Load Duration

Since plywood used in formwork has a maximum load duration of 7 days, the APA specifications allow an increase in the design values given in Table 3.14 by 25 percent.

KEY TO SPAN
RATING AND
SPECIES GROUP

Подпись: Thickness (in.) Span Rating (APA RATED SHEATHING grade) 12/0 16/0 20/0 24/0 32/16 40/20 48/24 Span Rating (STURD-I-FLOOR grade) 16 oc 20 oc 24 oc 48 oc 5/16 431 3/8 4 1 15/32 & 1/2 4 1<i) 19/32 & 5/8 41 23/32 & 3/4 41 7/8 3(2) 1-1/8 1 For panels with ‘‘Span Rating’’ as across top, and thickness as at left, use stress for species group given in table.

(1) Thicknesses not applicable to APA RATED STURD-I-FLOOR

(2) For APA RATED STURD-I-FLOOR 24

oc, use Group 4 stresses.

From Plywood Design Specification by The American Plywood Association 1997.

Table 3.11 Guide to Use of Allowable Stress and Section Properties Tables EXTERIOR APPLICATIONS

Typical

trademarks

Veneer grade

Common

thicknesses

Grade stress level (Table 3)

Section

property

table

Plywood grade

Description and use

Face

Back Inner

Species group

APA RATED SHEATHING EXT(3)

Unsanded sheathing grade with waterproof glue bond for wall, roof, subfloor and

C

C

C

5/16, 3/8, 15/32, 1/2, 19/32, 5/8,

S-1(6)

See ‘‘Key to Span Rating’’

Table 1 (unsanded)

APA

THE EIIGMEERED WOOD ASSOCIATION

industrial applications such as pallet bins.

RATED SHEATHING

48/24 23/32 INCH

SIZED FOR SPACING

EXTERIOR

PS 1-95 C-CPRP-108

23/32, 3/4

APA STRUCTURAL I RATED

SHEATHING EXT(3)

‘‘Structural’’ is a modifier for this unsanded sheath­ing grade. For engineered

C

C

C

5/16, 3/8, 15/32, 1/2, 19/32, 5/8,

S-1(6)

Group 1

Table 2 (unsanded)

APA

THE EIIGMEERED WOOD ASSOCIATON

applications in construc­tion and industry where full Exterior-type panels are required. Structural I

RATED SHEATHING STRUCTURAL I 24/0 3<8 INCH

SIZED FOR SPACING

EXPOSURE 1

PS 1-95 C-D PRP-108

23/32, 3/4

is made from Group 1 woods only.

APA RATED STURD-I-FLOOR

EXT(3)

For combination subfloor – underlayment where se­vere moisture conditions

C

plugged

C

C

19/32, 5/8, 23/32, 3/4

S-2

See ‘‘Key to Span Rating’’

Table 1

(touch-sanded)

APA

THE EIIGMEERED WOODASSOCIATION

may be present, as in bal­cony decks. Possesses high concentrated and im-

RATED STURD-I-FLOOR

20 OC 19/32INCH

SIZED FOR SPACING

EXTERIOR

pact load resistance during construction and occu­pancy. Touch-sanded. (4) Available with tongue-and – groove edges. (5)

C 1/2, 19/32, 5/8, 23/32, 3/4

 

S-2 As Specified Table 1

(touch-sanded)

 

APA

Underlayment for floor

APA

CC

UNDERLAYMENT

where severe moisture

plugged

EXT and APA

conditions may exist. Also

WOOD ASSOCIAnOH

C-C-PLUGGED EXT

for controlled atmosphere rooms and many industrial applications. Touch – sanded. Available with tongue-and-groove edges. (5)

C-C PLUGGED GROUP 2 EXTERIOR

 

Подпись: APA THE EIIGMEERED WOOD ASSOCIATION Подпись: B C 19/32, 5/8, S-2 Class I use 23/32, 3/4 Group 1; Class II use Group 3 Подпись: Table 1 (sanded)Подпись:APA B-B PLYFORM Concrete-form grade with CLASS I or II[4] high reuse factor. Sanded both sides, mill-oiled un­less otherwise specified.

Available in HDO. For re­fined design information on this special-use panel see APA Design/Construc­tion Guide: Concrete Form­ing, Form No. V345. De­sign using values from this specification will result in a conservative design. (5)

Подпись:Подпись: Table 2 (sanded)APA-MARINE EXT Superior Exterior-type ply – [marine-a-a-ext^ A

wood made only with APA *000* PS 1-95 or

Douglas-fir or Western B

Larch. Special solid-core construction. Available with MDO or HDO face.

