CRC · California Residential Code
Where are masonry/concrete wall solid-segment and reinforcement rules?
If you’re designing or checking concrete/masonry solid wall segments in California, the key rules live in **§ R608.7.2** (what counts and allowed small openings), **§ R608.7.2.1** (only segments ≥ 24 in count; max two between 24–48 in; 18 ft max clear opening), and **§ R608.7.2.2** (provide the specified horizontal and vertical reinforcement: minimum No. 4 bars, spacing limits, and development rules). Consult Table R608.7.1.1(6) and Figure R608.7.1.1(2) for the exact bar layouts and R3 reduction values.
Last reviewed: July 6, 2026
What the code requires — 2-4 sentences
The California Residential Code spells out requirements for solid wall segments (what counts as a solid segment, minimum lengths and spacing) in § R608.7.2. The minimum-length/spacing rules are in § R608.7.2.1 and the required horizontal, vertical and vertical‑shear reinforcement for those segments are in § R608.7.2.2. These sections must be read together with Table R608.7.1.1(6) and the vertical‑layout details in Figure R608.7.1.1(2) when selecting bar sizes, spacing and reduction factors for design strength.
The single most important practical rule: a wall segment must be at least 24 inches long to count toward the required solid‑wall length, and if you rely on reduced design strength (R3) you must provide the reinforcement specified in § R608.7.2.2.
Requirements in detail
What a “solid wall segment” is (short)
- A solid wall segment is a portion of a flat, waffle‑grid, or screen‑grid wall that runs the full story height without openings except limited utility penetrations as allowed by § R608.7.2.
- For flat and waffle‑grid walls, permitted small penetrations must be less than 30 square inches and no single dimension may exceed 6-1/4 inches, and they must be at least 6 inches from the segment side edge. For screen‑grid walls those small openings are allowed between cores provided no concrete is removed.
Minimum length, count limits and clear opening limit (from § R608.7.2.1)
- Only segments ≥ 24 inches count toward the required total length.
- No more than two segments that are ≥ 24 inches but < 48 inches may be included in the required total.
- The maximum clear opening width is 18 feet.
Decision‑relevant values (quick reference)
| Item | Value | Code Reference |
|---|---|---|
| Minimum length that may be counted | 24 in (610 mm) | § R608.7.2.1 |
| Count limit for segments 24–48 in | Max 2 segments | § R608.7.2.1 |
| Maximum clear opening width | 18 ft (5486 mm) | § R608.7.2.1 |
| Allowed small penetrations (flat/waffle) | < 30 sq in and no dimension > 6-1/4 in and ≥ 6 in from side edge | § R608.7.2 |
| Required flange thickness for waffle/screen-grid (through wall) | 5‑1/2 in (6‑in nominal forms) or 7‑1/2 in (8‑in nominal forms) | § R608.7.2 and Figure notes |
Reinforcement rules (from § R608.7.2.2)
- Controlling sections: § R608.7.2.2.1 (horizontal shear), § R608.7.2.2.2 (vertical), § R608.7.2.2.3 (vertical shear).
Horizontal shear reinforcement (§ R608.7.2.2.1)
- Where you take the R3 reduction that assumes shear reinforcement, provide minimum No. 4 horizontal bars (same grade as the vertical reinforcement at segment ends).
- Spacing: not more than the smaller of (one‑half segment length − 2 in) and 18 in.
- Terminate horizontal reinforcement per § R608.6.4.
Vertical reinforcement at segment ends (§ R608.7.2.2.2)
- Use the vertical layout detail from Figure R608.7.1.1(2) and Table R608.7.1.1(6) to select size/number/grade.
- There must be not less than two No. 4 bars at each end of each solid wall segment (minimum). One of those bars may satisfy the general vertical‑wall reinforcement required by § R608.6 when located per the figure.
- The vertical bars required around openings (from § R608.8.1.2) are permitted to be used as the end bars if placed per the figure.
Vertical development / anchorage adjacent to openings (§ R608.7.2.2.2)
- If wall height below the bottom of an adjacent opening is ≥ 22 in for No. 4 (or ≥ 28 in for No. 5), the reinforcement around openings per § R608.8.1 is sufficient.
- If the height is less, the vertical reinforcement must either be extended into the footing to develop the bar per § R608.5.4.4 or be lap‑spliced to a dowel embedded into the footing sufficient to develop tension.
Vertical shear reinforcement (§ R608.7.2.2.3)
- Where shear reinforcement is required for the R3 reduction, provide minimum No. 4 vertical shear bars (same grade as vertical end reinforcement).
- Spacing: not more than the smaller of one‑third the segment length and 18 in.
- Vertical shear reinforcement must be continuous between stories per § R608.6.3 and terminate per § R608.6.4.
How reinforcement ties to design strength (R3 / Table R608.7.1.1(6))
- The tabulated reduction factor R3 in Table R608.7.1.1(6) depends on the number/size/grade of vertical bars at segment ends and whether horizontal/vertical shear reinforcement is provided. Choose wall type/arrangement from Table R608.7.1.1(6) after computing the allowable R3 for your TL (see Equation 6‑2).
Exceptions & special cases
- Openings for utilities: small penetrations allowed in flat and waffle‑grid walls as noted (area and dimension limits) — these do not disqualify a segment if they comply with § R608.7.2. Screen‑grid walls are more permissive provided concrete is not removed.
