i

Design of Wood Structures—ASD/LRFD
Donald E. Breyer, P.E.
Professor Emeritus
Department of Engineering Technology
California State Polytechnic University
Pomona, California
Kenneth J. Fridley, Ph.D.
Professor and Head
Department of Civil, Construction, and Environmental Engineering
University of Alabama
Tuscaloosa, Alabama
Kelly E. Cobeen, S.E.
Principal
Cobeen & Associates Structural Engineering
Lafayette, California
David G. Pollock, Ph.D., P.E.
Associate Professor
Department of Civil and Environmental Engineering
Washington State University
Pullman, Washington
Sixth Edition

McGraw-Hill
New York Chicago San Francisco Lisbon London Madrid Mexico City Milan New
Delhi San Juan Seoul Singapore Sydney Toronto


ii

Copyright © 2007, 2003, 1998, 1993, 1988, 1980 by The McGraw-Hill Companies, Inc.
All rights reserved. Printed in the United States of America. Except as permitted under the United States Copyright Act of
1976, no part of this publication may be reproduced or distributed in any form or by any means, or stored in a data base or
retrieval system, without the prior written permission of the publisher.
1 2 3 4 5 6 7 8 9 0 DOC/DOC 0 1 2 1 0 9 8 7 6
ISBN-13: 978-0-07-145539-8
ISBN-10: 0-07-145539-6
The sponsoring editor for this book was Larry S. Hager and the production supervisor was Pamela A. Pelton. It was set
in Century Schoolbook by International Typesetting and Composition. The art director for the cover was Anthony
Landi.
Printed and bound by RR Donnelley.
McGraw-Hill books are available at special quantity discounts to use as premiums and sales promotions, or for use in
corporate training programs. For more information, please write to the Director of Special Sales, McGraw-Hill
Professional, Two Penn Plaza, New York, NY 10121-2298. Or contact your local bookstore.
This book is printed on acid-free paper.
Information contained in this work has been obtained by The McGraw-Hill Companies, Inc. (“McGraw-Hill”) from
sources believed to be reliable. However, neither McGraw-Hill nor its authors guarantee the accuracy or completeness of
any information published herein and neither McGraw-Hill nor its authors shall be responsible for any errors, omissions,
or damages arising out of use of this information. This work is published with the understanding that McGraw-Hill and its
authors are supplying information but are not attempting to render engineering or other professional services. If such
services are required, the assistance of an appropriate professional should be sought.


