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Chapter 4 — FOUNDATIONS

Section R403

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.

R403.1 General.

All exterior walls shall be supported on continuous solid or fully grouted masonry or concrete footings, crushed stone footings, wood foundations, or other approved structural systems that shall be of sufficient design to accommodate all loads according to Section R301 and to transmit the resulting loads to the soil within the limitations as determined from the character of the soil. Footings shall be

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.

FOUNDATIONS

TABLE R403.1(1) MINIMUM WIDTH AND THICKNESS FOR CONCRETE FOOTINGS FOR LIGHT-FRAME CONSTRUCTION (inches) a, b, c, d

GROUND SNOW LOAD
OR ROOF LIVE LOAD		 STORY AND TYPE OF STRUCTURE
WITH LIGHT FRAME		 LOAD-BEARING VALUE OF SOIL (psf)
GROUND SNOW LOAD
OR ROOF LIVE LOAD		 STORY AND TYPE OF STRUCTURE
WITH LIGHT FRAME		 1,500 2,000 2,500 3,000 3,500 4,000
20 psf roof live load or
25 psf ground snow
load		 1 story—slab-on-grade 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
20 psf roof live load or
25 psf ground snow
load		 1 story—with crawl space 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
20 psf roof live load or
25 psf ground snow
load		 1 story—plus basement 16 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
20 psf roof live load or
25 psf ground snow
load		 2 story—slab-on-grade 13 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
20 psf roof live load or
25 psf ground snow
load		 2 story—with crawl space 15 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
20 psf roof live load or
25 psf ground snow
load		 2 story—plus basement 19 × 6 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6
20 psf roof live load or
25 psf ground snow
load		 3 story—slab-on-grade 16 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
20 psf roof live load or
25 psf ground snow
load		 3 story—with crawl space 18 × 6 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6
20 psf roof live load or
25 psf ground snow
load		 3 story—plus basement 22 × 7 16 × 6 13 × 6 12 × 6 12 × 6 12 × 6
30 psf 1 story—slab-on-grade 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
30 psf 1 story—with crawl space 13 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
30 psf 1 story—plus basement 16 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
30 psf 2 story—slab-on-grade 13 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
30 psf 2 story—with crawl space 16 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
30 psf 2 story—plus basement 19 × 6 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6
30 psf 3 story—slab-on-grade 16 × 6 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6
30 psf 3 story—with crawl space 19 × 6 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6
30 psf 3 story—plus basement 22 × 7 16 × 6 13 × 6 12 × 6 12 × 6 12 × 6
50 psf 1 story—slab-on-grade 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
50 psf 1 story—with crawl space 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
50 psf 1 story—plus basement 18 × 6 13 × 6 12 × 6 12 × 6 12 × 6 12 × 6
50 psf 2 story—slab-on-grade 15 × 6 13 × 6 12 × 6 12 × 6 12 × 6 12 × 6
50 psf 2 story—with crawl space 17 × 6 13 × 6 12 × 6 12 × 6 12 × 6 12 × 6
50 psf 2 story—plus basement 21 × 7 15 × 6 12 × 6 12 × 6 12 × 6 12 × 6
50 psf 3 story—slab-on-grade 18 × 6 13 × 6 12 × 6 12 × 6 12 × 6 12 × 6
50 psf 3 story—with crawl space 20 × 6 15 × 6 12 × 6 12 × 6 12 × 6 12 × 6
50 psf 3 story—plus basement 24 × 8 18 × 6 14 × 6 12 × 6 12 × 6 12 × 6
70 psf 1 story—slab-on-grade 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
70 psf 1 story—with crawl space 16 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
70 psf 1 story—plus basement 19 × 6 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6
70 psf 2 story—slab-on-grade 17 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
70 psf 2 story—with crawl space 19 × 6 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6
70 psf 2 story—plus basement 22 × 7 17 × 6 13 × 6 12 × 6 12 × 6 12 × 6
70 psf 3 story—slab-on-grade 20 × 6 15 × 6 12 × 6 12 × 6 12 × 6 12 × 6
70 psf 3 story—with crawl space 22 × 7 16 × 6 13 × 6 12 × 6 12 × 6 12 × 6
70 psf 3 story—plus basement 24 × 8 19 × 6 15 × 6 13 × 6 12 × 6 12 × 6

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 47.9 N/m 2 . a. Linear interpolation of footing width is permitted between the soil bearing pressures in the table. Extrapolation is not permitted. b. The table is based on the following conditions and loads: building width, 32 feet; wall height, 9 feet; basement wall height, 8 feet; dead loads, 15 psf roof and

ceiling assembly, 10 psf floor assembly, 12 psf wall assembly; live loads, roof and ground snow loads as listed, 40 psf first floor, 30 psf second and third floors. Footing sizes are calculated assuming a clear span roof/ceiling assembly and an interior bearing wall or beam at each floor. c. Where the building width perpendicular to the wall footing is greater than 32 feet, the footing width shall be increased by 2 inches and footing depth shall be

increased by 1 inch for every 4 feet of increase in building width. d. Where the building width perpendicular to the wall footing is less than 32 feet, a 2-inch decrease in footing width and 1-inch decrease in footing depth is

permitted for every 4 feet of decrease in building width provided that the minimum width is 12 inches and minimum depth is 6 inches.

SLAB ON GRADE

CRAWL BASEMENT

SPACE

4-6 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.

FOUNDATIONS

TABLE R403.1(2)

