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Chapter 23 — WOOD

Section 2305

California Building Code (Title 24, Part 2) · 2022 edition · updated 2026-09-12 · California

Italicized text is a California amendment to the model code, as printed in the official publication.

GENERAL DESIGN REQUIREMENTS FOR

LATERAL FORCE-RESISTING SYSTEMS

2305.1 General.

Structures using wood-frame shear walls or wood-frame diaphragms to resist wind, seismic or other lateral 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 Additional requirements. [DSA-SS, DSA-SS/CC and OSHPD 1, 1R, 2, 4 & 5] See Section 2301.1.4 for modifications to AWC SDPWS.

2305.2 Diaphragm deflection.

The deflection of woodframe diaphragms shall be determined in accordance with AWC SDPWS. The deflection (Δdia) 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.

Δdia = 5 vL 3 /8 EAW + vL /4 Gt + 0.188 Len + Σ(xΔ c )/2 W

(Equation 23-1)

For SI: Δdia = 0.052 vL 3 / EAW + vL /4 Gt + Len /1627 + Σ(xΔ 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 ). en = 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).

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).

2305.3 Shear wall deflection.

The deflection of woodframe shear walls shall be determined in accordance with AWC SDPWS. The deflection (Δsw) of a blocked wood structural panel shear wall uniformly fastened throughout with staples is permitted to be calculated in accordance with Equation 23-2.

Δ sw = 8 vh 3 / EAb + vh /4 Gt + 0.75 hen + dah/b (Equation 23-2)

hen

For SI: Δ sw = vh 3 ⁄ 3 EAb + vh ⁄ Gt + ----------- - + dah ⁄ b

407.6

where:

A = Area of end-post cross section in square inches (mm 2 ).

b = Shear wall length, in feet (mm).

da = 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 ).

en = 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).

Copyright © 2022 by, or licensed to, International Code Council, Inc. (ALL RIGHTS RESERVED); licensed to California Building Standards Commission pursuant to License Agreement. No further reproductions is authorized. Any unauthorized reproduction or distribution is a violation of the federal copyright act and the license agreement, and subject to civil and criminal penalties thereunder.

WOOD

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 OF Gt (lb/in. panel depth or width)
PANEL TYPE SPAN
RATING		 SPAN
RATING		 Structural Sheathing Structural Sheathing Structural Sheathing Structural Sheathing Structural Sheathing Structural Sheathing Structural I Structural I Structural I Structural I Structural I Structural I Structural I
PANEL TYPE SPAN
RATING		 SPAN
RATING		 Plywood Plywood Plywood Plywood Plywood OSB Plywood Plywood Plywood Plywood Plywood Plywood OSB
PANEL TYPE SPAN
RATING		 SPAN
RATING		 3-ply 3-ply 4-ply 4-ply 5-plya 5-plya 3-ply 3-ply 4-ply 4-ply 5-plya 5-plya 5-plya
Sheathing 24/0 24/0 25,000 25,000 32,500 32,500 37,500 77,500 32,500 32,500 42,500 42,500 41,500 41,500 77,500
Sheathing 24/16 24/16 27,000 27,000 35,000 35,000 40,500 83,500 35,000 35,000 45,500 45,500 44,500 44,500 83,500
Sheathing 32/16 32/16 27,000 27,000 35,000 35,000 40,500 83,500 35,000 35,000 45,500 45,500 44,500 44,500 83,500
Sheathing 40/20 40/20 28,500 28,500 37,000 37,000 43,000 88,500 37,000 37,000 48,000 48,000 47,500 47,500 88,500
Sheathing 48/24 48/24 31,000 31,000 40,500 40,500 46,500 96,000 40,500 40,500 52,500 52,500 51,000 51,000 96,000
Single Floor 16 o.c. 16 o.c. 27,000 27,000 35,000 35,000 40,500 83,500 35,000 35,000 45,500 45,500 44,500 44,500 83,500
Single Floor 20 o.c. 20 o.c. 28,000 28,000 36,500 36,500 42,000 87,000 36,500 36,500 47,500 47,500 46,000 46,000 87,000
Single Floor 24 o.c. 24 o.c. 30,000 30,000 39,000 39,000 45,000 93,000 39,000 39,000 50,500 50,500 49,500 49,500 93,000
Single Floor 32 o.c. 32 o.c. 36,000 36,000 47,000 47,000 54,000 110,000 47,000 47,000 61,000 61,000 59,500 59,500 110,000
Single Floor 48 o.c. 48 o.c. 50,500 50,500 65,500 65,500 76,000 155,000 65,500 65,500 85,000 85,000 83,500 83,500 155,000
Structural Sheathing Structural Sheathing Structural Sheathing Structural Sheathing Structural Sheathing Structural Sheathing Structural I Structural I Structural I Structural I Structural I Structural I
Thickness (in.) Thickness (in.) A-A, A-C A-A, A-C Marine Marine All Other Grades All Other Grades A-A, A-C A-A, A-C Marine Marine All Other Grades All Other Grades
Sanded Ply-
wood		 Sanded Ply-
wood		 1/4 1/4 24,000 24,000 31,000 31,000 24,000 24,000 31,000 31,000 31,000 31,000 31,000 31,000
Sanded Ply-
wood		 Sanded Ply-
wood		 11/32 11/32 25,500 25,500 33,000 33,000 25,500 25,500 33,000 33,000 33,000 33,000 33,000 33,000
Sanded Ply-
wood		 Sanded Ply-
wood		 3/8 3/8 26,000 26,000 34,000 34,000 26,000 26,000 34,000 34,000 34,000 34,000 34,000 34,000
Sanded Ply-
wood		 Sanded Ply-
wood		 15/32 15/32 38,000 38,000 49,500 49,500 38,000 38,000 49,500 49,500 49,500 49,500 49,500 49,500
Sanded Ply-
wood		 Sanded Ply-
wood		 1/2 1/2 38,500 38,500 50,000 50,000 38,500 38,500 50,000 50,000 50,000 50,000 50,000 50,000
Sanded Ply-
wood		 Sanded Ply-
wood		 19/32 19/32 49,000 49,000 63,500 63,500 49,000 49,000 63,500 63,500 63,500 63,500 63,500 63,500
Sanded Ply-
wood		 Sanded Ply-
wood		 5/8 5/8 49,500 49,500 64,500 64,500 49,500 49,500 64,500 64,500 64,500 64,500 64,500 64,500
Sanded Ply-
wood		 Sanded Ply-
wood		 23/32 23/32 50,500 50,500 65,500 65,500 50,500 50,500 65,500 65,500 65,500 65,500 65,500 65,500
Sanded Ply-
wood		 Sanded Ply-
wood		 3/4 3/4 51,000 51,000 66,500 66,500 51,000 51,000 66,500 66,500 66,500 66,500 66,500 66,500
Sanded Ply-
wood		 Sanded Ply-
wood		 7/8 7/8 52,500 52,500 68,500 68,500 52,500 52,500 68,500 68,500 68,500 68,500 68,500 68,500
Sanded Ply-
wood		 Sanded Ply-
wood		 1 1 73,500 73,500 95,500 95,500 73,500 73,500 95,500 95,500 95,500 95,500 95,500 95,500
Sanded Ply-
wood		 Sanded Ply-
wood		 11/8 11/8 75,000 75,000 97,500 97,500 75,000 75,000 97,500 97,500 97,500 97,500 97,500 97,500