iii

Contents
Preface

ix


Nomenclature

xiii

Abbreviations

xvi

Chapter 1. Wood Buildings and Design Criteria

1.1

1.1 Introduction

1.1

1.2 Types of Buildings

1.2

1.3 Required and Recommended References

1.4

1.4 Building Codes and Design Criteria

1.7

1.5 ASD and LRFD


1.8

1.6 Organization of the Text

1.9

1.7 Structural Calculations

1.10

1.8 Detailing Conventions

1.12

1.9 Fire-Resistive Requirements

1.12

1.10 Industry Organizations

1.13

1.11 References

1.13

Chapter 2. Design Loads

2.1


2.1 Introduction

2.1

2.2 Dead Loads

2.3

2.3 Live Loads

2.7

2.4 Snow Loads

2.14

2.5 Soil Loads and Hydrostatic Pressure

2.21

2.6 Loads due to Fluids

2.21

2.7 Rain Loads

2.21

2.8 Flood Loads


2.22

2.9 Self-straining Loads

2.22

2.10 Wind Loads—Introduction

2.23

2.11 Wind Forces—Main Wind Force Resisting System

2.28

2.12 Wind Forces—Components and Cladding

2.37

2.13 Seismic Forces—Introduction

2.42


2.14 Seismic Forces

2.47

2.15 Seismic Forces—Primary System


2.61


iv

2.16 Seismic Forces—Wall Components

2.68

2.17 Load Combinations

2.73

2.18 Serviceability/Deflection Criteria

2.78

2.19 References

2.84

2.20 Problems

2.85

Chapter 3. Behavior of Structures under Loads and Forces

3.1

3.1 Introduction


3.1

3.2 Structures Subject to Vertical Loads

3.1

3.3 Structures Subject to Lateral Forces

3.5

3.4 Lateral Forces in Buildings with Diaphragms and Shearwalls

3.12

3.5 Design Problem: Lateral Forces on One-Story Building

3.18

3.6 Design Problem: Lateral Forces on Two-Story Building

3.33

3.7 References

3.53

3.8 Problems

3.53


Chapter 4. Properties of Wood and Lumber Grades

4.1

4.1 Introduction

4.1

4.2 Design Specification

4.2

4.3 Methods of Grading Structural Lumber

4.5

4.4 In-Grade Versus Clear Wood Design Values

4.7

4.5 Species and Species Groups

4.9

4.6 Cellular Makeup

4.11

4.7 Moisture Content and Shrinkage


4.12

4.8 Effect of Moisture Content on Lumber Sizes

4.20

4.9 Durability of Wood and the Need for Pressure Treatment

4.21

4.10 Growth Characteristics of Wood

4.24

4.11 Sizes of Structural Lumber

4.26

4.12 Size Categories and Commercial Grades

4.29

4.13 General Notation

4.33

4.14 Wet Service Factor CM

4.39


4.15 Load Duration Factor CD (ASD Only)

4.40

4.16 Time Effect Factor Ȝ (LRFD Only)

4.44

4.17 Size Factor CF

4.45

4.18 Repetitive Member Factor Cr

4.46

4.19 Flat Use Factor Cfu

4.47


4.20 Temperature Factor Ct

4.47

4.21 Incising Factor Ci

4.48


4.22 Resistance Factor

(LRFD Only)

4.48

4.23 Format Conversion Factor KF (LRFD Only)

4.49

4.24 Design Problem: Adjusted Design Values

4.50

4.25 Future Directions in Wood Design

4.60

4.26 References

4.61

4.27 Problems

4.62

Chapter 5. Structural Glued Laminated Timber

5.1


5.1 Introduction

5.1

5.2 Sizes of Glulam Members

5.1


v

5.3 Resawn Glulam

5.4

5.4 Fabrication of Glulams

5.5

5.5 Grades of Glulam Members

5.11

5.6 Adjustment Factors for Glulam

5.16

5.7 Design Problem: Adjusted Design Values

5.19


5.8 References

5.23

5.9 Problems

5.23

Chapter Beam Design
6.

