The required length of bracing along each braced wall line shall be determined as follows:
- All buildings in Seismic Design Categories A and B shall use Table R602.10.3(1) and the applicable adjustment factors in Table R602.10.3(2).
- Detached buildings in Seismic Design Category C shall use Table R602.10.3(1) and the applicable adjustment factors in Table R602.10.3(2).
- Townhouses in Seismic Design Category C shall use the greater value determined from Table R602.10.3(1) or R602.10.3(3) and the applicable adjustment factors in Table R602.10.3(2) or R602.10.3(4), respectively.
- All buildings in Seismic Design Categories D0, D1 and D2 shall use the greater value determined from Table R602.10.3(1) or R602.10.3(3) and the applicable adjustment factors in Table R602.10.3(2) or R602.10.3(4), respectively.
Only braced wall panels parallel to the braced wall line shall contribute toward the required length of bracing of that braced wall line. Braced wall panels along an angled wall meeting the minimum length requirements of Tables R602.10.5 and R602.10.5.2 shall be permitted to contribute its projected length toward the minimum required length of bracing for the braced wall line as shown in Figure R602.10.1.4. Any braced wall panel on an angled wall at the end of a braced wall line shall contribute its projected length for only one of the braced wall lines at the projected corner.
Exception: The length of wall bracing for dwellings in Seismic Design Categories D0, D1 and D2 with stone or masonry veneer installed in accordance with Section R703.8 and exceeding the first-story height shall be in accordance with Section R602.10.6.5.
BRACING REQUIREMENTS BASED ON WIND SPEED
| MINIMUM TOTAL LENGTH (FEET) OF BRACED WALL PANELS REQUIRED ALONG EACH BRACED WALL LINEa | ||||||
| Ultimate Design Wind Speed (mph) | Story Location | Braced Wall Line Spacing (feet)c | Method LIBb | Method GB | Methods DWB, WSP, SFB, PBS, PCP, HPS, BV-WSP, ABW, PFH, PFC, CS-SFB | Methods CS-WSP, CS-G, CS-PF |
| ≤ 110 |  | 10 | 3.5 | 3.5 | 2.0 | 1.5 |
| 20 | 6.0 | 6.0 | 3.5 | 3.0 | ||
| 30 | 8.5 | 8.5 | 5.0 | 4.5 | ||
| 40 | 11.5 | 11.5 | 6.5 | 5.5 | ||
| 50 | 14.0 | 14.0 | 8.0 | 7.0 | ||
| 60 | 16.5 | 16.5 | 9.5 | 8.0 | ||
 | 10 | 6.5 | 6.5 | 3.5 | 3.0 | |
| 20 | 11.5 | 11.5 | 6.5 | 5.5 | ||
| 30 | 16.5 | 16.5 | 9.5 | 8.0 | ||
| 40 | 21.5 | 21.5 | 12.5 | 10.5 | ||
| 50 | 26.5 | 26.5 | 15.5 | 13.0 | ||
| 60 | 31.5 | 31.5 | 18.0 | 15.5 | ||
 | 10 | NP | 9.5 | 5.5 | 4.5 | |
| 20 | NP | 17.0 | 10.0 | 8.5 | ||