- Using vertical reinforcement required for openings: vertical bars placed at openings per § R608.8.1.2 may serve as the required end bars for solid segments if located per Figure R608.7.1.1(2).
- Waffle/screen‑grid forms: where vertical bars are used in those walls, a concrete flange must be formed at each segment end with minimum through‑wall widths (5‑1/2 in for 6‑in nominal forms; 7‑1/2 in for 8‑in nominal forms) to ensure cover and bar placement. If necessary form material can be removed or flat forms used.
If a particular table cell or figure value is needed (e.g., specific R3 values for a particular wall thickness and bar layout), the code requires use of Table R608.7.1.1(6) and Figure R608.7.1.1(2) — consult those directly for the numeric selection.
Common mistakes
- Counting segments less than 24 in toward the required TL (they cannot be counted). § R608.7.2.1.
- Counting more than two segments between 24–48 in. § R608.7.2.1.
- Omitting horizontal shear bars when using R3 reductions that presume them (R3 is tied to the presence of shear reinforcement in the table). Use No. 4 minimum for horizontal shear when required. § R608.7.2.2.1 and Table R608.7.1.1(6).
- Failing to provide the minimum two No. 4 vertical bars at each end of a counted segment (or to follow the Figure R608.7.1.1(2) placement). § R608.7.2.2.2.
- Not developing or extending vertical bars into the footing when wall height below the adjacent opening is less than the required 22 in (No. 4) or 28 in (No. 5). § R608.7.2.2.2.
Worked example — counting segments and required reinforcement
Scenario: a flat exterior wall line contains three solid portions between windows: 20 in long, 30 in long, and 40 in long. You plan to use the R3 reduction that requires horizontal and vertical shear reinforcement.
Step 1 — Which segments count?
- 20 in: does not count (less than 24 in). § R608.7.2.1.
- 30 in and 40 in: both count (each ≥ 24 in). But they are both between 24–48 in, and the code allows not more than two such segments — so both may be included. § R608.7.2.1.
Total counted length TL = 30 in + 40 in = 70 in (5.83 ft).
Step 2 — Reinforcement required if using the R3 reduction
- Provide horizontal shear reinforcement: No. 4 bars minimum. Spacing ≤ the smaller of (0.5 × segment length − 2 in) and 18 in.
- For the 30 in segment: 0.5×30 − 2 = 13 in → spacing ≤ 13 in (so provide bars at 12 in or less). § R608.7.2.2.1.
- For the 40 in segment: 0.5×40 − 2 = 18 in → spacing ≤ 18 in (so 12 or 18 in are acceptable). § R608.7.2.2.1.
- Provide vertical reinforcement at each end: at least two No. 4 bars at each end, placed per Figure R608.7.1.1(2). One of these bars can satisfy the vertical‑wall requirement of § R608.6 if located correctly. § R608.7.2.2.2.
- Provide vertical shear reinforcement (No. 4) spaced not more than the smaller of (1/3 segment length) and 18 in.
- For 30 in segment: 1/3×30 = 10 in → spacing ≤ 10 in (so provide at 10 in or less). § R608.7.2.2.3.
Step 3 — If a window bottom leaves less than 22 in of wall below (for No. 4), the vertical bars must be developed into the footing or spliced to a dowel per § R608.7.2.2.2.
(This example shows counting and basic spacing/development; for final design you must verify the selected wall type against Table R608.7.1.1(6) and compute permissible R3 using Equation 6‑2 in the code.)
Related provisions (quick links to read next)
- § R608.7.1 — Length of solid wall (how much TL is required per wall line).
- § R608.7.1.1 — Length of solid wall for wind (UR tables R608.7.1.1(1)–(3)).
- Table R608.7.1.1(6) — Reduction factor R3 and tabulated wall arrangements (bar counts/sizes and R3 values).
- Figure R608.7.1.1(2) — Vertical reinforcement layout details for ends of solid wall segments.
- § R608.6 / § R608.6.3 / § R608.6.4 — Continuity, termination and development/anchorage rules for reinforcement.
- § R608.5.4.1 — Minimum concrete cover requirements referenced for flange/cover.
- § R608.8 / § R608.8.1.2 — Reinforcement around openings and lintel rules (interaction with solid segment end bars).
Code references
Grounded in the retrieved California Residential Code — click a citation to read the verbatim passage:
CRC § 7.2.2. High relevance — show source text
Horizontal and vertical shear reinforcement shall be provided in accordance with Section R608.7.2.2.
e. Each end of each solid wall segment shall have rectangular flanges. In the through-the-wall dimension, the flange shall be not less than 51/2 inches for 6-inch-nominal waffle-
and screen-grid walls, and not less than 71/2 inches for 8-inch-nominal waffle-grid walls. In the in-plane dimension, flanges shall be long enough to accommodate the vertical
reinforcement required by the layout detail selected from Figure R608.7.1.1(2) and provide the cover required by Section R608.5.4.1. If necessary to achieve the required
dimensions, form material shall be removed or use of flat wall forms is permitted.|For SI: 1 inch = 25.4 mm, 1,000 pounds per square inch = 6.895 MPa.
a. See Note e to Table R608.7.1.1(1) for application of adjustment factors in this table.
b. Yield strength in pounds per square inch of vertical wall reinforcement at ends of solid wall segments.
c. Values are based on concrete with a specified compressive strength,f’c, of 2,500 psi. Where concrete with_f’c_ of not less than 3,000 psi is used, values in shaded cells are
permitted to be decreased by multiplying by 0.91.