Ideal for boat hull con­struction.

Typical

trademarks

Veneer grade

Common

thicknesses

Grade stress level (Table 3)

Section

property

table

Plywood grade

Description and use

Face

Back Inner

Species group

APA APPEARANCE

Generally applied where a

APA

THE EltGmEERED WOOD ASSOCIATION

A-C GROUP 1 EXTERIOR

B

C C

1/4, 11/32,

A or C face &

As Specified

Table 1

GRADES EXT

high quality surface is re­quired. Includes APA, A-A, A-B, A-C, B-B, B-C, HDO and MDO EXT. (5)

or

better

or

better

3/8, 15/32, 1/2, 19/32, 5/8, 23/32, 3/4

back use S-1[5] 2 [6] [7] [8] [9] B face or back use S2

(sanded)

Table 3.12 Effective Section Properties for Plywood

FACE PLIES OF DIFFERENT SPECIES GROUP FROM INNER PLIES

(INCLUDES ALL PRODUCT STANDARD GRADES EXCEPT THOSE NOTED IN TABLE 2.)

Stress applied parallel to face grain Stress applied perpendicular to face grain

ts

I

KS

Ib/Q

I

KS

Ib/Q

Effective

Moment

Effective

Rolling

Moment

Effective

Rolling

Nominal

Approximate

thickness

A

of

section

shear

A

of

section

shear

thickness

weight

for shear

Area

inertia

modulus

constant

Area

inertia

modulus

constant

(in.)

(psf)

(in.)

(in.2/ft)

(in.4/ft)

(in.3/ft)

(in.2/ft)

(in.2/ft)

(in.4/ft)

(in.3/ft)

(in.2/ft)

Unsanded Panels

5/16-U

1.0

0.268

1.491

0.022

0.112

2.569

0.660

0.001

0.023

4.497

3/8-U

1.1

0.278

1.866

0.039

0.152

3.110

0.799

0.002

0.033

5.444

15/32- & 1/2-U

1.5

0.298

2.292

0.067

0.213

3.921

1.007

0.004

0.056

2.450

19/32- & 5/8-U

1.8

0.319

2.330

0.121

0.379

5.004

1.285

0.010

0.091

3.106

23/32- & 3/4-U

2.2

0.445

3.247

0.234

0.496

6.455

1.563

0.036

0.232

3.613

7/8-U

2.6

0.607

3.509

0.340

0.678

7.175

1.950

0.112

0.397

4.791

1-U

3.0

0.842

3.916

0.493

0.859

9.244

3.145

0.210

0.660

6.533

1-1/8-U

3.3

0.859

4.725

0.676

1.047

9.960

3.079

0.288

0.768

7.931

Stress applied parallel to face grain Stress applied perpendicular to face grain

ts

I

KS

Ib/Q

I

KS

Ib/Q

Effective

Moment

Effective

Rolling

Moment

Effective

Rolling

Nominal

Approximate

thickness

A

of

section

shear

A

of

section

shear

thickness

weight

for shear

Area

inertia

modulus

constant

Area

inertia

modulus

constant

(in.)

(psf)

(in.)

(in.2/ft)

(in.4/ft)

(in.3/ft)

(in.2/ft)

(in.2/ft)

(in.4/ft)

(in.3/ft)

(in.2/ft)