| 30 | NP | 24.5 | 14.0 | 12.0 | ||
| 40 | NP | 32.0 | 18.5 | 15.5 | ||
| 50 | NP | 39.5 | 22.5 | 19.0 | ||
| 60 | NP | 46.5 | 26.5 | 23.0 | ||
| ≤ 115 |  | 10 | 3.5 | 3.5 | 2.0 | 2.0 |
| 20 | 6.5 | 6.5 | 3.5 | 3.5 | ||
| 30 | 9.5 | 9.5 | 5.5 | 4.5 | ||
| 40 | 12.5 | 12.5 | 7.0 | 6.0 | ||
| 50 | 15.0 | 15.0 | 9.0 | 7.5 | ||
| 60 | 18.0 | 18.0 | 10.5 | 9.0 | ||
 | 10 | 7.0 | 7.0 | 4.0 | 3.5 | |
| 20 | 12.5 | 12.5 | 7.5 | 6.5 | ||
| 30 | 18.0 | 18.0 | 10.5 | 9.0 | ||
| 40 | 23.5 | 23.5 | 13.5 | 11.5 | ||
| 50 | 29.0 | 29.0 | 16.5 | 14.0 | ||
| 60 | 34.5 | 34.5 | 20.0 | 17.0 | ||
 | 10 | NP | 10.0 | 6.0 | 5.0 | |
| 20 | NP | 18.5 | 11.0 | 9.0 | ||
| 30 | NP | 27.0 | 15.5 | 13.0 | ||
| 40 | NP | 35.0 | 20.0 | 17.0 | ||
| 50 | NP | 43.0 | 24.5 | 21.0 | ||
| 60 | NP | 51.0 | 29.0 | 25.0 | ||
| ≤ 120 |  | 10 | 4.0 | 4.0 | 2.5 | 2.0 |
| 20 | 7.0 | 7.0 | 4.0 | 3.5 | ||
| 30 | 10.5 | 10.5 | 6.0 | 5.0 | ||
| 40 | 13.5 | 13.5 | 8.0 | 6.5 | ||
| 50 | 16.5 | 16.5 | 9.5 | 8.0 | ||
| 60 | 19.5 | 19.5 | 11.5 | 9.5 | ||
 | 10 | 7.5 | 7.5 | 4.5 | 3.5 | |
| 20 | 14.0 | 14.0 | 8.0 | 7.0 | ||
| 30 | 20.0 | 20.0 | 11.5 | 9.5 | ||
| 40 | 25.5 | 25.5 | 15.0 | 12.5 | ||
| 50 | 31.5 | 31.5 | 18.0 | 15.5 | ||
| 60 | 37.5 | 37.5 | 21.5 | 18.5 | ||
 | 10 | NP | 11.0 | 6.5 | 5.5 | |
| 20 | NP | 20.5 | 11.5 | 10.0 | ||
| 30 | NP | 29.0 | 17.0 | 14.5 | ||
| 40 | NP | 38.0 | 22.0 | 18.5 | ||
| 50 | NP | 47.0 | 27.0 | 23.0 | ||
| 60 | NP | 55.5 | 32.0 | 27.0 | ||
| ≤ 130 |  | 10 | 4.5 | 4.5 | 2.5 | 2.5 |
| 20 | 8.5 | 8.5 | 5.0 | 4.0 | ||
| 30 | 12.0 | 12.0 | 7.0 | 6.0 | ||
| 40 | 15.5 | 15.5 | 9.0 | 7.5 | ||
| 50 | 19.5 | 19.5 | 11.0 | 9.5 | ||
| 60 | 23.0 | 23.0 | 13.0 | 11.0 | ||
 | 10 | 8.5 | 8.5 | 5.0 | 4.5 | |
| 20 | 16.0 | 16.0 | 9.5 | 8.0 | ||
| 30 | 23.0 | 23.0 | 13.5 | 11.5 | ||
| 40 | 30.0 | 30.0 | 17.5 | 15.0 | ||
| 50 | 37.0 | 37.0 | 21.5 | 18.0 | ||
| 60 | 44.0 | 44.0 | 25.0 | 21.5 | ||
 | 10 | NP | 13.0 | 7.5 | 6.5 | |
| 20 | NP | 24.0 | 13.5 | 11.5 | ||
| 30 | NP | 34.5 | 19.5 | 17.0 | ||
| 40 | NP | 44.5 | 25.5 | 22.0 | ||
| 50 | NP | 55.0 | 31.5 | 26.5 | ||
| 60 | NP | 65.0 | 37.5 | 31.5 | ||
| < 140 |  | 10 | 5.5 | 5.5 | 3.0 | 2.5 |
| 20 | 10.0 | 10.0 | 5.5 | 5.0 | ||
| 30 | 14.0 | 14.0 | 8.0 | 7.0 | ||
| 40 | 18.0 | 18.0 | 10.5 | 9.0 | ||
| 50 | 22.5 | 22.5 | 13.0 | 11.0 | ||
| 60 | 26.5 | 26.5 | 15.0 | 13.0 | ||
 | 10 | 10.0 | 10.0 | 6.0 | 5.0 | |
| 20 | 18.5 | 18.5 | 11.0 | 9.0 | ||
| 30 | 27.0 | 27.0 | 15.5 | 13.0 | ||
| 40 | 35.0 | 35.0 | 20.0 | 17.0 | ||
| 50 | 43.0 | 43.0 | 24.5 | 21.0 | ||
