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Buildings shall be provided with exterior and interior braced wall lines as described in Sections 2308.6.1 through 2308.6.10.2.
2308.6.1 Braced Wall Lines
For the purpose of determining the amount and location of bracing required along each story level of a building, braced wall lines shall be designated as straight lines through the building plan in both the longitudinal and transverse direction and placed in accordance with Table 2308.6.1 and Figure 2308.6.1. Braced wall line spacing shall not exceed the distance specified in Table 2308.6.1. In structures assigned to Seismic Design Category D or E, braced wall lines shall intersect perpendicularly to each other.
For SI: 1 foot = 304.8 mm.
FIGURE 2308.6.1
BASIC COMPONENTS OF THE LATERAL BRACING SYSTEM
 
TABLE 2308.6.1
WALL BRACING REQUIREMENTSa
SEISMIC DESIGN CATEGORY STORY CONDITION (SEE SECTION 2308.2) MAXIMUM SPACING OF BRACED WALL LINES BRACED PANEL LOCATION, SPACING (O.C.) AND MINIMUM PERCENTAGE (X) MAXIMUM DISTANCE OF BRACED WALL PANELS FROM EACH END OF BRACED WALL LINE
Bracing methodb
LIB DWB, WSP SFB, PBS, PCP, HPS, GBc, d
A and B 35' - 0" Each end and ≤ 25'- 0" o.c. Each end and ≤ 25'- 0" o.c. Each end and ≤ 25'- 0" o.c. 12'- 6"
35'- 0" Each end and ≤ 25'- 0" o.c. Each end and ≤ 25'- 0" o.c. Each end and ≤ 25'- 0" o.c. 12'- 6"
35'- 0" NP Each end and ≤ 25'- 0" o.c. Each end and ≤ 25'- 0" o.c. 12'- 6"
C 35'- 0" NP Each end and ≤ 25'- 0" o.c. Each end and ≤ 25'- 0" o.c. 12'- 6"
35'- 0" NP Each end and ≤ 25'- 0" o.c. (minimum 25% of wall length)e Each end and ≤ 25'- 0" o.c. (minimum 25% of wall length)e 12'- 6"
D and E 25'- 0" NP SDS < 0.50: Each end and ≤ 25'- 0" o.c. (minimum 21% of wall length)e SDS < 0.50: Each end and ≤ 25'- 0" o.c. (minimum 43% of wall length)e 8'- 0"
0.5 ≤ SDS < 0.75: Each end and ≤ 25'- 0" o.c. (minimum 32% of wall length)e 0.5 ≤ SDS < 0.75: Each end and ≤ 25'- 0" o.c. (minimum 59% of wall length)e
0.75 ≤ SDS ≤ 1.00: Each end and ≤ 25'- 0" o.c. (minimum 37% of wall length)e 0.75 ≤ SDS ≤ 1.00: Each end and ≤ 25'- 0" o.c. (minimum 75% of wall length)
SDS > 1.00: Each end and ≤ 25'- 0" o.c. (minimum 48% of wall length)e SDS > 1.00: Each end and ≤ 25'- 0" o.c. (minimum 100% of wall length)e
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
NP = Not Permitted.
  1. This table specifies minimum requirements for braced wall panels along interior or exterior braced wall lines.
  2. See Section 2308.6.3 for full description of bracing methods.
  3. For Method GB, gypsum wallboard applied to framing supports that are spaced at 16 inches on center.
  4. The required lengths shall be doubled for gypsum board applied to only one face of a braced wall panel.
  5. Percentage shown represents the minimum amount of bracing required along the building length (or wall length if the structure has an irregular shape).
2308.6.2 Braced Wall Panels
Braced wall panels shall be placed along braced wall lines in accordance with Table 2308.6.1 and Figure 2308.6.1 and as specified in Table 2308.6.3(1). A braced wall panel shall be located at each end of the braced wall line and at the corners of intersecting braced wall lines or shall begin within the maximum distance from the end of the braced wall line in accordance with Table 2308.6.1. Braced wall panels in a braced wall line shall not be offset from each other by more than 4 feet (1219 mm). Braced wall panels shall be clearly indicated on the plans.
2308.6.3 Braced Wall Panel Methods
Construction of braced wall panels shall be by one or a combination of the methods in Table 2308.6.3(1). Braced wall panel length shall be in accordance with Section 2308.6.4 or 2308.6.5.
TABLE 2308.6.3(1)
BRACING METHODS
METHODS, MATERIAL MINIMUM THICKNESS FIGURE CONNECTION CRITERIAa
Fasteners Spacing
LIBa