d. Horizontal and vertical shear reinforcement shall be provided in accordance with Section R608.7.2.2.
e. Each end of each solid wall segment shall have rectangular flanges. In the through-the-wall dimension, the flange shall be not less than 51/2 inches for 6-inch-nominal waffle-
and screen-grid walls, and not less than 71/2 inches for 8-inch-nominal waffle-grid walls. In the in-plane dimension, flanges shall be long enough to accommodate the vertical
reinforcement required by the layout detail selected from Figure R608.7.1.1(2) and provide the cover required by Section R608.5.4.1. If necessary to achieve the required
dimensions, form material shall be removed or use of flat wall forms is permitted.|For SI: 1 inch = 25.4 mm, 1,000 pounds per square inch = 6.895 MPa.
a. See Note e to Table R608.7.1.1(1) for application of adjustment factors in this table.
b. Yield strength in pounds per square inch of vertical wall reinforcement at ends of solid wall segments.
c. Values are based on concrete with a specified compressive strength,f’c, of 2,500 psi. Where concrete with_f’c_ of not less than 3,000 psi is used, values in shaded cells are
permitted to be decreased by multiplying by 0.91.
d. Horizontal and vertical shear reinforcement shall be provided in accordance with Section R608.7.2.2.
e. Each end of each solid wall segment shall have rectangular flanges. In the through-the-wall dimension, the flange shall be not less than 51/2 inches for 6-inch-nominal waffle-
and screen-grid walls, and not less than 71/2 inches for 8-inch-nominal waffle-grid walls.CRC § 0.91. High relevance — show source text
Yield strength in pounds per square inch of vertical wall reinforcement at ends of solid wall segments.
c. Values are based on concrete with a specified compressive strength,f’c, of 2,500 psi. Where concrete with_f’c_ of not less than 3,000 psi is used, values in shaded cells are
permitted to be decreased by multiplying by 0.91.
d. Horizontal and vertical shear reinforcement shall be provided in accordance with Section R608.7.2.2.
e. Each end of each solid wall segment shall have rectangular flanges. In the through-the-wall dimension, the flange shall be not less than 51/2 inches for 6-inch-nominal waffle-
and screen-grid walls, and not less than 71/2 inches for 8-inch-nominal waffle-grid walls. In the in-plane dimension, flanges shall be long enough to accommodate the vertical
reinforcement required by the layout detail selected from Figure R608.7.1.1(2) and provide the cover required by Section R608.5.4.1. If necessary to achieve the required
dimensions, form material shall be removed or use of flat wall forms is permitted.|For SI: 1 inch = 25.4 mm, 1,000 pounds per square inch = 6.895 MPa.
a. See Note e to Table R608.7.1.1(1) for application of adjustment factors in this table.
b. Yield strength in pounds per square inch of vertical wall reinforcement at ends of solid wall segments.
c. Values are based on concrete with a specified compressive strength,f’c, of 2,500 psi. Where concrete with_f’c_ of not less than 3,000 psi is used, values in shaded cells are
permitted to be decreased by multiplying by 0.91.
d. Horizontal and vertical shear reinforcement shall be provided in accordance with Section R608.7.2.2.
e. Each end of each solid wall segment shall have rectangular flanges. In the through-the-wall dimension, the flange shall be not less than 51/2 inches for 6-inch-nominal waffle-
and screen-grid walls, and not less than 71/2 inches for 8-inch-nominal waffle-grid walls. In the in-plane dimension, flanges shall be long enough to accommodate the vertical
reinforcement required by the layout detail selected from Figure R608.7.1.1(2) and provide the cover required by Section R608.5.4.1. If necessary to achieve the required
dimensions, form material shall be removed or use of flat wall forms is permitted.|For SI: 1 inch = 25.4 mm, 1,000 pounds per square inch = 6.895 MPa.
a. See Note e to Table R608.7.1.1(1) for application of adjustment factors in this table.
b. Yield strength in pounds per square inch of vertical wall reinforcement at ends of solid wall segments.
c. Values are based on concrete with a specified compressive strength,f’c, of 2,500 psi. Where concrete with_f’c_ of not less than 3,000 psi is used, values in shaded cells are
permitted to be decreased by multiplying by 0.91.
d. Horizontal and vertical shear reinforcement shall be provided in accordance with Section R608.7.2.2.
e. Each end of each solid wall segment shall have rectangular flanges.CRC § 7.1.1 High relevance — show source text
In the in-plane dimension, flanges shall be long enough to accommodate the vertical
reinforcement required by the layout detail selected from Figure R608.7.1.1(2) and provide the cover required by Section R608.5.4.1. If necessary to achieve the required
dimensions, form material shall be removed or use of flat wall forms is permitted.|For SI: 1 inch = 25.4 mm, 1,000 pounds per square inch = 6.895 MPa.
a. See Note e to Table R608.7.1.1(1) for application of adjustment factors in this table.
b. Yield strength in pounds per square inch of vertical wall reinforcement at ends of solid wall segments.
c. Values are based on concrete with a specified compressive strength,f’c, of 2,500 psi. Where concrete with_f’c_ of not less than 3,000 psi is used, values in shaded cells are
permitted to be decreased by multiplying by 0.91.
d. Horizontal and vertical shear reinforcement shall be provided in accordance with Section R608.7.2.2.