| 60 | 51.0 | 51.0 | 29.0 | 25.0 | ||
 | 10 | NP | 15.0 | 8.5 | 7.5 | |
| 20 | NP | 27.5 | 16.0 | 13.5 | ||
| 30 | NP | 39.5 | 23.0 | 19.5 | ||
| 40 | NP | 51.5 | 29.5 | 25.0 | ||
| 50 | NP | 63.5 | 36.5 | 31.0 | ||
| 60 | NP | 75.5 | 43.0 | 36.5 | ||
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s.
- Linear interpolation shall be permitted.
- Method LIB shall have gypsum board fastened to not less than one side with nails or screws in accordance with Table R602.3(1) for exterior sheathing or Table R702.3.5 for interior gypsum board. Spacing of fasteners at panel edges shall not exceed 8 inches.
- Where a braced wall line has parallel braced wall lines on one or both sides of differing dimensions, the average dimension shall be permitted to be used for braced wall line spacing.
WIND ADJUSTMENT FACTORS TO THE REQUIRED LENGTH OF WALL BRACING
| ITEM NUMBER | ADJUSTMENT BASED ON | STORY/SUPPORTING | CONDITION | ADJUSTMENT FACTORa, b [multiply length from Table R602.10.3(1) by this factor] | APPLICABLE METHODS |
| 1 | Exposure category | One-story structure | B | 1.00 | All methods |
| C | 1.20 | ||||
| D | 1.50 | ||||
| Two-story structure | B | 1.00 | |||
| C | 1.30 | ||||
| D | 1.60 | ||||
| Three-story structure | B | 1.00 | |||
| C | 1.40 | ||||
| D | 1.70 | ||||
| 2 | Roof eave-to-ridge height | Roof only | ≤ 5 feet | 0.70 | |
| 10 feet | 1.00 | ||||
| 15 feet | 1.30 | ||||
| 20 feet | 1.60 | ||||
| Roof + 1 floor | ≤ 5 feet | 0.85 | |||
| 10 feet | 1.00 | ||||
| 15 feet | 1.15 | ||||
| 20 feet | 1.30 | ||||
| Roof + 2 floors | ≤ 5 feet | 0.90 | |||
| 10 feet | 1.00 | ||||
| 15 feet | 1.10 | ||||
| 20 feet | Not permitted | ||||
| 3 | Wall height adjustment | Any story | 8 feet | 0.90 | |
| 9 feet | 0.95 | ||||
| 10 feet | 1.00 | ||||
| 11 feet | 1.05 | ||||
| 12 feet | 1.10 | ||||
| 4 | Number of braced wall lines (per plan direction)c | Any story | 2 | 1.00 | |
| 3 | 1.30 | ||||
| 4 | 1.45 | ||||
| ≥ 5 | 1.60 | ||||
| 5 | Additional 800-pound hold-down device | Top story only | Fastened to the end studs of each braced wall panel and to the foundation or framing below | 0.80 | DWB, WSP, SFB, PBS, PCP, HPS |
| 6 | Interior gypsum board finish (or equivalent) | Any story | Omitted from inside face of braced wall panels | 1.40 | DWB, WSP, SFB, PBS, PCP, HPS, CS-WSP, CS-G, CS-SFB |
| 7 | Gypsum board fastening | Any story | 4 inches o.c. at panel edges, including top and bottom plates, and all horizontal joints blocked | 0.7 | GB |
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound = 4.48 N.
