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Wood Structural Panel Provisions

The table below lists the design code provisions applicable to design for wood structural panel sheathing from the AWC Special Design Provisions for Wind and Seismic (SDPWS) and the ASCE 7. One column is for the design code provision, the other is for the implementation in Shearwalls; in most cases they are the same.

Wood structural panels include the Structural Sheathing, Structural 1, and Plywood Siding materials. They are made of plywood or OSB, which is specified by a check box in Wall Input view. Design properties are identical for plywood and OSB; some parameters affecting deflection are influenced by the choice.

For some provisions, more detailed information is found in a table dedicated to the provision in another topic that is cross-referenced in this table.

Wood Structural Panels

 

Shearwalls

SDPWS / ASCE 7

Main References: SDPWS 4.3.7.1, SDPWS Tables 4.3A and 4.3B

Wall Construction

(for more details, see Wall Construction )

References

 

4.3.7.1. Table 4.3A, Table 4.3.5.3*, Table 3.2.1

Sud Spacing shear

12",16",19.2", 24"

Max 24”

Max stud spacing bending

12,16, 24

Table 3.2.1

Stud Thickness, nominal

Default 2"

2”

Orientation - shear

Horizontal or Vertical

Both - 4.3.7.1 (1)

Orientation - bending

Horizontal or Vertical

Both - Table 3.2.1 A

Blocking

Blocked or Unblocked

Blocked or Unblocked

Surface

Either or both

Either or both

Height Limitation

 

4.3.5.3, 4.3.2.3.(8.)

Unblocked walls

16'

16'

Perforated walls

Not applied

20'

Gypsum underneath

Allowed

Yes

 

* 19.2 stud spacing included for 20" option in Unblocked Adjustment Factor table 4.3.5.3

Sheathing Thickness and Type

Plywood shear

 

Table 4.3A,

All materials

5/16, 3/8

5/16, 3/8

Structural I and Plywood sheathing

also 7/16,15/32,

also 7/16, 15/32

Plywood sheathing

also 19/32

also 19/32

Plywood siding

5/16, 3/8 only

5/16, 3/8 only

 

 

 

Plywood Bending

-

Table 3.2.1

Plywood sheathing

5/16*,3/8,7/16,15/32,19/32, 23/32

3/8,7/16,15/32, 19/32, 23/32

Plywood siding

5/16, 3/8

Doesn't say

*5/16 values taken from the Wood Frame Construction Manual.

 

Fastener Types and Sizes

(for more details, see Table for Fastener type and lengths)

Common nail

6d,8d,10d,12d*

6d,8d,10d

Box nail

6d,8d,10d,12d*

6d,8d,10d

Galvanised casing

6d,8d

6d,8d

*12d size included for nail withdrawal calculations

 

Fastener spacing

(for more details, see Table for Fastener spacing)

Edge spacing

2,3,4,6”

2,3,4,6”

Intermediate Spacing

2,4,6,8,10,12”*

6” or 12” max

*Lower than maximum intermediate spacing values are provided for nail withdrawal resistance

 

Seismic Information

Allowable Design Categories

 

ASCE-7 Table 12.2-1,

65 Feet or less

Allows all

Allows all

Greater than 65 feet

Screen warning for D, E, F

Disallows D, E, F

 

 

 

Framing detail:

For capacity >350 on either side

Note 1 in Framing Materials Table

4.3.7.1(5.c)

Applicable zones

D,E,F

D,E,F

 

 

 

Response modification factor R

Input in Site Dialog, Prompts to change upon load generation

ASCE-7 Table 12.2-1, 12.8.1.1

R - bearing walls

Default 6.5

6.5

R - building frames

Default 7.0

7.0

Deflection amplification factor Cd

Input in Site Dialog, Prompts to change upon load generation

ASCE-7 Table 12.2-1,

12.8.6

Cd - bearing walls

Default 4.0

4.0

Cd - building frames

Default 4.5

4.5

Overstrength Factor W0 *

Cannot be overriden

ASCE-7 Table 12.2-1, inc. note b; 12.10.1.1.

