Adopting agency | BSC | BSC- CG |
SFM | HCD | DSA | OSHPD | BSCC | DPH | AGR | DWR | CEC | CA | SL | SLC | |||||||||
1 | 2 | 1/AC | AC | SS | SS/CC | 1 | 1R | 2 | 3 | 4 | 5 | ||||||||||||
Adopt entire chapter | X | ||||||||||||||||||||||
Adopt entire chapter as amended (amended sections listed below) |
X | X | X | X | X | X | X | X | X | ||||||||||||||
Adopt only those sections that are listed below |
X | X | |||||||||||||||||||||
Chapter / Section | |||||||||||||||||||||||
2301.1 | X | ||||||||||||||||||||||
2301.1.1 | X | X | X | X | X | X | X | ||||||||||||||||
2301.1.2 | X | X | X | X | X | X | X | ||||||||||||||||
2301.1.3 | X | X | X | X | |||||||||||||||||||
2301.1.3.1 | X | X | X | ||||||||||||||||||||
2301.1.3.2 | X | ||||||||||||||||||||||
2301.1.4 | X | X | X | X | X | X | X | ||||||||||||||||
2301.2, Item 4, Exception | X | X | X | ||||||||||||||||||||
2303.1.3.1 | X | X | X | X | X | X | X | ||||||||||||||||
2303.1.4.1 | X | X | X | X | X | X | X | ||||||||||||||||
2303.2 — 2303.2.9 | X | ||||||||||||||||||||||
2303.4.1.4.1, Exception 3 | X | X | X | X | X | X | X | ||||||||||||||||
2303.4.3.1 | X | X | X | X | X | X | X | ||||||||||||||||
2304.3.1.1 | X | ||||||||||||||||||||||
2304.3.4 | X | X | X | X | X | X | X | ||||||||||||||||
2304.4.1 | X | X | X | X | X | X | |||||||||||||||||
2304.10.1.1 | X | X | X | X | X | X | |||||||||||||||||
2304.12.1.1.1 | X | ||||||||||||||||||||||
2304.12.1.2, Exception | X | X | X | X | X | X | |||||||||||||||||
2304.12.1.4.1 | X | X | X | X | X | X | |||||||||||||||||
2304.12.8 | X | ||||||||||||||||||||||
2304.12.9 | X | ||||||||||||||||||||||
2305.1.2 | X | X | X | X | X | X | X | ||||||||||||||||
2308.1 | X | X | |||||||||||||||||||||
2308.2.7 | X | X | X | X | X | ||||||||||||||||||
2309.1.1 | X | X | X | X | X |
The Office of the State Fire Marshal's adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.
User notes:
Code development reminder: Code change proposals to this chapter will be considered by the IBC—Structural Code Development Committee during the 2019 (Group B) Code Development Cycle. See explanation on page ix.
Hillside buildings (buildings constructed upon slopes steeper than one unit vertical in three units horizontal [33.3% slope]) shall comply with LAMC Subsection 91.1613.9 (seismic design provisions for hillside buildings) and this division.
For the purposes of this chapter, where dimensions of lumber are specified, they shall be deemed to be nominal dimensions unless specifically designated as actual dimensions (see Section 2304.2).
The design of structural elements or systems, constructed partially or wholly of wood or wood-based products, shall be in accordance with one of the following methods:
- Allowable stress design in accordance with Sections 2304, 2305 and 2306.
- Load and resistance factor design in accordance with Sections 2304, 2305 and 2307.
- Conventional light-frame construction in accordance with Sections 2304 and 2308.
- AWC WFCM in accordance with Section 2309.
- The design and construction of log structures in accordance with the provisions of ICC 400.
- Dry or wet service conditions.
- Laminating combinations and stress requirements.
- Species group.
- Preservative material and retention, when preservative treatment is required.
- Provisions for protection during shipping and field handling, such as sealing and wrapping in accordance with AITC 111.
The design of fasteners and connections shall comply with AITC 117, Section I, Item 6 (Connection Design), and NDS Appendix E.
Wood required by Section 2304.12 to be preservative treated shall bear the quality mark of an inspection agency that maintains continuing supervision, testing and inspection over the quality of the preservative-treated wood. Inspection agencies for preservative-treated wood shall be listed by an accreditation body that complies with the requirements of the American Lumber Standards Treated Wood Program, or equivalent. The quality mark shall be on a stamp or label affixed to the preservative-treated wood, and shall include the following information:
- Identification of treating manufacturer.
- Type of preservative used.
- Minimum preservative retention (pcf).
- End use for which the product is treated.
- AWPA standard to which the product was treated.
- Identity of the accredited inspection agency.
In addition to the labels required in Section 2303.1.1 for sawn lumber and Section 2303.1.5 for wood structural panels, each piece of fire-retardant-treated lumber and wood structural panels shall be labeled. The label shall contain the following items:
- The identification mark of an approved agency in accordance with Section 1703.5.
- Identification of the treating manufacturer.
- The name of the fire-retardant treatment.
- The species of wood treated.
- Flame spread and smoke-developed index.