- Linear interpolation shall be permitted.
- The total adjustment factor is the product of all applicable adjustment factors.
- The adjustment factor is permitted to be 1.0 when determining bracing amounts for intermediate braced wall lines provided the bracing amounts on adjacent braced wall lines are based on a spacing and number that neglects the intermediate braced wall line.
TABLE R602.10.3(3) 91.5.602.10.3(3)
BRACING REQUIREMENTS BASED ON SEISMIC DESIGN CATEGORY
|
• SOIL CLASS D b • WALL HEIGHT = 10 FEET • 10 PSF FLOOR DEAD LOAD • 15 PSF ROOF/CEILING DEAD LOAD • BRACED WALL LINE SPACING ≤ 25 FEET |
MINIMUM TOTAL LENGTH (FEET) OF BRACED WALL PANELS REQUIRED ALONG EACH BRACED WALL LINEa | ||||||
| Seismic Design Category | Story Location | Braced Wall Line Length (feet)c | Method LIBdc | Method GBe | Methods DWB, SFB, PBS, PCPe, HPS, CS-SFBed |
Method WSP | Methods CS-WSP, CS-G |
| C (townhouses only) |  |
10 | 2.5 | 2.5 | 2.5 | 1.6 | 1.4 |
| 20 | 5.0 | 5.0 | 5.0 | 3.2 | 2.7 | ||
| 30 | 7.5 | 7.5 | 7.5 | 4.8 | 4.1 | ||
| 40 | 10.0 | 10.0 | 10.0 | 6.4 | 5.4 | ||
| 50 | 12.5 | 12.5 | 12.5 | 8.0 | 6.8 | ||
 |
10 | NP | 4.5 | 4.5 | 3.0 | 2.6 | |
| 20 | NP | 9.0 | 9.0 | 6.0 | 5.1 | ||
| 30 | NP | 13.5 | 13.5 | 9.0 | 7.7 | ||
| 40 | NP | 18.0 | 18.0 | 12.0 | 10.2 | ||
| 50 | NP | 22.5 | 22.5 | 15.0 | 12.8 | ||
 |
10 | NP | 6.0 | 6.0 | 4.5 | 3.8 | |
| 20 | NP | 12.0 | 12.0 | 9.0 | 7.7 | ||
| 30 | NP | 18.0 | 18.0 | 13.5 | 11.5 | ||
| 40 | NP | 24.0 | 24.0 | 18.0 | 15.3 | ||
| 50 | NP | 30.0 | 30.0 | 22.5 | 19.1 | ||
| D0 |  |
10 | NP | 2.8 5.6 | 2.8 5.6 | 1.8 | 1.6 |
| 20 | NP | 5.5 11.0 | 5.5 11.0 | 3.6 | 3.1 | ||
| 30 | NP | 8.3 16.6 | 8.3 16.6 | 5.4 | 4.6 | ||
| 40 | NP | 11.0 22.0 | 11.0 22.0 | 7.2 | 6.1 | ||
| 50 | NP | 13.8 27.6 | 13.8 27.6 | 9.0 | 7.7 | ||
 |
10 | NP | 5.3 NP | 5.3 NP | 3.8 | 3.2 | |
| 20 | NP | 10.5 NP | 10.5 NP | 7.5 | 6.4 | ||
| 30 | NP | 15.8 NP | 15.8 NP | 11.3 | 9.6 | ||
| 40 | NP | 21.0 NP | 21.0 NP | 15.0 | 12.8 | ||
| 50 | NP | 26.3 NP | 26.3 NP | 18.8 | 16.0 | ||
 |
10 | NP | 7.3 NP | 7.3 NP | 5.3 | 4.5 | |
| 20 | NP | 14.5 NP | 14.5 NP | 10.5 | 9.0 | ||
| 30 | NP | 21.8 NP | 21.8 NP | 15.8 | 13.4 | ||
| 40 | NP | 29.0 NP | 29.0 NP | 21.0 | 17.9 | ||
