your findings. Tool or equipment type
Weight
Shape
Size
Frequency of lifting (number of times a day)
Duration (mins)
Safe practice? (Y/N)
1 2 3 4 5 6 7 8 9 10 Reflection What do I do well? What could I do better and how can I achieve this?
Analyse the information you have gathered. Are there any tools and equipment that you manually handle that you could avoid lifting or possibly lift using an aid?
Lifting aids used for handling materials and equipment The Health and Safety at Work Act says that employers have a duty to protect the health, safety and welfare at work of their employees. Providing lifting aids is one way to achieve this because it reduces the risk of manual handling injuries. There are lots of different types of lifting aids available for use, but you must receive training and be considered competent before being allowed to use them safely.
Examples of lifting aids Large heavy loads can be moved and handled with the use of mechanical lifting equipment, such as a telescopic handler, a fork lift, a loader crane or a scissor lift. This type of machinery is used on construction sites and for the delivery of materials from suppliers. You will not be expected to use these mechanical lifting aids, but you will certainly be working with them and must have some awareness about their safe use.
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p Figure 6.35 Wheelbarrow
p Figure 6.36 Gin wheel
p Figure 6.37 Pallet truck
6 ACCESS EQUIPMENT AND WORKING AT HEIGHT A person is working at height when they may possibly fall any distance that could cause personal injury. This includes falling above or below the ground. For example, a delivery driver lifting timber from the back of his lorry is working at height; so too is someone working next to a hole in the ground. Working at height is still one of the main causes of fatalities and injuries in the construction industry. Many reported accidents are the result of falling from ladders, but also falling through fragile surfaces such as an old roof. This section looks at some simple practical measures that can be taken to reduce the chances of falling from height.
p Figure 6.38 Scissor lift
p Figure 6.39 Working at height on a ‘boom’
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Legislation for working at heights
INDUSTRY TIP Further guidance on working at height can be found on the Health and Safety Executive website: www.hse.gov.uk/
Employers and other people in control of work at height have duties under the Working at Height Regulations (WAHR) to prevent death and injuries caused from a fall. They must ensure that all work at height is planned and supervised and is only carried out by competent people. Before undertaking any work at height, consider whether the task could be completed another way that would avoid the hazard or reduce the risk. There are many tasks that can now be done at ground level with planning and the right equipment. For example, inspecting a roof can now be completed with a fixed camera on a drone, as shown in Figure 6.41, rather than by someone balancing on a long extension ladder. Using the drone for inspection eliminates the hazard. Employees do not have specific duties under Working at Height Regulations but they do have general duties to take reasonable care of themselves and others who may be affected by their actions. They must also co-operate with their employers to allow them to comply with their duties.
p Figure 6.40 Drone fitted with a camera
Any equipment used for working at height will be regulated by the Provision and Use of Work Equipment Regulations (PUWER) 1998, meaning that it must be suitable for its intended use, safe and maintained. Employers must ensure that equipment is only used by people who have received adequate information, instruction and training.
KEY TERM
Types of access equipment
Access equipment: any item of equipment used by a person to safely gain height.
Your choice of access equipment should be determined by your answers to the following questions. ● ●
INDUSTRY TIP Avoid using painted access equipment because the paint may be hiding defects that could weaken it.
● ● ● ● ● ●
How long will the job take? Will the access equipment be expected to support heavy loads? What type of work is being undertaken? How many people will be using the access equipment? What are the weather conditions? Are the ground conditions suitable to support the access equipment? Are you trained to use the access equipment? Are there any additional hazards, such as working near water, asbestos or live power lines?
Ladders The risk of a fall from a leaning ladder or a step ladder is extremely high. The HSE recommends that ladders and step ladders are only used when it is not reasonable to use other forms of equipment to complete the task or when only used for no more than 30 minutes at a time. Pole ladders made from wood are rarely used today because they are heavy and easily damaged. Aluminium ladders are much lighter and stronger than wood, but they can be dangerous when working near overhead electrical cables. Ladders made with fibreglass stiles (sides) do not conduct electricity so they are preferred by electricians. Leaning ladders must be positioned at an angle of 75° or a ratio of 1:4; this means that for every unit (for example, every metre) that the ladder projects out at the bottom, it must rise by four units in a vertical direction. 302
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Chapter 6 Health, safety and welfare in construction Whenever possible, ladders must be tied at the top (such as to a building or scaffold) and secured at the bottom to prevent them from slipping. They should never be rested against fragile surfaces, such as roof guttering, as they can be unstable and affect the steadiness of the ladder. Never use a ladder that has damaged or missing parts, such as the non-slip feet at the ends of the stiles. There is an element of risk when using a simple hop-up, even though the risk of injury may be less serious than a fall from a ladder. You should always follow the manufacturer’s instructions for safe use, inspection and maintenance of access equipment.
Strong upper resting point Adequate lap on extension ladders
IMPROVE YOUR MATHS Which one of the following leaning ladders is the correct angle? Use a protractor to find out.
A
B
C
D
Ground back slope should not exceed 6°
Ground side slope should not exceed 16°; ground should be clean and free of slippery algae and moss
p Figure 6.41 A leaning ladder Leaning ladder secured at the bottom
Knees positioned below the top step
Leaning ladder secured at the top
Leaning ladder extending past the working platform by at least 1 metre or 4 rungs, with an adequate handhold
Not overreaching on the ladder
Step ladder positioned directly in front of the work area, to avoid working from the side
p Figure 6.42 Safe working practices on leaning ladders and step ladders
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Working from the side can make stepladders unstable, so do not overreach
Stepladder should be fully open
p Figure 6.43 A roof ladder (the wheels are used to help position it on the roof when setting up to use)
p Figure 6.44 A wooden pole ladder being used to access scaffolding
Do not stand on the top three steps
Lock the stepladder open firm and level on the ground
p Figure 6.45 A stepladder
Other types of ladder Podiums are a safer alternative to step ladders for access to low heights because they have a small working platform and a suitable guard rail. They are made of lightweight aluminium, making them extremely strong and very stable to work from. The lockable gate on a podium prevents the user from falling, but also allows them to work freely with both hands.
Work platforms The risk assessment may identify that a work platform is the safest form of access equipment to use in order to carry out specific tasks. A platform provides an area for multiple people to work safely with both hands free; it also provides a place for some of the materials and tools needed to be stored for a short period of time. There are several different examples of working platforms, including: ●
p Figure 6.46 Podium
trestles – for low height work ● mobile tower scaffolds – used for lightweight work for short durations; the castors at the bottom of the tower allow it to be moved safely without completely dismantling it ● scaffolding – used for work at various heights. If there is a significant risk of falling from a work platform, then a suitable handrail should be used with an intermediate rail and toe board. Toe boards are used to prevent materials from being accidentally knocked off the work platform. If materials need to be stacked higher than the toe board, then a brick guard is normally used to totally enclose the gap between the handrail and the working platform.
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Chapter 6 Health, safety and welfare in construction Toe boards and hand rails
Intermediate rail
Not overloaded
Free from trip hazards or gaps through which persons or materials could fall
No debris or trip hazards
Sufficient dimensions to allow safe passage and safe use of equipment and materials
Level and stable ground
p Figure 6.47 A safely constructed trestle
Mobile tower scaffolding is produced in a kit form, which can quickly and simply be erected and disassembled by a competent person in the workplace following the manufacturer’s instructions. When the tower is positioned ready for use, all four castors must be in contact with the floor and the brakes applied. The work platform can then be accessed by ladders in the middle of the tower rather than ladders resting against the outside, as shown in Figure 3.48, because this would alter the centre of gravity and may cause it to become unstable and fall over. As you climb through the tower, you will have to go through an access hatch in the work platform. You must close this as soon as it is safe to do so. A tower scaffold should never be moved with people or materials on the platform. There are two forms of tubular scaffolding: independent and putlog. Independent scaffolding is self-supported with pairs of vertical poles known as ‘standards’ and a series of ledgers, transoms and braces to tie them together. Within a scaffold, there may be multiple continuous working platforms referred to as lifts.
Two-rung guardrail frame
End toe boards
Side toe boards
Platform (fixed and trap door decks) Horizontal brace
Ladder frame
Diagonal brace
Span frame
Figure 6.48 Mobile tower scaffold (proprietary scaffold) Putlog scaffolds are usually built into the brickwork of p a building as it is being constructed; this prevents the need for additional standards too close to the building. The putlogs are removed from the brickwork joints when the scaffolding is taken down and the holes are filled with mortar.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Standards Working platform Toe board
1.07m Standards
Putlogs
Working platform At least 75mm
Toe board Ledgers
1.8m
Ledgers Putlogs 1.8m
Transoms Tube wedged in window for tying in
Horizontal tie Tube wedged in window for tying in
Wall
Wall
Sole plate
Sole plate
p Figure 6.49 Independent scaffolding
p Figure 6.50 Putlog scaffolding Brick guard
Guardrails
Toe board
Working platform
150 mm
p Figure 6.51 Guard rails on a scaffold
p Figure 6.52 A debris chute
Tubular scaffolding should only be erected, altered and taken down by trained and competent scaffolders. Once it has been erected, the scaffolder will inspect it and issue a handover certificate to the site manager to confirm that it is safe to use. The scaffolder will return to the site again at regular intervals, often weekly, to complete routine inspections. If there has been any adverse weather that could affect the stability of the scaffolding in between planned inspection dates, then further safety inspections may be needed.