- Method of drying after treatment.
- Conformance with appropriate standards in accordance with Sections 2303.2.5 through 2303.2.8.
- For fire-retardant-treated wood exposed to weather, damp or wet locations, include the words "No increase in the listed classification when subjected to the Standard Rain Test" (ASTM D2898).
The written, graphic and pictorial depiction of each individual truss shall be provided to the building official for approval prior to installation. Truss design drawings shall be provided with the shipment of trusses delivered to the job site. Truss design drawings shall include, at a minimum, the following information:
- Slope or depth, span and spacing.
- Location of all joints and support locations.
- Number of plies if greater than one.
- Required bearing widths.
Design loads as applicable, including:
- Other lateral loads, including drag strut loads.
- Adjustments to wood member and metal connector plate design value for conditions of use.
- Maximum reaction force and direction, including maximum uplift reaction forces where applicable.
- Joint connection type and description, such as size and thickness or gage, and the dimensioned location of each joint connector except where symmetrically located relative to the joint interface.
- Size, species and grade for each wood member.
- Truss-to-truss connections and truss field assembly requirements.
- Calculated span-to-deflection ratio and maximum vertical and horizontal deflection for live and total load as applicable.
- Maximum axial tension and compression forces in the truss members.
- Required permanent individual truss member restraint location and the method and details of restraint/bracing to be used in accordance with Section 2303.4.1.2.
Where permanent restraint of truss members is required on the truss design drawings, it shall be accomplished by one of the following methods:
- Permanent individual truss member restraint/bracing shall be installed using standard industry lateral restraint/bracing details in accordance with generally accepted engineering practice. Locations for lateral restraint shall be identified on the truss design drawing.
- The trusses shall be designed so that the buckling of any individual truss member is resisted internally by the individual truss through suitable means (for example, buckling reinforcement by T-reinforcement or L-reinforcement, proprietary reinforcement). The buckling reinforcement of individual members of the trusses shall be installed as shown on the truss design drawing or on supplemental truss member buckling reinforcement details provided by the truss designer.
- A project-specific permanent individual truss member restraint/bracing design shall be permitted to be specified by any registered design professional.
- Where a cover sheet and truss index sheet are combined into a single sheet and attached to the set of truss design drawings, the single cover/truss index sheet is the only document required to be signed and sealed by the truss designer.
- Where a cover sheet and a truss index sheet are separately provided and attached to the set of truss design drawings, the cover sheet and the truss index sheet are the only documents required to be signed and sealed by the truss designer.
- [DSA-SS, DSA-SS/CC and OSHPD 1, 1R, 2, 4 & 5] Exceptions 1 and 2 are not permitted by DSA and OSHPD.
- Construction documents. The construction documents
prepared by the registered engineer or
licensed architect for the project shall indicate
all requirements for the truss design, including:
- Deflection criteria.
- Connection details to structural and nonstructural elements (e.g. non-bearing partitions).
- Requirements for approval. The truss design drawings and engineering analysis shall be provided to the enforcement agency and approved prior to truss fabrication, in accordance with the California Administrative Code (Title 24, Part 1). Alterations to the approved truss design drawings or manufactured trusses are subject to the approval of the enforcement agency.
- Engineering analysis shall be furnished that demonstrates compliance of wall framing elements and connections with Section 2302.1, Item 1 or 2.
-
Construction documents shall include detailing of sill
plate anchorage to supporting masonry or concrete
for all exterior and interior bearing, nonbearing and
shear walls. Unless specifically designed in accordance
with Item 1 above, sills under exterior walls,
bearing walls and shear walls shall be bolted to
masonry or concrete with 5/8 inch diameter by 12-inch
(16 mm by 305 mm) bolts spaced not more than four
(4) feet (1219 mm) on center, with a minimum of two
(2) bolts for each piece of sill plate. Anchor bolts
shall have a 4 inch minimum and a 12-inch maximum
clearance to the end of the sill plate, and 7-inch minimum
embedment into concrete or masonry.
Unless specifically designed in accordance with Item 1 above, sill plates under nonbearing interior partitions on concrete floor slabs shall be anchored at not more than four (4) feet (1219 mm) on center to resist a minimum allowable stress shear of 100 pounds per linear foot (1.4 kN/m) acting either parallel or perpendicular to the wall. - Construction documents shall include detailing and limitations for notches and bored holes in wall studs, plates and sills.
- Engineering analysis shall be furnished that demonstrates compliance of floor, roof and ceiling framing elements and connections with Section 2302.1, Items 1 or 2.
- Construction documents shall include detailing and limitations for notches and bored holes in floor and roof framing members.
Where wood structural panel sheathing is used as the exposed finish on the outside of exterior walls, it shall have an exterior exposure durability classification. Where wood structural panel sheathing is used elsewhere, but not as the exposed finish, it shall be of a type manufactured with exterior glue (Exposure 1 or Exterior). Wood structural panel sheathing, connections and framing spacing shall be in accordance with Table 2304.6.1 for the applicable wind speed and exposure category where used in enclosed buildings with a mean roof height not greater than 30 feet (9144 mm) and a topographic factor (Kz t) of 1.0.
