Shearwalls

SDPWS / ASCE 7

Seismic Information

Allowable Design Categories

ASCE-7 Table 12.2-1, SDPWS 4.3.7.5

35 feet or less

Sets gypsum capacity to 0 for E, F

Allows A, B, C, D

Greater than 35 feet

Sets gypsum capacity to 0 for D, E, F

Allows A, B, C

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 2.0

2.0

R -building frames

Default 2.5

2.5

Deflection amplification factor C_d

Input in Site Dialog, Prompts to change upon load generation

ASCE-7 Table 12.2-1,

12.8.6

C_d - bearing walls

Default 2.0

2.0

C_d - building frames

Default 2.5

2.5

Overstrength Factor W₀*

Cannot be overriden

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

W₀ - bearing walls, rigid diaphragms

2.5

2.5

W₀ - building frames, rigid diaphragms

2.5

2.5

W₀ - bearing walls, flexible diaphragms

2.0

2.0 or 2.5

W₀ - building frames, flexible diaphragms

2.0

2.0 or 2.5

*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 4.3.3.4.1

Deflection-based distribution

Allowed

Allowed

Capacity-based distribution

Contribution of gypsum ignored for seismic design

Not allowed

Aspect Ratio

= h/b, b_s = segment length, h = height, applies to wall segments or force-transfer piers. For more details see Aspect Ratio Limits and Factors.

Maximum aspect ratio

4.3.4, Table 4.3.4, Table 4.3.4 Note 21

Blocked

2:1

2:1

Unblocked

1.5:1

1.5:1

Shear Capacity Adjustments

ASD Reduction Factor*

Values in Table 4.3C divided by 2.0.

2.0 (Note 1 referring to 4.3.3)

Wind Increase Factor

None

None

Specific gravity factor

None

None

Aspect Ratio Factor

None

None

*The shear capacities shown below are those in Table 4.3C divided by 2.0.

Combination of Sheathing Capacities

For more details, refer to Combination of Sheathing Capacities,

Reference

SDPWS 4.3.3.3

Identical materials on both sides, seismic or wind

Add capacities

Add capacities

With gypsum-based material with different specs on other side, wind

V_wc =K_min G_ac

No guidance

With gypsum-based material with different specs on other side, seismic

V_sc =K_min G_ac

V_sc =K_min G_ac

With non-gypsum on other side, seismic

twice weakest or strongest

twice weakest or strongest

With lumber sheathing or fiberboard on other side, wind

twice weakest or strongest

twice weakest or strongest

With wood structural panels on other side, wind

Add capacities

Add capacities

Bending Resistance

Gypsum materials have no resistance to out-of-plane wind loads. If used on an exterior surface, no C&C loads should be applied to that building face.

Gypsum Wall Panels

Gypsum wallboard

Reference

Table 4.3C

Construction

Thickness

½”, 5/8”

½” or 5/8”

No. of Plies – ½”

1

1 only

No. of Plies – 5/8”

1 or 2

1 or 2

Blocking - ½”

Either

Either

Blocking - 1 ply 5/8”

Either

Either

Blocking - 2 ply 5/8”

Blocked

Blocked

Stud Spacing

½” , nails, unblocked

12,16,24”

16” ,24”

½” , nails, blocked

12,16”

16”

5/8” ,nails, unblocked

12,16,24”

24”

5/8”, nails, blocked

12,16”

16”

5/8”, 2 ply blocked

12,16”

16”

½”, Screws, 8” field, block

Not included

Doesn’t say

All other screws

Not included

16”

½”, Screws, 4,7 sp unblocked

16”,24”

16” ,24”

½”, Screws, 4/12 sp blocked

16, 24”

24”

5/8”, Screws, 4,7 sp unblocked

16,24”

24”

All Other screws

16"

16"

Fastener Types and Sizes

Cooler Nail (1/2”)

5d

5d

Cooler nail (5/8”)

6d

6d

Cooler nail – base ply

6d

6d

Cooler nail – face ply

6d,8d

8d

.120 nail (1/2”)

Not included

1.5”

.120 nail (5/8”)

Not included

1.75”

.120 nail - base ply

Not included

1.75”

.120 nail - face ply

Not included

2.375

Screw (1/2”)

#6 1 ¼”

#6 1 ¼”

Screw (5/8”)

#6 1 ¼”

#6 1 ¼”

Screw – 2 ply

Not included

Not included

Wallboard nail (1/2”)

Incl. as "5d Cooler/GWB nail"

0.086” x 1-5/8”

Wallboard nail (5/8”)

Incl. as "6d Cooler/GWB nail"

.0915” x 1-7/8”

Wallboard nail – base ply

Incl. as "6d Cooler/GWB nail"

.0915” x 1-7/8”

Wallboard nail – face ply

Incl. as "6d Cooler/GWB nail"

0.113" x 2-3/8”

Fastener Spacing

Edge – Nails – ½”

4 or 7

4 or 7

Field – Nails – ½”

4 or 7

Doesn’t say

Edge Nails – 5/8” unbl.

