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Chapter 4 — FOUNDATIONS

Section R402

California Residential Code (Title 24, Part 2.5) · 2022 edition · updated 2026-09-12 · California

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

MATERIALS

4-4 2022 CALIFORNIA RESIDENTIAL CODE

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.

40,000 psi (Grade 40) (276 MPa). Steel reinforcement for precast concrete foundation walls shall have a minimum concrete cover of 3 /4 inch (19.1 mm).

  1. Panel-to-panel connections shall be made with Grade II steel fasteners.

  2. The use of nonstructural fibers shall conform to ASTM C1116.

  3. Grout used for bedding precast foundations placed on concrete footings shall meet ASTM C1107.

R402.4 Masonry.

Masonry systems shall be designed and installed in accordance with this chapter and shall have a minimum specified compressive strength of 1,500 psi (10.3 MPa).

TABLE R402.2 MINIMUM SPECIFIED COMPRESSIVE

STRENGTH OF CONCRETE

FOUNDATIONS

supported on undisturbed natural soils or engineered fill. Concrete footing shall be designed and constructed in accordance with the provisions of Section R403 or in accordance with ACI 332.

R403.1.1 Minimum size. The minimum width, W, and thickness, T, for concrete footings shall be in accordance with Tables R403.1(1) through R403.1(3) and Figure R403.1(1) or R403.1.3, as applicable, but not less than 12 inches (305 mm) in width and 6 inches (152 mm) in depth. The footing width shall be based on the load-bearing value of the soil in accordance with Table R401.4.1. Footing projections, P, shall be not less than 2 inches (51 mm) and shall not exceed the thickness of the footing. Footing thickness and projection for fireplaces shall be in accordance with Section R1001.2. The size of footings supporting piers and columns shall be based on the tributary load and allowable soil pressure in accordance with Table R401.4.1. Footings for wood foundations shall be in accordance with the details set forth in Section R403.2, and Figures R403.1(2) and R403.1(3). Footings for precast foundations shall be in accordance with the details set forth in Section R403.4, Table R403.4, and Figures R403.4(1) and R403.4(2).

R403.1.2 Continuous footing in Seismic Design Catego- ries D0, D1 and D2. Exterior walls of buildings located in Seismic Design Categories D0, D1 and D2 shall be supported by continuous solid or fully grouted masonry or concrete footings. Other footing materials or systems shall be designed in accordance with accepted engineering practice. Required interior braced wall panels in buildings located in Seismic Design Categories D0, D1 and D2 with plan dimensions greater than 50 feet (15 240 mm) shall be supported by continuous solid or fully grouted masonry or concrete footings in accordance with Section R403.1.3.4, except for two-story buildings in Seismic Design Category D2, in which all braced wall panels, interior and exterior, shall be supported on continuous foundations.

Exception: Two-story buildings shall be permitted to have interior braced wall panels supported on continuous foundations at intervals not exceeding 50 feet (15 240 mm) provided that:

  1. The height of cripple walls does not exceed 4 feet (1219 mm).

  2. First-floor braced wall panels are supported on doubled floor joists, continuous blocking or floor beams.

  3. The distance between bracing lines does not exceed twice the building width measured parallel to the braced wall line.

R403.1.3 Footing and stem wall reinforcing in Seismic Design Categories D0, D1 and D2. Concrete footings located in Seismic Design Categories D0, D1 and D2, as established in Table R301.2, shall have minimum reinforcement in accordance with this section and Figure R403.1.3. Reinforcement shall be installed with support and cover in accordance with Section R403.1.3.5.

TYPE OR LOCATION OF
CONCRETE CONSTRUCTION		 MINIMUM SPECIFIED
COMPRESSIVE STRENGTHa (f′)
c
TYPE OR LOCATION OF
CONCRETE CONSTRUCTION		 Weathering Potentialb Weathering Potentialb Weathering Potentialb
TYPE OR LOCATION OF
CONCRETE CONSTRUCTION		 Negligible Moderate Severe
Basement walls, foundations
and other concrete not exposed
to the weather		 2,500 2,500 2,500c
Basement slabs and interior
slabs on grade, except garage
floor slabs		 2,500 2,500 2,500c
Basement walls, foundation
walls, exterior walls and other
vertical concrete work exposed
to the weather		 2,500 3,000d 3,000d
Porches, carport slabs and steps
exposed to the weather, and
garage floor slabs		 2,500 3,000d, e, f 3,500d, e, f

For SI: 1 pound per square inch = 6.895 kPa. a. Strength at 28 days psi. b. See Table R301.2 for weathering potential. c. Concrete in these locations that is subject to freezing and thawing during

construction shall be air-entrained concrete in accordance with Note d. d. Concrete shall be air-entrained. Total air content (percent by volume of

concrete) shall be not less than 5 percent or more than 7 percent. e. See Section R402.2 for maximum cementitious materials content. f. For garage floors with a steel-troweled finish, reduction of the total air

content (percent by volume of concrete) to not less than 3 percent is permitted if the specified compressive strength of the concrete is increased to not less than 4,000 psi.

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▸Contents — California Residential Code (Title 24, Part 2.5)
California Residential Code (Title 24, Part 2.5)
  1. Chapter 2 — DEFINITIONS AND ABBREVIATIONS
  2. Appendix AF — RADON CONTROL
  3. Appendix AI — PRIVATE SEWAGE
  4. Appendix AJ — EXISTING
  5. Appendix AK — SOUND
  6. Appendix AO — AUTOMATIC
  7. Appendix AR — LIGHT STRAW-CLAY
  8. Appendix AS — STRAWBALE
  9. Appendix AU — COB CONSTRUCTION
  10. Appendix AV — BOARD
  11. Appendix AW — 3D-PRINTED BUILDING
  12. Chapter 1 — SCOPE AND APPLICATION
  13. Chapter 3 — BUILDING PLANNING
  14. ▸Chapter 4 — FOUNDATIONS
    Overview
    1. Section R401
    2. Section R402
    3. Section R403
    4. Section R404
    5. Section R405
    6. Section R406
    7. Section R407
    8. Section R408
  15. Chapter 5 — FLOORS
  16. Chapter 6 — WALL CONSTRUCTION
  17. Chapter 7 — WALL COVERING
  18. Chapter 8 — ROOF-CEILING CONSTRUCTION
  19. Chapter 9 — ROOF ASSEMBLIES
  20. Chapter 10 — CHIMNEYS AND FIREPLACES
  21. Chapter 44 — REFERENCED STANDARDS
  22. Appendix AH — PATIO COVERS
  23. Appendix AL — PERMIT FEES
  24. Appendix AQ — TINY HOUSES
  25. Appendix AT — SOLAR-READY PROVISIONS—DETACHED ONE- AND
  26. Appendix AX — SWIMMING POOL SAFETY ACT
  27. Appendix AY — AREAS PROTECTED BY THE FACILITIES
  28. Appendix AZ — EMERGENCY HOUSING

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