6.1

6.1 Introduction

6.1

6.2 Bending

6.2

6.3 Lateral Stability

6.14

6.4 Adjusted Bending Design Value Summary

6.23


6.5 Shear

6.29

6.6 Deflection

6.36

6.7 Design Summary

6.38

6.8 Bearing at Supports

6.40

6.9 Design Problem: Sawn Beam

6.47

6.10 Design Problem: Rough-Sawn Beam Using ASD

6.54

6.11 Design Problem: Notched Beam

6.56

6.12 Design Problem: Sawn-Beam Analysis


6.58

6.13 Design Problem: Glulam Beam with Full Lateral Support

6.62

6.14 Design Problem: Glulam Beam with Lateral Support at 8 ft-0 in.

6.68

6.15 Design Problem: Glulam Beam with Lateral Support at 48 ft-0
in.

6.72

6.16 Design Problem: Glulam with Compression Zone Stressed in
Tension

6.75

6.17 Cantilever Beam Systems

6.79

6.18 Lumber Roof and Floor Decking

6.83

6.19 Fabricated Wood Components


6.85

6.20 References

6.94

6.21 Problems

6.95

Chapter Axial Forces and Combined Bending and Axial Forces
7.
7.1 Introduction

7.1
7.1


7.2 Axial Tension Members

7.2

7.3 Design Problem: Tension Member

7.7

7.4 Columns

7.11


7.5 Detailed Analysis of Slenderness Ratio

7.19

7.6 Design Problem: Axially Loaded Column

7.25

7.7 Design Problem: Capacity of a Glulam Column

7.30

7.8 Design Problem: Capacity of a Bearing Wall

7.36

7.9 Built-Up Columns

7.39

7.10 Combined Bending and Tension

7.42

7.11 Design Problem: Combined Bending and Tension

7.47

7.12 Combined Bending and Compression


7.52

7.13 Design Problem: Beam-Column

7.59

7.14 Design Problem: Beam-Column Action in a Stud Wall Using
LRFD

7.64

7.15 Design Problem: Glulam Beam-Column Using ASD

7.73

7.16 Design for Minimum Eccentricity

7.80


vi

7.17 Design Problem: Column with Eccentric Load Using ASD

7.81

7.18 References

7.87


7.19 Problems

7.88

Chapter 8. Wood Structural Panels

8.1

8.1 Introduction

8.1

8.2 Panel Dimensions and Installation Recommendations

8.3

8.3 Plywood Makeup

8.5

8.4 Species Groups for Plywood

8.8

8.5 Veneer Grades

8.11

8.6 Exposure Durability Classifications


8.13

8.7 Plywood Grades

8.14

8.8 Other Wood Structural Panels

8.17

8.9 Roof Sheathing

8.20

8.10 Design Problem: Roof Sheathing

8.23

8.11 Floor Sheathing

8.27

8.12 Design Problem: Floor Sheathing

8.30

8.13 Wall Sheathing and Siding

8.32


8.14 Stress Calculations for Wood Structural Panels

8.36

8.15 References

8.47

8.16 Problems

8.47

Chapter 9. Diaphragms

9.1

9.1 Introduction

9.1

9.2 Basic Diaphragm Action

9.2

9.3 Shear Resistance

9.7

9.4 Diaphragm Chords


9.16

9.5 Design Problem: Roof Diaphragm

9.20

9.6 Distribution of Lateral Forces in a Shearwall

9.28

9.7 Collector (Strut) Forces

9.32

9.8 Diaphragm Deflections

9.37

9.9 Diaphragms with Interior Shearwalls

9.43

9.10 Interior Shearwalls with Collectors

9.47

9.11 Diaphragm Flexibility

9.51


9.12 References

9.54

9.13 Problems

9.55


Chapter 10. Shearwalls

10.1

10.1 Introduction

10.1

10.2 Basic Shearwall Action

10.2

10.3 Shearwalls Using Wood Structural Panels

10.3

10.4 Other Sheathing Materials

10.9

10.5 Shearwall Chord Members


10.11

10.6 Design Problem: Shearwall

10.13

10.7 Alternate Shearwall Design Methods

10.22

10.8 Anchorage Considerations

10.33

10.9 Vertical (Gravity) Loads

10.34

10.10 Lateral Forces Parallel to a Wall

10.35


vii

10.11 Shearwall Deflection

10.39


10.12 Lateral Forces Perpendicular to a Wall

10.45

10.13 References

10.47

10.14 Problems

10.47

Chapter 11. Wood Connections—Background

11.1

11.1 Introduction

11.1

11.2 Types of Fasteners and Connections

11.1

11.3 Yield Model for Laterally Loaded Fasteners

11.7

11.4 Factors Affecting Strength in Yield Model


11.10

11.5 Dowel Bearing Strength

11.13

11.6 Plastic Hinge in Fastener

11.17

11.7 Yield Limit Mechanisms

11.21

11.8 References

11.26

11.9 Problems

11.26

Chapter 12. Nailed and Stapled Connections

12.1

12.1 Introduction

12.1


12.2 Types of Nails

12.2

12.3 Power-Driven Nails and Staples

12.5

12.4 Yield Limit Equations for Nails

12.7

12.5 Applications of Yield Limit Equations

12.14

12.6 Adjustment Factors for Laterally Loaded Nails

12.22

12.7 Design Problem: Nail Connection for Knee Brace

12.29

12.8 Design Problem: Top Plate Splice

12.34

12.9 Design Problem: Shearwall Chord Tie


12.42

12.10 Design Problem: Laterally Loaded Toenail

12.46

12.11 Design Problem: Laterally Loaded Connection in End Grain

12.50

12.12 Nail Withdrawal Connections

12.52

12.13 Combined Lateral and Withdrawal Loads

12.58

12.14 Spacing Requirements