Let-in-bracing
1" × 4" wood or approved metal straps attached at 45° to 60° angles to studs at maximum of 16" o.c. Table 2304.10.2 Wood: per stud plus top and bottom plates
Metal strap: installed in accordance with manufacturer's recommendations Metal strap: installed in accordance with manufacturer's recommendations
DWB

Diagonal wood boards
3/4" thick (1" nominal) × 6" minimum width to studs at maximum of 24" o.c. Table 2304.10.2 Per stud
WSP

Wood structural panel
3/8" in accordance with Table 2308.6.3(2) or 2308.6.3(3) Table 2304.10.2 6" edges 12" field
SFB

Structural fiberboard sheathing
1/2" in accordance with Table 2304.10.2 to studs at maximum 16" o.c. Table 2304.10.2 3" edges 6" field
GB

Gypsum board (Double sided)
1/2" or 5/8" by not less than 4' wide to studs at maximum of 24" o.c. Section 2506.2 for exterior and interior sheathing: 5d annual ringed cooler nails (15/8" × 0.086") or 11/4" screws (Type W or S) for 1/2" gypsum board or 15/8" screws (Type W or S) for 5/8" gypsum board For all braced wall panel locations: 7" o.c. along panel edges (including top and bottom plates) and 7" o.c. in the field
PBS

Particleboard sheathing
3/8" or 1/2" in accordance with Table 2308.6.3(4) to studs at maximum of 16" o.c. 6d common (2" long × 0.113" dia.) nails for 3/8" thick sheathing or 8d common (21/2" long × 0.131" dia.) nails for 1/2" thick sheathing 3" edges 6" field
PCP

Portland cement plaster
Section 2510 to studs at maximum of 16" o.c. 11/2" long, 11 gage, 0.120" dia., 7/16" dia. head nails or 7/8" long, 16 gage staples 6" o.c. on all framing members
HPS

Hardboard panel siding
7/16" in accordance with Table 2308.6.3(5) Table 2304.10.2 4" edges 8" field
ABW

Alternate braced wall
3/8" Figure 2308.6.5.1 and Section 2308.6.5.1 Figure 2308.6.5.1
PFH