e. Each end of each solid wall segment shall have rectangular flanges. In the through-the-wall dimension, the flange shall be not less than 51/2 inches for 6-inch-nominal waffle-
and screen-grid walls, and not less than 71/2 inches for 8-inch-nominal waffle-grid walls. In the in-plane dimension, flanges shall be long enough to accommodate the vertical
reinforcement required by the layout detail selected from Figure R608.7.1.1(2) and provide the cover required by Section R608.5.4.1. If necessary to achieve the required
dimensions, form material shall be removed or use of flat wall forms is permitted.|For SI: 1 inch = 25.4 mm, 1,000 pounds per square inch = 6.895 MPa.
a. See Note e to Table R608.7.1.1(1) for application of adjustment factors in this table.
b. Yield strength in pounds per square inch of vertical wall reinforcement at ends of solid wall segments.
c. Values are based on concrete with a specified compressive strength,f’c, of 2,500 psi. Where concrete with_f’c_ of not less than 3,000 psi is used, values in shaded cells are
permitted to be decreased by multiplying by 0.91.
d. Horizontal and vertical shear reinforcement shall be provided in accordance with Section R608.7.2.2.
e. Each end of each solid wall segment shall have rectangular flanges. In the through-the-wall dimension, the flange shall be not less than 51/2 inches for 6-inch-nominal waffle-
and screen-grid walls, and not less than 71/2 inches for 8-inch-nominal waffle-grid walls. In the in-plane dimension, flanges shall be long enough to accommodate the vertical
reinforcement required by the layout detail selected from Figure R608.7.1.1(2) and provide the cover required by Section R608.5.4.1. If necessary to achieve the required
dimensions, form material shall be removed or use of flat wall forms is permitted.|6-134 2025 CALIFORNIA RESIDENTIAL CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
WALL CONSTRUCTION
CRC § 7.2 High relevance — show source text
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
WALL CONSTRUCTION
R608.7.2 Solid wall segments. Solid wall segments that contribute to the required length of solid wall shall comply with this section. Reinforcement shall be provided in accordance with Section R608.7.2.2 and Table R608.7.1.1(6). Solid wall segments shall extend the full story-height without openings, other than openings for the utilities and other building services passing through the wall. In flat walls and waffle-grid walls, such openings shall have an area of less than 30 square inches (19 355 mm [2] ) without any dimension exceeding 6 [1] / 4 inches (159 mm), and shall not be located within 6 inches (152 mm) of the side edges of the solid wall segment. In screen-grid walls, such openings shall be located in the portion of the solid wall segment between horizontal and vertical cores of concrete and opening size and location are not restricted provided there is not any concrete removed.
R608.7.2.1 Minimum length of solid wall segment and maximum spacing. Only solid wall segments equal to or greater than 24 inches (610 mm) in length shall be included in the total length of solid wall required by Section R608.7.1. In addition, not more than two solid wall segments equal to or greater than 24 inches (610 mm) in length and less than 48 inches (1219 mm) in length shall be included in the required total length of solid wall. The maximum clear opening width shall be 18 feet (5486 mm). See Figure R608.7.1.1(1).
R608.7.2.2 Reinforcement in solid wall segments.
R608.7.2.2.1 Horizontal shear reinforcement. Where reduction factors for design strength, R 3, from Table R608.7.1.1(6) based on horizontal and vertical shear reinforcement being provided are used, solid wall segments shall have horizontal reinforcement consisting of minimum No. 4 bars. Horizontal shear reinforcement shall be the same grade of steel required for the vertical reinforcement at the ends of solid wall segments by Section R608.7.2.2.2.
The spacing of horizontal reinforcement shall not exceed the smaller of one-half the length of the solid wall segment, minus 2 inches (51 mm), and 18 inches (457 mm). Horizontal shear reinforcement shall terminate in accordance with Section R608.6.4.
R608.7.2.2.2 Vertical reinforcement. Vertical reinforcement applicable to the reduction factor(s) for design strength, R 3, from Table R608.7.1.1(6) that is used, shall be located at each end of each solid wall segment in accordance with the applicable detail in Figure R608.7.1.1(2). The No. 4 vertical bar required on each side of an opening by Section R608.8.1.2 is permitted to be used as reinforcement at the ends of solid wall segments where installed in accordance with the applicable detail in Figure R608.7.1.1(2). There shall be not less than two No. 4 bars at each end of solid wall segments located as required by the applicable detail in Figure R608.7.1.1(2). One of the bars at each end of solid wall segments shall be deemed to meet the requirements for vertical wall reinforcement required by Section R608.6.
CRC § 7.2.2 High relevance — show source text
R608.7.2.2 Reinforcement in solid wall segments.
R608.7.2.2.1 Horizontal shear reinforcement. Where reduction factors for design strength, R 3, from Table R608.7.1.1(6) based on horizontal and vertical shear reinforcement being provided are used, solid wall segments shall have horizontal reinforcement consisting of minimum No. 4 bars. Horizontal shear reinforcement shall be the same grade of steel required for the vertical reinforcement at the ends of solid wall segments by Section R608.7.2.2.2.
The spacing of horizontal reinforcement shall not exceed the smaller of one-half the length of the solid wall segment, minus 2 inches (51 mm), and 18 inches (457 mm). Horizontal shear reinforcement shall terminate in accordance with Section R608.6.4.