12.59

12.15 Nailing Schedule

12.63

12.16 References

12.63


12.17 Problems

12.64

Chapter 13. Bolts, Lag Bolts, and Other Connectors
13.1 Introduction

13.1
13.1


13.2 Bolt Connections

13.2

13.3 Bolt Yield Limit Equations for Single Shear

13.5

13.4 Bolt Yield Limit Equations for Double Shear

13.14

13.5 Adjustment Factors for Bolts

13.18

13.6 Tension and Shear Stresses at a Multiple Fastener Connection

13.30


13.7 Design Problem: Multiple-Bolt Tension Connection

13.34

13.8 Design Problem: Bolted Chord Splice for Diaphragm

13.40

13.9 Shear Stresses in a Beam at a Connection

13.47

13.10 Design Problem: Bolt Connection for Diagonal Brace

13.49

13.11 Lag Bolt Connections

13.55

13.12 Yield Limit Equations for Lag Bolts

13.59


viii

13.13 Adjustment Factors for Lag Bolts in Shear Connections


13.62

13.14 Design Problem: Collector (Strut) Splice with Lag Bolts

13.67

13.15 Lag Bolts in Withdrawal

13.73

13.16 Combined Lateral and Withdrawal Loads

13.76

13.17 Split Ring and Shear Plate Connectors

13.77

13.18 References

13.83

13.19 Problems

13.83

Chapter 14. Connection Details and Hardware

14.1


14.1 Introduction

14.1

14.2 Connection Details

14.1

14.3 Design Problem: Beam-to-Column Connection

14.19

14.4 Cantilever Beam Hinge Connection

14.27

14.5 Prefabricated Connection Hardware

14.29

14.6 References

14.33

Chapter 15. Diaphragm-to-Shearwall Anchorage

15.1

15.1 Introduction


15.1

15.2 Anchorage Summary

15.1

15.3 Connection Details—Diaphragm to Wood-Frame Wall

15.6

15.4 Connection Details—Diaphragm to Concrete or Masonry
Walls

15.15

15.5 Subdiaphragm Anchorage of Concrete and Masonry Walls

15.31

15.6 Design Problem: Subdiaphragm

15.37

15.7 References

15.45

Chapter 16. Advanced Topics in Lateral Force Design

16.1


16.1 Introduction

16.1

16.2 Seismic Forces—Regular Structures

16.1

16.3 Seismic Forces—Irregular Structures

16.3

16.4 Overturning—Background

16.14

16.5 Overturning—Review

16.14

16.6 Overturning—Wind

16.19

16.7 Overturning—Seismic

16.23

16.8 Lateral Analysis of Nonrectangular Buildings


16.29

16.9 Rigid Diaphragm Analysis

16.34

16.10 Additional Topics in Diaphragm Design

16.45


16.11 References

16.45

Appendix Equivalent Uniform Weights of Wood Framing
A.

A.1

Appendix Weights of Building Materials
B.

B.1

Appendix Selected Tables and Figures from the International Building Code,
C. 2006 Edition

C.1


Appendix Sl Units
D.

D.1

Index

I.1


ix

Preface
The purpose of this book is to introduce engineers, technologists, and architects to the design of wood
structures. It is designed to serve either as a text for a course in timber design or as a reference for systematic
self-study of the subject.
The book will lead the reader through the complete design of a wood structure (except for the foundation).
The sequence of the material follows the same general order that it would in actual design:
1. Vertical design loads and lateral forces
2. Design for vertical loads (beams and columns)
3. Design for lateral forces (horizontal diaphragms and shearwalls)
4. Connection design (including the overall tying together of the vertical- and lateral-force-resisting systems)
The need for such an overall approach to the subject became clear from experience gained in teaching
timber design at the undergraduate and graduate levels.
This text pulls together the design of the various elements into a single reference. A large number of
practical design examples are provided throughout the text. Because of their widespread usage, buildings
naturally form the basis of the majority of these examples. However, the principles of member design and
diaphragm design have application to other structures (such as concrete formwork and falsework).
This book relies on practical, current industry literature as the basis for structural design. This includes

publications of the American Forest and Paper Association (AF&PA), the International Codes Council (ICC),
the American Society of Civil Engineers (ASCE), APA—The Engineered Wood Association, and the
American Institute of Timber Construction (AITC).
In the writing of this text, an effort has been made to conform to the spirit and intent of the reference
documents. The interpretations are those of the authors and are intended to reflect current structural design
practice. The material presented is suggested as a guide only, and final design responsibility, lies with the
structural engineer.