M MINIMUM WIDTH AND THICKNESS FOR CONC CONSTRUCTION WITH BRICK VENEER OR CRETE FOOTINGS FOR LIGHT-FRAME LATH AND PLASTER (inches)a, b, c, d
GROUND SNOW LOAD OR
ROOF LIVE LOAD		 STORY AND TYPE OF STRUCTURE WITH BRICK
VENEER
 LOAD-BEARING VALUE OF SOIL (psf) LOAD-BEARING VALUE OF SOIL (psf) LOAD-BEARING VALUE OF SOIL (psf) LOAD-BEARING VALUE OF SOIL (psf) LOAD-BEARING VALUE OF SOIL (psf) LOAD-BEARING VALUE OF SOIL (psf)
GROUND SNOW LOAD OR
ROOF LIVE LOAD		 STORY AND TYPE OF STRUCTURE WITH BRICK
VENEER
 1,500
 2,000
 2,500
 3,000
 3,500
 4,000
20 psf roof live load or
25 psf ground snow load		 1 story—slab-on-grade 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
20 psf roof live load or
25 psf ground snow load		 1 story—with crawl space
 15 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
20 psf roof live load or
25 psf ground snow load		 1 story—plus basement
 18 × 6
 14 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
20 psf roof live load or
25 psf ground snow load		 2 story—slab-on-grade
 18 × 6
 13 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
20 psf roof live load or
25 psf ground snow load		 2 story—with crawl space
 20 × 6
 15 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
20 psf roof live load or
25 psf ground snow load		 2 story—plus basement
 23 × 8
 17 × 6
 14 × 6
 12 × 6
 12 × 6
 12 × 6
20 psf roof live load or
25 psf ground snow load		 3 story—slab-on-grade
 23 × 8
 17 × 6
 14 × 6
 12 × 6
 12 × 6
 12 × 6
20 psf roof live load or
25 psf ground snow load		 3 story—with crawl space
 25 × 9
 19 × 6
 15 × 6
 13 × 6
 12 × 6
 12 × 6
20 psf roof live load or
25 psf ground snow load		 3 story—plus basement
 29 × 11
 21 × 7
 17 × 6
 14 × 6
 12 × 6
 12 × 6
30 psf 1 story—slab-on-grade
 13 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
30 psf 1 story—with crawl space
 15 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
30 psf 1 story—plus basement
 18 × 6
 14 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
30 psf 2 story—slab-on-grade
 18 × 6
 14 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
30 psf 2 story—with crawl space
 20 × 6
 15 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
30 psf 2 story—plus basement
 24 × 8
 18 × 6
 14 × 6
 12 × 6
 12 × 6
 12 × 6
30 psf 3 story—slab-on-grade
 23 × 8
 18 × 6
 14 × 6
 12 × 6
 12 × 6
 12 × 6
30 psf 3 story—with crawl space
 26 × 9
 19 × 6
 15 × 6
 13 × 6
 12 × 6
 12 × 6
30 psf 3 story—plus basement
 29 × 11
 22 × 7
 17 × 6
 14 × 6
 12 × 6
 12 × 6
50 psf 1 story—slab-on-grade
 14 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
50 psf 1 story—with crawl space
 17 × 6
 13 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
50 psf 1 story—plus basement
 20 × 60
 15 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
50 psf 2 story—slab-on-grade
 20 × 6
 15 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
50 psf 2 story—with crawl space
 22 × 7
 17 × 6
 13 × 6
 12 × 6
 12 × 6
 12 × 6
50 psf 2 story—plus basement
 25 × 9
 19 × 6
 15 × 6
 13 × 6
 12 × 6
 12 × 6
50 psf 3 story—slab-on-grade
 25 × 9
 19 × 6
 15 × 6
 13 × 6
 12 × 6
 12 × 6
50 psf 3 story—with crawl space
 27 × 10
 21 × 7
 16 × 6
 14 × 6
 12 × 6
 12 × 6
50 psf 3 story—plus basement
 31 × 12
 23 × 8
 18 × 6
 15 × 6
 13 × 6
 12 × 6
70 psf 1 story—slab-on-grade
 14 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
70 psf 1 story—with crawl space
 17 × 6
 14 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
70 psf 1 story—plus basement
 22 × 7
 16 × 6
 13 × 6
 12 × 6
 12 × 6
 12 × 6
70 psf 2 story—slab-on grade
 21 × 7
 16 × 6
 13 × 6
 12 × 6
 12 × 6
 12 × 6
70 psf 2 story—with crawl space
 24 × 8
 18 × 6
 14 × 6
 12 × 6
 12 × 6
 12 × 6
70 psf 2 story—plus basement
 27 × 10
 20 × 6
 16 × 6
 13 × 6
 12 × 6
 12 × 6
70 psf 3 story—slab-on-grade
 27 × 10
 20 × 6
 16 × 6
 13 × 6
 12 × 6
 12 × 6
70 psf 3 story—with crawl space
 29 × 11
 22 × 7
 17 × 6
 15 × 6
 12 × 6
 12 × 6
70 psf 3 story—plus basement 32 × 12 24 × 8 19 × 6 16 × 6 14 × 6 12 × 6

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 47.9 N/m 2 . a. Linear interpolation of footing width is permitted between the soil bearing pressures in the table. Extrapolation is not permitted. b. The table is based on the following conditions and loads: building width, 32 feet; wall height, 9 feet; basement wall height, 8 feet; dead loads, 15 psf roof and

ceiling assembly, 10 psf floor assembly, 12 psf wall assembly; live loads, roof and ground snow loads as listed, 40 psf first floor, 30 psf second and third floors. Footing sizes are calculated assuming a clear span roof/ceiling assembly and an interior bearing wall or beam at each floor. c. Where the building width perpendicular to the wall footing is greater than 32 feet, the footing width shall be increased by 2 inches and footing depth shall be

increased by 1 inch for every 4 feet of increase in building width. d. Where the building width perpendicular to the wall footing is less than 32 feet, a 2-inch decrease in footing width and 1-inch decrease in footing depth is

permitted for every 4 feet of decrease in building width provided that the minimum width is 12 inches and minimum depth is 6 inches.

SLAB ON GRADE

CRAWL BASEMENT

SPACE

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.

FOUNDATIONS

TABLE R403.1(3) MINIMUM WIDTH AND THICKNESS FOR CONCRETE FOOTINGS WITH CAST-IN-PLACE CONCRETE OR PARTIALLY GROUTED MASONRY WALL CONSTRUCTION (inches) a, b, c, d