R608.7.2.2.2 Vertical reinforcement. Vertical reinforcement applicable to the reduction factor(s) for design strength, R 3, from Table R608.7.1.1(6) that is used, shall be located at each end of each solid wall segment in accordance with the applicable detail in Figure R608.7.1.1(2). The No. 4 vertical bar required on each side of an opening by Section R608.8.1.2 is permitted to be used as reinforcement at the ends of solid wall segments where installed in accordance with the applicable detail in Figure R608.7.1.1(2). There shall be not less than two No. 4 bars at each end of solid wall segments located as required by the applicable detail in Figure R608.7.1.1(2). One of the bars at each end of solid wall segments shall be deemed to meet the requirements for vertical wall reinforcement required by Section R608.6.
The vertical wall reinforcement at each end of each solid wall segment shall be developed below the bottom of the adjacent wall opening [see Figure R608.7.1.1(3)] by one of the following methods:
Where the wall height below the bottom of the adjacent opening is equal to or greater than 22 inches (559 mm) for No. 4 or 28 inches (711 mm) for No. 5 vertical wall reinforcement, reinforcement around openings in accordance with Section R608.8.1 shall be sufficient.
Where the wall height below the bottom of the adjacent opening is less than required by Item 1, the vertical wall reinforcement adjacent to the opening shall extend into the footing far enough to develop the bar in tension in accordance with Section R608.5.4.4 and Figure R608.5.4(2), or shall be lap-spliced with a dowel that is embedded in the footing far enough to develop the dowel-bar in tension.
R608.7.2.2.3 Vertical shear reinforcement. Where reduction factors for design strength, R 3, from Table R608.7.1.1(6) based on horizontal and vertical shear reinforcement being provided are used, solid wall segments shall have vertical reinforcement consisting of minimum No. 4 bars. Vertical shear reinforcement shall be the same grade of steel required by Section R608.7.2.2.2 for the vertical reinforcement at the ends of solid wall segments. The spacing of vertical reinforcement throughout the length of the segment shall not exceed the smaller of one third the length of the segment, and 18 inches (457 mm). Vertical shear reinforcement shall be continuous between stories in accordance with Section R608.6.3, and shall terminate in accordance with Section R608.6.4.
CRC § 1.1 High relevance — show source text
1.1(6)—REDUCTION FACTOR FOR DESIGN STRENGTH, R, FOR FLAT, WAFFLE- AND SCREEN-GRID WALLSa, c
3Col2 Col3 Col4 Col5 Col6 Col7 Col8 ** NOMINAL**
THICKNESS
OF WALL
(inches)** VERTICAL BARS**
AT EACH END OF
SOLID WALL SEGMENT** VERTICAL BARS**
AT EACH END OF
SOLID WALL SEGMENT** VERTICAL**
REINFORCEMENT
LAYOUT DETAIL
[see Figure R608.7.1.1(2)]** REDUCTION FACTOR,****_R_3, FOR LENGTH OF SOLID WALL** ** REDUCTION FACTOR,****_R_3, FOR LENGTH OF SOLID WALL** ** REDUCTION FACTOR,****_R_3, FOR LENGTH OF SOLID WALL** ** REDUCTION FACTOR,****_R_3, FOR LENGTH OF SOLID WALL** ** NOMINAL**
THICKNESS
OF WALL
(inches)** VERTICAL BARS**
AT EACH END OF
SOLID WALL SEGMENT** VERTICAL BARS**
AT EACH END OF
SOLID WALL SEGMENT** VERTICAL**
REINFORCEMENT
LAYOUT DETAIL
[see Figure R608.7.1.1(2)]** Horizontal and vertical shear reinforcement provided** ** Horizontal and vertical shear reinforcement provided** ** Horizontal and vertical shear reinforcement provided** ** Horizontal and vertical shear reinforcement provided** ** NOMINAL**
THICKNESS
OF WALL
(inches)** Number**
of bars** Bar**
size** Bar**
size** No** ** No** ** Yesd** ** Yesd** ** NOMINAL**
THICKNESS
OF WALL
(inches)** Number**
of bars** Bar**
size** Bar**
size** 40,000b** ** 60,000b** ** 40,000b** ** 60,000b** Flat walls Flat walls Flat walls Flat walls Flat walls Flat walls Flat walls Flat walls 4 2 4 1 0.74 0.61 0.74 0.50 4 3 4 2 0.61 0.61 0.52 0.27 4 2 5 1 0.61 0.61 0.48 0.25 4 3 5 2 0.61 0.61 0.26 0.18 6 2 4 3 0.70 0.48 0.70 0.48 6 3 4 4 0.49 0.38 0.49 0. CRC § 7.1.1 High relevance — show source text
See Note e to Table R608.7.1.1(1) for application of adjustment factors in this table.
b. Yield strength in pounds per square inch of vertical wall reinforcement at ends of solid wall segments.
c. Values are based on concrete with a specified compressive strength,f’c, of 2,500 psi. Where concrete with_f’c_ of not less than 3,000 psi is used, values in shaded cells are
permitted to be decreased by multiplying by 0.91.
d. Horizontal and vertical shear reinforcement shall be provided in accordance with Section R608.7.2.2.