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Chapter 6 Health, safety and welfare in construction To reduce the risk of falls from height, guardrails are installed 950 mm above the work platform and toe boards are fitted to prevent materials falling. Additional intermediate rails are fitted between the toe boards and handrails to reduce the gap to no more than 470 mm. The risk assessment may require you to wear a harness and lanyard, which is a form of PPE that will prevent you from falling from height. Waste materials should never be thrown over the sides of the scaffold to the ground below, because of the risk to people working below and to passers-by. It is far safer to use a chute to drop debris into a skip below, possibly covering the top of the skip with netting to reduce the risk further. Temporary safety netting and airbags may also be installed in areas where there are people working at height. These will not prevent workers from falling (and should never be jumped onto) but they will reduce the severity of any injuries caused by a fall.
7 WORKING WITH ELECTRICAL EQUIPMENT IN THE WORKPLACE Avoiding risks to yourself and others Carpenters and joiners are at risk of the dangers of electrical equipment almost every day in the workplace. For example, many of the tools you use for cutting, shaping and sanding are powered in some way by electricity. Other hazards that you may encounter on site include cables buried in walls, floors and ceilings or overhead power lines when working at height on ladders and scaffolding. The power supplied to a domestic home in the UK is 230–240 V, which is enough to kill somebody if they had an electric shock. The power supply recommended for use on construction sites and joinery workshops is reduced to 110 V, because this provides enough power to operate the tools and equipment but reduces the risk of death. It is important to remember that the risk of electrocution from a 240 V supply is the same as 110 V, but the outcome of an accident may be vastly different. 110 V tools are connected to a 240 V supply through a transformer unit/box. Transformers have a short lead and plug to keep the unit near to the 240 V supply, reducing the risk of death or serious injury by keeping the length of the high voltage lead as short as possible. Extension leads and tools are then plugged into one of several sockets on the transformer and safely routed above head height or clear of walkways to where they are needed. 110 V and 230 V supplies can also be supplied above head height in joinery shops, with ‘power cubes’ suspended from the ceiling, to reduce the risk of harm. The risk of electrocution can be reduced further if an alternative source of power is used, such as using compressed air with pneumatic tools.
KEY TERM Transformer: an electrical appliance that is used to reduce 230–240 V supply to 110 V.
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HEALTH AND SAFETY If you cannot avoid placing trailing leads across walkways, they should be covered up with a cable cover protector (shown in Figure 6.53) to reduce the risk of a tripping.
Mains-powered electrical tools and equipment used in the construction industry usually have different-shaped plugs and sockets to those used at home. These more robust plugs and sockets are designed to keep moisture and dirt out of the connection and provide a strong joint that cannot be easily pulled apart by mistake. If it is not possible to use a 110 V supply, you may use a protection device known as a residual current device (RCD) as an alternative. These are trip switches that stop the supply of the electricity as soon as a fault is detected in the system. The RCDs that you are likely to use at work will be on a plug, on an extension lead or on a fixed socket in a wall. There are usually two buttons on RCDs, one to test that it is working and the other to reset it; you should always check them before use.
p Figure 6.53 Cable cover protector
The Electricity at Work Regulations 1989 state that any electrical equipment that has the potential to cause an injury must be maintained in a safe condition. Power tools often get knocked and damaged because of the environment they are used in, so they must be examined for any visual signs of wear and tear before each use. First, isolate the tool from the power supply. Then complete the following checks. ● ●
p Figure 6.54 A transformer ● ● ●
Plugs: make sure the casing of the plug is intact and there are no missing or loose pins. Leads: look for signs of cuts or damage to the outer cable (sheath) exposing any bare wires. Make sure that there is a secure connection between the cable and the tool or plug. Look for any early signs that the inner wires are twisted or broken because of winding the cable around the tool after use. Body of the tool: check for any obvious signs of cracks or missing parts. Make sure that any guards operate freely. Switches: make sure that the on/off switches work freely and that any other functions operate smoothly without defects. Tooling (for example, blades, cutters and discs): check that the tooling is correct for the task in hand and that it is sharp and free from defects.
Some defects on power tools cannot be found by visual inspections alone, so further routine tests should be completed by a competent person. Most employers will have their tools and equipment portable appliance tested (PAT) to ensure they are safe to use. Items that have passed the test are usually
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Chapter 6 Health, safety and welfare in construction labelled with a small sticker, with the name of the person who completed the test and the date when the test took place. Any tools or equipment that fail the test are no longer safe to use; they must be put out of service immediately and either marked for repair or scrapped. It is currently recommended that power tools used on construction sites are PAT tested every 3 months. Your employer may suggest a longer period between tests for tools that are used in lower risk environments. During your visual inspections of power tools, you should always check for a current PAT certificate or label; if it is not in date, you must stop work and report the tool to your supervisor.
Dangers of using electrical equipment When voltages above 110 V must be used for tools, equipment and machinery, then a defined set of procedures, known as a safe system of work, needs to be put in place. This considers the people, equipment and substances involved in a task. It then identifies all the possible hazards and assesses the risks. A method statement can then be produced, detailing a process for workers to follow to minimise the risks involved in the task. Safe systems of work do not have to be written down; they can be verbal or made up of less formal lists. However, written systems of work are the preferred method because they are clear and can be referred to in the future.
p Figure 6.55 PAT testing label
Where there is no access to connect to a main source of power on site, you may have to use a generator. Generators are powered with either petrol or diesel engines to produce electricity. They produce toxic exhaust fumes, which can damage your heath, especially when working in confined spaces. Therefore, they should always be used in well-ventilated areas, ideally outdoors.
p Figure 6.56 Voltages and colour coding
The leads connected to power tools and equipment contain copper wires that conduct the electricity from the supply. Different wires are encased in differentcoloured plastic. Blue (neutral) and brown (live) wires are used to make the electrical circuit, and the green and yellow (earth) wire is the safety wire. If the live wire becomes loose and touches the casing of the tools or equipment, the earth wire provides a path for the electricity to flow and causes the fuse to blow, which then switches off the appliance. Figure 6.57 illustrates the wiring of a 240 V plug.
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E
If the tool has a plastic casing or is designed so that if the live wire becomes loose it cannot touch the casing, it will not conduct electricity and is known as double-insulated. Double-insulated tools and equipment do not need an earth wire and are labelled with the symbol shown in Figure 6.58.
L Fuse
Neutral wire N
Live wire Cable grip Outer insulation
p Figure 6.57 A wired plug
You should never attempt to repair a tool by wiring a plug or replacing a cable at work unless you are a qualified electrician. It is safer to use battery-powered tools than mains-powered tools because their voltage is low, typically only 18 V. This means that there is little chance of suffering a serious accident. Battery-powered tools do not have any trailing leads, so they can be used safely in remote locations and damp conditions. However, battery charging units need mains power and they must be used safely. Your employer may have a designated charging station set up in a safe location at your place of work to control the risk.
p Figure 6.58 Double-insulated symbol
p Figure 6.59 A battery-powered jigsaw
Methods of storing electrical equipment Portable power tools are some of the most expensive items of equipment that a carpenter and joiner will use or possibly own, so they should be looked after. During the working day, power tools and their trailing leads should be stored clear of walkways to prevent trip hazards for the user and other people. While moving power tools from one location to another or lowering them down from height, they should never be held by their leads because this will weaken the connections.
p Figure 6.60 Power tool in a moulded storage box
Tools that are neglected are a hazard, will become unsafe to use and have the potential to cause an electric shock, electric burns and fires. Manufacturers have a duty to reduce this risk by providing specific instructions on the safe use, handling and maintenance of power tools. In general, tools should be cleaned after use and inspected for any signs of wear or damage or for missing parts. Early signs of wear identified at this stage may not be significant enough to stop you from continuing to use the tool but will give you or your employer enough time to source replacement parts.
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Chapter 6 Health, safety and welfare in construction Many power tools are stolen from construction sites and workshops every day. When not in use, they must be stored in a dry and secure location and never left unattended. Storing power tools in a work vehicle may provide adequate protection during the day, but it is not recommended for overnight storage.
p Figure 6.61 Stackable power tool storage boxes
8 USING PERSONAL PROTECTIVE EQUIPMENT (PPE) Legislation governing the use of PPE
INDUSTRY TIP Suppliers do not always provide storage boxes with their power tools, although they can also usually be purchased from the manufacturer. Most carpenters and joiners prefer to use square stackable boxes that can be neatly clipped together to secure them while they are in transit or in a central storage area in a joinery shop. Some suppliers also make moulded inserts to match the power tools and accessories. These are a useful addition to help you organise your equipment and prevent it from getting damaged.
Personal protective equipment must be provided to employees when a risk has been identified that cannot be controlled in other ways. In other words, it is a last resort. This section looks at some of the different types of PPE that are used to protect people at work from harm and why PPE must be worn. The Personal Protective Equipment at Work Regulations 1992 control the provision, suitability, maintenance and use of PPE. Both employers and employees have responsibilities under the law, which they must uphold, as shown in Table 6.6. q Table 6.6 Employers’ and employee's responsibilities under the Personal Protective Equipment at Work Regulations 1992 Employers’ duties
Assess the PPE before it is used to make sure that it will control the risk. Provide PPE free of charge and replace it when necessary. Provide information, instructions and training for employees to make sure that they know how to use the PPE correctly. Make sure that the PPE is properly used. Make sure that the PPE is cared for by employees.
Employees’ duties Wear the PPE provided by their employer as they have been trained and instructed to.
