ANSI_AF&PA NDS-2001– National Design Specification for Wood Construction

ANSI / AF&PA NDS-2001 (revised standard)

Approval Date: November 30, 2001

FOR WOOD CONSTRUCTION

American Forest &

Paper Association

American Wood Council

2001 Edition ANSI/ AF&PA NDS-2001

(revised standard)

Approval Date: November 30, 2001

NATIONAL DESIGN SPECIFICATION ®

FOR WOOD CONSTRUCTION

CopYright © 2()O I

American Forest & Paper AssoCiation. Inc.

NDS21lO 2 FMpmci 31 13/D2 . 11:00AM

NATIONAL DESIGN SPECIFICATION FOR WOOD CONSTRUCTION

AMERICAN WOOD COUNCil

NDS21lO2 FMpmci 3113/D2 . 11:00AM


FOREWORD

The N(I{iO/w/ Desigll Speci/icorio// (;) j()}' \\1r)()d COII

s/mc/io/l (NDS'~ ) was li rst lss ued by the National Lumber Man ufact urers Association (now the Ame ri can f'orest & Paper Assoc iation) (A f'&PA) In 1944. under the tit le No/iO/w{ Desigll Spec~fi("(//iol1j()r S/rcss-Gmde LIlI//her {//ill

I fS FOSft'llillgs. By 197 1 the scope of the Specllicat ion had broadened to include additional wood products . [n 1977 the ti t[e was changed to retlec tt he new nature of the Spec ifica ti on . and the content was rearranged to simplify its use. The 199 I ed ition was reorganized in an cas ier to use "equatIOn format '". and many sections were rewrillen to prov ide greater clari ty.

[n 1992 . Af & PA (formerly the National f ores t Products Association) was accredited as a canvass sponsor by the American Natl ona[ Standards [ns ti tute (ANS[). The Specdlca tlon subsequen tly gamed approval as an American Na tl ona[ S tandard designated ANSJlN f o PA NDS-1991 with an approval date of October 16 . 1992. The curren t edit ion of the Standard IS des lgllated ANS II AF&PA NDS-2001wi th an approval date of November 30. 2001 .

In developlllg the proVisions of th iS Spccillca ti on . the most reliable data available fromlahoratory tests and experience with struc tures In serv ice have been carefully analyzed and evaluated for the purpose of provid ing. m convenien t form . a national standard of prac tice.

It is in tended that tlus Spec dlca tion be used In conj unct ion With co mpe ten t eng ineering design . acc urate fabrica tion and adequa te superv Ision of cons truc ti on. Part icul ar all en tlon IS directed to Section 2. I .2 . rela ting to the des igner's respons ibi lity to make adjus tments for part icular end uses of structures .

Since the firs t edit ion of the Nallonal Design SpeCification in 1944. the Associ ation 's Tec hnical Advisory Commillee has conti nued to st udy and eval uate new da ta and developments in wood deS ign . Subsequent ed itions of the SpeCilica ti on have included appropriate reviS ions to provide for use of such new IIlformat ion. ThiS ed iti on incorporated nll merous changes as a result of the ANS I! Af & PA Canvass Comm it tee 's cons ideration of recommended changes by industry and others. The contributions of the members of this Commillee to improvement of the Specificat ion as a natl omtl design standard for wood cons truction are espeCially recognized.

Acknowledgemen t IS made to the Forest Prod ucts Laborat ory. U.S. Department ofAgn culture. for data and pu hlicatl ons generously made ava ilable . and to the eng ineers . SCientis ts and other users who have suggested changes in the con tent of the Spec i Ilca tlon . The ASSOC iat ion invites and welcomes commen ts. inq uiries . suggestions and new data relative to the proV ISIOns of th is document.

[t is lil t ended that thiS doc umen t be used in conJ unc t ion wllh co m peten t engineering deS ign. acc ura te fabrication . and adeq uate superviS ion of cons truc tion . Af & PA does not ass ume any respons ibi lity for errors or o mi ssions In the doc umen t. nor for engllleering des igns . plans . or construc ti on prepared from it.

Those using tillS standard assume all liability arislllg from its use. The design of engllleered struc tures is with in the scope of expert ise of hcensed engineers . arclll tecis. or other licensed professionals for appl ications to a particu lar structure.

Ame ri can Forest & Paper ASSOCiation

AMERICAN FOREST & PAPER ASSOCIATION

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TABLE OF CONTENTS

Par(fTilk

1 General Requirements for Structural Design .. . .. .. .. .. .. .. .. .. .. .. ... . 1

1.1 Sl:ope 2 1.2 General Requ irements 2 1.3 Standard as a Whole 2 1.4 Design Loads 2 1.5 Specifications and Plans 3 1.6 Notati on 3

2 Design Values for Structural Members . ...... .. .......... .. .. .. ...... . ...... .. ...... . 7

2. 1 General X 2.2 Design Valu es X 2.3 Adjustment of Design Values X

3 Design Provisions and Equations .. . 11

3. 1 Genera l 12 3.2 Bending Members - General 13 3.3 Bending Members - r kxure 13 3.4 Bending Members - Shear 15 3.5 Bending Members - Del1eclion IX 3.6 Compression Members - General IX 3.7 Solid Columns I~

