2305 General Design Requirements for Lateral Force-Resisting Systems — 2025 California Building Code
California Building Code (Title 24, Part 2) · 2025 edition · updated 2026-09-25 · California
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Italicized text is a California amendment to the model code, as printed in the official publication.
Cite as: 2025 California Building Code (Title 24, Part 2) § 2305 · Effective January 1, 2026 · Official source: Building Standards Commission
2305.1 General.¶
Structures using wood shear walls or wood diaphragms to resist wind or seismic loads shall be designed and constructed in accordance with AWC SDPWS and the applicable provisions of Sections 2305, 2306 and 2307.
2305.1.1 Openings in shear panels. Openings in shear panels that materially affect their strength shall be detailed on the plans and shall have their edges adequately reinforced to transfer all shearing stresses.
2305.1.2 Permanent load duration. Permanent loads are associated with permanent load duration in accordance with the ANSI/AWC NDS. For wood shear walls and wood diaphragms designed to resist lateral loads of permanent load duration only and that are not in combination with wind or seismic lateral loads, the design unit shear capacities shall be taken as the AWC SDPWS nominal unit shear capacities, multiplied by 0.2 for use with allowable stress design in Section 2306 and 0.3 for use with load and resistance factor design in Section 2307.
2305.1.3 Additional requirements. [DSA-SS, DSA-SS/CC, OSHPD 1, 1R, 2, 4 & 5] See Section 2301.1.5 for modifications to AWC SDPWS.
2305.2 Diaphragm deflection.¶
The deflection of wood-frame diaphragms shall be determined in accordance with AWC SDPWS. The deflection (Δ dia ) of a blocked wood structural panel diaphragm uniformly fastened throughout with staples is permitted to be calculated in accordance with Equation 23-1. If not uniformly fastened, the constant 0.188 (For SI: 1/1627) in the third term shall be modified by an approved method. Equation 23-1 Δ dia = 5 vL 3/8 EAW + vL /4 Gt + 0.188 Le n + Σ( x Δ c )/2 W For SI: Δ dia = 0.052 vL [3] / EAW + vL /4 Gt + Le n /1627 + Σ( x Δ c )/2 W
where:
A = Area of chord cross section, in square inches (mm [2] ). E = Modulus of elasticity of diaphragm chords, in pounds per square inch (N/mm [2] ).
e n = Staple slip, in inches (mm) [see Table 2305.2(1)].
Gt = Panel rigidity through the thickness, in pounds per inch (N/mm) of panel width or depth [see Table 2305.2(2)].
L = Diaphragm length (dimension perpendicular to the direction of the applied load), in feet (mm).
v = Induced unit shear in pounds per linear foot (plf) (N/mm).
W = Diaphragm width [in the direction of applied force, in feet (mm)].
x = Distance from chord splice to nearest support, in feet (mm).
Δ c = Diaphragm chord splice slip at the induced unit shear, in inches (mm). Δ dia = Maximum mid-span diaphragm deflection determined by elastic analysis, in inches (mm).
WOOD
TABLE 2305.2(1)—e VALUES (inches) FOR USE IN CALCULATING
n
DIAPHRAGM AND SHEAR WALL DEFLECTION DUE TO FASTENER SLIP (Structural I)a, c
| LOAD PER FASTENERb (pounds) | FASTENER DESIGNATIONS |
|---|---|
| LOAD PER FASTENERb (pounds) | 14-Ga staple × 2 inches long |
| 60 | 0.011 |
| 80 | 0.018 |
| 100 | 0.028 |
| 120 | 0.04 |
| 140 | 0.053 |
| 160 | 0.068 |
| For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound = 4.448 N. a. Increase_en_ values 20 percent for plywood grades other than Structural I. b. Load per fastener = maximum shear per foot divided by the number of fasteners per foot at interior panel edges. c. Decrease_en_ values 50 percent for seasoned lumber (moisture content < 19 percent). |
TABLE 2305.2(2)—VALUES OF Gt FOR USE IN CALCULATING
DEFLECTION OF WOOD STRUCTURAL PANEL SHEAR WALLS AND DIAPHRAGMS
| PANEL TYPE |
SPAN RATING |
VALUES OFGt (lb/ |
VALUES OFGt (lb/ |
VALUES OFGt (lb/ |
VALUES OFGt (lb/ |
VALUES OFGt (lb/ |
VALUES OFGt (lb/ |
VALUES OFGt (lb/ |
VALUES OFGt (lb/ |