Not mistreat the PPE and store it in the facilities provided when not in use. Report any damaged or lost items of PPE.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma PPE is considered to be work equipment, so it is also controlled by the Provision and Use of Work Equipment Regulations (PUWER) 1998. This legislation requires that PPE must be safe, well-maintained and inspected before use and should only be used by workers who have been suitably trained and informed. Although you may consider it to be common sense to wear certain types of PPE, such as a hard hat or dust mask, you must also know how to use the PPE correctly, because if they are not fitted correctly they could compromise your safety.
Types of PPE used in the workplace Types of PPE used in the workplace are given in Table 6.7, together with hazards associated with their use. q Table 6.7 Types of PPE and hazards associated with their use Body part protected
Hazards that could harm the body part
Body
Extremes of heat and cold, falls from height, the weather, vehicles
Disposable overalls, aprons, boiler suits and chemical suits, high-visibility clothing such as high-vis vests, waterproofs, harness and lanyard.
Ears
Loud noises
Earmuffs, ear plugs, semi-insert/canal caps
Eyes
Chemicals, dust, flying objects, sparks, strong sunlight
Safety goggles and glasses, visors, face shields, face screens
Feet and legs
Uneven and slippery surfaces, water, chemicals (such as cement), discarded timber with nails sticking out, heavy objects with the potential to crush
Wellington boots with midsole protection, safety boots, safety shoes and safety trainers, knee pads
Personal protective equipment (PPE) to protect the body part
➜
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Chapter 6 Health, safety and welfare in construction Body part protected
Hazards that could harm the body part
Hands and arms
Splinters and sharp edges (such as glass), vibration, extremes of heat and cold, chemicals
Barrier cream; various types of protective gloves, such as cut-resistant and anti-vibration; gauntlets and protective sleeves that cover the forearm
Head
Falling materials and objects, risks of bumping your head, machinery
Hard hat, bump cap, hair net
Lungs
Contaminated air (such as wood and silica dust or asbestos), lack of oxygen
Dust masks, half-face and full-face respirators, powered respirators and breathing apparatus
Skin
Sunlight, chemicals
Sunscreen, covering bare skin with clothing
Personal protective equipment (PPE) to protect the body part
There are types of PPE that are designed to protect your lungs from harmful substances in the atmosphere or when there is a lack of oxygen. These are referred to as RPE (respiratory protective equipment). RPE supplied by your employer must be fitted to your face and tested before use; this process is known as face-fit testing. The assessment is carried out to make sure that an adequate seal is formed to prevent harmful dust and so on from entering the mask. Facial hair, prescription glasses or poorly adjusted straps can cause a leak between the mask and your face and increase the amount of dust that can get into your lungs. If an adequate seal cannot be achieved with the RPE provided, your employer must consider an alternative method of protection or prevent you from undertaking the task. The Health and Safety Executive estimates that over 12,000 lung disease deaths are linked to people having been exposed to workplace hazards in their past.
KEY TERM Silica: a mineral found in common building materials like concrete, rock and sand. Silica dust can cause serious damage to your lungs if it is breathed in when cutting or drilling materials that contain it unless the proper precautions are taken.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma At times, you may be required to wear several items of PPE at the same time, so it is important that they are compatible with each other and still provide the same level of protection. For example, you may be unable to wear standard earmuffs correctly with a hard hat. In this case, the safer option would be to use a hard hat with ear defenders attached or to substitute the earmuffs for ear plugs. If you are unsure what PPE you should select and use, you must speak to your supervisor.
ACTIVITY Identify the PPE that you could use to protect yourself from the following injuries, diseases and ill health. ● Entanglement of long hair in a woodworking machine ● A bump on the head from a piece of scaffolding as you walk underneath it ● Cement burns to your legs ● A nail in your eye from a nail gun ● Abrasions to your knees ● Skin cancer ● Tinnitus ● Dermatitis
The importance of PPE Each item of PPE has a different purpose and various types are discussed throughout this chapter. You will probably wear PPE in the workplace because your employer tells you to do so and that it is a site or workshop rule; it is also a legal requirement. It makes sense to wear safety equipment that could potentially save your life or prevent you from becoming ill or injured. If the equipment you are wearing does not fit correctly or becomes uncomfortable, report it to your supervisor.
Checking and reporting damaged PPE PPE that is not in use must be stored in the facilities provided, such as a cupboard or locker, so that it remains clean, dry and in a good condition for future use. Equipment that has been left exposed to the elements on scaffolding or work benches can get lost, damaged or contaminated with dirt and germs. Part of the training you will receive from your employer involves identifying the most suitable PPE, how to use it properly and how to detect and report any faults or damage. The PPE that your employer provides must be in good condition. They are unlikely to inspect it every day before use; that is your responsibility. If you discover that any PPE has been lost or damaged or has gone missing, you must report it to your supervisor immediately so that it can be replaced. As of 2020, UK law requires that PPE supplied by your employer must be manufactured to European standards and display the CE mark. PPE that is not made to these standards or has been neglected in the workplace may not offer the same level of protection if an accident occurs.
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9 CAUSES OF FIRE AND FIRE EMERGENCY PROCEDURES Essential elements of a fire The Fire and Rescue Authorities (FRAs) deal with life-threatening fires in the construction industry every year. Unfortunately, many of these fires could be prevented if some basic precautions were followed. So what are the main causes of fire? Arson accounts for more fires than any other cause. Although it may not be possible to completely prevent this from happening, measures can be taken to secure the workplace at night when fires are most likely to start. Of course, fires also start during the day, mostly because of the nature of the work being carried out. Poorly installed electrical systems and faulty tools and equipment are sources of ignition that could be avoided with regular maintenance and the installation of work by competent people. Employers or a responsible person (somebody in control) are required to plan for an emergency by completing a fire risk assessment. They will have to identify the hazard, the people at risk and the measures that can be taken to protect them. The information from the assessment will then help employers to plan for emergencies, so that they can inform and train others. As shown in Figure 6.63, three elements are needed for a fire to burn: oxygen, fuel and heat. These are referred to as the fire triangle. If just one of these elements is removed from the triangle, the fire will stop burning and be extinguished. If employers are aware of how fires can spread from one place to another, they can reduce the risk by preparing a fire action plan. There are four ways that fire can spread. ●
Direct burning: fire spreads by igniting other combustible materials. ● Convection: as a fire starts to spread in an enclosed space, such as a room, the hot smoke rises from the flames and becomes trapped when it reaches the ceiling, causing the heat to travel horizontally and spreading the fire. ● Conduction: some solid materials, such as metal, can absorb heat and carry it to another place away from the original source, where it can set fire to further combustible materials ● Radiation: heat from a fire can be transmitted through the air to other combustible items, such as wood. As they start to absorb the heat, they begin to smoulder and eventually burn, causing the material to set alight.
ACTIVITY Your employer has asked you to help complete a fire risk assessment for your workshop or construction. Your task is to identify all the possible sources of ignition and list them, such as faulty electrical equipment.
p Figure 6.62 The fire triangle
KEY TERMS Fire action plan: a written plan of the actions to be taken in the event of an emergency in the workplace and the control measures to be used, such as fire doors, escape routes, fire alarm and fire extinguishers. Convection: a process where a liquid or gas circulates, causing the warmer parts to rise and the colder, heavier parts to sink, which results in heat being transferred.
Methods of fire prevention Now that you know how a fire can start and spread, you should look at what you can do to reduce the likelihood of a fire happening in the first place. Some benefits of keeping work areas clean and tidy have already been mentioned, but an untidy workspace littered with waste materials can also be a fuel source for fires to start. Your employer will expect you to follow their organisational rules for fire safety, 315
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma including removing all waste materials and disposing of them in the appropriate areas to prevent it from building up. Your supervisor or other workers will identify poor standards of cleanliness in the workplace and this could result in disciplinary action being taken against you if you disregard the rules. Some of the things that can be done to avoid the risk of fires include: ● ● ● ● ● ● ● ● ●
avoiding burning waste on site providing and using designated smoking areas risk assessing and controlling high-risk activities, such as hot works (for example welding and grinding metal) planning escape routes and practising emergency drills always keeping escape routes and fire doors clear disposing of waste in the designated bins or skips storing flammable liquids and chemicals safely clearing up chemical spills securing the workplace to reduce the likelihood of unauthorised access and arson.
We are all responsible for reducing the likelihood of an accident in the workplace, so you should be aware of what can cause a fire and report any unsafe conditions to your supervisor immediately.
Actions to take on discovering a fire Would you know what to do in the event of a fire in the workplace? Your employer should explain what actions you will need to take, how to escape the building you are in and where to assemble. The method for raising the alarm and the systems used are likely be different in each workplace, so it is important that you are told about them and that you understand them clearly. Your employer will display ‘fire action points’ on safety signs/notices with fire extinguishers and in various other locations. The following steps outline the general procedure to follow upon discovering a fire.
p Figure 6.63 Fire action sign/ notice
1 Raise the alarm as instructed by your organisation. This could be a wired or wireless sound system or a manual alarm such as a bell or whistle. 2 Alert others to the danger by raising your voice. 3 Leave the building via the nearest emergency escape route. Do not stop to save your belongings. 4 Assemble at the correct assembly point (sometimes referred to as the ‘muster point’). 5 Do not leave the assembly point until you have been accounted for and instructed. 6 Do not return to the building until you have been authorised to do so by the fire marshal. If it is safe to do so, you should close, but not lock, all the doors on your way out of a building to help slow down the spread of the fire. When the emergency services arrive at the scene of the fire, their priority will be to save people’s lives. It is vital that everybody can be accounted for at the assembly points. If you do not go to the correct assembly point, it could cause a delay in accounting for you and could potentially put lives at risk. Do not leave or go straight home. Wait for instructions.