x

The sixth edition of this book was promoted by five major developments:
1. Publication of new dual-format (ASD/LRFD) wood design criteria in the 2005 National Design
Specification for Wood Construction (NDS).
2. Publication of the new Special Design Provisions for Wind and Seismic (SDPWS) Supplement to the
NDS.
3. Publication of the comprehensive ASD/LRFD Manual for Engineered Wood Construction.
4. Publication and increased adoption nationally of the 2006 International Building Code.
5. Publication of updated load standards in the 2005 edition of Minimum Design Loads for Buildings and
Other Structures (ASCE 7-05).
The National Design Specification (NDS) is published by the American Forest & Paper Association
(AF&PA) and represents the latest structural design recommendations by the wood industry. The 2005 NDS
presents both traditional allowable stress design (ASD) provisions as well as new load and resistance factor
design (LRFD) provisions. The inclusion of the LRFD provisions is new to the NDS for the 2005 edition. As
such, the 2005 NDS is considered a dualformat design specification. While ASD has been and may continue
to be the method of choice for many designers of wood buildings, the acceptance and use of LRFD for wood
design is increasing.
The 2006 ASD/LRFD Manual for Engineered Wood Construction includes design supplements, guidelines,
and manuals helpful for wood engineering design. It includes design information for sawn lumber, structural
glued laminated timber, structural-use panels, shearwalls and diaphragms, poles and piles, I-joists, structural

composite lumber, structural connections (nails, bolts, screws), and pre-engineered metal connectors. The
Manual was first introduced in 1999 for the 1997 NDS, and has evolved into a comprehensive design support
document.
The International Building Code (IBC) is a product of the International Codes Council (ICC). The ICC
brought together the three regional model building code organizations to develop and administer a single
national building code. The first edition of the IBC was published in 2000, and now nearly all regions of the
U.S. have adopted all or part of the IBC at either the state or local level.
Traditionally, the NDS has been based on the principles of what is termed allowable stress design (ASD).
In ASD allowable stresses of a material are compared to calculated working stresses resulting from service
loads. Recently, the wood industry and design community completed the development of a load and
resistance factor design (LRFD) specification for wood construction. In LRFD, adjusted nominal capacities
(resistance) are compared to the effect of factored loads. The factors are developed for both resistance and
loads such that uncertainty and consequence of failure are explicitly recognized. The LRFD approach to wood
design is now included in the 2005 edition of the NDS. This sixth edition of Design of Wood Structures
presents both ASD and LRFD guidelines as provided in the NDS. In many examples, both ASD and LRFD
approaches are presented to allow the reader a direct, side-by-side comparison of the two methods.


xi

If this book is used as a text for a formal course, an Instructor’s Manual is available. Requests on school
letterhead should be sent to: Civil Engineering Editor, McGraw-Hill Professional, 2 Penn Plaza, New York,
NY 10121-2298.
Questions or comments about the text or examples may be addressed to any of the authors. Direct any
correspondence to:
Prof. Emeritus Donald E. Breyer
Department of Engineering Technology
California State Polytechnic University
3801 West Temple Avenue
Pomona, CA 91768

Prof. Kenneth J. Fridley
Department of Civil, Construction, and Environmental Engineering
University of Alabama
Box 870205
Tuscaloosa, AL 35487-0205
Prof. David G. Pollock
Department of Civil and Environmental Engineering
Washington State University
P.O. Box 642910
Pullman, WA 99164-2910
Ms. Kelly E. Cobeen
Cobeen & Associates Structural Engineering
251 Lafayette Circle, Suite 230
Lafayette, CA 94549
Acknowledgment and appreciation for help in writing this text are given to Philip Line and Bradford
Douglas of the American Forest and Paper Association; Jeff Linville of the American Institute of Timber
Construction; John Rose, Thomas Skaggs, and Thomas Williamson of APA—The Engineered Wood
Association; and Kevin Cheung of the Western Wood Products Association. Numerous other individuals also
deserve recognition for their contributions to various editions of the text, including Rosdinah Baharin, Russell
W. Krivchuk, William A. Baker, Michael Caldwell, Thomas P. Cunningham, Jr., Mike Drorbaugh, John R.
Tissell, Ken Walters, B. J. Yeh, Thomas E. Brassell, Frank Stewart, Lisa Johnson, Edwin G. Zacher, Edward
F. Diekmann, Lawrence A. Soltis, Robert Falk, Don Wood, William R. Bloom, Frederick C. Pneuman, Robert
M. Powell, Sherm Nelson, Bill McAlpine, Karen Colonias, and Ronald L. Carlyle. Suggestions and
information were obtained from many other engineers and suppliers, and their help is gratefully recognized.