].X TensIOn Membe rs 20 3.t) Combined Bending and AXial

Load ing 21 3.1 0 Des ign for Bear lllg 22

4 Sawn Lumber ........... . .. .. .. .. .. . .. .. .. .. .... 23 4. 1 General 24 4 .2 Design Valu es 25 4.3 Adjustment of Design Values 26 4.4 Special Des ign Considerations 2X

5 Structural Glued Laminated Timber .. .. .. .. .......... . .. .. .. .. .. . .. .. .. .. .... 31

5. 1 General 5.2 Design Valu es 5.3 Adjustment of Design Values 5A Specia l Des ign Considerat ions

32 33 33 35

6 Round Timber Poles and Piles ... .. .. .. .. .. .. .. .. ..... .. ... .. .. .. .. .. .. .. .. .37

6 . 1 General 3X 6.2 Des ign Va lues 3X 6.3 Adjustment of Des ign Values 3X

7 Prefabricated Wood I-Joists . 43 7.1 General 44 7.2 Design Va lues 44 7.3 Adj us tment of Des ign Va lues 44 7.4 Spec ial Design Cons iderations 45

8 Structural Composite Lumber ... ....... .. ....... ... .. .. . ... ....... .. . 47

g.1 General 4g K2 Des ign Values 4S g.3 Adjustment of Des ign Values 4g g.4 Spel:ial Design Cons iderations 50

9 Wood Structural Panels . .. .51 9 . 1 General 52 9.2 Design Va lues 52 9.3 Adjustment of Des ign Values 5J 9.4 Des ign Considerat ions 53

10 Mechanical Connections ........ . 55 10.1 General 5()

10.2 Design Values 57 10.3 Adjustment of Design Values 57

11 Dowel-Type Fasteners . .. .. ....... . 65 11 .1 General 6() 11 .2 Withdrawa l Design Va lues 6X 11 .3 Lateral Des ign Values 71 II A Combined Late ra l and Withdrawal

Loads 11 .5 Adjus tmen t of Design Val ues 11 .6 Mult iple Fa~ teners

12 Split Ring and Shear Plate

76 7(,

79

Connectors ..... .. .. .. .. .. .. .. .. .. .. .. ... ....... 103 12. I General 104 12.2 Des ign Valu es 105 12.3 Placemen t of Splil Ring and

Shear Plate Conneclors I I I


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•

TABLE OF CONTENTS

PanfTitk

13 Timber Rivets 13.1 General 13.2 Design Valu cs 13.3 Placemenl of Timber Rive ls

14 Shear Walls and

115 116 116 l iS

Diaphragms ... .. .. .. .. .. .. .. .. .. .. .. .... . .. .. . 127 14. 1 General 12H 14.2 Design Princi pl es 12H 14.3 Shear Walls 12H 14.4 Diaphragms 12l)

15 Special Loading Conditions .131 15. 1 Laleral Disl rlbulion of a

Concenlra led Load 132 15.2 Spaced Co lumns 132 15 .3 BUI ll-Up Columns 134 15.4 Wood Co lumns Wilh Sidc

Loads and Ecce nlrlcily 137

16 Fire Design of Wood Members .. .. . . .. .. .. .. .. .. .. .. .. .. .. .. . 139

16.1 General 1411 16.2 Des ign Proceedures for Exposed

Wood Members 1411 16.3 Wood Connec tions 141

P"rtfTitk

Appendix Appendix A (Non-mandalory)

Construc llon and Des ign Pract ices Appendix B (Non-mandalory )

Load Duration Appendix C (Non-mandalory)

Temperature Effec ts Appendix D (Non-mandatory)

Lateral Slabi llt y of Beams Appendix E (Non- mandatory)

Local Stresses in Faste ner Groups Appendix F (Non-mandatory)

Design for Cree p and Cnlical Dellec ti on Appl icallons

Appendix G (Non-mandalory)

143

144

146

14S

149

1511

154

Effect ive Column Lenglh 156 Appendix H (Non-mandalory)

Lateral Slabillt y of Columns 157 Appendix I (Non-mandatory)

Yi eld Limit Equali ons for Connections 15H Appendix J (Non -mandatory)

Solulion of Hankinson Formula Appendix K (Non-mandalory)

Typ ical Dimens ions for Spli t Ring and Shear Plate Connectors

Appendix L (Non-mandatory) Typ ical Dimensions for Standard

Hex Bolls

161

164

165 Hex Lag Screws 166 Wood Screws 167 Common. Box and Sinker Nalls 16H

Appendix M (Non-mandatory) Manufacturing Tolerances for Rivets and Slee l Side Plates for Timber Ri vet Conneclions (See Chapter 13) 169