Sanded Panels

1/4-S

0.8

0.267

0.996

0.008

0.059

2.010

0.348

0.001

0.009

2.019

11/32-S

1.0

0.284

0.996

0.019

0.093

2.765

0.417

0.001

0.016

2.589

3/8-S

1.1

0.288

1.307

0.027

0.125

3.088

0.626

0.002

0.023

3.510

15/32-S

1.4

0.421

1.947

0.066

0.214

4.113

1.204

0.006

0.067

2.434

1/2-S

1.5

0.425

1.947

0.077

0.236

4.466

1.240

0.009

0.087

2.752

19/32-S

1.7

0.546

2.423

0.115

0.315

5.471

1.389

0.021

0.137

2.861

5/8-S

1.8

0.550

2.475

0.129

0.339

5.824

1.528

0.027

0.164

3.119

23/32-S

2.1

0.563

2.822

0.179

0.389

6.581

1.737

0.050

0.231

3.818

3/4-S

2.2

0.568

2.884

0.197

0.412

6.762

2.081

0.063

0.285

4.079

7/8-S

2.6

0.586

2.942

0.278

0.515

8.050

2.651

0.104

0.394

5.078

1-S

3.0

0.817

3.721

0.423

0.664

8.882

3.163

0.185

0.591

7.031

1-1/8-S

3.3

0.836

3.854

0.548

0.820

9.883

3.180

0.271

0.744

8.428

Touch-Sanded Panels

1/2-T

1.5

0.342

2.698

0.083

0.271

4.252

1.159

0.006

0.061

2.746

19/32- & 5/8-T

1.8

0.408

2.354

0.123

0.327

5.346

1.555

0.016

0.135

3.220

23/32- & 3/4-T

2.2

0.439

2.715

0.193

0.398

6.589

1.622

0.032

0.219

3.635

1-1/8-T

3.3

0.839

4.548

0.633

0.977

11.258

4.067

0.272

0.743

8.535

From Plywood Design Specification by The American Plywood Association 1997.

Table 3.13 Effective Section Properties for Plywood (Structural I and Marine) STRUCTURAL I AND MARINE

Stress applied parallel to face grain Stress applied perpendicular to face grain

ts

I

KS

Ib/Q

I

KS

Ib/Q

Effective

Moment

Effective

Rolling

Moment

Effective

Rolling

Nominal

Approximate

thickness

A

of

section

shear

A

of

section

shear

thickness

weight

for shear

Area

inertia

modulus

constant

Area

inertia

modulus

constant

(in.)

(psf)

(in.)

(in.2/ft)

(in.4/ft)

(in.3/ft)

(in.2/ft)

(in.2/ft)

(in.4/ft)

(in.3/ft)

(in.2/ft)

Unsanded Panels

5/16-U

1.0

0.356

1.619

0.022

0.126

2.567

1.188

0.002

0.029

6.037

3/8-U

1.1

0.371

2.226

0.041

0.195

3.107

1.438

0.003

0.043

7.307

15/32- & 1/2-U

1.5

0.535

2.719

0.074

0.279

4.157

2.175

0.012

0.116

2.408

19/32- & 5/8-U

1.8

0.707

3.464

0.154

0.437

5.685

2.742

0.045

0.240

3.072

23/32- & 3/4-U

2.2

0.739

4.219

0.236

0.549

6.148

2.813

0.064

0.299

3.540

7/8-U

2.6

0.776

4.388

0.346

0.690

6.948

3.510

0.131

0.457

4.722

1-U

3.0

1.088

5.200

0.529

0.922

8.512

5.661

0.270

0.781

6.435

1-1/8-U

3.3

1.118

6.654

0.751

1.164

9.061

5.542

0.408

0.999

7.833

Stress applied parallel to face grain Stress applied perpendicular to face grain

ts

I

KS

Ib/Q

I

KS

Ib/Q

Effective

Moment

Effective

Rolling

Moment

Effective

Rolling

Nominal

Approximate

thickness

A

of

section

shear

A

of

section

shear

thickness

weight

for shear

Area

inertia

modulus

constant

Area

inertia

modulus

constant

(in.)

(psf)

(in.)

(in.2/ft)

(in.4/ft)

(in.3/ft)

(in.2/ft)

(in.2/ft)

(in.4/ft)

(in.3/ft)

(in.2/ft)

Sanded Panels

1/4-S

0.8

0.342

1.280

0.012

0.083

2.009

0.626

0.001

0.013

2.723

11/32-S

1.0

0.365

1.280

0.026

0.133

2.764

0.751

0.001

0.023

3.397

3/8-S

1.1

0.373

1.680

0.038

0.177

3.086

1.126

0.002

0.033

4.927

15/32-S

1.4

0.537

1.947

0.067

0.246

4.107

2.168

0.009

0.093

2.405

1/2-S

1.5

0.545

1.947

0.078

0.271

4.457

2.232

0.014

0.123

2.725

19/32-S

1.7

0.709

3.018

0.116

0.338

5.566

2.501

0.034

0.199

2.811

5/8-S

1.8

0.717

3.112

0.131

0.361

5.934

2.751

0.045

0.238

3.073

23/32-S

2.1

0.741

3.735

0.183

0.439

6.109

3.126

0.085

0.338

3.780

3/4-S

2.2

0.748

3.848

0.202

0.464

6.189

3.745

0.108

0.418

4.047

7/8-S

2.6

0.778

3.952

0.288

0.569

7.539

4.772

0.179

0.579

5.046

1-S

3.0

1.091

5.215

0.479

0.827

7.978

5.693

0.321

0.870

6.981

1-1/8-S

3.3

1.121

5.593

0.623

0.955

8.841

5.724

0.474

1.098

8.377

Touch-Sanded Panels

1/2-T

1.5

0.543

2.698

0.084

0.282

4.511

2.486

0.020

0.162

2.720

19/32- & 5/8-T

1.8

0.707

3.127

0.124

0.349

5.500

2.799

0.050

0.259

3.183

23/32- & 3/4-T

2.2

0.739

4.059

0.201

0.469

6.592

3.625

0.078

0.350

3.596

From Plywood Design Specification by The American Plywood Association 1997.