Dedication
To our families:
Matthew, Kerry, Daniel, and Sarah
Paula, Justin, Connor, and Alison
Chris and Matthew

Lynn, Sarah, and Will
Donald E. Breyer, P.E.
Kenneth J. Fridley, Ph.D.
Kelly E. Cobeen, S.E.
David G. Pollock, Ph.D., P.E.


xiii

Nomenclature
Organizations
AF&PA
American Forest and Paper Association
American Wood Council (AWC)
1111 19th Street, NW, Suite 800
Washington, DC 20036
www.afandpa.org
www.awc.org
AITC
American Institute of Timber Construction
7012 South Revere Parkway, Suite 140
Centennial, CO 80112
www.aitc-glulam.org
ALSC
American Lumber Standard Committee, Inc.
P.O. Box 210
Germantown, MD 20875-0210
www.alsc.org
APA
APA—The Engineered Wood Association

P.O. Box 11700
Tacoma, WA 98411-0700
www.apawood.org
ASCE
American Society of Civil Engineers
1801 Alexander Bell Drive
Reston, VA 20191
www.asce.org
ATC
Applied Technology Council
201 Redwood Shores Parkway, Suite 240
Redwood City, CA 94065
www.atcouncil.org
AWPA
American Wood-Preservers’ Association
P.O. Box 388
Selma, AL 36702-0388
www.awpa.com
BSSC
Building Seismic Safety Council
National Institute of Building Sciences
1090 Vermont Avenue, N.W., Suite 700
Washington, DC 20005
/>CANPLY
Canadian Plywood Association
735 West 15 Street


North Vancouver, British Columbia, Canada V7M 1T2
www.canply.org

CWC
Canadian Wood Council
99 Bank Street, Suite 400
Ottawa, Ontario, Canada K1P 6B9
www.cwc.ca
CPA–CWC
Composite Panel Association
Composite Wood Council
18922 Premiere Court
Gaithersburg, MD 20879-1574
301-670-0604
www.pbmdf.com


xiv

FPL
U.S. Forest Products Laboratory
USDA Forest Service
One Gifford Pinchot Drive
Madison, WI 53726-2398
www.fpl.fs.fed.us
ICC
International Codes Council
5203 Leesburg Pike
Suite 600
Falls Church, VA 22041
www.iccsafe.org
ISANTA
International Staple, Nail and Tool Association

512 West Burlington Avenue, Suite 203
La Grange, IL 60525-2245
www.isanta.org
MSRLPC
MSR Lumber Producers Council
P.O. Box 6402
Helena, MT 59604
www.msrlumber.org
NFBA
National Frame Builders Association
4840 West 15th Street, Suite 1000
Lawrence, KS 66049-3876
www.postframe.org
NHLA
National Hardwood Lumber Association
P.O. Box 34518
Memphis, TN 38184-0518
www.natlhardwood.org
NLGA
National Lumber Grades Authority
#406 First Capital Place
960 Quayside Drive
New Westminster, British Columbia, Canada V3M 6G2
www.nlga.org
NELMA
Northeastern Lumber Manufacturers Association
272 Tuttle Road
P.O. Box 87A
Cumberland Center, ME 04021
www.nelma.org

NSLB
Northern Softwood Lumber Bureau
272 Tuttle Road
P.O. Box 87A
Cumberland Center, ME 04021
www.nelma.org
NWPA
Northwest Wood Products Association
149 SE 9th, #2
Bend, OR 97702


www.nwpa.org
PLIB
Pacific Lumber Inspection Bureau
33442 First Way South, #300
Federal Way, WA 98003-6214
www.plib.org
SEAOC
Structural Engineers Association of California
1414 K Street, Suite 260
Sacramento, CA 95814
www.seaoc.org
SLMA
Southeastern Lumber Manufacturers Association
P.O. Box 1788
Forest Park, GA 30298-1788
www.slma.org
SFPA
Southern Forest Products Association