References References

... .. .. ... ... .. .. . .. .. .. .. .. . .. .. .. .. ... ... 171 172


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LIST OF TABLES

2.3.2 Freq uen tly Used Load Duration Factors. Co ... .. .. .. .. .. ... .. .. .. .. .. .. ... .. .. .. .. .. ... .. .. .. .. . lJ

2.3.3 Temperature Factor. C! ..... ... .. .. ... .. .. .. .. .. ... .. .. ... lJ

3.3.3 Effective Lenglh . (c ' for Bending Members .. 14

3.3.4 Form Factors. Cr ... .. .. .. .. .. ... .. ... ... .. .. ... .. .. ... ... 15

.1 . 10.4 Bearing Area Factors. C" ... .. ... ... .... ... .. .. .. ... .. 21

4.3.1 Applicability of AdJusLment Factors for

4.H

5 . 1..1

5 .3. I

6A

(,B

6 .3.1

6 .3.5

6 . .1 .1 2

7.3. I

8.3.1

lJ.J . I

10.3. I

10.3.3

10.3.4

IO.3.6A

Sawn Lum ber ......................... . . .... . 27

Inc is ing Factors. C, ... .. .. .. .. .. .. .. ... .. .. .. .. .. .. .. ... . 27

Nel Finished Widlhs of Glued Laminaled Timbers .. ... .. .. .. .. .. . . ... .. ... .. .. . 32

Applicability of Adjuslment Faclors for Glued Lamillated Timber ... .. .. .. .. .. .. .. .. .. .. .. .. .. 34

Design Values for Trealed Round Tim ber Piles .. .. .. ... .. .. .. .. .. ... .. .. .. .. ... .. .. .. .. .. ... .. . 3lJ

Design Values for Poles Graded in Accordance wilh ASTM D3200

Applicability of Adjuslment Faclors for

... ... 3lJ

Round Timber Poles and Pi les .. .. ... .. .. .. .. .. .. .. 3lJ

Un lreated Factors. Cu' for Timber Poles and Piles ... .. .. ... .. .. .. .. .. ... .. .. .. .. ... .... ... ... .. .... .. .. 40

Single Pile Factors. C,p. for Round Timber Piles .. .. .. ... .. .. .. .. .. ... .. .. .. .. ... .. .. .. .. .. ... .. . 41

Applicability of AdJusLmcnt Faclors for Prefabricaled Wood I-Joisls .. .. .. ... .. .. .. .. ... .. .. . 44

Applicability of AdJusLment Factors for Structural Co mpos lie Lumber ... .. .. .. ... . 49

Applicability of Adjuslment Faclors for Wood Slructural Panels .. .. .. .. ... .. .. .. ... .. .. .. .. ... . 53

Applicability of AdJusLmcnt Faclors for Connecllons ... .. .. ... .. .. .. .. ... .... ... ... .. .. .. ... .. .. .. .. . 5,s

Wet Service Faclors . C~l' for Connections .... .. 5lJ

Temperature Factors. C,. for Conneclions ... .. .. 5lJ

Group Aclion raclors. Cf

• for Bolt or Lag Screw Connections Wilh Wood Side Members .. .. .. .. .. ... .. .. .. .. .. .. . .. .. ... ... .. 62

IO.J .6B Group Act ion Factors. C~ . for 4" Spilt Ring or Shear Plate Connectors With Wood Side Members ... .. .. .. ... .. .. .. .. .. .. .. .. .. .. .. .. 62

IO.J,(,C Group Action raclors. Cg• for Boll or Lag Screw Connections With Sled Side Plates .. .. ... .. .. .. .. .. .. ... .. .. .. .. .. .. ... .. .. .. .. .. .. ... 63

IO.J,(,D Group Action ractors. Cg• for 4" Shear Plate Connectors With Steel Side Plates ... .. . 64

11 .2A La g Screw Withdrawal Design Values (W) .... .. .. .. .. . ....... ....... .. 6,s

11.2B Cu l Thread or Rolled Thread Wood Screw Withdrawal Design Values (W) .. ..... .. 6lJ

11 .2C Nail and Spike Wilhdrawal DeSign Values (W) .... .. .. .. .. .. ... .. .. .. .. ... .. .. .. .. .. ... .. .. .. .. .. 70

11. J . IA Yield Limit Equations .... ... .. .. ... .. .. .. ... .. .. .. .. ... 71

I 1 . .1 . 1 B Reduc ll on Terms ... .. ..... .. ... ... .. .. .. 72

II .J .2 Dowel Bearing Slrengths ... .. .. .. .. ... .. .. .. .. .. .. .. . 7J

I 1 . .l .2A Ass igned Specdic Gravities .. .. .. .. .. .. .. .. ... .. .. .. 74

II. J .2B Dowel Bearing Strenglhs for Wood Slru ctural Panels .. . . ....... ....... .. 75

II .5 . IA Edge Distance Requirements .... .. .. .. .. .. .. ... .. .. 76

II .5 . IB End Dis Lance Requirements ... ... .. .. .. .. .. ... .. .. .. 77

II .5 . IC Spacing Req ulremenls for Fasleners III a Row ... .. .. .. ... .. .. .. .. .. .. ... .. .. .. .. .. . 78