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Types of fire extinguishers and their uses Fire extinguishers are designed to tackle small fires or to be used if a fire is blocking your safe exit from a building. They will be positioned at various locations in your workplace where they are most likely to be needed in the event of a fire. It is important that they remain in these positions until they are needed, are always accessible and are never used for wedging doors open. If you are expected to use a fire extinguisher in an emergency, your employer must train you to use it safely. There are different types of extinguishers and their contents are designed to remove one or more of the three elements of the fire triangle. Some extinguishers will put out different types of fires, while others can make them worse if they are used on the wrong type. For example, using water to extinguish a hot oil fire can cause a huge fireball. Water and foam extinguishers will conduct electricity, so they should never be used on electrical fires.
ACTIVITY Watch this video demonstration of the effect of water on a hot oil fire: www.youtube.com/ watch?v=dPr-tOZHmOA Using Figure 6.64, can you identify what type of fire extinguisher it is safe to use on a hot oil fire?
The different types of fire extinguishers and the types of fire they should be used on are shown in Figure 6.64.
CO2 extinguisher: used for flammable liquids, flammable gases, electrical fires.
Dry powder extinguisher: used for Water extinguisher: used wood, paper, hair, textiles, flammable for wood, paper, hair, liquids, flammable gases, flammable textiles. metals, electrical fires.
Foam extinguisher: used for wood, paper, hair, textiles, flammable liquids.
Figure 6.64 Fire extinguishers and their uses
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Practical task Choose one of the following scenarios
Scenario 2
Scenario 1
You are a joinery workshop manager of a large company, which employs 25 staff. You are responsible for training new employees on the workplace hazards by raising awareness. Make a list of all the potential workplace hazards in the joinery workshop and create a visual presentation for use with new employees.
You are a construction site manager for a new housing development and are responsible for writing a ‘site induction’ for a presentation. Make a list of all the topics that need to be covered in the induction, such as welfare and toilet facilities, and create a visual presentation for use.
Test your knowledge 1 What responsibilities does an employee have under the Health and Safety at Work Act?
c
d
e
2 What actions can the HSE take against employers who do not follow health and safety regulations? 3 Where would you find information on the safe use, transportation, handling and disposal of hazardous chemicals? 4 List the welfare facilities that must be provided on construction sites. 5 What voltage is recommended for use on construction sites and what colour cables does it use? 6 What checks should you make on a mainspowered portable power tool before use? 7 What actions should you take on discovering a fire at work? 8 What are the three elements of the fire triangle? 9 What do the following safety signs mean?
a 10 Label the wires in this illustration of a 230–240 V domestic plug.
b
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Test your knowledge answers
Answers CHAPTER 1 Improve your maths, page 23 9.75 m × 8.65 m × 0.4 m = 33.735 m³
Activity, page 27 a 3 and 4 b 1 and 2 c 4 d 1 and 2
Improve your maths, page 34 3 m x 15.7 m = 47.1 m² (Area of one side of the wall) 2 m x 1 m = 2 m² (Area of the door opening) 47.1 m² – 2 m² = 45.1 m² (Area of one side of the wall, less the door) WB 45.1 m² + 45. 1m² = 90.2 m² (The total area of both sides of the wall) 2.4 m x 1.2 m = 2.88 m² (Area of one sheet of plasterboard) 90.2 m² ÷ 2.88 m² = 31.319 m²
Wash basin
Improve your maths, page 45 5.5 m (A) + 5.6 m (B) + 7 m (C) + 5.6 m (D) + 5.5 m (E) + Sink 11.2 m (F) + 18 m (G) + 11.2 m (H) = 69.6Sinktop linear metres
Improve your maths, page 57 Bath
Radiator
Using this method, treat the whole middle rail as 195 mm. Divided by 3, each part measures 65 mm.
Test your knowledge 1 WC a
Radiator
North point
1 (b) 2 (d) 3 (c) 4 (b) 5 (a)
Wash
6 (a) 7 (b) 8 (a) 9 (d) 10 (c) basin
Bath
CHAPTER 3
Lamp
Shower tray Improve your maths,
Window
page 149
Door
Radiator
The optimum peripheral speed is 24,188 rpm, rounded down to a maximum of 24,000 rpm.
Sawn timber (unwrot)
Concrete
Test your knowledge
b
Lamp 1 (c)
Switch c d
CHAPTER 2 WB Test your knowledge Shower tray
Bath
32 whole sheets of plasterboard are needed
Door
2 Set start and completion date; sequence the stages of building; organise materials, resources and tradespeople; help to avoid financial penalty as a result of missed deadlines. 3 Strip, raft, pile, pad 4 10° 5 A lintel 6 A client is the most important person in the building team because they are responsible for requesting and funding the construction project. 7 Knotting 8 Installing a kitchen, door linings, dado rails, picture rails and so on. 9 Prevent heat loss; improve the energy efficiency of the building; reduce bills; conform to Building Regulations. 10 Date; time; the name of the person for whom the message is intended; the name of the caller; the name of the person who received the phone call; a contact phone number; message content.
Blockwork
Sawn timber (unwrot) Insulation
2 (a) 3 (d) 4 (b) 5 (c)
Socket Stonework
Concrete Brickwork Top
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North
6 (b) 7 (c) point 8 (a) 9 (c) 10 (d)
Sawn timber (unw Earth (subsoil) Stairs up319
Blockwork Bottom
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CHAPTER 4
Test your knowledge
a Tangential b Radial
1 (c) 2 (d) 3 (b) 4 (d) 5 (a)
Improve your maths, page 182
CHAPTER 6
Activity, page 181
48% - 15% = 33% moisture to be lost 33% ÷ 3 days = 11% moisture to be lost each day
Test your knowledge 1 Air seasoning and kiln seasoning 2 Off the ground on bearers or in a rack and undercover 3 a bull nose b splayed c torus d ogee e grooved 4 Scribed internal corners and mitred external corners 5 To check that the diagonal lengths of a frame are equal and to make sure that it is square 6 1:6 in softwood, 1:8 in hardwood, but 1:7 sometimes preferred for both 7 Face side Face edge
8 Tenon saw 9 Arris 10 Widening, lengthening and framing joints
CHAPTER 5 Improve your maths, page 231 Timber 15 mm thick would need a 40 mm nail; timber 30 mm thick would need a 75 mm nail; and timber 44 mm thick would need 100 mm nail.
6 (b) 7 (c) 8 (a) 9 (c) 10 (d)
Improve your maths, page 303 c – 75 degrees (ratio 1:4)
Test your knowledge 1 Take reasonable care for the health and safety of yourself, and others who may be affected by the things you do or do not do; co-operate with your employer to enable their duty or requirement to be performed or complied with; not intentionally or recklessly interfere with or misuse anything provided in the interests of health, safety or welfare. 2 They can issue improvement notices, prohibition notices and fines. 3 On a COSHH safety data sheet 4 Toilets; drinking water; washing facilities; changing rooms with lockers; facilities to rest 5 110 V; a yellow cable 6 Make the following checks. ● Plugs – make sure that the casing of the plug is intact and that there are no missing or loose pins. ● Leads – look for signs of cuts or abrasions to the outer cable (sheath) exposing any bare wires. Make sure that there is a secure connection between the cable and the tool or plug. Look for any early signs that the inner wires are twisted or broken as a result of winding the cable around the tool after use. ● Body of the tool – check for any obvious signs of cracks or missing parts. Make sure that any guards operate freely. ● Switches – make sure that the on/off switches work freely and that any other functions operate smoothly without defects. ● Tooling (blades, cutters and discs) – check that the tooling is correct for the task in hand and that it is sharp and free from defects.
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Test your knowledge answers 7 Take the following actions. 1 Raise the alarm as instructed by your organisation. 2 Alert others to the danger by raising your voice. 3 Leave the building via the nearest emergency escape route without stopping to save your belongings. 4 Assemble at the correct assembly point. 5 Do not leave the assembly point until you have been accounted for and instructed to leave. 6 Do not return to the building until you have been authorised to do so by the fire marshal. 8 Fuel, heat and oxygen 9 Meanings of safety signs are as follows. a Warning sign – slippery surface b Prohibition sign – no unauthorised entry
c Mandatory sign – eye protection must be worn d Safe conditions sign – first aid point e COSHH sign – corrosive 10
Earth wire
E
L Fuse
Neutral wire N
Live wire Cable grip Outer insulation
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Glossary Abrasive: having a rough surface that will rub away at another surface. Access equipment: any item of equipment used by a person to safely gain height. Acute angle: an angle of less than 90˚. Angle of hook or rake: the angle at which the face of the saw tooth slopes from the tooth tip, either down and forwards from the tip, as in the case of negative tooth profiles for cross cutting, or down and backwards from the tooth tip, as in the case of positive tooth profiles for ripping. Architrave: a timber trim or moulding often used to cover the joint between a door lining and a wall. Arris: the edge of a piece of timber. Back set: the distance between the face of the lock and the centre of the handle, knob spindle or key hole. Backing plaster: an alternative material to traditional cement render. Browning, Bonding coat and Hardwall are three examples of backing plasters that can be used on masonry walls to make them flat, before applying the finishing coats of plaster. Backing plasters dry much faster than cement render and are often preferred for use on internal walls. Beading: a small section of timber, often shaped with a decorative profile. Bearers: lengths of timber positioned on the ground at equal spacings so that timber can be stored on them off the ground. They are used to prevent the timber absorbing moisture from the ground, which may cause warping, twisting and other defects. Binding: when something is prevented from moving freely, such as a door being prevented from opening fully because it is binding against the
architrave, or the side of the saw sticking and rubbing on the material during the cutting process. Bisecting: dividing a line or angle into two equal parts geometrically. Bleaching: a change in the natural colour in a solid timber or timberbased material caused by the exposure to UV light, such as in sunlight. Break-out: the damage caused when a tool, such as a chisel or drill bit, is used from one face of a piece of timber and exits the opposite side. Break-out can be reduced if a clamp is used to hold a scrap piece of timber behind the area being worked on.
leaving the outside dry but the centre still wet. It typically causes the material to bend and twist during cutting, resulting in binding on the saw blade and kickback. Centre of gravity: the point of an object where the weight is evenly distributed. Collated nail strips: grouped individual nails in an ordered system, usually held in place by paper or glue. Chasing: channelling out a wall to allow pipes and cables to be buried in it and covered with plaster. Chuck: the housing that the shank of the drill bit fits into.