| 50 | NP | 36.3 NP | 36.3 NP | 26.3 | 22.3 | ||
|
• SOIL CLASS D b • WALL HEIGHT = 10 FEET • 10 PSF FLOOR DEAD LOAD • 15 PSF ROOF/CEILING DEAD LOAD • BRACED WALL LINE SPACING ≤ 25 FEET |
MINIMUM TOTAL LENGTH (FEET) OF BRACED WALL PANELS REQUIRED ALONG EACH BRACED WALL LINEa | ||||||
| Seismic Design Category | Story Location | Braced Wall Line Length (feet)c | Method LIBd c | Method GBe | Methods DWB, SFB, PBS, PCPe, HPS, CS-SFBed |
Method WSP | Methods CS-WSP, CS-G |
| D1 |  |
10 | NP | 3.0 6.0 | 3.0 6.0 | 2.0 | 1.7 |
| 20 | NP | 6.0 12.0 | 6.0 12.0 | 4.0 | 3.4 | ||
| 30 | NP | 9.0 18.0 | 9.0 18.0 | 6.0 | 5.1 | ||
| 40 | NP | 12.0 24.0 | 12.0 24.0 | 8.0 | 6.8 | ||
| 50 | NP | 15.0 30.0 | 15.0 30.0 | 10.0 | 8.5 | ||
 |
10 | NP | 6.0 NP | 6.0 NP | 4.5 | 3.8 | |
| 20 | NP | 12.0 NP | 12.0 NP | 9.0 | 7.7 | ||
| 30 | NP | 18.0 NP | 18.0 NP | 13.5 | 11.5 | ||
| 40 | NP | 24.0 NP | 24.0 NP | 18.0 | 15.3 | ||
| 50 | NP | 30.0 NP | 30.0 NP | 22.5 | 19.1 | ||
 |
10 | NP | 8.5 NP | 8.5 NP | 6.0 | 5.1 | |
| 20 | NP | 17.0 NP | 17.0 NP | 12.0 | 10.2 | ||
| 30 | NP | 25.5 NP | 25.5 NP | 18.0 | 15.3 | ||
| 40 | NP | 34.0 NP | 34.0 NP | 24.0 | 20.4 | ||
| 50 | NP | 42.5 NP | 42.5 NP | 30.0 | 25.5 | ||
| D2 |  |
10 | NP | 4.0 8.0 | 4.0 8.0 | 2.5 | 2.1 |
| 20 | NP | 8.0 16.0 | 16.0 | 5.0 | 4.3 | ||
| 30 | NP | 12.0 24.0 | 24.0 | 7.5 | 6.4 | ||
| 40 | NP | 16.0 32.0 | 16.0 32.0 | 10.0 | 8.5 | ||
| 50 | NP | 20.0 40.0 | 20.0 40.0 | 12.5 | 10.6 | ||
 |
10 | NP | 7.5 NP | 7.5 NP | 5.5 | 4.7 | |
| 20 | NP | 15.0 NP | 15.0 NP | 11.0 | 9.4 | ||
| 30 | NP | 22.5 NP | 22.5 NP | 16.5 | 14.0 | ||
| 40 | NP | 30.0 NP | 30.0 NP | 22.0 | 18.7 | ||
| 50 | NP | 37.5 NP | 37.5 NP | 27.5 | 23.4 | ||
 |
10 | NP | NP | NP | NP | NP | |
| 20 | NP | NP | NP | NP | NP | ||
| 30 | NP | NP | NP | NP | NP | ||
| 40 | NP | NP | NP | NP | NP | ||
| 50 | NP | NP | NP | NP | NP | ||
| Cripple wall below one- or two-story dwelling | 10 | NP | NP | NP | 7.5 | 6.4 | |
| 20 | NP | NP | NP | 15.0 | 12.8 | ||
| 30 | NP | NP | NP | 22.5 | 19.1 | ||
| 40 | NP | NP | NP | 30.0 | 25.5 | ||
| 50 | NP | NP | NP | 37.5 | 31.9 | ||
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 305 mm, 1 pound per square foot = 0.0479 kPa.