I 1.5 . 1 D Spacing Reqlllrements Belween Rows .... .. .. 7,s

11 .5 . 1 E Edge and End Distance and Spacing Reqlllrements for Lag Screws Loaded In

IIA

liB

Withdrawal and Nol Loaded Laterally .. .. .. .. . 7,s

BOLTS: DeSign Values (Z) for Single Shear (lWO member) Connect ions for Sawn Lumber or SCL w ith bOlh members of Ident ical specd"ic gravlly ... .. ... .. ,s0

BOLTS: DeSign Values (Z) for Single Shear (lWO member) Connections for Sawn Lumber or SCL with 1/4" ASTM A36 steel s id e plate .. .. .. .. .. .. ... .. .. .. .. .. .. .. .. ... .. .. ,s2


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lie

110

l iE

I IF

I IC

I IH

III

III

11K

IlL

11M

ND S21lO2 FMpmci

LIST OF TABLES

BOLTS: Des ign Valu es (Z) lor Single Shear (two member) Connect ions for Glu ed Laminated Timber ma lll member with sawn lumber side member of ident ic al speci fi c gravit y ... ... .. .. .. .. ... .. .. .... .. .. S3

BOLTS: Des ign Val ues (Z) for Single Shear (Iwo mem ber) Connect ions lor Glu ed Laminated Timber with 1/4" ASTM A36 steel side plate ... .. ... .. .. .. .. .. .. ... .. . S4

BOLTS: Des ign Values (Z) lor Single Shear ( two member) Connections for Sawn Lum ber or SCL to concrete .. .. .. .. .. .. ... . S5

BOLTS: Des ign Values (Z ) for Double Shear (three member) Connections lor Sawn Lum ber or SCL with bot h mem bers of Identi cal specific grav it y ... .. .. ... .. .. .. .. .. .. .. .. S6

BOLTS: Des ign Values (Z) for Double Shear (three member) Connections for Sawn Lumber or SCL wit h 1/4" ASTM A36 steel si de plat e ... .. .. .. .. .. ... .. .. .. .. ... .. ... .. .. . Sg

BOLTS: Des ign Valu es (Z) for Double Shear (three member) Connections lor Glu ed Laminated Timber main member with sawn lumber side member of ident ic al species ... .. .. .. .. .. ... .. .. .. ... .. ... .. .. .. .. .. .. SlJ

BOLTS: Des ign Val ues (Z ) for Double Shear (three member) Connect ions for Glu ed Laminated Tim ber with 1/4" ASTM A36 steel side plate ... .. ... .. .. .. .. .. .. ... .. . 90

LAG SCREWS: Des ign Valu es (Z) for Singh~ Shear (two member) Connections for Sawn Lumber or SCL wi th both members of Identi cal specific gravity .. .. .. ... . 92

LAG SCREWS : Design Val ues (Z) lor Single Shear (two member) Connections wllh 1/4" ASTM A36 steel side plate. or ASTM A653. Grade 33 steel side plat e (for t,<1/4") .. .. .. .. .. .. .. ... .. .. .. .. .. .. ... .. .. .. .. .. .. ... .. . 94

WOOD SCREWS: Des ign Valu es (Z) lor Single Shear (two member) Connections for Sawn Lumber or SCL wi th both mem bers of Identical speCIfic gravity .. .. .. ... . 95

WOOD SCREWS: Des ign Valu es (Z) for Single Shear (two member) Connections wit h ASTM A65 3. Grade 33 steel side pl:lt e ... .. ... .. .. .. .. .. .. .. ... .. .. .. .. .. .. .. .. ... .. .. .. .. .. .. .. ... . 96

l i N

l iP

I IQ

I IR

COMMON WIRE. BOX. or SINKER NA ILS: Design Values (Z ) for Single Shear (two membe r) Connect ions for sawn lum ber or SCL wllh both members of Identical spec ific gra vlly .. .. .. .. ... .. .. .. .. .. .. ... lJ 7

COMMON WIRE. BOX. or S INKER NA ILS : Design Values (Z ) lor Single Shear (two member) Connections wllh ASTM A653 . Grade 33 steel side plates ... .. .. .. lJS

COMMON WIRE. BOX. or SINKER NA ILS: Design Values (Z ) for Single Shear (two mem ber) Connect ions wi th Wood Structural Panel si de members with an effec tive G = 0.50 ... .... . 100

COMMON WIRE. BOX. or SINKER NA ILS: Design Values (Z ) for Single Shear (two mem ber) Connec tions with Wood Structural Panel si de members with an effective G = 0.42 ... .. .. ... .. .. . 10 1

12A Species Groups lor Split Ring and Shear Plate Connectors .. .. ... .. .. .. ... .. .. .. ... .. .. . 105

12.2A Spl it Ring Connector Unit Des ign Val ues ... .. ... .. .. .. .. ... .. .. .. .. . .. .. ... .. .. .. .. .. ... . 106