|---|---|---|---|---|---|---|---|---|---|
| PANEL TYPE |
SPAN RATING |
Structural Sheathing | Structural Sheathing | Structural Sheathing | Structural Sheathing | Structural I | Structural I | Structural I | Structural I |
| PANEL TYPE |
SPAN RATING |
Plywood | Plywood | Plywood | OSB | Plywood | Plywood | Plywood | OSB |
| PANEL TYPE |
SPAN RATING |
3-ply | 4-ply | 5-plya | 5-plya | 3-ply | 4-ply | 5-plya | 5-plya |
| Sheathing | 24/0 | 25,000 | 32,500 | 37,500 | 77,500 | 32,500 | 42,500 | 41,500 | 77,500 |
| Sheathing | 24/16 | 27,000 | 35,000 | 40,500 | 83,500 | 35,000 | 45,500 | 44,500 | 83,500 |
| Sheathing | 32/16 | 27,000 | 35,000 | 40,500 | 83,500 | 35,000 | 45,500 | 44,500 | 83,500 |
| Sheathing | 40/20 | 28,500 | 37,000 | 43,000 | 88,500 | 37,000 | 48,000 | 47,500 | 88,500 |
| Sheathing | 48/24 | 31,000 | 40,500 | 46,500 | 96,000 | 40,500 | 52,500 | 51,000 | 96,000 |
| Single Floor |
16 o.c. | 27,000 | 35,000 | 40,500 | 83,500 | 35,000 | 45,500 | 44,500 | 83,500 |
| Single Floor |
20 o.c. | 28,000 | 36,500 | 42,000 | 87,000 | 36,500 | 47,500 | 46,000 | 87,000 |
| Single Floor |
24 o.c. | 30,000 | 39,000 | 45,000 | 93,000 | 39,000 | 50,500 | 49,500 | 93,000 |
| Single Floor |
32 o.c. | 36,000 | 47,000 | 54,000 | 110,000 | 47,000 | 61,000 | 59,500 | 110,000 |
| Single Floor |
48 o.c. | 50,500 | 65,500 | 76,000 | 155,000 | 65,500 | 85,000 | 83,500 | 155,000 |
| Structural Sheathing | Structural I | ||||||
|---|---|---|---|---|---|---|---|
| Thickness (in.) |
A-A, A-C | Marine | All Other Grades |
A-A, A-C | Marine | All Other Grades |
|
| Sanded Plywood |
1/4 | 24,000 | 31,000 | 24,000 | 31,000 | 31,000 | 31,000 |
| Sanded Plywood |
11/32 | 25,500 | 33,000 | 25,500 | 33,000 | 33,000 | 33,000 |
| Sanded Plywood |
3/8 | 26,000 | 34,000 | 26,000 | 34,000 | 34,000 | 34,000 |
| Sanded Plywood |
15/32 | 38,000 | 49,500 | 38,000 | 49,500 | 49,500 | 49,500 |
| Sanded Plywood |
1/2 | 38,500 | 50,000 | 38,500 | 50,000 | 50,000 | 50,000 |
| Sanded Plywood |
19/32 | 49,000 | 63,500 | 49,000 | 63,500 | 63,500 | 63,500 |
| Sanded Plywood |
5/8 | 49,500 | 64,500 | 49,500 | 64,500 | 64,500 | 64,500 |
| Sanded Plywood— continued |
23/32 | 50,500 | 65,500 | 50,500 | 65,500 | 65,500 | 65,500 |
| Sanded Plywood— continued |
3/4 | 51,000 | 66,500 | 51,000 | 66,500 | 66,500 | 66,500 |
| Sanded Plywood— continued |
7/8 | 52,500 | 68,500 | 52,500 | 68,500 | 68,500 | 68,500 |
| Sanded Plywood— continued |
1 | 73,500 | 95,500 | 73,500 | 95,500 | 95,500 | 95,500 |
| Sanded Plywood— continued |
11/8 | 75,000 | 97,500 | 75,000 | 97,500 | 97,500 | 97,500 |
| For SI: 1 inch = 25.4 mm, 1 pound/ a. 5-ply applies to plywood with five or more layers. For 5-ply plywood with three layers, use values for 4-ply panels. |
23-26 2025 CALIFORNIA BUILDING CODE
WOOD
2305.3 Shear wall deflection.¶
The deflection of wood-frame shear walls shall be determined in accordance with AWC SDPWS. The deflection (Δ sw ) of a blocked wood structural panel shear wall uniformly fastened throughout with staples is permitted to be calculated in accordance with Equation 23-2. Equation 23-2 Δ sw = 8 vh [3] / EAb + vh /4 Gt + 0.75 he n + d a h / b
For SI:
Δ sw = vh 3 3EAb⁄ + vh Gt⁄ + -----------407.6 he n - + d a h b⁄
where:
A = Area of end-post cross section in square inches (mm [2] ).
b = Shear wall length, in feet (mm).
d a = Total vertical elongation of wall anchorage system (such as fastener slip, device elongation, rod elongation) in inches (mm), at the induced unit shear in the shear wall ( v ).
E = Modulus of elasticity of end posts, in pounds per square inch (N/mm [2] ).
e n = Staple slip, in inches (mm) [see Table 2305.2(1)].
Gt = Panel rigidity through the thickness, in pounds per inch (N/mm) of panel width or depth [see Table 2305.2(2)].
h = Shear wall height, in feet (mm).
v = Induced unit shear, in pounds per linear foot (N/mm).
Δ sw = Maximum shear wall deflection determined by elastic analysis, in inches (mm).
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