P.O. Box 641700
Kenner, LA 70064-1700
Street address: 2900 Indiana Avenue
Kenner, LA 70065
www.sfpa.org
www.southernpine.com
SPIB
Southern Pine Inspection Bureau, Inc.
4709 Scenic Highway
Pensacola, FL 32504-9094
www.spib.org
SBA
Structural Board Association
25 Valleywood Drive, Unit 27
Markham, Ontario, Canada L3R 5L9
www.osbguide.com


xv

TPI
Truss Plate Institute
218 N. Lee Street, Suite 312
Alexandria, VA 22314
www.tpinst.org
WCLIB
West Coast Lumber Inspection Bureau
P.O. Box 23145
Portland, OR 97281-3145
www.wclib.org

WRCLA
Western Red Cedar Lumber Association
1501-700 West Pender Street
Vancouver, British Columbia, Canada V6C 1G8
www.wrcla.org
WWPA
Western Wood Products Association
522 Southwest Fifth Avenue, Suite 500
Portland, OR 97204-2122
www.wwpa.org
WIJMA
Wood I-Joist Manufacturing Association
200 East Mallard Drive
Boise, ID 83706
www.i-joist.org
WTCA
Wood Truss Council of America
One WTCA Center
6300 Enterprise Lane
Madison, WI 53719
www.woodtruss.com

Publications
ASCE 7: American Society of Civil Engineers (ASCE). 2006. Minimum Design Loads for Buildings
and Other Structures (ASCE 7-05), ASCE, Reston, VA.
ASD/LRFD American Forest and Paper Association (AF&PA). 2006. ASD/LRFD Manual for
Manual: Engineered Wood Construction, 2005 ed., AF&PA, Washington, DC.
IBC: International Codes Council (ICC). 2006. International Building Code (IBC), 2006 ed.,
ICC, Falls Church, VA.
NDS: American Forest and Paper Association (AF&PA). 2005. National Design Specification

(NDS) for Wood Construction, ANSI/AF&PA NDS-2005, AF&PA, Washington, DC.
SDPWS: American Forest & Paper Association (AF&PA). 2005. Special Design Provisions for
Wind and Seismic (SDPWS) Supplement to the NDS, AF&PA, Washington, DC.
TCM: American Institute of Timber Construction (AITC). 2005. Timber Construction Manual, 5th
ed., John Wiley & Sons Inc., Hoboken, NJ.
Additional publications given at the end of each chapter.

Units


ft

foot, feet

ft2

square foot, square feet

in.
in.

inch, inches
2

square inch, square inches

k

1000 lb (kip, kilopound)


ksi

kips per square inch (k/in.2)

mph

miles per hour

pcf

pounds per cubic foot (lb/ft3)

plf

pounds per lineal foot (lb/ft)

psf

pounds per square foot (lb/ft2)

psi

pounds per square inch (lb/in.2)

sec

second


xvi


Abbreviations
Adj.

adjusted

Allow.

allowable

ASD

allowable stress design

B&S

Beams and Stringers

c.-to-c.

center to center

cg

center of gravity

DF-L

Douglas Fir-Larch


Ecc.

eccentric

EMC

equilibrium moisture content

FBD

free-body diagram

FS

factor of safety

FSP

fiber saturation point

glulam

structural glued laminated timber

ht

height

IP


inflection point (point of reverse curvature and point of zero moment

J&P

Joists and Planks

lam

lamination

LF

Light Framing

LRFD

load and resistance factor design

LFRS

lateral-force-resisting system

LVL

laminated veneer lumber

max.

maximum


MC

moisture content based on oven-dry weight of wood

MDO

medium density overlay (plywood)

MEL

machine evaluated lumber

min.

minimum

MSR

machine stress rated lumber

NA

neutral axis

o.c.

on center

OM


overturning moment

OSB

oriented strand board

PL

plate

P&T

Posts and Timbers

PSL

parallel strand lumber

Q/A

quality assurance