12.2B Shear Plate Connec tor Unit Des ign Values ... .. ... .. .. .. .. ... .. .. .. .. .. ... .. .. .. .. ... .. .. .. .. .. ... . 107

12.2.3 Penetrati on Depth factor. CJ' for Split Ring and Shear Plate Connectors Used wi th Lag Screws ... .. ... .. .. .. ... .. .. .. ... .. .. .. ... .. .. .. 109

12.2.4 Metal S ide Pla te Factors . C". for 4" Shear Plate Connectors Loaded Parall el to Grain ... ... .. lOS

12 . .1 Geomet ry Factors . C~. for Spltt Ring and Shear Plate Connec tors .. .. .. ... .. .. .. .. ... .. . I 13

13.2.3 Metal S ide Plate factor. C". for Timber Ri ve t Connec tions .. ... .. .. .. .. .. ... .. .. .. .. ... . 117

13.3 .2 Minimum End and Edge Distances for Ti mber Ri vet JOints ... ... .. .. .. .. .. .. ... .. .. .. .. .. .. ... l i S

13.2.IA Nominal Wood Capac ity Parallel to Graill. P" . for Ti mber Rivets (Rivet Lengt h = 1- 1/2" sp= I" s~= 1") ... ... .. .. ... . 119

13.2.I B Nominal Wood Capac ity Parallel to Graill. P" . for Ti mber Rivets (Rivet Length = 1-112" sp= 1- 1/2" s~= I") ... .. .. 120


31 13/D2 . 11:00AM


13.2.IC Nomi nal Wood CapacilY Parallel 10

Grain. PI" for Timber Ri vels (Rivel Lcng lh=2- 1/2" \ ,= I" S4= I"). . . ... 12 1

13.2. I 0 Nominal Wood CapacilY Parallel 10

Grain. PI" for Timber Ri vels (Rivel Leng lh = 2-1/2'" Sl' = 1-1/2" S4 = I") .... 122

13.2. I E Nominal Wood Capacity Parallel to Graltl. PI" for Timber Ri ve ts (Rivet Leng th=3- 1/2'" Sl'= I" S4= I").. . ... 123

13.2. I F Nominal Wood Capacity Parallel to Graltl. PIA ' for Timber Ri ve ts (Rivet Leng th = 3-1/2'" Sl' = 1-1/2" S4 = I") .... 124

13.2.2A Values 01 q" (lbs.) PerpelH.licular to Gram for Ti mber Ri vets ... .. ... .. .. .. .. .. .. ... .. .. .. 125

13.2.28 Gt:ometry Factor. C~. for Timber Ri vet Connections Load ed Perpend icular to Gram ... .. .. ... .. .. .. .. ... .. .. .. .. ... .. .. .. .. ... .. .. .. .. ... .. .. 125

15.1.1 Lateral Distribu ti on factors for Moment ... .. .. .. ... .. .. .. .. .. ... .. .. .. .. .. .. ... .. .. .. .. .. ... . 132

15.1.2 Lateral Dis tribution In Terms of Proport ion of Tolal Load ... .. .. ... .. .. .. .. .. ... .. .. . 132

16.2 .1 Effective Char Ratt:s and Char Layer Thicknesses (for p" = 1.5 in.lhr. ) 140

16.2 .2 Adj us tment factors for f ire Des ign ... ... .. .. . 141

PI

G I

I I

Coerticients of Van at ion m Modulus of Elastic it y (COVd for Lumber and Glued Laminated Ti mber .. .. .. .. .. ... .. .. .. ... .. .. .. ... .. .. .. . 154

Buckling Length CoeJTicienls. K~ .... .. .. ... .. . 156

f as tener Bending Yi eld Strengths . F)b ... .. .. 160

LIST OF TABLES IN THE NDS SUPPLEMENT

IA NOllllllal and Mlnlmllm Dressed S izes of Sawn Lumber .. .. .. .. .. ... .. .. .. .. .. ... .. .. .. .. .. ... .. .. .. .. .. .. ... 13

I B Section Properties of Standard Dresst:d (S4S) Sawn Lumber .. ... .. .. .. .. .. ... .. .. .. .. ... .. .. .. .. .... .. 14

I C Sec tion Properties 01 \Vi:'s/em Spccics Glued Laminatt:d Timber .. .. ... .. .. .. .. .. ... .. .. .. .. .. ... .. .. .. .. .. .. .. 16

1 D Section Properties of SOllflicm Pi llc Glued Lamina ted Timber .. .. ... .. .. .. .. .. ... .. .. .. .. .. ... .. .. .. .. .. .. .. 22

4A Base Design Values for Visually Graded Dimension Lumber (2'" -4" thick) (All speCIes except Sou thern Pine) .. .. .. ... .. .. ... .. .. ... .. .. ... .. .. ... .. .. 30

4B Des ign Values lor Visually Graded Southern Pine DimenSIOn Lumber (2" -4" th ick) .. ... .. .. ... .. . 36