Breathable felt: a lightweight waterproof material used in roofing and external wall construction. Water cannot penetrate through the felt from the outside face, but air from the inside can pass through it to provide ventilation to a building.
Clearance hole: a hole that is slightly drilled through only the upper component being fixed. This hole should be slightly wider in diameter than the gauge or diameter of the screw. This enables the screw to pass cleanly through the material without binding.
Bridging: when moisture travels through a cavity wall in the materials used to construct it. Poorly installed cavity wall insulation and wall ties are examples of materials that can result in water bridging a cavity in a wall.
Collated: assembled in the correct order and held together in strips usually with glue, plastic or paper.
Building control officer: a professional who represents the local authority’s planning department or an independent organisation. Part of their role is to visit construction sites and monitor the standard of the building work at various stages throughout the project, to make sure it meets with national Building Regulations. Butt hinge: a type of hinge consisting of two flat leaves revolving around a pin (hinge), the knuckle of which pivots. Commonly used to support internal and external timber doors. Case hardening: a defect caused by the timber being dried too rapidly,
Compound cut: a type of angled cut that incorporates two angles simultaneously cut, one from the mitre angle of the saw and one from the bevel or canted angle of the saw. Concrete slab: the solid mass of concrete poured to create a floor. Control measures: a system used to protect people from harm, such as the use of PPE, guards on machinery, safety signs and fire extinguishers. Convection: a process where a liquid or gas circulates, causing the warmer parts to rise and the colder, heavier parts to sink, which results in heat being transferred. Converted: sawing along the grain of a tree trunk to produce sawn boards of timber.
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Glossary Countersunk: shaped so that the head of the screw sits below the surface of the timber when it is fixed. Courses: arrangements of bricks and blocks laid in rows by bricklayers. Crown: the top section of a tree containing the branches. Cupping: the curling (distortion) of timber away from the centre of the tree. Curing: the chemical process adhesives go through before they achieve their full strength. Cutting in: carefully painting up to a surface with a different colour, paint, stain or material using a brush. Cutting list: a detailed list of the components, types of materials, dimensions and the quantities needed for a task. Cutting lists are used by the wood machinists to prepare timber to manufacture joinery products. Damp-proof course: a layer of plastic, supplied on a roll, used to prevent damp rising from the ground through the brickwork. Dead load: the weight of all the materials used to construct a building or structure. Decibels: a unit used to measure the intensity of sound levels. It is often abbreviated to dB. Delaminate: when layers of materials split apart. Domestic building: a property that no more than one family lives in, such as a house. Door jamb: the part of the door frame running vertical on either side of the door opening. Dry fitting: a stage in the process of manufacturing joinery, when a product is put together without glue to make the final checks. After the checks have been made, the joinery can be taken apart and the internal faces sanded (also referred to as papered-up)
before being reassembled with a wood adhesive for the final time.
fire doors, escape routes, fire alarm and fire extinguishers.
Dry rot: a type of fungus found in timber that causes it to decay.
First fixing: the primary work completed in a building before the walls and ceilings are plastered, such as installing windows, doors frames and stairs.
Durability: how hard and resistant something is. Some timbers are more resistant to the weather than others because of their natural oils and resins and are therefore more suitable for exterior work. Dusting brush: a small hand brush used by painters and decorators, to prepare surfaces to be painted by removing any loose dirt and dust. Eccentric circles: where one smaller circle is offset within a larger circle. Equilibrium moisture content: the point at which the moisture contained within the timber is equal to the environment it is in. Timber with a high moisture content in a dry setting, for example a heated room, will rapidly dry out and shrink to reveal gaps in the joints of connecting timbers. Ergonomics: designing equipment in a way that improves overall performance and comfort based on an understanding of human actions, such as how well it suits the body of the user or whether it is comfortable to hold. Expansion gaps: spaces left between materials to allow them to move freely if they shrink or expand. If gaps are not left and the materials expand, they are likely to buckle and distort. The joint between floorboards and a wall is a good example of where an expansion gap should be left. Joiners also use expansion gaps between tongue and grooved boards when they are making matchboarded doors. Felling: cutting down a tree. Fire action plan: a written plan of the actions to be taken in the event of an emergency in the workplace, and the control measures to be used, such as
Fixings: types of screws, nails, adhesives and sealants used within carpentry and joinery and the construction industry as a whole. Footprint: the area of ground that a building is constructed on. Galvanised: a protective zinc coating that is applied to steel and iron to help prevent rusting. Grooves: narrow cuts or channels along the grain of the timber. Growth (or annular) rings: produced every year that a tree grows, therefore increasing its size. Trees generally grow more in spring and summer than they do in the colder winter months. The amount of growth that has taken place during these seasons can be seen on the end grain: the lighter rings are produced in the summer and the darker rings in the autumn and winter. Hardwood: a category of timber that comes from deciduous trees, such as oak. Hatching: evenly spaced parallel lines, running in the same direction, at 45° from each other. Haunch: a portion of a tenon that has been removed to strengthen the joint. A haunch also creates a space where wedges can be driven down the sides of the tenon to strengthen it further. Hazard: something that has the potential to cause harm. For example, a nail gun has the potential to cause harm to your eyes or body from the nails it fires. The noise that it creates could also cause damage to your hearing over a period of time. Remember, your employer has a legal responsibility to protect you from all potential hazards in the workplace.
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Horizontal: flat and level, such as water would lay.
Kinetic lifting: the action of using the human body to move, lift, lower, pull and carry objects.
Horns: portions of waste material left on a frame to strengthen the joints before they are later removed after final assembly and finishing.
Labour: a term used to describe physical work. Lead time: the time between the start of a process until its conclusion.
Housekeeping: keeping a space clean, tidy and organised.
Legislation: a law or legal regulation. For example, the Health and Safety at Work Act 1974 is a piece of legislation.
Head: the top component in a frame.
Housings: joints consisting of a groove usually cut across the grain, into which the end of another member is housed or fitted to form a joint. Improvement notice: a formal document issued by the HSE to employers when they have fallen short of their health and safety responsibilities, usually in non-life-threatening ways that can be easily corrected. Infinite: used to describe something that will last indefinitely (forever), such as water. Natural materials like oil, coal and gas are finite resources, which means that they cannot be replaced once they have been used. Interlocking grain: the grain or fibres of the timber grow at a slight incline and change direction in different years of growth. This change in grain direction can create a striped effect on the surface of the timber. Interlocked grain can be difficult to plane and may result in the timber surface tearing out. Ironmongery: hardware, such as locks, handles and hinges. Ironmongery schedule: a document used to list repeated ironmongery that is used throughout a project, such as new build housing. Jambs: the long lengths of timber used to form the vertical sides of a door lining or frame. Joist hangers: metal brackets shaped to support the ends of timber floor joists. Kerf: the total width of the saw cut.
Leptospirosis or Weil’s disease: a rare infection that can be passed from infected animals, such as rats, to humans through contaminated water or urine. Lifting aid: an item or piece of equipment used to reduce the risks involved in manual handling, such as a wheelbarrow or a sack truck. Listed building: an old structure that has special architectural or historical interest. When a building or structure becomes listed it is registered on the British Listed Buildings database, whose purpose is to protect and maintain buildings for future generations. It is a criminal offence to carry out any work on the inside or outside of a listed building without the consent of the local planning office. Live loads: the additional weights that a foundation has to support after it has been constructed and in use. People, furniture, wind and snow are just some of the live loads that a building has to be designed to support. Load-bearing: supporting a weight. Elements of a building that are loadbearing could include a floor, wall, roof or chimney. Internal or external loadbearing walls should never be removed without consulting a structural engineer first. Loose fill: insulation used in a cavity; commonly made from water-resistant polystyrene beads. Loose tenon: a length of timber or plywood used to form the joint of
a mortice and tenon joint that is separate from (loose) both pieces of timber that are to be jointed. This contrasts with the traditional tenon that is a part of one of the pieces being jointed together. Masking up: protecting areas of a wall, floor or ceiling from paint with masking tape and paper. Matchboard: a term given to tongue and grooved timber boarding, often used on doors and gates. Method statement: a document used to detail how to carry out a job safely to control the hazards identified in the risk assessment. Misfire: a nail gun failing to operate properly, causing the nail or fixing to get jammed in the chamber of the tool. Always follow the manufacturer’s instructions to avoid this happening. Mortar: a building material produced when building sand, cement and water are mixed together. Mortar is the glue that sticks or bonds bricks and concrete blocks together to build walls. Mortice: a rectangular hole, often created with mortice chisels or a mortice machine. Mortice and tenon joint: a traditional woodworking joint used to build frames. Musculoskeletal system: the parts of the human body that provides its shape, movement and stability. This includes the skeleton (bones), muscles and joints. Near miss: an incident that occurred that could have caused harm to someone but did not. It is important to report near-miss incidents to prevent them from happening again. Negligent: a term often referred to in health and safety law when someone does not fulfil their responsibilities. Networking: professional people interacting with each other to
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Glossary exchange information and create new contacts. Non-porous: when water cannot soak through a material or building component. Notch: a shallow recess cut into a piece of timber.
splitting when the fixing screws are inserted.