GROUND SNOW LOAD OR
ROOF LIVE LOAD		 STORY AND TYPE OF STRUCTURE
WITH CMU OR CONCRETE		 LOAD-BEARING VALUE OF SOIL (psf)
GROUND SNOW LOAD OR
ROOF LIVE LOAD		 STORY AND TYPE OF STRUCTURE
WITH CMU OR CONCRETE
 1,500
 2,000
 2,500
 3,000
 3,500
 4,000
20 psf roof live load or
25 psf ground snow load		 1 story—slab-on-grade 13 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
20 psf roof live load or
25 psf ground snow load		 1 story—with crawl space
 16 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
20 psf roof live load or
25 psf ground snow load		 1 story—plus basement 19 × 6 14 × 6 12 × 6 12 × 6 12 × 6 12 × 6
20 psf roof live load or
25 psf ground snow load		 2 story—slab-on-grade
 19 × 6
 14 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
20 psf roof live load or
25 psf ground snow load		 2 story—with crawl space 22 × 7 16 × 6 13 × 6 12 × 6 12 × 6 12 × 6
20 psf roof live load or
25 psf ground snow load		 2 story—plus basement
 25 × 9
 19 × 6
 15 × 6
 12 × 6
 12 × 6
 12 × 6
20 psf roof live load or
25 psf ground snow load		 3 story—slab-on-grade 25 × 9 19 × 6 15 × 6 13 × 6 12 × 6 12 × 6
20 psf roof live load or
25 psf ground snow load		 3 story—with crawl space
 28 × 10
 21 × 7
 17 × 6
 14 × 6
 12 × 6
 12 × 6
20 psf roof live load or
25 psf ground snow load		 3 story—plus basement 31 × 12 23 × 8 18 × 6 15 × 6 13 × 6 12 × 6
30 psf 1 story—slab-on-grade
 13 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
30 psf 1 story—with crawl space
 16 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
30 psf 1 story—plus basement
 19 × 7
 14 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
30 psf 2 story—slab-on-grade
 19 × 6
 15 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
30 psf 2 story—with crawl space
 22 × 7
 16 × 6
 13 × 6
 12 × 6
 12 × 6
 12 × 6
30 psf 2 story—plus basement
 25 × 9
 19 × 6
 15 × 6
 13 × 6
 12 × 6
 12 × 6
30 psf 3 story—slab-on-grade
 26 × 9
 19 × 6
 15 × 6
 13 × 6
 12 × 6
 12 × 6
30 psf 3 story—with crawl space
 28 × 10
 21 × 7
 17 × 6
 14 × 6
 12 × 6
 12 × 6
30 psf 3 story—plus basement
 31 × 12
 23 × 8
 19 × 6
 16 × 6
 13 × 6
 12 × 6
50 psf 1 story—slab-on-grade
 15 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
50 psf 1 story—with crawl space
 18 × 6
 13 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
50 psf 1 story—plus basement
 21× 7
 16 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
50 psf 2 story—slab-on-grade
 21 × 7
 16 × 6
 13 × 6
 12 × 6
 12 × 6
 12 × 6
50 psf 2 story—with crawl space
 24 × 8
 18 × 6
 14 × 6
 12 × 6
 12 × 6
 12 × 6
50 psf 2 story—plus basement
 27 × 10
 20 × 6
 16 × 6
 13 × 6
 12 × 6
 12 × 6
50 psf 3 story—slab-on-grade
 27 × 10
 20 × 6
 16 × 6
 14 × 6
 12 × 6
 12 × 6
50 psf 3 story—with crawl space
 30 × 11
 22 × 7
 18 × 6
 15 × 6
 13 × 6
 12 × 6
50 psf 3 story—plus basement
 33 × 13
 25 × 9
 20 × 6
 16 × 6
 14 × 6
 12 × 6
70 psf 1 story—slab-on-grade
 17 × 6
 13 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
70 psf 1 story—with crawl space
 19 × 6
 14 × 6
 12 × 6
 12 × 6
 12 × 6
 12 × 6
70 psf 1 story—plus basement
 22 × 7
 17 × 6
 13 × 6
 12 × 6
 12 × 6
 12 × 6
70 psf 2 story—slab-on-grade
 23 × 8
 17 × 6
 14 × 6
 12 × 6
 12 × 6
 12 × 6
70 psf 2 story—with crawl space
 25 × 9
 19 × 6
 15 × 6
 12× 6
 12 × 6
 12 × 6
70 psf 2 story—plus basement
 28 × 10
 21 × 7
 17 × 6
 14 × 6
 12 × 6
 12 × 6
70 psf 3 story—slab-on-grade
 29 × 11
 22 × 7
 17 × 6
 14 × 6
 12 × 6
 12 × 6
70 psf 3 story—with crawl space
 31 × 12
 23 × 8
 19 × 6
 16 × 6
 13 × 6
 12 × 6
70 psf 3 story—plus basement 34 × 13 26 × 9 21 × 7 17 × 6 15 × 6 13 × 6

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 47.9 N/m 2 . a. Linear interpolation of footing width is permitted between the soil bearing pressures in the table. Extrapolation is not permitted. b. The table is based on the following conditions and loads: building width, 32 feet; wall height, 9 feet; basement wall height, 8 feet; dead loads, 15 psf roof and

ceiling assembly, 10 psf floor assembly, 12 psf wall assembly; live loads, roof and ground snow loads as listed, 40 psf first floor, 30 psf second and third floors. Footing sizes are calculated assuming a clear span roof/ceiling assembly and an interior bearing wall or beam at each floor. c. Where the building width perpendicular to the wall footing is greater than 32 feet, the footing width shall be increased by 2 inches and footing depth shall be

increased by 1 inch for every 4 feet of increase in building width. d. Where the building width perpendicular to the wall footing is less than 32 feet, a 2-inch decrease in footing width and 1-inch decrease in footing depth is

permitted for every 4 feet of decrease in building width provided that the minimum width is 12 inches and minimum depth is 6 inches.

SLAB ON GRADE

CRAWL BASEMENT

SPACE

4-8 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.

FOUNDATIONS

For SI: 1 inch = 25.4 mm. W = Width of footing, T = Thickness of footing and P = Projection per Section R403.1.1.

NOTES: a. See Section R404.3 for sill requirements. b. See Section R403.1.6 for sill attachment. c. See Section R506.2.3 for vapor barrier requirements. d. See Section R403.1 for base. e. See Figure R403.1.3 for additional footing requirements for structures in Seismic Design Categories D0, D1 and D2 and townhouses in Seismic Design

Category C. f. See Section R408 for under-floor ventilation and access requirements.

FIGURE R403.1(1) PLAIN CONCRETE FOOTINGS WITH MASONRY AND CONCRETE STEM WALLS IN SEISMIC DESIGN CATEGORIES A, B AND C a, b, c, d, e, f

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.

FOUNDATIONS

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mil = 0.0254 mm.

FIGURE R403.1(2) PERMANENT WOOD FOUNDATION BASEMENT WALL SECTION

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mil = 0.0254 mm.

FIGURE R403.1(3) PERMANENT WOOD FOUNDATION CRAWL SPACE SECTION

4-10 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.

FOUNDATIONS

BEARING WALL OR

CONSTRUCTION JOINT

PER SECTION R403.1.3.3

12″ MIN DEPTH

AND R403.1.4.1

R506.1

#3 MIN

DOWELS WITH

EACH END PER

SLAB-ON-GROUND WITH DOWELS FOR SLAB-ON-GROUND

SLAB-ON-GROUND WITH

For SI: 1 inch = 25.4 mm. W = Width of footing, T = Thickness of footing and P = Projection per Section R403.1.1. NOTES: a. See Section R404.3 for sill requirements. b. See Section R403.1.6 for sill attachment. c. See Section R506.2.3 for vapor barrier requirements. d. See Section R403.1 for base. e. See Section R408 for under-floor ventilation and access requirements. f. See Section R403.1.3.5 for reinforcement requirements.

FIGURE R403.1.3 REINFORCED CONCRETE FOOTINGS AND MASONRY AND CONCRETE STEM WALLS IN SDC D0, D1 AND D2a, b, c, d, e, f

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.