4C Design Val ues for Mec han ically Graded Dimension Lum bel .... .. .. .. .. .. ... .. .. .. .. .. .. ... .. .. .. .. .. ... . 3lJ

4D Design Va lues lor Visually Graded Ti mbers (5" x 5" and larger) .. .. .. .. .. .. .. .. ... .. .. .. ... .. .. .. .. ... .. .. .. 43

4E Design Values for Visually Graded Deck ing ... .. .. 50

4F Base Des ign Values for Non-North American Visually Graded Di menS ion Lum ber (2"-4" thi ck) .. .. . .. .. .. ... .. .. .. .. .. ... .. .. .. .. .. ... .. .. .. .. . 53

5A Design Values for St ru ctural Glued Laminated Softwood Timber (Members stressed primarily In bending) .... .. .. .. .. ... .. .. .. .. .. .. . 57

5B Design Values for Structural Glued Laminated Softwood Timber (Members stressed primarily in aXial tensIOn or compression) ... .. .. .. .. .. ... .. .. .. .. ... .. .. .. .. .. ... .. .. .. .. ... .. .. 63

5C Design Values for St nl ctural Gl ued Laminated Hardwood Tim ber (Members stressed primarily In bending) ... .. .. .. .. .. ... .. .. .. .. .. .. . 68

5D Design Values for St nl ctural Gl ued Laminated Hardwood Tim ber (Members stressed primarily in aXial lens ion or compression) ... .. .. ... .. .. .. .. .. ... .. .. .. .. ... .. .. 711

AMERtCAN FOREST & PAPER ASSOCIATION

NDS21lO 2 FM pmci 31 13/D2 . 11:00 AM


LIST OF FIGURES

3A

3B

3D

3E

3F

3G

3H

31

3J

4A

Spacing of Siaggered Fasleners .. .... 12

Nel Cross Seclion al a Splil Ring or Shear Plale Connection ... ... .. .. .. .. .. .. ... .. .. .. .. .. ... .. .. .. .. .. .. 12

Shear at Supports .. .. ... .. .. .... ... .. .. . . . .. .. . I (I

Bending Member End-Nolched on Compression Face .. .. .. ... .. .. ... ... .. .. ... .. .. ... .. ... .. .. . 17

ElTeclive Depth, de. of i'vkmbcrs al Connections ... .. ... .. .. .. .. .. ... .. .. .. .. .. ... .. .. .. .. .. .. ... .. .. 17

Simple Solid Column ... .. .. .. .. ... .. .. .. .. ... .. .. .. .. .. ... . 18

Combined Bending and Axial Tension .. ... .. .. .. . 21

Combined Bending and Axial Compression .... 21

Bearing at an Angle 10 Grain .. .. .. .. .. .. .. .. ... .. .. .. .. 22

Nolch Limitations for Sawn Lumber Beams .. . 29

SA Curved Bending MembcI ... ... .. .. .. .. .. .. .. .. ... .. .. .. .. 35

lOA Eccentric Conneclions ... .... ... ... .. .. ... .. .. .. .. .. .. ... .. 5(1

lOB Group Action f{n Staggered Fasleners ... .. ... .. .. . 61

IIA Toe-Nail Connection .. ... ... .... ... .. .. ... .. ... .... ... ... .. 67

II B Singh: Shear Bolled Conneclion ... .. ... .. .. .. .. .. .. .. 72

Ill' Double Sb,,,, Bolted Connections .... .. .. .. .. .. .. ... 72

110 Mu ltiple Shear Bolted Connection .. .. ... .. .. .. .. .. . 75

II E Shear Area for BoIled Conneclions ... ... .. .. ... .. .. 75

II F Combincd Lalcral and Withdrawal Loading .. .. 76

II G Bolted Connection Geometry ... .. .. .. .. ... .. .. .. .. .. .. 77

11 1-1 Spacing Bctween Ouler Rows of Bolls ... .. ... .. .. 78

12A Splil Ring Conneclot .. ... .. .. ... ... .... ... .. . . ... . 104

12B Pressed Slecl Shear Plate Connector .. ... .. .. .. .. 104

12C Mulbble Imn She", P],,,, Conneel", .. .. ... .. .. 104

120 Axis of Cut for Symlm:trical Sloping End CuI ... .. .. .. .. ... .. .. .. .. ... .. .. .. .. ... .. .. .. ... .. .. .. .. ... .. 109

12E Axis of Cut for Asymmetrical Sloping End CuI ... .. .. .. .. ... .. .. .. .. ... .. .. .. .. ... .. .. .. ... .. .. .. .. ... .. 109

12F Square End Cut ... .. ... .. .. .. .. ... .. .. .. .. ... .. .. .. ... .. .. .. . 110

12(; Sloping End Cui with Load Parallel 10Axis of CuI Up=OU). . 110

12H Sloping End Cui with Load Perpendicular \0

121

Axis of CuI (q)=900) .. .. .. . .. .. .. .. .. . .. .. .. .. . .. .. .. .. .. . . 110