- Linear interpolation shall be permitted.
- Wall bracing lengths are based on a soil site class "D". Interpolation of bracing length between the Sds values associated with the Seismic Design Categories shall be permitted when a site-specific Sds value is determined in accordance with Section 1613.3 of the California Building Code International Building Code.
- Where the braced wall line length is greater than 50 feet, braced wall lines shall be permitted to be divided into shorter segments having lengths of 50 feet or less, and the amount of bracing within each segment shall be in accordance with this table.
- Method LIB (methods defined by LAMC Table 91.5.602.10.4) shall have gypsum board fastened to not less than at least one side with nails or screws in accordance with per CRC Table R602.3(1) for exterior sheathing or CRC Table R702.3.5 for interior gypsum board. Spacing of fasteners at panel edges shall not exceed 8 inches (203.2 mm).
- Method CS-SFB does not apply in Seismic Design Categories D0, D1 and D2 applies in SDC C only.
- Methods GB and PCP braced wall panel h/w ratio shall not exceed 1:1 in SDC D0, D1, and D2. Methods DWB, SFB, PBS, and HPS are not permitted in SDC D0, D1, and D2.
SEISMIC ADJUSTMENT FACTORS TO THE REQUIRED LENGTH OF WALL BRACING
| ITEM NUMBER | ADJUSTMENT BASED ON: | STORY | CONDITION | ADJUSTMENT FACTORa, b [Multiply length from Table R602.10.3(3) by this factor] | APPLICABLE METHODS |
| 1 | Story height (Section 301.3) | Any story | ≤ 10 feet > 10 feet and ≤ 12 feet | 1.0 1.2 | All methods |
| 2 | Braced wall line spacing, townhouses in SDC C | Any story | ≤ 35 feet > 35 feet and ≤ 50 feet | 1.0 1.43 | |
| 3 | Braced wall line spacing, in SDC D0, D1, D2c | Any story | > 25 feet and ≤ 30 feet > 30 feet and ≤ 35 feet | 1.2 1.4 | |
| 4 | Wall dead load | Any story | > 8 psf and < 15 psf < 8 psf | 1.0 0.85 | |
| 5 | Roof/ceiling dead load for wall supporting | 1-, 2- or 3-story building | ≤15 psf | 1.0 | |
| 2- or 3-story building | > 15 psf and ≤ 25 psf > 15 psf and ≤ 25 psf | 1.1 | |||
| 1-story building | |||||
| 6 | Walls with stone or masonry veneer, townhouses in SDC Cd, e |  | 1.0 | All methods | |
 | 1.5 | ||||
 | 1.5 | ||||
| 7 | Walls with stone or masonry veneer, detached one- and two-family dwellings in SDC D0 — D2d, f | Any story | See Table R602.10.6.5 | BV-WSP | |
| 8 | Interior gypsum board finish (or equivalent) | Any story | Omitted from inside face of braced wall panels | 1.5 | DWB, WSP, SFB, PBS, PCP, HPS, CS-WSP, CS-G, CS-SFB |
For SI: 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
- Linear interpolation shall be permitted.
- The total length of bracing required for a given wall line is the product of all applicable adjustment factors.
- The length-to-width ratio for the floor/roof diaphragm shall not exceed 3:1. The top plate lap splice nailing shall be in accordance with Table R602.3(1), Item 13.
- Applies to stone or masonry veneer exceeding the first story height.
- The adjustment factor for stone or masonry veneer shall be applied to all exterior braced wall lines and all braced wall lines on the interior of the building, backing or perpendicular to and laterally supported veneered walls.
- See Section R602.10.6.5 for requirements where stone or masonry veneer does not exceed the first-story height.