FOUNDATIONS

R403.1.3.1 Concrete stem walls with concrete foot- ings. In Seismic Design Categories D0, D1 and D2 where a construction joint is created between a concrete footing and a concrete stem wall, not fewer than one No. 4 vertical bar shall be installed at not more than 4 feet (1219 mm) on center. The vertical bar shall have a standard hook and extend to the bottom of the footing and shall have support and cover as specified in Section R403.1.3.5.3 and extend not less than 14 inches (357 mm) into the stem wall. Standard hooks shall comply with Section R608.5.4.5. Not fewer than one No. 4 horizontal bar shall be installed within 12 inches (305 mm) of the top of the stem wall and one No. 4 horizontal bar shall be located 3 to 4 inches (76 mm to 102 mm) from the bottom of the footing.

R403.1.3.2 Masonry stem walls with concrete foot- ings. In Seismic Design Categories D0, D1 and D2 where a masonry stem wall is supported on a concrete footing, not fewer than one No. 4 vertical bar shall be installed at not more than 4 feet (1219 mm) on center. The vertical bar shall have a standard hook and extend to the bottom of the footing and shall have support and cover as specified in Section R403.1.3.5.3 and extend not less than 14 inches (357 mm) into the stem wall. Standard hooks shall comply with Section R608.5.4.5. Not fewer than one No. 4 horizontal bar shall be installed within 12 inches (305 mm) of the top of the wall and one No. 4 horizontal bar shall be located 3 to 4 inches (76 mm to 102 mm) from the bottom of the footing. Masonry stem walls shall be solid grouted.

n Section R403.1.3.5.3 and extend not less than 14 inches (357 mm) into the stem wall. Standard hooks shall comply with Section R608.5.4.5. Not fewer than one No. 4 horizontal bar shall be installed within 12 inches (305 mm) of the top of the wall and one No. 4 horizontal bar shall be located 3 to 4 inches (76 mm to 102 mm) from the bottom of the footing. Masonry stem walls shall be solid grouted.

R403.1.3.3 Slabs-on-ground with turned-down foot- ings. In Seismic Design Categories D0, D1 and D2, slabs-on-ground cast monolithically with turned-down footings shall have not fewer than one No. 4 bar at the top and the bottom of the footing or one No. 5 bar or two No. 4 bars in the middle third of the footing depth.

Where the slab is not cast monolithically with the footing, No. 3 or larger vertical dowels with standard hooks on each end shall be installed at not more than 4 feet (1219 mm) on center in accordance with Figure R403.1.3, Detail 2. Standard hooks shall comply with Section R608.5.4.5.

R403.1.3.4 Interior bearing and braced wall panel footings in Seismic Design Categories D0, D1 and D2. In Seismic Design Categories D0, D1 and D2, interior footings supporting bearing walls or braced wall panels, and cast monolithically with a slab on grade, shall extend to a depth of not less than 12 inches (305 mm) below the top of the slab.

R403.1.3.5 Reinforcement. Footing and stem wall reinforcement shall comply with Sections R403.1.3.5.1 through R403.1.3.5.4.

R403.1.3.5.1 Steel reinforcement. Steel reinforcement shall comply with the requirements of ASTM A615, A706M or A996M. ASTM A996 bars produced from rail steel shall be Type R. The minimum yield strength of reinforcing steel shall be 40,000 psi (Grade 40) (276 MPa).

R403.1.3.5.2 Location of reinforcement in wall. The center of vertical reinforcement in stem walls shall be located at the centerline of the wall. Horizontal and vertical reinforcement shall be located in footings and stem walls to provide the minimum cover required by Section R403.1.3.5.3.

R403.1.3.5.3 Support and cover. Reinforcement shall be secured in the proper location in the forms with tie wire or other bar support system to prevent displacement during the concrete placement operation. Steel reinforcement in concrete cast against the earth shall have a minimum cover of 3 inches (75 mm). Minimum cover for reinforcement in concrete cast in removable forms that will be exposed to the earth or weather shall be 1 1 /2 inches (38 mm) for No. 5 bars and smaller, and 2 inches (50 mm) for No. 6 bars and larger. For concrete cast in removable forms that will not be exposed to the earth or weather, and for concrete cast in stay-inplace forms, minimum cover shall be 3 /4 inch (19 mm).

or reinforcement in concrete cast in removable forms that will be exposed to the earth or weather shall be 1 1 /2 inches (38 mm) for No. 5 bars and smaller, and 2 inches (50 mm) for No. 6 bars and larger. For concrete cast in removable forms that will not be exposed to the earth or weather, and for concrete cast in stay-inplace forms, minimum cover shall be 3 /4 inch (19 mm).

R403.1.3.5.4 Lap splices. Vertical and horizontal reinforcement shall be the longest lengths practical. Where splices are necessary in reinforcement, the length of lap splice shall be in accordance with Table R608.5.4(1) and Figure R608.5.4(1). The maximum gap between noncontact parallel bars at a lap splice shall not exceed the smaller of one-fifth the required lap length and 6 inches (152 mm) [see Figure R608.5.4(1)].

R403.1.3.6 Isolated concrete footings. In detached one- and two-family dwellings that are three stories or less in height and constructed with stud bearing walls, isolated plain concrete footings supporting columns or pedestals are permitted.

R403.1.4 Minimum depth. Exterior footings shall be placed not less than 12 inches (305 mm) below the undisturbed ground surface. Where applicable, the depth of footings shall also conform to Section R403.1.4.1. Deck footings shall be in accordance with Section R507.3.

R403.1.4.1 Frost protection. Except where otherwise protected from frost, foundation walls, piers and other permanent supports of buildings and structures shall be protected from frost by one or more of the following methods:

  1. Extended below the frost line specified in Table R301.2.

  2. Constructed in accordance with Section R403.3.

  3. Constructed in accordance with ASCE 32.

  4. Erected on solid rock.

Footings shall not bear on frozen soil unless the frozen condition is permanent.

Exceptions:

  1. Protection of free-standing accessory structures with an area of 600 square feet (56 m 2 ) or less, of light-frame construction, with an eave

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FOUNDATIONS

  1. Connection of walls 12 inches (305 mm) total length or shorter connecting offset braced wall panels to the foundation without anchor bolts shall be permitted. The wall shall be attached to adjacent braced wall panels at corners as shown in Item 9 of Table R602.3(1).

R403.1.6.1 Foundation anchorage in Seismic Design Categories C, D0, D1 and D2. In addition to the requirements of Section R403.1.6, the following requirements shall apply to wood light-frame structures in Seismic Design Categories D0, D1 and D2 and wood light-frame townhouses in Seismic Design Category C.

  1. Plate washers conforming to Section R602.11.1 shall be provided for all anchor bolts over the full length of required braced wall lines except where approved anchor straps are used. Properly sized cut washers shall be permitted for anchor bolts in wall lines not containing braced wall panels.