Sloping End Cut with Load al an Angle <p 10 Axis of CuI . 110

12J Connection Geometry for Splil Rings and Shear Plates . III

12K End Distance for Members with Sloping End Cui .................... . III

13A End and Edge Dislance Requirements for Timber Rivel Joints .. ... .. .. ... .... ... ... .. .. ... .. .. .. .. ... 118

14.4.1 Diaphragm Lenglh and Width ... .. .. ... .. .. .. ... .. .. . 129

15A Spaced Column Joined by Split Ring or Shear Plale Connectors ... .. ... .. .. ..... .. ... 133

15B Mechanically La minated Buill-Up Column .. . 135

15C TypIcal Nailing Schedules for Built-up Columns .... .. .. .. .. .. ... .. .. .. .. ... .. .. .. .. .. ... .. .. .. .. ... .. .. . 136

ISO Typical Bolling Schedules for Buill-up Columns .... ... ... .. .. ... .. .. .. .. ... .. .. .. .. .. ... .. .. .. .. ... .. .. . 136

15E Eccenlrically Loaded Column .. .. ... .. .. .. ... .. .. .. . 138

BI Load Duration Faclors, CD' for Various Load Durations ... .. ... .. .. .. . . 147

EI Siaggered Ruws of Bolls .. .. .. ... .. .. .. .. ... .. .. .. .. ... . lSI

E2 Single Row of Bolts ... .. .. .. ... .. .. .. .. .. ... .. .. .. .. ... .. . 152

E3 Single Row of Split Ring Connectors .. .. .. .. .. .. 153

J I Connection Yield Modes ... .. .. .. ... .. .. .. .. .. ... .. .. .. 159

J 1 Solution of Hankinson Formula .. ... .. .. .. ... .. .. ... 163

J2 Connection Loaded al an Angle 10 Grain 163


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5 U P P L E MEN ,

DESIGN VALUES FOR WOOD CONSTRUCTION

American Forest &

Paper Association

American Wood Council

2001 Edition

5 U P P L E MEN ,

NATIONAL DESIGN SPECIFICATION ®

I Su.pp FM D, alt.pmd

DESIGN VALUES FOR WOOD CONSTRUCTION

Copyright :O 200 I American Forest & Paper Association, Inc.

3i l 1i02 . 10 :1SAM

Introduction

This Supplement is an integral part or the Nariol/a/ Desigll 5'pec!licaliol/ ' (NDS' j for Wood COIISTructioll .

200 I Edition . It provides design values for structural sawn lumber and structural glued laminated limber.

Lumber The design values for lumber in this Supplement are

obtained from grading rules published by seven agencies: National Lumber Grades Authority (a Canadian agency), Northeastern Lumber Manufacturers Association, Northern Softwood Lumber Bureau. Redwood Inspection Service. Southern Pine Inspection Bureau, West Coast Lumber Inspection Bureau amI Western Wood Products Association . The grading mles promulgated by these agencies , including Ihe desi gn values therein, have been approved by the Board of Review oflhe American Lumber Siandards Commillee and cerlified for conformance wilh U.S. Deparlment of Commerce Voluntary Product Siandard PS 20-99, (American Soflwood Lumber Slandard).

Design values fo r most species and grades of visually graded dimension lumber are based on Ihe provisions of ASTM Siandard 01990-00'1 (Establishing Allowable Properties for Visually Graded Dimension Lumber fro m In-Grade Tests of rull-Size Specimens) . Design values for visually graded timbers. decking. and some species and grades of dimension lumber are based on the provisions of AST M Slandard 0245-00" 1 (Establishing Siruciural Grades and Re1aled Allowable Propel1ies for Visually Graded Lumber). T he melhods in AST M Siandard 0 245-00,.1 involve adjusling the slrength properties of small clear specimens of wood, as given in ASTM Siandard 02555-98 (Eslab

lishing Clear Wood Strenglh Values). fo r Ihe elrecls of knols. slope of grain . splils. checks. size . dunllion of load . moisture conlenl and olher inl1uencing factors, to obtain design values applicable 10 normal condilions of service . Lumber struclures designed on Ihe basis of working stresses dcrived from ASTM Slimdard 0245 procedures and standard design crileria have a long hislory of satisfactory performance .

Design values for machine Slress rated (MSR) lumber and machine evalualcd lumbcr (MEL) are based on nondestructive Icsting of individual pieces. Cerlain visual grade requirements also apply to such lumber. The st ress rating syslem used for MSR and MEL lumber is regularly checked by the responsible grading agency for conformance to established certification and quality conlrol procedures.

For additional information on developmenl and applicabilit y oflumber design values, the grading rules published by the individual agencies and the refercnced AS TM Standards shoul d be consulted.

Clued Litminated Timber Design values in this Supplement for glued laminaled

limber are developed and published by the Amcrican Inslitule of T imber Conslruclion (A ITC) and A PA-T he Engineered Wood Associalion (A PA) in accordance wilh principles originally cstablishcd by the U.S . rorest Products Laboratory mthe carly 1950s. These principles involve adjusling strenglh properties of clear straight grained lumber to account for knOb . slope of gralll . densily. size of member, numbcr of laminalions and other factors unique 10 laminated timbcr.