W0- bearing walls, rigid diaphragms

3.0

2.5

W0- building frames, rigid diaphragms

4.5

4.5

W0 - bearing walls, flexible diaphragms

4.0

4.0 or 4.5

W0 - building frames, flexible diaphragms

3.5

3.5 or 4.0

*for drag strut force from discontinuous shear lines above, only

 

Permissible Force Distribution Method

Refer to Shear Force Distribution Methods for more a description of these methods and how they are selected.

Reference

 

SDPWS 4.3.5.5.1 , inc. Exception 1

Deflection-based distribution

Allowed, no reduction applied

Allowed

Capacity-based distribution

Allowed, but more stringent aspect ratio adjustment applied

Allowed with more stringent aspect ratio adjustment

 

Aspect Ratios and Capacity Adjustment

Aspect ratio = h/b; b = segment length, h =height. Applies to wall segments or FTAO piers.

( For more details see Aspect Ratio Limits and Factors )

Maximum aspect ratio

Aspect ratio shown in Elevation view and in Wall and Shearline output table

SDPWS 4.3.3, Table 4.3.3

Blocked, unadjusted

3.5:1

3.5:1

Blocked, adjusted

2:1

2:1

Unblocked

2:1

2:1

Shear Capacity Adjustment

Shown in Shear Design Results. If not 1.0, shown in Elevation view.

 

Segmented or FTAO walls*

 

SDPWS 4.3.3.2, 4.3.5.5.1 Exception 1.

Capacity-based force distribution

2b/h

2b/h

Deflection-based distribution

1.25 - 0.125 h/b

1.25 - 0.125 h/b

Perforated walls

 

SDPWS 4.3.5.6, 4.3.3.4, Eqn. 4.3-5

 

Sbi /Sb; bi = 2b/h when h/b > 2

Sbi /Sb; bi = 2b/h when h/b > 2

*Applies to blocked shear wall segments with aspect ratio between 2 and 3.5.

 

Shear Capacity Adjustments and Notes

The following factors and adjustments are applied to nominal shear capacities vn

Reference

Notes under Sheathing Materials Table

SDPWS Table 4.3A Notes, 4.3.7.1 , 4.3.3

increase 3/8, 7/16 to values for 15/32 for spacing >= 16" and horizontal orientation

Note 3

Note 2

3” framing, staggered nails for certain conditions

Note 2

4.3.7.1 (5)

Specific Gravity (G) factor

1 - ( 0.5 - G)

1 - ( 0.5 - G)

Note for specific gravity factor

Note 1

Note 3:

ASD Reduction Factor

Incorporated into design values

SDPWS 4.1.4

Wind design

2.0

2.0

Seismic design

2.8

2.8

Note for ASD Factor

No note

Note 1 referring to 4.1.4

Unblocked Factor*

Shown in Shear Design Results table for each wall

4.3.5.3, Table 4.3.5.3, Eqn. 4.3.2.

Stud spacings, inches

12, 16, 19.2, 24

12, 16, 20, 24

6" intermediate nail spacing

1.0, 0.8, 0.6, 0.5

1.0, 0.8, 0.6,0.5

12" intermediate nail spacing

0.8, 0.6, 0.5, 0.4

0.8, 0.6, 0.5, 0.4

*In addition to the factor, the shear capacity used is that for 6" edge spacing regardless of the nail spacing.

Hold-downs with 10d Nails**

0.92

0.92

Note for 10d / Hold-down

Note 7

Note 10

**Factor always applied on assumption that hold-downs are always required (doesn't take into account situations where dead load greater than shear uplift). Does not apply to walls with gypsum underlay, as note is not in Table 4.3B.

Perforated Wall Factor Co

Refer to Shear Capacity Adjustment

Aspect Ratio Factor

See section above this one

See above section

 

Gypsum Underlay

Allowed

Table 4.3B

 

Combination of Sheathing Capacities

For more details, refer to Combination of Sheathing Capacities,

Reference

 

SDPWS 4.3.5.4, 4.3.5.4.2 Exception

Identical materials on both sides

Add capacities

Add capacities

With wood structural panels with different specs on other side, same blocking

Vwc=Kmin Gac

Vsc =Kmin Gac

With non-wood-structural panels on other side, seismic

Twice weakest or strongest

Twice weakest or strongest

Blocked WSP on one side, unblocked WSP on the other

Twice weakest or strongest

Twice weakest or strongest

With lumber siding, fiberboard or lath/plaster on other side, wind

Twice weakest or strongest

Ttwice weakest or strongest

With gypsum wallboard or gypsum sheathing board on other side, wind

Add capacities

Add capacities*

Twice weakest or strongest: vn(c) = max ( 2 x min ( vn(1) ,vn(2)) , max( vn(1),vn(2) ) )