e. Each end of each solid wall segment shall have rectangular flanges. In the through-the-wall dimension, the flange shall be not less than 51/2 inches for 6-inch-nominal waffle-
and screen-grid walls, and not less than 71/2 inches for 8-inch-nominal waffle-grid walls. In the in-plane dimension, flanges shall be long enough to accommodate the vertical
reinforcement required by the layout detail selected from Figure R608.7.1.1(2) and provide the cover required by Section R608.5.4.1. If necessary to achieve the required
dimensions, form material shall be removed or use of flat wall forms is permitted.|6-134 2025 CALIFORNIA RESIDENTIAL CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
WALL CONSTRUCTION
R608.7.2 Solid wall segments. Solid wall segments that contribute to the required length of solid wall shall comply with this section. Reinforcement shall be provided in accordance with Section R608.7.2.2 and Table R608.7.1.1(6). Solid wall segments shall extend the full story-height without openings, other than openings for the utilities and other building services passing through the wall. In flat walls and waffle-grid walls, such openings shall have an area of less than 30 square inches (19 355 mm [2] ) without any dimension exceeding 6 [1] / 4 inches (159 mm), and shall not be located within 6 inches (152 mm) of the side edges of the solid wall segment. In screen-grid walls, such openings shall be located in the portion of the solid wall segment between horizontal and vertical cores of concrete and opening size and location are not restricted provided there is not any concrete removed.
R608.7.2.1 Minimum length of solid wall segment and maximum spacing. Only solid wall segments equal to or greater than 24 inches (610 mm) in length shall be included in the total length of solid wall required by Section R608.7.1. In addition, not more than two solid wall segments equal to or greater than 24 inches (610 mm) in length and less than 48 inches (1219 mm) in length shall be included in the required total length of solid wall. The maximum clear opening width shall be 18 feet (5486 mm). See Figure R608.7.1.1(1).
R608.7.2.2 Reinforcement in solid wall segments.
CRC § 1807.1.6.3 High relevance — show source text
- Vertical reinforcement shall have a minimum yield strength of 60,000 psi (414 MPa).
- The specified location of the reinforcement shall equal or exceed the effective depth distance, d, noted in Tables 1807.1.6.3(2), 1807.1.6.3(3) and 1807.1.6.3(4) and shall be measured from the face of the exterior (soil) side of the wall to the center of the vertical reinforcement. The reinforcement shall be placed within the tolerances specified in TMS 602 for the specified location.
- Grout shall comply with Section 2103.3.
- Concrete masonry units shall comply with ASTM C90.
- Clay masonry units shall comply with ASTM C652 for hollow brick, except compliance with ASTM C62 or ASTM C216 shall be permitted where solid masonry units are installed in accordance with Table 1807.1.6.3(1) for plain masonry.
- Masonry units shall be laid in running bond and installed with Type M or S mortar in accordance with Section 2103.2.1.
- The unfactored axial load per linear foot of wall shall not exceed 1.2 tf′ m where t is the specified wall thickness in inches and f′ m is the specified compressive strength of masonry in pounds per square inch.
2025 CALIFORNIA BUILDING CODE 18-11
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
SOILS AND FOUNDATIONS
Not less than 4 inches (102 mm) of solid masonry shall be provided at girder supports at the top of hollow masonry unit foundation walls.
Corbeling of masonry shall be in accordance with Section 2104.1. Where an 8-inch (203 mm) wall is corbeled, the top corbel shall not extend higher than the bottom of the floor framing and shall be a full course of headers not less than 6 inches (152 mm) in length or the top course bed joint shall be tied to the vertical wall projection. The tie shall be W2.8 (4.8 mm) and spaced at a maximum horizontal distance of 36 inches (914 mm). The hollow space behind the corbelled masonry shall be filled with mortar or grout.
TABLE 1807.1.6.3(1)—PLAIN MASONRY FOUNDATION WALLSa, b, c Col2 Col3 Col4 Col5 MAXIMUM WALL HEIGHT
(feet)MAXIMUM UNBALANCED
BACKFILL HEIGHTe
(feet)MINIMUM NOMINAL WALL THICKNESS (inches) MINIMUM NOMINAL WALL THICKNESS (inches) MINIMUM NOMINAL WALL THICKNESS (inches) MAXIMUM WALL HEIGHT
(feet)MAXIMUM UNBALANCED
BACKFILL HEIGHTe
(feet)Design lateral soil loada (psf per foot of depth) Design lateral soil loada (psf per foot of depth) Design lateral soil loada (psf per foot of depth) MAXIMUM WALL HEIGHT
(feet)MAXIMUM UNBALANCED
**BACKFILL HEIGHTeCRC § 7.2.1. High relevance — show source text
The total length of solid wall in a wall line, TL, shall be not less than that provided by two solid wall segments complying with the minimum length requirements of Section R608.7.2.1.
To facilitate determining the required wall thickness, wall type, number and grade of vertical bars at each end of each solid wall segment, and whether shear reinforcement is required, use of Equation 6-2 is permitted.
Equation 6-2
R 3 ≤ ------------------------------ TL R 1 × R 2 × UR
After determining the maximum permitted value of the reduction factor for design strength, R 3, in accordance with Equation 6-2, select a wall type from Table R608.7.1.1(6) with R 3 less than or equal to the value calculated.