‘risk assessments and method statements’.
Pitch: something that is angled (for example, a pitched roof has sloping rafters so that the rainwater can run off).
Rafters: the main structural timbers in a roof; they are used to support the roof covering.
Nylon: a type of plastic. Obtuse angle: an angle of more than 90˚.
Pitch marks: the marks left on the timber surface from rotary power tools, such as power planes and surface planers.
Oriented strand board (OSB): board comprising wood fibres that lie in opposing directions to each other, in a similar way to plywood.
Plant: a piece of heavy machinery or equipment, or a construction vehicle, such as a dumper truck, crane or generator.
Oscillating: move back and forth in a consistent repeated movement.
Porous: a porous surface or material absorbs moisture because it contains lots of small holes.
Passivated: a protective coating, usually zinc. PAT certificate: portable appliance testing (PAT) is an examination of electrical appliances and equipment to ensure they are safe to use; a label is fixed to the power tool stating date of test. Peripheral speed: the distance the rotating cutting edge travels, expressed as metres per second (m/s). Personal protective equipment (PPE): safety equipment worn by an individual to protect themselves from workplace hazards. There are many different types of PPE including protective gloves, safety goggles and ear defenders. PPE designed to protect against respiratory hazards is referred to as RPE (respiratory protective equipment). This protects the user’s lungs and airways. Pier: a brick, block or concrete pillar that is not connected to a wall. Piling sticks: lengths of thin batten used to create a space between stored timber layers to allow air to flow between the boards. Stacking timber for a long period without the use of piling sticks may result in an increase in the moisture content in the centre of a pack. Pilot hole: a small hole drilled (or bored) into timber to prevent it from
Profile: the shape of a section of timber, for example a rebate, pencil round and ovolo are profiles that can be found on timber. Profiled: material which has had a decorative edge added to one or more sides. Profiles: decorative shapes formed along the edge of materials, such as rebates, ovolo, ogee, bullnose, lamb’s tongue, and scotia. Pulley wheel: a type of wheel that a drive belt fits around; they come in different diameters to give different drive speeds for the drill bit. Pulleys: a type of wheel that a drive belt fits around and used in different diameters to give different drive speeds for the drill bit. Purlins: large timber beams used to support the rafters in a traditional roof. Push stick: a length of timber used to help feed and control the material being cut. PVCu: polyvinyl chloride unplasticised. This is often referred to as uPVC, but the abbreviation was changed in the 1980s to PVCu, so that British manufacturers now use the same term as their European counterparts. RAMS: an abbreviation often used in the construction industry for
Raze: to destroy or demolish to the ground. Resin: a thick, sticky fluid contained within timber. Ridge board: a structural beam, usually found at the top of a traditional roof. Ring shank: a nail with small ridges around the shank, which increase the nail’s resistance against pulling loose. Saddle: a type of jig used to support the timber during the cutting process. Scribed: a shape that has been replicated, marked out and cut on a piece of timber to fit over another surface. Seasoning: a process of drying timber to reduce its moisture content. Second fixing: carpentry work completed after the walls and ceilings have been plastered, such as installing skirting, architraves and doors. Segregate: to divide, isolate or keep apart. Set: a saw’s side clearance. Shakes: natural splits that occur in timber. Shank: the end of the drill bit that fits into the chuck of the drill; the noncutting part of the router cutter that is fitted into the collet of the router; the part of the nail between the nail point and the nail head. Shelf life: the expiry date of a material. Shoulders: a part of some woodworking joints (such as a tenon) could have shoulders on both sides of the joint to provide extra support. Silica: a mineral found in common building materials like concrete, rock and sand. Silica dust can cause serious damage to your lungs if it is breathed in when cutting or drilling materials that contain it, unless the proper precautions are taken.
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma Softwood: a category of timber that comes from coniferous trees, such as pine.
in the concrete and causes them to rise to the surface, therefore strengthening the concrete.
Solvent: a substance that can dissolve other substances.
Tangential: timber boards that have been converted so that the end grain is at an angle of less than 45°.
Specification: a written document that an architect produces. It contains additional information about a project that cannot be fitted onto the working drawings. Spelching: the uncontrolled breakout of material, resulting in damaged and/ or weakened edges. Squaring rod: a thin piece of batten with either a point or a nail on the end of it. It is used to measure the diagonal distances in a frame to check that it is square. Steamed: a process timber goes through after it has been converted but before it is seasoned that changes its colour. Stiles: the vertical sections on the outer edges of a door. Stock: the handle of a square or the sliding heads on a mortice gauge, marking gauge and cutting gauge. Stock rotation: using the oldest products first to maximise shelf life and avoid wasting materials. Stroboscopic effect: the flickering or flashing of a light source, which can cause headaches and nausea. Stroboscopic effects can also lead to dangerous situations when using rotating tooling such as saws and routers. The flashing or flickering of the light source makes the tooling appear to be stationary or moving very slowly or even backwards. Subsidence: when the weight of a building or structure sinks into the ground. Surface planing machine: an industrial fixed bed machine that uses rotating cutter blocks to produce a flat, smooth and straight length of timber. Tamping: the process of gently tapping the surface of wet concrete with a batten or plank after it has been laid. Tamping releases trapped pockets of air
Tungsten carbide tip (TCT): a tip made of hard-wearing metal used to form the cutting edges of tooling such as saw blade teeth. Verge: the edge of a pitched roof on a gable end.
Thermal insulation: a product used to retain the heat in a building, therefore making it more energy efficient. Other types of insulation include sound insulation and fireproof insulation.
Vertical: hanging straight down, such as a weighted plumb line would hang.
Tile lath: length of treated timber used to help hold roof tiles in place.
Vibrating concrete poker: a power tool used to remove pockets of air from freshly poured concrete. When the vibrating poker head is submerged into the wet concrete the vibrations cause any bubbles present to rise to the surface.
Tinnitus: a permanent ringing in the ears. This is often caused to carpenters and joiners by long exposure to noise produced by routers and woodcutting machinery when adequate protective measures have not been taken. Toolbox talk: small bite-size training sessions covering a specific area such as PPE use, safe operation of a power tool or hygiene requirements. Torque: the rotating force produced to turn an object. Touch dry: a surface that has not fully hardened, such as paint, but has formed a thin dry layer, referred to as a ‘skin’. Timber that is touch dry can usually be handled with care; soft paint can easily get damaged if it is not stored and moved correctly. Tracking: adjusting the front roller so the abrasive paper will run central to the pulley rollers. Transformer: an electrical appliance that is used to convert 230–240 V supply to 110 V. Trench: a groove cut across the grain of a piece of timber. Trunking: a hollow plastic tube or box section, commonly used by electricians and plumbers to hide pipes and cables. Some trunking has a removable cover for easy access and maintenance to the services.
Vertical spindle moulder: industrial fixed bed machine used to produce decorative finishes on the edges of timber.
Wall plate: a length of timber positioned on top of a structural wall so that rafters and joists used for a roof (or floor) can be nailed to it. Wall plates provide a good fixing point and help to spread the weight of the roof evenly along the length of the wall down to the foundations below. Wall plates used for roofs are secured to the wall below with metal restraint straps, also referred to as wall plate straps. Waste area: the part of the timber removed to create the joint. Watertight: used to describe a stage of building, usually when the walls and roof have been constructed and waterproofed, at least with breathable felt. All the doors and windows should also be installed at this stage, or the openings in the walls need to be covered to protect the building from the weather. Whiskers: the small pieces of wood fibre remaining after cutting the joint. Leaving these timber fibres in place can cause an obstruction when assembling the joint. Workability: how easy or difficult the timber is to plane, saw, machine and finish.