Spccific mclhods uscd 10 establish design values have been periodically revised and improved to rellectlhe resulls oflests oflarge glued laminated timber members conducted by the U.S. rorest Producls Laboralory and other accredi\ed tesling agencies. The perfonnance hislory of structures made wilh glued laminaled timber conforming to AITC specifications and manufactured in accordance wilh American National Siandard ANSUAITC A 190.1-1992 (Slruclural Glucd Laminaled Timber) has demonstrated the vali dilY of Ihe methods used 10 establish glued laminated timber design values.

Conditions of Use Design values presented in this Supplement are for

normal load duration under dry conditions of service. Because the strength of wood varies wilh conditions under which it is used. these design values should only be applied in conjunclion wilh appropriate design and service recommendations from the NDS. Additionally, the deSIgn values in Ihis Supplement apply only 10 malerial identified by Ihe grade mark of. or certificate of inspection issued by. a grading or inspeclion bureau or agency recognized as being compelent.

AMERtCAN WOODCa.n:: IL

Su.pp FM D, alt.pmd 3i11 i02 . 10 :1SAM

TABLE OF CONTENTS

C]'''plcr 'Titk

1 Sawn Lumber Grading Agencies 1

1.1 Lisl or Sawn Lumber Grading Agencies

2 Species Combinations 3 2. I Li st 01 Sawn Lum ber Species

Comb ina ti ons 4 2.2 Li sl of Non-North American Sawn

Lumber Spec ies Combinati ons 7 2.3 Li st of Siruclural Glued Lammaled

Timber Spec ies Co mbina ti ons g

LIST OF TABLES

I A N0Il1111al and Milll1l1UIl1 Dressed S izes of Sawn Lumber ... .. .. .. .. .. ... .. .. .. .. .. .. ... .. .. .. .. . .. .. . 13

113 Section Properl ies of Standard Dressed (S4S) Sawn Lumber .... .. .. .. ... .. .. .. .. ... .. .. .. .. ... .. .. .. .. 14

I C Section Properties of IVi:'.I"/c/"li Spl'cie.\' G lued Lam inated Tim ber .... .. .. .. .. ... .. .. .. .. .. ... .. .. .. .. ... .. .. .. . 16

10 Section Prope rli es of SOIlfI'1'1"II Pille Glu ed Lam inaled Timber .... .. .. .. .. ... .. .. .. .. .. . .. .. . 22

4A Base Design Values for Vis ually Graded Di mension Lumber (2"-4" lh ick) (All spec ies excepl So ulhern Pine) ... .. .. .. .. .. ... .. .. .. .. .. . .. .. . 30

413 Design Value s lor Visua lly Graded Soulhern Pi ne DimenS ion Lumber (2 "-4 " lhlCk) .... .. .. .. .. . 36

4C Design Values tor Mechanically Graded Dimension L umber ... .. .. .. .. ... .. .. .. .. ... .. .. .. .. ... .. .. .. .. 39

40 Design Values tor Visually Graded Ti mbers (S'. x S'. and larger) ... .. .. .. .. ... .. .. .. .. ... .. .. .. .. ... .. .. .. . .43

4E Design Value s for Visua lly Grad ed Deck ing .. . 50

3 Section Properties 11 3.1 Section Properlies Dr Sawn Lumber

and Glued Laminated Timber

4 Design Values 29

4F Base Design Values for Non-North A meri can Visually Graded Di mension Lu mber (2"-4" lhl ck) ... .. .. .. ... .. .. .. .. ... .. .. .. .. ... .. .. .. .. ... .. .. .. .. .. 53

5A Des ign Val ues for Slrucl ural Glued Lamina led Softwood Timbe r (Members slressed primarily In be nd ing) ... .. .. .. .. .. ... .. .. .. .. .. 57

5 8 Des ign Values for Slrucl ural Glu ed Lamina led Softwood Timbe r (Members slressed pri mari ly in axial tension or co mpressIOn) .... ... .. .. ... .. .. .. . .

5C DeS ign Values tor Strucl ural Glu ed Lanlillaled Hardwood Ti mber (M embers

. .. 63

slressed primari ly in bending) . . ....... .. 6S

5 0 DeS ign Values tor Slrucl ural Glued Lanlillaled Hardwood Ti mber (M embers slressed pri mari ly In axial lens Ion or co m pressIOn) ... .. .. .. .. ... .. .. .. .. ... .. .. .. .. ... .. .. .. .. ... .. .. .. . 70

Nv1ERICAN FOREST &PAPER ASSOCIATION

Su.pp FM D, alt.pmd 3i11 i02 . 10 :1SAM

AMERICAN WOODCa.n:: IL

Su.pp FM D, a lt. pmd • 3i11i02 . 10 :1SAM

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Documents

ANSI_AF&PA NDS-2001– National Design Specification for Wood Construction