  2. Interior braced wall plates shall have anchor bolts spaced at not more than 6 feet (1829 mm) on center and located within 12 inches (305 mm) of the ends of each plate section where supported on a continuous foundation.

  3. Interior bearing wall sole plates shall have anchor bolts spaced at not more than 6 feet (1829 mm) on center and located within 12 inches (305 mm) of the ends of each plate section where supported on a continuous foundation.

  4. The maximum anchor bolt spacing shall be 4 feet (1219 mm) for buildings over two stories in height.

  5. Stepped cripple walls shall conform to Section R602.11.2.

  6. Where continuous wood foundations in accordance with Section R404.2 are used, the force transfer shall have a capacity equal to or greater than the connections required by Section R602.11.1 or the braced wall panel shall be connected to the wood foundations in accordance with the braced wall panel-to-floor fastening requirements of Table R602.3(1).

R403.1.7 Footings on or adjacent to slopes. The placement of buildings and structures on or adjacent to slopes steeper than 1 unit vertical in 3 units horizontal (33.3percent slope) shall conform to Sections R403.1.7.1 through R403.1.7.4.

R403.1.7.1 Building clearances from ascending slopes. In general, buildings below slopes shall be set a sufficient distance from the slope to provide protection from slope drainage, erosion and shallow failures. Except as provided in Section R403.1.7.4 and Figure R403.1.7.1, the following criteria will be assumed to provide this protection. Where the existing slope is steeper than 1 unit vertical in 1 unit horizontal (100percent slope), the toe of the slope shall be assumed to be at the intersection of a horizontal plane drawn from the top of the foundation and a plane drawn tangent to

height of 10 feet (3048 mm) or less shall not be required.

  1. Protection of free-standing accessory structures with an area of 400 square feet (37 m 2 ) or less, of other than light-frame construction, with an eave height of 10 feet (3048 mm) or less shall not be required.

R403.1.5 Slope. The top surface of footings shall be level. The bottom surface of footings shall not have a slope exceeding 1 unit vertical in 10 units horizontal (10-percent slope). Footings shall be stepped where it is necessary to change the elevation of the top surface of the footings or where the slope of the bottom surface of the footings will exceed 1 unit vertical in 10 units horizontal (10-percent slope).

R403.1.6 Foundation anchorage. Wood sill plates and wood walls supported directly on continuous foundations shall be anchored to the foundation in accordance with this section.

Cold-formed steel framing shall be anchored directly to the foundation or fastened to wood sill plates in accordance with Section R505.3.1 or R603.3.1, as applicable. Wood sill plates supporting cold-formed steel framing shall be anchored to the foundation in accordance with this section.

Wood sole plates at all exterior walls on monolithic slabs, wood sole plates of braced wall panels at building interiors on monolithic slabs and all wood sill plates shall be anchored to the foundation with minimum 1 /2-inchdiameter (12.7 mm) anchor bolts spaced not greater than 6 feet (1829 mm) on center or approved anchors or anchor straps spaced as required to provide equivalent anchorage to 1 /2-inch-diameter (12.7 mm) anchor bolts. Bolts shall extend not less than 7 inches (178 mm) into concrete or grouted cells of concrete masonry units. The bolts shall be located in the middle third of the width of the plate. A nut and washer shall be tightened on each anchor bolt. There shall be not fewer than two bolts per plate section with one bolt located not more than 12 inches (305 mm) or less than seven bolt diameters from each end of the plate section. Interior bearing wall sole plates on monolithic slab foundation that are not part of a braced wall panel shall be positively anchored with approved fasteners. Sill plates and sole plates shall be protected against decay and termites where required by Sections R317 and R318. Anchor bolts shall be permitted to be located while concrete is still plastic and before it has set. Where anchor bolts resist placement or the consolidation of concrete around anchor bolts is impeded, the concrete shall be vibrated to ensure full contact between the anchor bolts and concrete.

Exceptions:

  1. Walls 24 inches (610 mm) total length or shorter connecting offset braced wall panels shall be anchored to the foundation with not fewer than one anchor bolt located in the center third of the plate section and shall be attached to adjacent braced wall panels at corners as shown in Item 9 of Table R602.3(1).

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.

FOUNDATIONS

the slope at an angle of 45 degrees (0.79 rad) to the horizontal. Where a retaining wall is constructed at the toe of the slope, the height of the slope shall be measured from the top of the wall to the top of the slope.

R403.1.7.2 Footing setback from descending slope surfaces. Footings on or adjacent to slope surfaces shall be founded in material with an embedment and setback from the slope surface sufficient to provide vertical and lateral support for the footing without detrimental settlement. Except as provided for in Section R403.1.7.4 and Figure R403.1.7.1, the following setback is deemed adequate to meet the criteria. Where the slope is steeper than 1 unit vertical in 1 unit horizontal (100-percent slope), the required setback shall be measured from an imaginary plane 45 degrees (0.79 rad) to the horizontal, projected upward from the toe of the slope.

R403.1.7.3 Foundation elevation. On graded sites, the top of any exterior foundation shall extend above the elevation of the street gutter at point of discharge or the inlet of an approved drainage device not less than 12 inches (305 mm) plus 2 percent. Alternate elevations are permitted subject to the approval of the building official, provided that it can be demonstrated that required drainage to the point of discharge and away from the structure is provided at all locations on the site.

R403.1.7.4 Alternate setbacks and clearances. Alternate setbacks and clearances are permitted, subject to the approval of the building official. The building official is permitted to require an investigation and recommendation of a qualified engineer to demonstrate that the intent of this section has been satisfied. Such an investigation shall include consideration of material, height of slope, slope gradient, load intensity and erosion characteristics of slope material.

R403.1.8 Foundations on expansive soils. Foundation and floor slabs for buildings located on expansive soils shall be designed in accordance with Section 1808.6 of the California Building Code .

Exception: Slab-on-ground and other foundation systems that have performed adequately in soil conditions similar to those encountered at the building site

are permitted subject to the approval of the building official.

R403.1.8.1 Expansive soils classifications. Soils meeting all of the following provisions shall be considered to be expansive, except that tests to show compliance with Items 1, 2 and 3 shall not be required if the test prescribed in Item 4 is conducted:

  1. Plasticity Index (PI) of 15 or greater, determined in accordance with ASTM D4318.

  2. More than 10 percent of the soil particles pass a No. 200 sieve (75 μm), determined in accordance with ASTM D422.

  3. More than 10 percent of the soil particles are less than 5 micrometers in size, determined in accordance with ASTM D422.

  4. Expansion Index greater than 20, determined in accordance with ASTM D4829.

R403.2 Footings for wood foundations.