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Index
Index A abrasive paper 47, 108, 162–6 access equipment 301–7 accidents 278–84 acute angles 61 additives 21 adhesives 109–10, 215–16, 241–2 aggregate 21 air bags 108 air source heating 13 alcohol 287–8 angle grinders 169–70 angle of hook or rake 128 angles 61–3 bisecting 63, 223 architect 49 architect’s instruction 5 architraves 210, 220–3 area, calculating 32–3 asbestos 287, 289 ash 185 assembly drawings 6 auger bit 102, 105–6 B backed saws 66, 68–9 backing plaster 34 barge board 42 batteries 116–17 beading 210 bearers 183 beech 185 belt sander 162 bench grinder 96 bench planes 76 bevel edge chisel 89–90, 92 bill of quantities 5 binding 221 biomass heating 12 biscuit joints 155, 155–9, 158, 206 bitumen felt 39 black japanned screw 235 bleaching 183 block and beam system 35–6 block plane 78–9
block plans 8 blocks 28 blue jean insulation 15 blue staining 183, 189 board see manufactured board bolts 251–3 bonds 30 bowing 137, 191 boxed heart sawn timber 180 box square 60 brass 236 breaker drill 125 breathable felt 25 bricklayer 49 bricks 25, 28 brickwork, bonds 30 bridle joints 208 British Standards Institute (BSI) 8 brown water 16 building control inspector 49 building control officer 18, 203 Building Regulations 203, 255 bulk insulation 15 bullnose plane 80 butt hinges 242–3, 257–9 butt joints 207–8 buyer 49 C Canadian lumber stock (CLS) 28, 31, 187 carbon dioxide (CO2) 11 carpenter 49 case hardening 182, 191 cavity fixings 240 cavity tray 24 cavity walls 24–6 cedar 184 ceiling 37 cement 21, 26 chasing 27 chipboard 203 chisels 89–91 common faults 194 sharpening 95–101 techniques 91–5
circular saws 128–33, 136–7 civil engineer 49 clamping equipment 107–8 claw hammer 106 clay tiles 42 clerk of works 49 climate change 11 coach screws and bolts 238–9 coal 11 collated nails 161, 230 combination gauge 64 combination square 59–60 communication 48, 50 methods 51–2 taking a message 52 compass 61 compasses 61–3 compass plane 81 component range drawings 7 compound cuts 134 compressed air 117–18 computer-aided design (CAD) 51 concrete 21 calculating volume 22–3 cure rate 35 mixing ratios 21 oversite 37 concrete screw 235 concrete slab 36 conduit 27 Construction, Design and Management Regulations 2015 270 construction manager 49 Construction Skills Certification Scheme (CSCS) 277 contact adhesive 110, 241 Control of Asbestos at Work Regulations 2012 270 Control of Noise at Work Regulations 2005 272 Control of Substances Hazardous to Health 2002 271, 289, 294 Control of Vibration at Work Regulations 2005 272, 290
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma coping saw 69 countersink bit 102 countersinking 105 countersunk screws 235 course aggregate 21 courses 30 crosscut saws 66–7, 68 crosscutting technique 213 cupboard hinge 245 cupping 137, 179, 191 cup shakes 188 curing 216 customer role 49 cut clasp nails 229 cut roof 41 cutting gauge 64 cutting in 35 cutting list 197 cylinder night latch 248, 263–4 D damp-proof course (DPC) 18, 29, 38 damp-proof membrane (DPM) 37 datums 10 dead load 16 debarking 178 delamination 203 delivery note 5 detached piers 20 detail sander 165 detectors 170–1 diamonding 179 diamond stone 97 discrimination 51 displacement piles 20 dividers 61 documents 5–6 domino joints 156–9, 206 door closers 255 door furniture 250–6 doors, hanging 256 dormer roof 40 double glazing 14 double roof 40 douglas fir 184 dovetail jig 152 dovetail joints 208
step by step 214–15 dovetail saw 69 dowel joint 206 draught excluder 14 drawer runners 255 drawings see working drawings dressing 223 drill and counter bore 103 drills breaker 125 chuck types 123 common faults 195 common problems 126 drill bits 102, 105–6 drilling 105 hammer drills 122, 124 hand-operated 101 impact drivers 122, 124 pillar drill 125 power drills 122–3 swing brace 101 wheel brace 101 drugs 287–8 dry lining 26 dry mix screed 37 dry rot 181 drywall 32 dusting brush 47 E eccentric circles 163–4 eco joists 36 eggshell paint 34 electrician 49 electricity 11–13 extension leads 116 health and safety 115, 307–10 power supply 115, 307 voltages 115–16, 309 wiring 171 Electricity at Work Regulations 1989 272, 308 elevation drawings 7 emulsion 34 end grain 78, 87–8 energy efficiency 13–16 renewable 11–13
sources 11–13 engineered timber joists 36 engineering bricks 18 environmental impact 11 EPDM rubber 39 Equality Act 2010 51 equilibrium moisture content 179 equipment health and safety 55 see also hand tools ergonomics 121 escutcheon 253 espagnolette bolts 251 estimator 49 Euro pattern lock 249 European redwood 185 expanding foam adhesive 110 expansion gaps 221 extension leads 116 external walls 24–6, 28–9 F fascia 42 F clamp 107 ferrous metal 228–9 fibreglass roofs 39 fillet 223 fine aggregate 21 firefighting signs 293 fire safety 315–17 firmer chisel 90 first fixing stage 2 fixings cavity fixings 240 coach screws and bolts 238–9 nails 161, 229–31 screws 231–4 timber pellets 238 walls 239 see also adhesives flat roofs 39 flat/spade bit 103 flexi ply 204 floor plans 7 floors block and beam system 35–6 covering 38 ground 35–7
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Index insulation 37, 38 materials 37 solid concrete 35, 37 sub-base 37 suspended ground 35–6 suspended upper 36 timber 36–8 upper 36–7 flush hinge 244 flushing shoulders 88–9 forstner bit 103 fossil fuels 11 foundations loads 16–17 materials 21–3 types 18–20 frame marking out 199–201 producing and assembling 211 framing joints 207–8 frogged bricks 25, 28 fungal attack 192 G gable-ended roof 40 galvanised nails 161, 230 Gantt chart 4 gas-powered tools 117 gauges 64, 195, 201 G clamp 107 gents saw 69 Global Positioning System (GPS) 10 global warming 11 gluing-up 216 gouges 90–1 grab adhesive see synthetic resin grab adhesive grain 179 end grain 78, 87–8 interlocking 78 sloping 190 green flat roof 40 greenhouse gases 11 green oak 181 grinding 96–7 grooves 145 ground floors 35–7
ground heave 17 ground source heating 13 growth rings 179 gypsum plaster 32 H halving joints 209 hammer drills 122, 124 hammers 106–7, 194 hand/arm vibration syndrome (HAVS) 290 handsaws backed 66, 68–9, 73–4 common faults 194 coping 69 crosscut 66–7, 68 hardpoint 66–7 mitre 69 panel 67–8, 72–3 ripsaws 66, 68 sharpening 70–1 technique 71–4 tooth profiles 66 hand tools 55–9, 59–64, 106–9 common faults 193–5 health and safety 55 legislation 205 marking out 59–64, 196, 201–2 storing and transporting 110–11 see also chisels; drills; planes; saws; screwdrivers hand washing 288–9 hardboard 204 hardcore 37 hardpoint saws 66–7 hardwoods 184, 185–6 hatchings 8–9, 212 hatch linings 217–20 hazards 272, 284–91 heading joints 207 head plate 26, 31 health and safety accidents 278–84 electricity 115, 307–10 employee responsibilities 275 employer responsibilities 272–5 first aid 283
foundation trenches 18 hand tools 55 hazards 272, 284–91 legislation 268–72, 278–9 method statements 285 nail guns 161 near miss 275 personal protective equipment (PPE) 34, 120 power saws 139 power tools 118–21 risk assessment 272–3, 284 site inductions 277–8 sources of information 276–7 Health and Safety at Work Act 1974 269, 275, 287 Health and Safety Executive (HSE) 276 hearing loss 286–7 heart shake 189 heating engineer 49 height, working at 301–7 hex screw head 237 hinges 242–6 recess cutting 91–3 recess jig 152 hip and valley roof 40 hole saw 103 honing 97 see also sharpening hook and band hinge 245 horns 216 housing joints 145, 209–10 step by step 95, 214 hydration 21 hydroelectric energy 12 I impact drivers 122, 124 improvement notice 276 inclinometers 58 insect infestation 190 insulation 14, 24–5 floors 37, 38 materials 14–15, 24, 28 sound 38 interlocking grain 78 internal walls 26–7, 31–2
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma invoice 5 ironmongery 196 door furniture 250–6 hinges 242–6 installing 256–64 locks and latches 246–50 J jack plane 77 jambs 221 Japanese handsaw 67, 70 jigs 152 jigsaws 133–4, 140–1 job roles 48–50 job sheet 5 joiner 49 jointer 77 jointers 155–9 jointing techniques 157–9, 211–16 joints classification 205–6 framing 207–8 gluing-up 216 lengthening 207 regulations 217 shoulders 212 waste area 211 widening 206 joist hangers 36 joists 36–7, 38, 41 just in time ordering 5 K kerf 66, 71 keyhole 253 kiln seasoning 183 kinetic lifting 289 knives 91 knots 188 knotting 47 L labour 5 labourer 50 ladders 302–3 lamb’s wool insulation 15 laminated panels 204 laser distance measure 56 laser levels 10, 58 latches 248–50
laths 42 lead 287 lead time 5 lean-to roof 40 lengthening joints 207 leptospirosis 288 letter plate 254 levels 57–9 lifting 288–301 Lifting Operations and Lifting Equipment Regulations 1998 272, 289 lime 30 linear measurement 43–5 lintels 29 lip and spur bit 102 liquid screed 37 listed buildings 39 live loads 16 load-bearing walls 23, 26 local exhaust ventilation (LEV) 127, 286 locks 246 loft hatches see hatch linings loose fill insulation 24 loose tenon 156 lost head nails 230 M mallets 107, 194 mandatory signs 293 Manual Handling Operations Regulations 1992 271, 288 manufactured board 203–5 maple 186 margins 221 marking gauge 64, 201 marking knife 91 marking out 59–64, 196, 201–2 step by step 199–201 masking up 35 masonry bit 102 masonry nails 231 materials abbreviations 203 just in time ordering 5 sheet materials 203 storing 291