4 or 7

4 or 7

Field Nails – 5/8 unbl

4 or 7

Doesn’t say

Edge Nails – 5/8” blck.

4 or 7

4 or 7

Field Nails – 5/8 blck

4 or 7

Doesn’t say

Edge – Nails – 2 ply 5/8”

9b / 7f

7 face 9 base

Field – Nails – 2 ply 5/8”

9b / 7f

Doesn’t say

Edge – screws unblock

8

8

Edge, screws ½” blocked

4,6,8

4,6,8

Edge – screws 5/8”

8

8

Field – screws 5/8”

12

12

Field, screws ½” blocked

12,16

12,16

Field – screws unblock

12

12

Shear resistance

½”, 4” nail sp, unb 24”

110

110*

½”, 7” nail sp, unb 24”

75

75*

½”, 4” nail sp, unb 16”

125

125*

½”, 7” nail sp, unb 16”

100

100*

½”, 4” nail sp, blk 16”

150

150*

½”, 7” nail sp, blk 16”

125

125*

5/8”, 4” nail sp, unb 24”

145

145*

5/8”, 7” nail sp, unb 24”

115

115*

5/8”, 4” nail sp, blk 16”

175

175*

5/8”, 7” nail sp, blk 16”

145

145*

5/8” 2 ply nail

250

250

½”, 8/12” screw sp, unb

60

60

½”, 4/12” screw sp, blk

155

155

½”, 6/12” screw sp, blk

90

90

½”, 8/12” screw sp, blk

70

70

½”, 4/16” screw sp, blk

160

160

5/8”, screw 8”/12” unblock

70

70

5/8”, screw, 8”/12” blocked

90

90

*The shear capacities shown here are those in Table 4.3C divided by the 2.0 ASD factor from 4.3.3

Gypsum Sheathing

Reference

Table 4.3C

Sheathing Sizes

Thickness

½” or 5/8”

½” or 5/8”

Widths

2’ or 4’

2’ or 4’

Blocking

½” x 2’

Unblocked

Unblocked

½” x 4’

Either

Either

5/8” x 4’

Blocked

Blocked

Stud Spacing

½ x 4’ Blocked

12,16,24”

24” max

All other

12,16”

16” max

Fastener Types

Galvanized nail (1/2" sheathing”)

11 ga, 1-3/4"

.120” x 1¾”

"Nail" (5/8” sheathing)

11 ga, 1-3/4"

.120” x 1¾”

Galvanized cooler nail (5/8” sheathing )

Not included

6d, .092” x 1-7/8”

Wallboard Nail (5/8” sheathing)

Not included

.0915 x 1-7/8”

Fastener Spacing

Edge – ½ x 2’

4

4

Edge – ½ x 4’ , blocked

4

4

Edge – ½ x 4’ unblocked

7

7

Edge – 5/8 x 4’

4

4

Field – ½ x 2’

4

Doesn't say

Field – ½ x 4’ blocked

4

Doesn’t say

Field – ½ x 4’ unblocked

7

Doesn’t say

Field – 5/8 x 4’

7

7

Shear Resistance

½” x 2’

75

75

½” x 4’ blocked

75

175

½” x 4’ unblocked

100

100

5/8” x 4’

200

200

Lath and Plaster

Wire lath and plaster

Shearwalls

SDPWS

Reference

T4.3C

Thickness

7/8”

7/8”

Blocking

Unblocked

Unblocked

Stud Spacing

12”,16”

16”

Fastener Types

Staple

Not included

None

Nail

Not included

.120” 1.5” long

Fastener spacing

Edge nail spacing

6”

6”

Field nail spacing

6”

Doesn’t say

Shear Resistance

180

180

Gypsum lath

Important Note - Shearwalls does not implement Gypsum lath with vertical joints staggered

General Reference

T 4.3B

Construction

Thickness

7/8”

7/8”

Blocking

Unblocked

Unblocked

Stud Spacing

12,16”

16”

Fastener Types

Plasterboard Nail

13 ga, 1-1/8”

Not included

GWB blued nail

Not included

0.092” x 1-1/8”

Other nails

Not included

0.120" x 1-1/4"

Fastener spacing

Edge nail spacing

5”

5”

Field nail spacing

5”

Doesn’t say

Shear Resistance

Vertical Joints Staggered

not included

180

Vertical Joints not staggered

100

100