Footings for wood foundations shall be in accordance with Figures R403.1(2) and R403.1(3). Gravel shall be washed and well graded. The maximum size stone shall not exceed 3 /4 inch (19.1 mm). Gravel shall be free from organic, clayey or silty soils. Sand shall be coarse, not smaller than 1 /16-inch (1.6 mm) grains and shall be free from organic, clayey or silty soils. Crushed stone

where the monthly mean temperature of the building is maintained at not less than 64°F (18°C), footings are not required to extend below the frost line where protected from frost by insulation in accordance with Figure R403.3(1) and Table R403.3(1). Foundations protected from frost in accordance with Figure R403.3(1) and Table R403.3(1) shall not be used for unheated spaces such as porches, utility rooms, garages and carports, and shall not be attached to basements or crawl spaces that are not maintained at a minimum monthly mean temperature of 64°F (18°C).

Materials used below grade for the purpose of insulating footings against frost shall be labeled as complying with ASTM C578.

For SI: 1 foot = 304.8 mm.

FIGURE R403.1.7.1 FOUNDATION CLEARANCE FROM SLOPES

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FOUNDATIONS

For SI: 1 inch = 25.4 mm. a. See Table R403.3(1) for required dimensions and R -values for vertical and horizontal insulation and minimum footing depth.

FIGURE R403.3(1) INSULATION PLACEMENT FOR FROST-PROTECTED FOOTINGS IN HEATED BUILDINGS

TABLE R403.3(1) MINIMUM FOOTING DEPTH AND INSULATION REQUIREMENTS FOR FROST-PROTECTED FOOTINGS IN HEATED BUILDINGS a

AIR-FREEZING
INDEX (°F days)b		 MINIMUM FOOTING
DEPTH, D (inches)		 VERTICAL
INSULATION
R-VALUEc, d		 HORIZONTAL INSULATION
R-VALUEc, e		 HORIZONTAL INSULATION DIMENSIONS
PER Figure R403.3(1) (inches)
AIR-FREEZING
INDEX (°F days)b		 MINIMUM FOOTING
DEPTH,****D (inches)		 VERTICAL
INSULATION
R-VALUEc, d		 Along walls At corners A B C
1,500 or less 12 4.5 Not required Not required Not required Not required Not required
2,000 14 5.6 Not required Not required Not required Not required Not required
2,500 16 6.7 1.7 4.9 12 24 40
3,000 16 7.8 6.5 8.6 12 24 40
3,500 16 9.0 8.0 11.2 24 30 60
4,000 16 10.1 10.5 13.1 24 36 60

For SI: 1 inch = 25.4 mm, °C = [(°F) – 32]/1.8. a. Insulation requirements are for protection against frost damage in heated buildings. Greater values could be required to meet energy conservation standards. b. See Figure R403.3(2) or Table R403.3(2) for Air-Freezing Index values. c. Insulation materials shall provide the stated minimum R -values under long-term exposure to moist, below-ground conditions in freezing climates. The following

R -values shall be used to determine insulation thicknesses required for this application: Type II expanded polystyrene (EPS)-3.2 R per inch for vertical insulation and 2.6 R per inch for horizontal insulation; Type IX expanded polystyrene (EPS)-3.4 R per inch for vertical insulation and 2.8 R per inch for horizontal insulation; Types IV, V, VI, VII, and X extruded polystyrene (XPS)-4.5 R per inch for vertical insulation and 4.0 R per inch for horizontal insulation. d. Vertical insulation shall be expanded polystyrene insulation or extruded polystyrene insulation. e. Horizontal insulation shall be expanded polystyrene insulation or extruded polystyrene insulation.

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.

FOUNDATIONS

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FOUNDATIONS

TABLE R403.3(2) AIR-FREEZING INDEX FOR US LOCATIONS BY COUNTY
STATE AIR-FREEZING INDEX AIR-FREEZING INDEX AIR-FREEZING INDEX AIR-FREEZING INDEX AIR-FREEZING INDEX AIR-FREEZING INDEX
STATE 1,500 or less 2,000 2,500 3,000 3,500 4,000
Alabama All counties — — — — —
Alaska Ketchikan Gate-
way, Prince of
Wales-Outer Ket-
chikan (CA), Sitka,
Wrangell-Peters-
burg (CA)		 — Aleutians West
(CA), Haines,
Juneau, Skagway-
Hoonah-Angoon
(CA), Yakutat		 — — All counties not
listed
Arizona All counties — — — — —
Arkansas All counties — — — — —
California All counties not
listed		 Nevada, Sierra — — — —
Colorado All counties not
listed		 Archuleta, Custer,
Fremont, Huer-
fano, Las Animas,
Ouray, Pitkin, San
Miguel		 Clear Creek, Cone-
jos, Costilla,
Dolores, Eagle, La
Plata, Park, Routt,
San Juan, Summit		 Alamosa, Grand,
Jackson, Larimer,
Moffat, Rio
Blanco, Rio Grande		 Chaffee, Gunni-
son, Lake,
Saguache		 Hinsdale, Mineral
Connecticut All counties not
listed		 Hartford, Litchfield — — — —
Delaware All counties — — — — —
District of
Columbia		 All counties — — — — —
Florida All counties — — — — —
Georgia All counties — — — — —
Hawaii All counties — — — — —
Idaho All counties not
listed		 Adams, Bannock,
Blaine, Clearwater,
Idaho, Lincoln,
Oneida, Power,
Valley, Washington		 Bingham, Bonne-
ville, Camas, Cari-
bou, Elmore,
Franklin, Jeffer-
son, Madison,
Teton		 Bear Lake, Butte,
Custer, Fremont,
Lemhi		 Clark —
Illinois All counties not
listed		 Boone, Bureau,
Cook, Dekalb,
DuPage, Fulton,
Grundy, Hender-
son, Henry, Iro-
quois,
Jo Daviess, Kane,
Kankakee, Kend-
all, Knox,
La Salle, Lake, Lee,
Livingston, Mar-
shall, Mason,
McHenry, McLean,
Mercer, Peoria,
Putnam, Rock
Island, Stark, Taze-
well, Warren,
Whiteside, Will,
Woodford		 Carroll, Ogle, Ste-
phenson, Win-
nebago		 — — —

(continued)

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.