For SI: 1 inch = 25.4 mm, 1 pound/inch = 0.1751 N/mm. a. 5-ply applies to plywood with five or more layers. For 5-ply plywood with three layers, use values for 4-ply panels.

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▸Contents — California Building Code (Title 24, Part 2)
California Building Code (Title 24, Part 2)
  1. Chapter 2 — DEFINITIONS AND ABBREVIATIONS
  2. Appendix G — FLOOD-RESISTANT
  3. Appendix L — EARTHQUAKE RECORDING
  4. Appendix M — TSUNAMI-GENERATED
  5. Appendix N — REPLICABLE
  6. Appendix O — PERFORMANCE-BASED
  7. Chapter 1 — SCOPE AND ADMINISTRATION
  8. Chapter 3 — OCCUPANCY CLASSIFICATION AND USE
  9. Chapter 4 — SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY A…
  10. Chapter 5 — GENERAL BUILDING HEIGHTS AND AREAS
  11. Chapter 6 — TYPES OF CONSTRUCTION
  12. Chapter 7 — FIRE AND SMOKE PROTECTION FEATURES
  13. Chapter 7A — MATERIALS AND CONSTRUCTION
  14. Chapter 8 — INTERIOR FINISHES
  15. Chapter 9 — FIRE PROTECTION AND LIFE SAFETY SYSTEMS
  16. Chapter 10 — MEANS OF EGRESS
  17. Chapter 11A — HOUSING ACCESSIBILITY
  18. Chapter 11B — ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMM…
  19. Chapter 12 — INTERIOR ENVIRONMENT
  20. Chapter 14 — EXTERIOR WALLS
  21. Chapter 15 — ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
  22. Chapter 16 — STRUCTURAL DESIGN
  23. Chapter 16A — STRUCTURAL DESIGN
  24. Chapter 17 — SPECIAL INSPECTIONS AND TESTS
  25. Chapter 18 — SOILS AND FOUNDATIONS
  26. Chapter 19 — CONCRETE
  27. Chapter 20 — ALUMINUM
  28. Chapter 21 — MASONRY
  29. Chapter 22 — STEEL
  30. ▸Chapter 23 — WOOD
    Overview
    1. Section 2301
    2. Section 2302
    3. Section 2303
    4. Section 2304
    5. Section 2305
    6. Section 2306
    7. Section 2307
    8. Section 2308
    9. Section 2309
  31. Chapter 24 — GLASS AND GLAZING
  32. Chapter 25 — GYPSUM BOARD, GYPSUM PANEL PRODUCTS AND PLASTER
  33. Chapter 26 — PLASTIC
  34. Chapter 27 — ELECTRICAL
  35. Chapter 28 — MECHANICAL SYSTEMS
  36. Chapter 30 — ELEVATORS AND CONVEYING SYSTEMS
  37. Chapter 31 — SPECIAL CONSTRUCTION
  38. Chapter 31B — PUBLIC POOLS
  39. Chapter 31C — RADIATION
  40. Chapter 31D — FOOD ESTABLISHMENTS
  41. Chapter 31F — MARINE OIL TERMINALS
  42. Chapter 32 — ENCROACHMENTS INTO THE PUBLIC RIGHT-OF-WAY
  43. Chapter 33 — SAFEGUARDS DURING CONSTRUCTION
  44. Chapter 35 — REFERENCED STANDARDS
  45. Appendix A — EMPLOYEE QUALIFICATIONS
  46. Appendix B — BOARD OF APPEALS
  47. Appendix C — GROUP U – AGRICULTURAL BUILDINGS
  48. Appendix D — FIRE DISTRICTS
  49. Appendix F — RODENTPROOFING
  50. Appendix H — SIGNS
  51. Appendix I — PATIO COVERS
  52. Appendix J — GRADING
  53. Appendix K — GROUP R-3 AND GROUP R-3.1 OCCUPANCIES
  54. Appendix P — EMERGENCY HOUSING

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