Malcolm Jacob James Harrington Bill Robinson The Structural Use of Timber Handbook for Eurocode 5: Part 1-1 The Structural Use of Timber – Timber The Structural Use of Handbook for Eurocode 5: Part 1-1 Eurocode Handbook for NATIONAL COUNCIL FOR FOREST RESEARCH & DEVELOPMENT AN COMHAIRLE NÁISÚNTA UM THAIGDE AGUS FORBAIRT FORAOISE Malcolm Jacob James Harrington Bill Robinson The Structural Use of Timber Handbook for Eurocode 5: Part 1-1 COFORD Department of Agriculture, Food and the Marine Agriculture House Kildare Street Dublin 2 Ireland First published in 2018 by COFORD ISBN: 978-1-902696-84-3 Title: The Structural Use of Timber - Handbook for Eurocode 5: Part 1-1 Authored by: Malcolm Jacob, James Harrington and Bill Robinson Citation: Jacob, M., Harrington, J., Robinson, B. 2018. The Structural Use of Timber - Handbook for Eurocode 5: Part 1-1. COFORD, Department of Agriculture, Food and the Marine, Dublin. © COFORD, 2018 All rights reserved. No part of this publication may be reproduced, or stored in a retrieval system or transmitted in any form or by any means electronic, electrostatic, magnetic tape, mechanical, photocopying, recording or otherwise, without prior permission from COFORD. Dedicated to the memory of James Harrington in recognition of his contribution to the structural use of Irish timber and his work in timber standards. The Structural Use of Timber – Handbook for Eurocode 5: Part 1-1 Contents Foreword by the Minister ...................................................................................i Introduction .......................................................................................................iii Disclaimer .................................................................................................................iv Conventions and abbreviations .......................................................................iv Conventions ..............................................................................................................iv Abbreviations............................................................................................................iv 1 General ............................................................................................................ 1 1.1 Eurocode 5 in the Eurocode family ...................................................................1 1.2 National Annexes and nationally determined parameters .................................1 1.3 Eurocode 1 - Actions on structures ....................................................................2 1.4 Eurocode 0 – Basis of structural design ............................................................2 1.5 The Construction Products Regulation (CPR) ...................................................3 1.6 Execution of timber structures ...........................................................................5 2 Solid timber and glued solid timber products ............................................. 6 2.1 General ...............................................................................................................6 2.2 Solid timber .......................................................................................................7 2.3 Finger jointed solid timber .................................................................................9 2.4 Glued laminated timber and glued solid timber ................................................9 2.4.1 Glued laminated timber (glulam) ............................................................................... 10 2.4.2 Glued solid timber ...................................................................................................... 10 2.4.3 Glulam with large finger joints .................................................................................. 10 2.4.4 Block glued glulam .................................................................................................... 10 2.4.5 Deviation in sizes ...................................................................................................... 10 2.4.6 Correction of sizes due to moisture content change ................................................... 11 2.5 Laminated veneer lumber ................................................................................ 11 2.5.1 Deviation in sizes ...................................................................................................... 12 2.5.2 Correction of sizes due to moisture content change ................................................... 12 2.6 Cross-laminated timber ....................................................................................12 2.6.1 The harmonised product standard EN 16351 ............................................................. 14 2.6.2 Deviation in sizes ...................................................................................................... 15 2.6.3 Correction of sizes due to moisture content change ................................................... 15 2.7 Adhesives for glued timber products ...............................................................16 2.7.1 Type 1 and Type 2 adhesives ...................................................................................... 16 2.7.2 Sub-classes ................................................................................................................. 16 2.7.3 Glue line thickness ..................................................................................................... 17 2.7.4 Maximum test temperature ........................................................................................ 17 2.7.5 Adhesive application .................................................................................................. 17 2.7.6 Moisture contents of timber for glued joints at assembly .......................................... 17 2.8 Effect of change in moisture content on floor, roof and wall plates ................17 The Structural Use of Timber – Handbook for Eurocode 5: Part 1-1 2.9 Deviation from straightness .............................................................................17 2.9.1 Design assumptions .................................................................................................... 17 2.9.2 Product straightness requirements.............................................................................. 18 3 Wood-based panel products used as structural elements ......................... 19 3.1 General .............................................................................................................19 3.2 Classification of wood-based panel products ..................................................20 3.3 Performance characteristics .............................................................................20 3.4 Characteristic strength, stiffness and density values .......................................21 3.4.1 Plywood...................................................................................................................... 21 3.4.2 OSB, particleboard and fibreboard ............................................................................. 22 3.5 Wall constructions ............................................................................................23 3.6 Floor constructions .........................................................................................24 4 Effects of material variability, load-duration and moisture content ....... 25 4.1 Partial factors for material property γM ...........................................................25 4.2 Load-duration classes ......................................................................................25 4.3 Service classes .................................................................................................25 4.4 Strength modification factors kmod for service and load-duration classes ........25 4.5 Deformation modification factors kdef for service class ...................................25 5 Durability of timber, timber products and wood-based panels ............... 26 5.1 Use classes .......................................................................................................26 5.2 Natural durability of timber .............................................................................27 5.3 Specifying treatment ........................................................................................28 5.4 Service classes .................................................................................................29 6 Fasteners and connectors ............................................................................ 30 6.1 General .............................................................................................................30 6.2 Dowel-type fasteners .......................................................................................30 6.2.1 General ....................................................................................................................... 30 6.2.2 Load-carrying capacity............................................................................................... 30 6.2.3 Resistance to corrosion .............................................................................................. 32 6.3 Connectors .......................................................................................................33 6.3.1 General ....................................................................................................................... 33 6.3.2 Split ring, shear plate and