FOUNDATIONS

TABLE R403.3(2)—continued AIR-FREEZING INDEX FOR US LOCATIONS BY COUNTY
STATE AIR-FREEZING INDEX AIR-FREEZING INDEX AIR-FREEZING INDEX AIR-FREEZING INDEX AIR-FREEZING INDEX AIR-FREEZING INDEX
STATE 1,500 or less 2,000 2,500 3,000 3,500 4,000
Indiana All counties not
listed		 Allen, Benton,
Cass, Fountain,
Fulton, Howard,
Jasper, Kosciusko,
La Porte, Lake,
Marshall, Miami,
Newton, Porter,
Pulaski, Starke,
Steuben, Tippeca-
noe, Tipton,
Wabash, Warren,
White		 — — — —
Iowa Appanoose, Davis,
Fremont, Lee, Van
Buren		 All counties not
listed		 Allamakee, Black
Hawk, Boone,
Bremer, Buchanan,
Buena Vista, But-
ler, Calhoun, Cerro
Gordo, Cherokee,
Chickasaw, Clay,
Clayton, Delaware,
Dubuque, Fayette,
Floyd, Franklin,
Grundy, Hamilton,
Hancock, Hardin,
Humboldt, Ida,
Jackson, Jasper,
Jones, Linn, Mar-
shall, Palo Alto,
Plymouth, Poca-
hontas, Poweshiek,
Sac, Sioux, Story,
Tama, Webster,
Winnebago, Wood-
bury, Worth,
Wright		 Dickinson, Emmet,
Howard, Kossuth,
Lyon, Mitchell,
O’Brien, Osceola,
Winneshiek		 — —
Kansas All counties — — — — —
Kentucky All counties — — — — —
Louisiana All counties — — — — —
Maine York Knox, Lincoln,
Sagadahoc		 Androscoggin,
Cumberland, Han-
cock, Kennebec,
Waldo, Washing-
ton		 Aroostook, Frank-
lin, Oxford, Penob-
scot, Piscataquis,
Somerset		 — —
Maryland All counties — — — — —
Massachusetts All counties not
listed		 Berkshire, Frank-
lin, Hampden,
Worcester		 — — — —

(continued)

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FOUNDATIONS

TABLE R403.3(2)—continued AIR-FREEZING INDEX FOR US LOCATIONS BY COUNTY
STATE AIR-FREEZING INDEX AIR-FREEZING INDEX AIR-FREEZING INDEX AIR-FREEZING INDEX AIR-FREEZING INDEX AIR-FREEZING INDEX
STATE 1,500 or less 2,000 2,500 3,000 3,500 4,000
Michigan Berrien, Branch,
Cass, Kalamazoo,
Macomb, Ottawa,
St. Clair, St. Joseph		 All counties not
listed		 Alger, Charlevoix,
Cheboygan, Chip-
pewa, Crawford,
Delta, Emmet,
Iosco, Kalkaska,
Lake, Luce, Macki-
nac, Menominee,
Missaukee, Mont-
morency, Ogemaw,
Osceola, Otsego,
Roscommon,
Schoolcraft, Wex-
ford		 Baraga, Dickinson,
Iron, Keweenaw,
Marquette		 Gogebic, Hough-
ton, Ontonagon		 —
Minnesota — — Houston, Winona All counties not
listed		 Aitkin, Big Stone,
Carlton, Crow
Wing, Douglas,
Itasca, Kanabec,
Lake, Morrison,
Pine, Pope, Stea-
rns, Stevens, Swift,
Todd, Wadena		 Becker, Beltrami,
Cass, Clay, Clear-
water, Grant, Hub-
bard, Kittson,
Koochiching, Lake
of the Woods,
Mahnomen, Mar-
shall, Norman,
Otter Tail, Penning-
ton, Polk, Red
Lake, Roseau, St.
Louis, Traverse,
Wilkin
Mississippi All counties — — — — —
Missouri All counties not
listed		 Atchison, Mercer,
Nodaway, Putnam		 — — — —
Montana Mineral Broadwater,
Golden Valley,
Granite, Lake, Lin-
coln, Missoula,
Ravalli, Sanders,
Sweet Grass		 Big Horn, Carbon,
Jefferson, Judith
Basin, Lewis and
Clark, Meagher,
Musselshell, Pow-
der River, Powell,
Silver Bow, Still-
water, Westland		 Carter, Cascade,
Deer Lodge, Fal-
con, Fergus, Flat-
head, Gallatin,
Glacier, Madison,
Park, Petroleum,
Ponder, Rosebud,
Teton, Treasure,
Yellowstone		 Beaverhead, Blaine,
Chouteau, Custer,
Dawson, Garfield,
Liberty, McCone,
Prairie, Toole,
Wibaux		 Daniels, Hill, Phil-
lips, Richland, Roo-
sevelt, Sheridan,
Valley
Nebraska Adams, Banner,
Chase, Cheyenne,
Clay, Deuel,
Dundy, Fillmore,
Franklin, Frontier,
Furnas, Gage, Gar-
den, Gosper, Har-
lan, Hayes,
Hitchcock, Jeffer-
son, Kimball, Mor-
rill, Nemaha,
Nuckolls, Pawnee,
Perkins, Phelps,
Red Willow, Rich-
ardson, Saline,
Scotts Bluff,
Seward, Thayer,
Webster		 All counties not
listed		 Boyd, Burt, Cedar,
Cuming, Dakota,
Dixon, Dodge,
Knox, Thurston		 — — —

(continued)

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.

FOUNDATIONS

TABLE R403.3(2)—continued AIR-FREEZING INDEX FOR US LOCATIONS BY COUNTY
STATE AIR-FREEZING INDEX AIR-FREEZING INDEX AIR-FREEZING INDEX AIR-FREEZING INDEX AIR-FREEZING INDEX AIR-FREEZING INDEX
STATE 1,500 or less 2,000 2,500 3,000 3,500 4,000
Nevada All counties not listed Elko, Eureka, Nye,
Washoe, White
Pine		 — — — —
New Hamp-
shire		 — All counties not
listed		 — — — Carroll, Coos,
Grafton
New Jersey All counties — — — — —
New Mexico All counties not listed Rio Arriba Colfax, Mora, Taos — — —
New York Albany, Bronx,
Cayuga, Columbia,
Cortland, Dutchess,
Genessee, Kings,
Livingston, Monroe,
Nassau, New York,
Niagara, Onondaga,
Ontario, Orange,
Orleans, Putnam,
Queens, Richmond,
Rockland, Seneca,
Suffolk, Wayne,
Westchester, Yates		 All counties not
listed		 Clinton, Essex,
Franklin, Hamil-
ton, Herkimer, Jef-
ferson, Lewis, St.
Lawrence, Warren		 — — —
North Carolina All counties — — — — —
North Dakota — — — Billings, Bowman Adams, Dickey,
Golden Valley,
Hettinger, LaM-
oure, Oliver, Ran-
som, Sargent,
Sioux, Slope, Stark		 All counties not
listed
Ohio All counties not listed Ashland, Craw-
ford, Defiance,
Holmes, Huron,
Knox, Licking,
Morrow, Paulding,
Putnam, Richland,
Seneca, Williams		 — — — —
Oklahoma All counties — — — — —
Oregon All counties not listed Baker, Crook,
Grant, Harney		 — — — —
Pennsylvania All counties not listed Berks, Blair, Brad-
ford, Cambria,
Cameron, Centre,
Clarion, Clear-
field, Clinton,
Crawford, Elk,
Forest, Hunting-
don, Indiana, Jef-
ferson,
Lackawanna,
Lycoming, McK-
ean, Pike, Potter,
Susquehanna,
Tioga, Venango,
Warren, Wayne,
Wyoming		 — — — —