matt paint 34 measuring tape 55–6, 195 medium density fibreboard (MDF) 67, 204 memos 51 metals ferrous 228–9 non-ferrous 229 metal stud walls 26–7, 31 method statements 285 microporous paint 34 mill file 71 mineral wool 15 mist coat 34 mitre adhesive 242 mitre joints 210 mitre saw 69 mitre square 59 mobile extraction units 127 mobile phones 48 moisture meter 181 mono-pitch roof 40 mortar 21, 26, 30 mortice and tenon joints 25, 65, 210–11 mortice chisel 90 mortice dead locks 247 mortice gauge 64–5 mortice joints 207 step by step 94, 214 mortice latch 248, 259–62 multifoil insulation 15 musculoskeletal disorders 288 N nail guns 160–1, 289 nails 161, 229–31 National Grid 11 near miss 275 networking 52 noggins 26, 31 noise 286–7, 296 non-ferrous metal 229 notches 36 O oak 181, 186 obtuse angles 61 oil 11
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Index oil stone 97 orbital sander 164 ordnance benchmarks (OBM) 10 Ordnance Survey maps 10 oriented strand board (OSB) 157, 178, 205 oscillating multi-tools 166–9 oversite concrete 37 P pad foundations 20 pad saw 70 paint cutting in 35 emulsion 34–5 mist coat 34 timber 46–7 painter and decorator 49 panic bolt 251 Parliament hinge 244 partition walls 26–7 passivated nails 161 pattern rafter 41 pein hammer 106 pencils 61 percentages 45–6 peripheral speed 149 personal protective equipment (PPE) 34, 120, 291, 311–14 Personal Protective Equipment Regulations 2018 271, 311–12 Phillips screw head 104, 236 photovoltaic (PV) panels 12 piers 20 pile foundations 20 piling sticks 182 pillar drill 125 pilot holes 105 pitch 39 pitched roofs 40, 207–8 pitch marks 77, 144 pith 190 planes bench plane 76 block plane 78–9 common faults 194–5 jack plane 77 jointer 77
maintaining 82–5 power planers 142–5 rebate plane 79–80 sharpening 95–101 smoothing plane 77 specialist 79–81 try plane 77 planing end grain 87–8 flushing shoulders 88–9 techniques 85–7 plant 50 plant operator 49 plant technician 49 plaster 32, 34 plasterboard 32, 34, 37 plasterer 49 plasticiser 21 plate compactor 37 platforms 304–5 plinth feet 255 plug cutter 103 plumber 49 plunge saws 129–33 plywood 67, 203 pollution 11 polyurethane fixing foam 110, 242 porosity 34 portable appliance testing (PAT) 308 power saws 128 blades 128 circular saws 128–33, 136–7 health and safety 139 jigsaws 133–4, 140–1 plunge saws 129–33 reciprocating saws 134, 141 sliding mitre saws 134–6 table ripsaws 136–7, 139–40 power tools angle grinders 169–70 battery-powered 116–17, 310 compressed air 117–18 gas-powered 117 health and safety 118–21, 308–10 jointers 155–9
mobile extraction units 127 nail guns 160–1 oscillating multi-tools 166–9 planers 142–5 portable 121 portable appliance testing (PAT) 308 routers 145–59 sanders 162–6 scanners and detectors 170–1 storing and transporting 172, 310–11 voltages 115–16 see also drills; power saws Pozidriv screw head 104, 236 privacy locks 247 profiles 145, 148, 197 programme of work 4–5 prohibition signs 293 proprietary threshold 254 protractor 61 Provision and Use of Work Equipment Regulations 1998 96, 202, 271 PU (polyurethane) glue 109, 216, 241 purlins 40, 207 PVA (polyvinyl acetate) glue 109, 215, 241 PVCu (polyvinyl chloride unplasticised) 231 Q quantity surveyor 49 quarter sawn timber 179 quick-release clamp 108 quicksilver wood screw 234 quirk 223 R rack bolt 264 radial cut timber 179 rafters 40 raft foundations 19 random orbital sander 163–4 rebate cutting, step by step 154 rebate plane 79–80 recess cutting, step by step 91–3 reciprocating saws 134, 141
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The City & Guilds Textbook: Carpentry & Joinery for the Level 1 Diploma recycling, water 16 reflective insulation board 15 render 29, 31, 34 renewable energy 11–13 Reporting Injuries, Diseases and Dangerous Occurrences Regulations 2013 271 requisition order 5 residual current device (RCD) 115, 308 retarders 32 ridge boards 207 rim lock 248 ring shank nails 161, 230 ripsawing technique 213 ripsaws 66, 68 rising damp 29 risk assessment 272–3, 284 riving knife 132 roofer 49 roofing square 60 roofs components 41–2 flat 39 joints 207–8 materials 39–40 pitched 40–1 round head nails 230 router plane 81 routers 145–59 rules (measuring) 57 Russian softwoods 178 S safe condition signs 293 safety signs 51, 292–4 sand binding 37 sanders 162–6 sap ducts 188 sapele 186 sapwood 189 sash clamp 107 satin paint 35 sawing techniques 213 saws see handsaws; power saws saw set 71 scaffolding 305–7 scale rules 57 scales 6
Scandinavian softwoods 178 scanners 170–1 scarf joints 207 schedules 2, 4 scratch coat 31 screed 37 screw cups 235 screwdriver bits 236–7 screwdrivers 104, 195, 237 screw heads 104, 236–7 screws 231–4 seasoning timber 181–3 second fixing stage 2 section drawings 7 security viewer 253 set square 59 setting out rods 6, 51, 196–8 shakes 181, 189 sharpening chisels 95–101 drill bits 105–6 handsaws 70–1 plane irons 95–101 sheet materials 203 shingles 42 shoulder plane 80 shrinking 137 shrinking and twisting 179 side rebate plane 80 signage 51, 292–4 site diary 5 site inductions 277–8 site plans 8 skeleton gun 241 skew nailing 208 skirtings 220, 223–5 slates 42 sleeper walls 35, 38 sliding bevel 60 sliding mitre saws 134–6 sloping grain 190 slotted screw head 104, 236 smoothing plane 77 social media 52 soffits 42 calculating quantities 44–5 softwoods 178, 184–5 soil sampling 17
solar energy 12 sole plate 26, 31 solid concrete floors 35, 37 solvents 289 Soss hinge 246 specifications 2–3, 203 spelching 87, 126 spill kits 289 spirit levels 57–8 splits 191 spokeshave 81 spring hinge 245 springing 137, 191 square recess screw 237 squares 195 squaring rod 216 stainless steel wood screw 234 star shake 189 statement 5 steel rules 57 stepladders 303–4 stock rotation 291 stone 28 stretcher bond 30 strip foundations 18 structural engineer 49 structural grade softwood 28 studs 26–7, 31 subsidence 19 substructure 18 sun protection 289 supervisors 49, 50 surface planing machine 77 surveyor 49 suspended ground floors 35–6 suspended upper floors 36 sustainable materials 13 swing brace drill 101 symbols 8–9 synthetic resin grab adhesive 110, 223, 241 T table ripsaws 136–7, 139–40 tamping 21 tanalised timber 28, 67 T bar clamp 107 technical drawings 51 see also working drawings
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Index tee hinge 245 tee square 59 temperature 285 temporary benchmark (TBM) 10 tenon saw 68 text messages 52 thatch 42 thermal insulation 24 see also insulation three dimensional drawings 2 through and through sawn timber 179 thumb latch 249 thunder shake 192 tile lath 231 timber 42, 78 Canadian lumber stock (CLS) 28, 31, 187 conversion 178–9 cutting 137–8 damage 192 defects 188–92 distortions 179 floors 36–8 grades 178, 187–8 growth rings 179 hardwoods 184, 185–6 knotting 47 moisture content 181 painting 46–7 rough sawn 31 sawn types 179–80 seasoning 181–3 shrinking and twisting 137, 191 softwoods 178, 184–5 standard sizes 86, 187 storing and protecting 183 stress grading 187–8 structural grade softwood 28 studs 31 tanalised 28, 67 tree trunk 187 timber frame walls 25–6 timber pellets 238 timesheet 5 tinnitus 272 tolerance 217 tongue and groove 206
tool bags 110 toolboxes 110 toolbox talks 278 torque 104 Torx screw head 237 tower scaffold 305–7 tracking 162 trammel heads and beam 61 transformer 307–8 tree roots 20 trench blocks 18 trench fill foundation 19 trench safety 18 trestles 109, 304–5 trickle vents 254 triple glazing 14 trunking 27 trussed roof 41 try plane 77 try square 59–60 tungsten carbide tips (TCT) 128 twisting 137, 191 two dimensional drawings 2 two-way radios 51 U UF (urea-formaldehyde) glue 109, 216, 241 undercloaking 42 underlay 41–2 upper floors 36–7 utility knife 91 V veneer 203 ventilation 13 floors 35 roofs 42 verbal communication 52 vertical spindle moulder 79 vibrating concrete poker 21 vibration white finger 290 vice 108 vinyl silk paint 35 voltage indicator pens 171 voltages 115–16, 309 volume, calculating 22–3 W wall plates 38, 41 wall plugs 239
walls calculating area 32–3 cavity 24–6 external 24–6, 28–9 internal 26–7, 31–2 load-bearing 23, 26 materials 28–9, 31–2 partition 26–7 sleeper 35, 38 solid 24 timber frame 25–6 wall ties 24–5, 29 waney edge 188 warning signs 293 warrington hammer 106 wash boarding 192 waste management 16, 292 water hydroelectric energy 12 recycling 16 water levels 58–9 water stone 97 wattle and daub 25 weather seals 255 weep holes 24 welfare facilities 295–6 wheel brace drill 101 whiskers 94 whitewood 185 widening joints 206 wide strip foundations 18 wind energy 12 wired plug 310 woodworm 190 Work at Height Regulations 2005 271, 302 working drawings 2–4, 6–8, 203 abbreviations 9, 203 scales 6 symbols 8–9 worktop jig 152 written communication 52 Y yellow passivated wood screw 234 yellow pine 185 Z zinc 39
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