Portal frame with hold-downs
3/8" Figure 2308.6.5.2 and Section 2308.6.5.2 Figure 2308.6.5.2
For SI: 1 foot = 304.8 mm, 1 degree = 0.01745 rad.
  1. Method LIB shall have gypsum board fastened to one or more side(s) with nails or screws
EXPOSED PLYWOOD PANEL SIDING
MINIMUM THICKNESSa (inch) MINIMUM NUMBER OF PLIES STUD SPACING (inches) Plywood siding applied directly to studs or over sheathing
3/8 3 16b
1/2 4 24
For SI: 1 inch = 25.4 mm.
  1. Thickness of grooved panels is measured at bottom of grooves.
  2. Spans are permitted to be 24 inches if plywood siding applied with face grain perpendicular to studs or over one of the following: 1-inch board sheathing; 7/16 - inch wood structural panel sheathing; or 3/8-inch wood structural panel sheathing with strength axis (which is the long direction of the panel unless otherwise marked) of sheathing perpendicular to studs.
WOOD STRUCTURAL PANEL WALL SHEATHINGb
(Not exposed to the weather, strength axis parallel or perpendicular to studs except as indicated)
MINIMUM THICKNESS (inch) PANEL SPAN RATING STUD SPACING (inches)
Siding nailed to studs Nailable sheathing
Sheathing parallel to studs Sheathing perpendicular to studs
3/8,15/32,1/2 16/0, 20/0, 24/0, 32/16 Wall—24" o.c. 24 16 24
7/16,15/32,1/2 24/0, 24/16, 32/16 Wall—24" o.c. 24 24a 24
For SI: 1 inch = 25.4 mm.
  1. Plywood shall consist of four or more plies.
  2. Blocking of horizontal joints shall not be required except as specified in Section 2308.6.4.
ALLOWABLE SPANS FOR PARTICLEBOARD WALL SHEATHING
(Not exposed to the weather, long dimension of the panel parallel or perpendicular to studs)
GRADE THICKNESS (inch) STUD SPACING (inches)
Siding nailed to studs Sheathing under coverings specified in Section 2308.6.3 parallel or perpendicular to studs
M-S "Exterior Glue" and M-2 "Exterior Glue" 3/8 16
1/2 16 16
For SI: 1 inch = 25.4 mm.
HARDBOARD SIDING
SIDING MINIMUM NOMINAL THICKNESS (inch) 2 × 4 FRAMING MAXIMUM SPACING NAIL SIZEa, b, d NAIL SPACING
General Bracing panelsc
1. Lap siding
Direct to studs 3/8 16" o.c. 8d 16" o.c. Not applicable
Over sheathing 3/8 16" o.c. 10d 16" o.c. Not applicable
2. Square edge panel siding
Direct to studs 3/8 24" o.c. 6d 6" o.c. edges; 12" o.c. at intermediate supports 4" o.c. edges; 8" o.c. at intermediate supports
Over sheathing 3/8 24" o.c. 8d 6" o.c. edges; 12" o.c. at intermediate supports 4" o.c. edges; 8" o.c. at intermediate supports
3. Shiplap edge panel siding
Direct to studs 3/8 16" o.c. 6d 6" o.c. edges; 12" o.c. at intermediate supports 4" o.c. edges; 8" o.c. at intermediate supports
Over sheathing 3/8 16" o.c. 8d 6" o.c. edges; 12" o.c. at intermediate supports 4" o.c. edges; 8" o.c. at intermediate supports
For SI: 1 inch = 25.4 mm.
  1. Nails shall be corrosion resistant.
  2. Minimum acceptable nail dimensions:
      Panel Siding (inch) Lap Siding (inch)
    Shank diameter 0.092 0.099
    Head diameter 0.225 0.240
  3. Where used to comply with Section 2308.6.
  4. Nail length must accommodate the sheathing and penetrate framing 11/2 inches.
2308.6.4 Braced Wall Panel Construction
For Methods DWB, WSP, SFB, PBS, PCP and HPS, each panel must be not less than 48 inches (1219 mm) in length, covering three stud spaces where studs are spaced 16 inches (406 mm) on center and covering two stud spaces where studs are spaced 24 inches (610 mm) on center. Braced wall panels less than 48 inches (1219 mm) in length shall not contribute toward the amount of required bracing. Braced wall panels that are longer than the required length shall be credited for their actual length. For Method GB, each panel must be not less than 96 inches (2438 mm) in length where applied to one side of the studs or 48 inches (1219 mm) in length where applied to both sides.
Vertical joints of panel sheathing shall occur over studs and adjacent panel joints shall be nailed to common framing members. Horizontal joints shall occur over blocking or other framing equal in size to the studding except where waived by the installation requirements for the specific sheathing materials. Sole plates shall be nailed to the floor framing in accordance with Section 2308.6.7 and top plates shall be connected to the framing above in accordance with Section 2308.6.7.2. Where joists are perpendicular to braced wall lines above, blocking shall be provided under and in line with the braced wall panels.
2308.6.5 Alternative Bracing
An alternate braced wall (ABW) or a portal frame with hold-downs (PFH) described in this section is permitted to substitute for a 48-inch (1219 mm) braced wall panel of Method DWB, WSP, SFB, PBS, PCP or HPS. For Method GB, each 96-inch (2438 mm) section (applied to one face) or 48-inch (1219 mm) section (applied to both faces) or portion thereof required by Table 2308.6.1 is permitted to be replaced by one panel constructed in accordance with Method ABW or PFH.
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