*SDPWS refers only to gypsum wallboard (GWB), not gypsum sheathing board (GSB), but WoodWorks interprets the intention of the provision to include GSB

 

Combination of Apparent Stiffness Ga

For more details, refer to Combination of Sheathing Stiffness

Reference

 

SDPWS 4.3.5.4

Identical materials on both sides

Add stiffnesses

Add stiffnesses

With wood structural panels with different specs on other side, same blocking

Add stiffnesses

Add stiffnesses

With non-wood-structural panels on other side

Twice side with weakest capacity or side with strongest cap.

Twice side with weakest capacity or side with strongest

With blocked WSP on one side and unblocked WSP on the other

Twice side with weakest capacity or side with strongest cap.

Twice side with weakest capacity or side with strongest

Twice weakest capacity or side with strongest cap: Ga(c) = max (2 x Ga (min ( vn(1) ,vn(2))) , Ga (max( vn(1),vn(2) )))

 

Bending Resistance

Reference

 

SDPWS Table 3.2.1

5/16” thickness

Uses WFCM

Not included

All other sizes, spacings

Uses SDPWS

From Table 3.2.1

 

Shear Capacity

Wood Structural Panels - Structural I

 

 

Shearwalls

SDPWS Table 4.3A

Panel Thick.

Nail Size

Panel Edge Nail Spacing

Panel Edge Nail Spacing

 

 

6

4

3

2

6

4

3

2

 

 

Wind

Seis

Wind

Seis

Wind

Seis

Wind

Seis

Unfactored by ASD Factor

5/16

6d

280

200

420

300

545

389.3

715

510.7

560

840

1090

1430

3/8

8d

322.5

230.4

505

360.7

645

460.7

855

610.7

645

1010

1290

1710

7/16

8d

357.5

255.4

552.5

394.6

707.5

505.4

937.5

669.6

715

1105

1415

1875

15/32

8d

392.5

280.4

602.5

430.4

770

550

1022.5

730.4

785

1205

1540

2045

15/32

10d

475

339.3

715

510.7

930

664.3

1217.5

869.6

950

1430

1860

2435

Wood Structural Panels - Structural Sheathing

 

 

Shearwalls

SDPWS Table 4.3A

Panel Thick.

Nail Size

Panel Edge Nail Spacing

Panel Edge Nail Spacing

 

 

6

4

3

2

6

4

3

2

 

 

Wind

Seis

Wind

Seis

Wind

Seis

Wind

Seis

Unfactored by ASD Factor

5/16

6d

252.5

180.4

377.5

269.6

490

350

630

450

505

755

980

1260

3/8

6d

280

200

420

300

545

389.3

715

510.7

560

840

1090

1430

3/8

8d

307.5

219.6

447.5

319.6

575

410.7

742.5

530.4

615

895

1150

1485

7/16

8d

335

239.3

490

350

630

450

820

585.7

670

980

1260

1640

15/32

8d

365

260.7

532.5

380.4

685

489.3

895

639.3

730

1065

1370

1790

15/32

10d

435

310.7

645

460.7

840

600

1077.5

769.6

870

1290

1680

2155

19/32

10d

475

339.3

715

510.7

930

664.3

1217.5

869.6

950

1430

1860

2435

Wood Structural Panels - Plywood Siding

 

 

Shearwalls

SDPWS Table 4.3A

Panel Thick.

Nail Size

Panel Edge Nail Spacing

Panel Edge Nail Spacing

 

 

6

4

3

2

6

4

3

2

 

 

Wind

Seis

Wind

Seis

Wind

Seis

Wind

Seis

Unfactored by ASD Factor

5/16

6d

195

139.3

295

210.7

385

275

505

360.7

390

590

770

1010

3/8

8d

225

160.7

335

239.3

435

310.7

575

410.7

450

670

870

1150

See Also

Provisions by Sheathing Material Type

Gypsum Provisions

Fibreboard Provisions

Lumber Siding Provisions

Gypsum Underlay