Table 3.14 Allowable Stresses for Plywood (psi)*

ALLOWABLE STRESSES FOR PLYWOOD (psi) conforming to Voluntary Product Standard PS 1-95 for Construction and Industrial Plywood. Stresses are based on normal duration of load, and on common structural applications where panels are 24" or greater in width. For other use conditions, see Section 3.3 for modifications.

Grade stress level(1)

Species group of

S-1

S-2

S-3

Type of stress

face ply

Wet

Dry

Wet

Dry

Dry only

EXTREME FIBER STRESS IN BENDING (F)

Fb

&

1

1430

2000

1190

1650

1650

TENSION IN PLANE OF PLIES (F)

2, 3

980

1400

820

1200

1200

Face Grain Parallel or Perpendicular to Span (At 45° to Face Grain Use 1/6 Ft)

Ft

4

940

1330

780

1110

1110

COMPRESSION IN PLANE OF PLIES

1

970

1640

900

1540

1540

2

730

1200

680

1100

1100

Parallel to Perpendicular to Face Grain

Fc

3

610

1060

580

990

990

(At 45° to Face Grain Use 1/3 Fc)

4

610

1000

580

950

950

SHEAR THROUGH THE THICKNESS®

1

155

190

155

190

160

Parallel or Perpendicular to Face Grain

Fv

2, 3

120

140

120

140

120

(At 45° to Face Grain Use 2 Fv)

4

110

130

110

130

115

ROLLING SHEAR (IN THE PLANE OF PLIES)

Fs

Marine & Structural I

63

75

63

75

Parallel or Perpendicular to Face Grain (At 45° to Face Grain Use 1-1/3 Fs)

All Other(2)

44

53

44

53

48

Type of stress

Species group of face ply

Grade stress level(1)

S-1

S-2

S-3

Wet

Dry

Wet

Dry

Dry only

MODULUS OR RIGIDITY

1

70,000

90,000

70,000

90,000

82,000

(OR SHEAR MODULUS)

2

60,000

75,000

60,000

75,000

68,000

Shear in Plane Perpendicular to Plies

G

3

50,000

60,000

50,000

60,000

55,000

(through the thickness)

4

45,000

50,000

45,000

50,000

45,000

(At 45° to Face Grain Use 4G)

BEARING (ON FACE)

1

210

340

210

340

340

Perpendicular to Plane of Plies

FC1

2, 3

135

210

135

210

210

4

105

160

105

160

160

MODULUS OF ELASTICITY IN

1

1,500,000

1,800,000

1,500,000

1,800,000

1,800,000

BENDING IN PLANE OF PLIES

2

1,300,000

1,500,000

1,300,000

1,500,000

1,500,000

E

3

1,100,000

1,200,000

1,000,000

1,200,000

1,200,000

For Grain Parallel or Perpendicular to Span

4

900,000

1,000,000

900,000

1,000,000

1,000,000

(1) See pages 12 and 13 for Guide.

To qualify for stress level S-1, gluelines must be exterior and veneer grades N, A, and C (natural, not repaired) are allowed in either face or back.

For stress level S-2, gluelines must be exterior and veneer grade B, C-Plugged and D are allowed on the face or back.

Stress level S-3 includes all panels with interior or intermediate (IMG) gluelines.

(2) Reduce stresses 25% for 3-layer (4- or 5-ply) panels over 5/8" thick. Such layups are possible under PS 1-95 for APA RATED SHEATHING, APA RATED STURD-I-FLOOR, UNDERPAYMENT, C-C Plugged and C-D Plugged grades over 5/8" through 3/4" thick.

(3) Shear-through-the-thickness stresses for MARINE and SPECIAL EXTERIOR grades may be increased 33%. See Section 3.8.1 for condi­tions under which stresses for other grades may be increased.

* Stresses are based on normal duration of load, and on common structural applications where panels are 24 in. or greater in width. From Plywood Design Specification by The American Plywood Association 1997.

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