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Chapter 23 — WOOD

Section 2305

California Building Code (Title 24, Part 2) · 2019 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(xΔc)/2 W

(Equation 23-1)

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

W = Diaphragm width [in the direction of applied force,

in feet (mm)]. x = Distance from chord splice to nearest support, in

feet (mm). Δc = Diaprhagm chord splice slip at the induced unit

shear, in inches (mm).

For SI:

Copyright © 2019 ICC. ALL RIGHTS RESERVED. Accessed by Kevin Day (kevin.day@dgs.ca.gov), (California Building Standards Commission) Order Number #100735044 on Jul 24, 2019 03:54 PM (PDT) pursuant to License Agreement with ICC. No further reproduction or distribution authorized. Single user only, copying and networking prohibited. 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.

100735044

WOOD

TABLE 2305.2(2) VALUES OF Gt FOR USE IN CALCULATING DEFLECTION OF WOOD STRUCTURAL PANEL SHEAR WALLS AND DIAPHRAGMS

VALUES OF Gt (lb/in. panel depth or width)
PANEL SPAN Structural Structural ** Sheathing** Structural I
TYPE RATING 3-ply Plywood
4-ply		 Plywood
4-ply		 5-plya OSB 3-ply Plywood
4-ply
5-plya		 OSB
24/0 25,000 32,500 37,500 77,500 32,500 42,500
41,500		 77,500
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
40/20 28,500 37,000 43,000 88,500 37,000 48,000
47,500		 88,500
48/24 31,000 40,500 46,500 96,000 40,500 52,500
51,000		 96,000
16 o.c. 27,000 35,000 40,500 83,500 35,000 45,500
44,500		 83,500
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
32 o.c. 36,000 47,000 54,000 110,000 47,000 61,000
59,500		 110,000
48 o.c. 50,500 65,500 76,000 155,000 65,500 85,000
83,500		 155,000
Structural Sheathing Structural Sheathing Structural Sheathing Structural I
Thickness
(in.)		 Thickness
(in.)		 A-A,
A-C		 Marine All Other
Grades		 A-A,
A-C
Marine		 All Other
Grades
1/4 24,000 31,000 24,000 31,000
31,000		 31,000
31,000		 31,000
11/32 11/32 25,500 33,000 25,500 33,000
33,000		 33,000
33,000		 33,000
3/8 26,000 34,000 26,000 34,000
34,000		 34,000
34,000		 34,000
15/32 15/32 38,000 49,500 38,000 49,500
49,500		 49,500
49,500		 49,500
1/2 38,500 50,000 38,500 50,000
50,000		 50,000
50,000		 50,000
Sanded Plywood 19/32
5/8		 19/32
5/8		 49,000
49,500		 63,500
64,500		 49,000
49,500		 63,500
63,500
64,500
64,500		 63,500
63,500
64,500
64,500		 63,500
64,500
23/32 23/32 50,500 65,500 50,500 65,500
65,500		 65,500
65,500		 65,500
3/4 51,000 66,500 51,000 66,500
66,500		 66,500
66,500		 66,500
7/8 52,500 68,500 52,500 68,500
68,500		 68,500
68,500		 68,500
1 73,500 95,500 73,500 95,500
95,500		 95,500
95,500		 95,500
11/ 8 75,000 97,500 75,000 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. Chapter 1 — SCOPE AND ADMINISTRATION
  6. Chapter 3 — OCCUPANCY CLASSIFICATION AND USE
  7. Chapter 4 — SPECIAL DETAILED REQUIREMENTS BASED
  8. Chapter 5 — GENERAL BUILDING HEIGHTS AND AREAS
  9. Chapter 6 — TYPES OF CONSTRUCTION
  10. Chapter 7 — FIRE AND SMOKE PROTECTION FEATURES
  11. Chapter 7A — MATERIALS AND CONSTRUCTION
  12. Chapter 8 — INTERIOR FINISHES
  13. Chapter 9 — FIRE PROTECTION AND LIFE SAFETY SYSTEMS
  14. Chapter 10 — MEANS OF EGRESS
  15. Chapter 11A — HOUSING ACCESSIBILITY
  16. Chapter 11B — ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMM…
  17. Chapter 12 — INTERIOR ENVIRONMENT
  18. Chapter 14 — EXTERIOR WALLS
  19. Chapter 15 — ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
  20. Chapter 16 — STRUCTURAL DESIGN
  21. Chapter 16A — STRUCTURAL DESIGN
  22. Chapter 17 — SPECIAL INSPECTIONS AND TESTS
  23. Chapter 18 — SOILS AND FOUNDATIONS
  24. Chapter 19 — CONCRETE
  25. Chapter 20 — ALUMINUM
  26. Chapter 21 — MASONRY
  27. Chapter 22 — STEEL
  28. ▸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
  29. Chapter 24 — GLASS AND GLAZING
  30. Chapter 25 — GYPSUM BOARD, GYPSUM PANEL PRODUCTS AND PLASTER
  31. Chapter 26 — PLASTIC
  32. Chapter 27 — ELECTRICAL
  33. Chapter 28 — MECHANICAL SYSTEMS
  34. Chapter 30 — ELEVATORS AND CONVEYING SYSTEMS
  35. Chapter 31 — SPECIAL CONSTRUCTION
  36. Chapter 31B — PUBLIC POOLS
  37. Chapter 31C — RADIATION
  38. Chapter 31D — FOOD ESTABLISHMENTS
  39. Chapter 31F — MARINE OIL TERMINALS
  40. Chapter 32 — ENCROACHMENTS INTO THE PUBLIC RIGHT-OF-WAY
  41. Chapter 33 — SAFEGUARDS DURING CONSTRUCTION
  42. Chapter 35 — REFERENCED STANDARDS
  43. Appendix A — EMPLOYEE QUALIFICATIONS
  44. Appendix B — BOARD OF APPEALS
  45. Appendix C — GROUP U – AGRICULTURAL BUILDINGS
  46. Appendix D — FIRE DISTRICTS
  47. Appendix F — RODENTPROOFING
  48. Appendix H — SIGNS
  49. Appendix I — PATIO COVERS
  50. Appendix J — GRADING
  51. Appendix K — GROUP R-3 AND GROUP R-3.1 OCCUPANCIES
  52. Appendix N — REPLICABLE BUILDINGS
  53. Appendix O — EMERGENCY HOUSING

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