6-124 2025 CALIFORNIA RESIDENTIAL CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
WIND PERPENDICULAR TO RIDGE
WIND
PARALLEL TO RIDGE
WALL CONSTRUCTION
FIGURE R608.7.1.1(1)—MINIMUM SOLID WALL LENGTH
ONE STORY OR TOP STORY OF TWO STORY
[TABLE R608.7.1.1(2)]
FIRST STORY OF TWO STORY
[TABLE R608.7.1.1(1)]
ONE STORY OR TOP STORY OF TWO STORY
[TABLE R608.7.1.1(3)]
FIRST STORY OF TWO STORY
[TABLE R608.7.1.1(3)]
BE APPLICABLE TO THE MINIMUM SOLID WALL LENGTH EQUATIONS SEE SECTION R608.7.2
2025 CALIFORNIA RESIDENTIAL CODE 6-125
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
WALL CONSTRUCTION
FIGURE R608.7.1.1(2)—VERTICAL REINFORCEMENT LAYOUT DETAIL
DETAIL
NO.NOM. WALL
THICKNESS, IN.REINFORCEMENT LAYOUT AT ENDS OF
SOLID WALL SEGMENTSNOTES 1 4 3 inch Max. Typical
2 inch TypicalFor SI: 1 inch = 25.4 mm.
1. See Table R608.7.1.1(6) for use
of details.
2. Minimum length of solid wall
segment and size and grade
of reinforcement in each end
of each solid wall segment
shall be determined from
Table R608.7.1.1(6).
3. For minimum cover requirements,
see Section R608.5.4.1.
4. For details 3 - 8 where two
or more bars are in the same
row parallel to the end of the
segment, place bars so that
corner bars are as close to the
sides of the wall segments as
minimum cover requirements
of Section R608.5.4.1 will permit.
5. For waffle- and screen-grid walls,
each end of each solid wall
segment shall have rectangular
flanges.CRC § 7.1.1 High relevance — show source text
The vertical wall reinforcement at each end of each solid wall segment shall be developed below the bottom of the adjacent wall opening [see Figure R608.7.1.1(3)] by one of the following methods:
Where the wall height below the bottom of the adjacent opening is equal to or greater than 22 inches (559 mm) for No. 4 or 28 inches (711 mm) for No. 5 vertical wall reinforcement, reinforcement around openings in accordance with Section R608.8.1 shall be sufficient.
Where the wall height below the bottom of the adjacent opening is less than required by Item 1, the vertical wall reinforcement adjacent to the opening shall extend into the footing far enough to develop the bar in tension in accordance with Section R608.5.4.4 and Figure R608.5.4(2), or shall be lap-spliced with a dowel that is embedded in the footing far enough to develop the dowel-bar in tension.
R608.7.2.2.3 Vertical shear reinforcement. Where reduction factors for design strength, R 3, from Table R608.7.1.1(6) based on horizontal and vertical shear reinforcement being provided are used, solid wall segments shall have vertical reinforcement consisting of minimum No. 4 bars. Vertical shear reinforcement shall be the same grade of steel required by Section R608.7.2.2.2 for the vertical reinforcement at the ends of solid wall segments. The spacing of vertical reinforcement throughout the length of the segment shall not exceed the smaller of one third the length of the segment, and 18 inches (457 mm). Vertical shear reinforcement shall be continuous between stories in accordance with Section R608.6.3, and shall terminate in accordance with Section R608.6.4. Vertical shear reinforcement required by this section is permitted to be used for vertical reinforcement required by Table R608.6(1), R608.6(2), R608.6(3) or R608.6(4), whichever is applicable.
R608.7.2.3 Solid wall segments at corners. At all interior and exterior corners of exterior walls, a solid wall segment shall extend the full height of each wall story . The segment shall have the length required to develop the horizontal reinforcement above and below the adjacent opening in tension in accordance with Section R608.5.4.4. For an exterior corner, the limiting dimension is measured on the outside of the wall, and for an interior corner the limiting dimension is measured on the inside of the wall. See Section R608.8.1. The length of a segment contributing to the required length of solid wall shall comply with Section R608.7.2.1.
The end of a solid wall segment complying with the minimum length requirements of Section R608.7.2.1 shall be located not more than 6 feet (1829 mm) from each corner.
R608.8 Requirements for lintels and reinforcement around openings.
2025 CALIFORNIA RESIDENTIAL CODE 6-135
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
WALL CONSTRUCTION
FIGURE R608.8(1)—REINFORCEMENT OF OPENINGS
CONTINUOUS BAR AS REQUIRED
SEE FIGURES R608.8(2), R608.8(3) AND R608.8(4)
TOP OF WALL STORY
Col1 Col2 Col3 Col4 A A ≥ 2 FT CRC § 7.2 High relevance — show source text
BE APPLICABLE TO THE MINIMUM SOLID WALL LENGTH EQUATIONS SEE SECTION R608.7.2
2025 CALIFORNIA RESIDENTIAL CODE 6-125
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
WALL CONSTRUCTION
FIGURE R608.7.1.1(2)—VERTICAL REINFORCEMENT LAYOUT DETAIL
DETAIL
NO.NOM. WALL
THICKNESS, IN.REINFORCEMENT LAYOUT AT ENDS OF
SOLID WALL SEGMENTSNOTES 1 4 3 inch Max. Typical
2 inch TypicalFor SI: 1 inch = 25.4 mm.
1. See Table R608.7.1.1(6) for use
of details.
2. Minimum length of solid wall
segment and size and grade
of reinforcement in each end
of each solid wall segment
shall be determined from
Table R608.7.1.1(6).
3. For minimum cover requirements,
see Section R608.5.4.1.