(continued)

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FOUNDATIONS

TABLE R403.3(2)—continued AIR-FREEZING INDEX FOR US LOCATIONS BY COUNTY
STATE AIR-FREEZING INDEX AIR-FREEZING INDEX AIR-FREEZING INDEX AIR-FREEZING INDEX AIR-FREEZING INDEX AIR-FREEZING INDEX
STATE 1,500 or less 2,000 2,500 3,000 3,500 4,000
Rhode Island All counties — — — — —
South Carolina All counties — — — — —
South Dakota — Bennett, Custer,
Fall River, Law-
rence, Mellette,
Shannon, Todd,
Tripp		 Bon Homme,
Charles Mix, Davi-
son, Douglas, Greg-
ory, Jackson, Jones,
Lyman		 All counties not
listed		 Beadle, Brookings,
Brown, Campbell,
Codington, Corson,
Day, Deuel,
Edmunds, Faulk,
Grant, Hamlin,
Kingsbury, Mar-
shall, McPherson,
Perkins, Roberts,
Spink, Walworth		 —
Tennessee All counties — — — — —
Texas All counties — — — — —
Utah All counties not
listed		 Box Elder, Mor-
gan, Weber		 Garfield, Salt Lake,
Summit		 Carbon, Daggett,
Duchesne, Rich,
Sanpete, Uintah,
Wasatch		 — —
Vermont — Bennington, Grand
Isle, Rutland,
Windham		 Addison, Chitten-
den, Franklin,
Orange, Washing-
ton, Windsor		 Caledonia, Essex,
Lamoille, Orleans		 — —
Virginia All counties — — — — —
Washington All counties not
listed		 Chelan, Douglas,
Ferry, Okanogan		 — — — —
West Virginia All counties — — — — —
Wisconsin — Kenosha,
Kewaunee, Racine,
Sheboygan, Wal-
worth		 All counties not
listed		 Ashland, Barron,
Burnett, Chippewa,
Clark, Dunn, Eau
Claire, Florence,
Forest, Iron, Jack-
son, La Crosse,
Langlade, Mara-
thon, Monroe,
Pepin, Polk, Por-
tage, Price, Rust, St.
Croix, Taylor,
Trempealeau, Vilas,
Wood		 Bayfield, Douglas,
Lincoln, Oneida,
Sawyer, Washburn		 —
Wyoming Goshen, Platte Converse, Crook,
Laramie, Niobrara		 Campbell, Carbon,
Hot Springs, John-
son, Natrona, Sheri-
dan, Uinta, Weston		 Albany, Big Horn,
Park, Washakie		 Fremont, Teton Lincoln, Sublette,
Sweetwater

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.

FOUNDATIONS

For SI: 1 inch = 25.4 mm. a. See Table R403.3(1) for required dimensions and R -values for vertical and horizontal insulation.

FIGURE R403.3(3) INSULATION PLACEMENT FOR FROST-PROTECTED FOOTINGS ADJACENT TO UNHEATED SLAB-ON-GROUND STRUCTURE

FIGURE R403.3(4) INSULATION PLACEMENT FOR FROST-PROTECTED FOOTINGS ADJACENT TO HEATED STRUCTURE

4-22 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.

R403.3.1 Foundations adjoining frost-protected shal- low foundations. Foundations that adjoin frost-protected shallow foundations shall be protected from frost in accordance with Section R403.1.4.

R403.3.1.1 Attachment to unheated slab-on- ground structure. Vertical wall insulation and horizontal insulation of frost-protected shallow foundations that adjoin a slab-on-ground foundation that does not have a monthly mean temperature maintained at not less than 64°F (18°C) shall be in accordance with Figure R403.3(3) and Table R403.3(1). Vertical wall insulation shall extend between the frost-protected shallow foundation and the adjoining slab foundation. Required horizontal insulation shall be continuous under the adjoining slab foundation and through any foundation walls adjoining the frost- protected shallow foundation. Where insulation passes through a foundation wall, it shall be either of a type complying with this section and having bearing capacity equal to or greater than the structural loads imposed by the building, or the building shall be designed and constructed using beams, lintels, cantilevers or other means of transferring building loads such that the structural loads of the building do not bear on the insulation.

R403.3.1.2 Attachment to heated structure. Where a frost-protected shallow foundation abuts a structure that has a monthly mean temperature maintained at not less than 64°F (18°C), horizontal insulation and vertical wall insulation shall not be required between the frostprotected shallow foundation and the adjoining structure. Where the frost-protected shallow foundation abuts the heated structure, the horizontal insulation and vertical wall insulation shall extend along the adjoining foundation in accordance with Figure R403.3(4) a distance of not less than Dimension A in Table R403.3(1).

Exception: Where the frost-protected shallow foundation abuts the heated structure to form an inside corner, vertical insulation extending along the adjoining foundation is not required.

R403.3.2 Protection of horizontal insulation below ground. Horizontal insulation placed less than 12 inches (305 mm) below the ground surface or that portion of horizontal insulation extending outward more than 24 inches (610 mm) from the foundation edge shall be protected against damage by use of a concrete slab or asphalt paving on the ground surface directly above the insulation or by cementitious board, plywood rated for below-ground use, or other approved materials placed below ground, directly above the top surface of the insulation.

R403.3.3 Drainage. Final grade shall be sloped in accordance with Section R401.3. In other than Group I Soils, as detailed in Table R405.1, gravel or crushed stone beneath

FOUNDATIONS

horizontal insulation below ground shall drain to daylight or into an approved sewer system.

R403.3.4 Termite protection. The use of foam plastic in areas of “very heavy” termite infestation probability shall be in accordance with Section R318.4.

R403.4 Footings for precast concrete foundations.

Footings for precast concrete foundations shall comply with Section R403.4.

R403.4.1 Crushed stone footings. Clean crushed stone shall be free from organic, clayey or silty soils. Crushed stone shall be angular in nature and meet ASTM C33, with the maximum size stone not to exceed 1 /2 inch (12.7 mm) and the minimum stone size not to be smaller than 1/16 inch (1.6 mm). Crushed stone footings for precast foundations shall be installed in accordance with Figure R403.4(1) and Table R403.4. Crushed stone footings shall be consolidated using a vibratory plate in not greater than 8-inch (203 mm) lifts. Crushed stone footings shall be limited to Seismic Design Categories A, B and C.

R403.4.2 Concrete footings. Concrete footings shall be installed in accordance with Section R403.1 and Figure R403.4(2).

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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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