4. For details 3 - 8 where two
or more bars are in the same
row parallel to the end of the
segment, place bars so that
corner bars are as close to the
sides of the wall segments as
minimum cover requirements
of Section R608.5.4.1 will permit.
5. For waffle- and screen-grid walls,
each end of each solid wall
segment shall have rectangular
flanges. In the through-the-wall
dimension, the flange shall be not
less than 5½ inches for 6-inch
nominal waffle- and screen-grid
forms, and not less than 7½
inches for 8-inch nominal waffle-
grid forms. In the in-plane
dimension, flanges shall be long
enough to accommodate the
vertical reinforcement required
by the layout detail selected and
provide the cover required by
Section R608.5.4.1. If necessary
to achieve the required
dimensions, form material shall be
removed or flat wall forms are
permitted. See Table R608.7.1.1(6),
Note e.2 4 3 8
6
104 6 5 8 1 inch Min. clear spacing Typical 1 inch Min. clear spacing Typical 6 8 7 10 8 10 * For minimum cover see Section R608.5.4.1 ** For minimum cover see Section R608.5.4.1 *6-126 2025 CALIFORNIA RESIDENTIAL CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
FOOTING
WALL CONSTRUCTION
FIGURE R608.7.1.1(3)—VERTICAL WALL REINFORCEMENT ADJACENT TO WALL OPENINGS
VERTICAL WALL REINFORCEMENT
AT END OF SOLID WALL SEGMENT.
WALL HEIGHT
BELOW LOWEST
ADJACENT
OPENING MORE
THAN REQUIRED
BY SECTION
R608.7.2.2.2
CRC § 7.2.2.2 Medium relevance — show source text
The vertical reinforcement required on each side of an opening by this section is permitted to serve as reinforcement at the ends of solid wall segments in accordance with Section R608.7.2.2.2, provided it is located as required by the applicable detail in Figure R608.7.1.1(2). Where the vertical reinforcement required by this section is used to satisfy the requirements of Section R608.7.2.2.2 in waffle- and screen-grid walls, a concrete flange shall be created at the ends of the solid wall segments in accordance with Table R608.7.1.1(6), Note e. In the top-most story, the reinforcement shall terminate in accordance with Section R608.6.4.
R608.8.2 Lintels. Lintels shall be provided over all openings equal to or greater than 2 feet (610 mm) in width. Lintels with uniform loading shall conform to Sections R608.8.2.1 and R608.8.2.2, or Section R608.8.2.3. Lintels supporting concentrated loads, such as from roof or floor beams or girders, shall be designed in accordance with ACI 318.
R608.8.2.1 Lintels designed for gravity load-bearing conditions. Where a lintel will be subjected to gravity load conditions 1 through 5 of Table R608.8(1), the clear span of the lintel shall not exceed that permitted by Tables R608.8(2) through R608.8(8). The maximum clear span of lintels with and without stirrups in flat walls shall be determined in accordance with Tables R608.8(2) through R608.8(5), and constructed in accordance with Figure R608.8(2). The maximum clear span of lintels with and without stirrups in waffle-grid walls shall be determined in accordance with Tables R608.8(6) and R608.8(7), and constructed in accordance with Figure R608.8(3). The maximum clear span of lintels with and without stirrups in screen-grid walls shall be determined in accordance with Table R608.8(8), and constructed in accordance with Figure R608.8(4).
Where required by the applicable table, No. 3 stirrups shall be installed in lintels at a maximum spacing of d /2 where d equals the depth of the lintel, D, less the cover of the concrete as shown in Figures R608.8(2) through R608.8(4). The smaller value of d computed for the top and bottom bar shall be used to determine the maximum stirrup spacing. Where stirrups are required in a lintel with a single bar or two bundled bars in the top and bottom, they shall be fabricated like the letter “c” or “s” with 135-degree (2.36 rad) standard hooks at each end that comply with Section R608.5.4.5 and Figure R608.5.4(3) and installed as shown in Figures R608.8(2) through R608.8(4). Where two bars are required in the top and bottom of the lintel and the bars are not bundled, the bars shall be separated by not less than 1 inch (25 mm).
Frequently asked questions
Can small utility penetrations disqualify a solid wall segment?
No — in flat and waffle‑grid walls small penetrations are allowed if they are less than 30 sq in, have no dimension > 6‑1/4 in, and are not within 6 in of the segment side edge. Screen‑grid walls are more permissive provided concrete is not removed. § R608.7.2.
What is the minimum reinforcement at the ends of every counted segment?
There shall be not less than two No. 4 bars at each end of each solid wall segment; use the applicable detail in Figure R608.7.1.1(2) and Table R608.7.1.1(6) for final selection. § R608.7.2.2.2.
If my segment is 36 inches long, can I count it and how many such segments are allowed?
Yes — 36 in ≥ 24 in, so it counts. However, you may include no more than two segments that are ≥ 24 in and < 48 in in the required total. § R608.7.2.1.
What bar size is the minimum for horizontal shear reinforcement?
Where horizontal shear reinforcement is required for an R3 reduction, provide minimum No. 4 horizontal bars (same grade as the vertical reinforcement). § R608.7.2.2.1.
Where do I look to convert reinforcement/layout into an allowable R3 reduction?
Use Equation 6‑2 and then select a wall arrangement in Table R608.7.1.1(6) that has R3 ≤ the value from Equation 6‑2. § R608.7.1.1(6) and associated text.
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