MAXIMUM ALLOWABLE STRESS DESIGN WIND SPEED, Vasd PERMITTED FOR WOOD STRUCTURAL PANEL WALL SHEATHING USED TO RESIST WIND PRESSURESa, b, c
MINIMUM NAIL | MINIMUM WOOD STRUCTURAL PANEL SPAN RATING | MINIMUM NOMINAL PANEL THICKNESS (inches) | MAXIMUM WALL STUD SPACING (inches) | PANEL NAIL SPACING | MAXIMUM ALLOWABLE STRESS DESIGN WIND SPEED, Vasd d (MPH) | ||||
Size | Penetration (inches) | Edges (inches o.c.) | Field (inches o.c.) | Wind exposure category | |||||
B | C | D | |||||||
6d common (2.0" × 0.113") | 1.5 | 24/0 | 3/8 | 16 | 6 | 12 | 110 | 90 | 85 |
24/16 | 7/16 | 16 | 6 | 12 | 110 | 100 | 90 | ||
6 | 150 | 125 | 110 | ||||||
8d common (2.5" × 0.131") | 1.75 | 24/16 | 7/16 | 16 | 6 | 12 | 130 | 110 | 105 |
6 | 150 | 125 | 110 | ||||||
24 | 6 | 12 | 110 | 90 | 85 | ||||
6 | 110 | 90 | 85 |
For SI: 1 inch = 25.4 mm, 1 mile per hour = 0.447 m/s.
- Panel strength axis shall be parallel or perpendicular to supports. Three-ply plywood sheathing with studs spaced more than 16 inches on center shall be applied with panel strength axis perpendicular to supports.
- The table is based on wind pressures acting toward and away from building surfaces in accordance with Section 30.7 of ASCE 7. Lateral requirements shall be in accordance with Section 2305 or 2308.
- Wood structural panels with span ratings of wall-16 or wall-24 shall be permitted as an alternative to panels with a 24/0 span rating. Plywood siding rated 16 on center or 24 on center shall be permitted as an alternative to panels with a 24/16 span rating. Wall-16 and plywood siding 16 on center shall be used with studs spaced not more than 16 inches on center.
- Vasd shall be determined in accordance with Section 1609.3.1.
Structural floor sheathing and structural roof sheathing shall comply with Sections 2304.8.1 and 2304.8.2, respectively.
ALLOWABLE SPANS FOR LUMBER FLOOR AND ROOF SHEATHING
SPAN (inches) | MINIMUM NET THICKNESS (inches) OF LUMBER PLACED | |||
Perpendicular to supports | Diagonally to supports | |||
Surfaced drya | Surfaced unseasoned | Surfaced drya | Surfaced unseasoned | |
Floors | ||||
24 | 3/4 | 25/32 | 3/4 | 25/32 |
16 | 5/8 | 11/16 | 5/8 | 11/16 |
Roofs | ||||
24 | 5/8 | 11/16 | 3/4 | 25/32 |
For SI: 1 inch = 25.4 mm.
- Maximum 19-percent moisture content.
SOLID FLOOR OR ROOF SHEATHING | SPACED ROOF SHEATHING | GRADING RULES |
Utility | Standard | NLGA, WCLIB, WWPA |
4 common or utility | 3 common or standard | NLGA, WCLIB, WWPA, NSLB or NELMA |
No. 3 | No. 2 | SPIB |
Merchantable | Construction common | RIS |
ALLOWABLE SPANS AND LOADS FOR WOOD STRUCTURAL PANEL SHEATHING AND SINGLE-FLOOR GRADES CONTINUOUS OVER TWO OR MORE SPANS WITH STRENGTH AXIS PERPENDICULAR TO SUPPORTSa
SHEATHING GRADES | ROOFb | FLOORc | ||||
Panel span rating roof/ floor span | Panel thickness (inches) | Maximum span (inches) | Loadd(psf) | Maximum span (inches) | ||
With edge supporte | Without edge support | Total load | Live load | |||
16/0 | 3/8 | 16 | 16 | 40 | 30 | 0 |
20/0 | 3/8 | 20 | 20 | 40 | 30 | 0 |
24/0 | 3/8, 7/16, 1/2 | 24 | 20f | 40 | 30 | 0 |
24/16 | 7/16, 1/2 | 24 | 24 | 50 | 40 | 16 |
32/16 | 15/32, 1/2, 5/8 | 32 | 28 | 40 | 30 | 16g |
40/20 | 19/32, 5/8, 3/4, 7/8 | 40 | 32 | 40 | 30 | 20g,h |
48/24 | 23/32, 3/4, 7/8 | 48 | 36 | 45 | 35 | 24 |
54/32 | 7/8, 1 | 54 | 40 | 45 | 35 | 32 |
60/32 | 7/8, 11/8 | 60 | 48 | 45 | 35 | 32 |
SINGLE FLOOR GRADES | ROOFb | FLOORc | ||||
Panel span rating | Panel thickness (inches) | Maximum span (inches) | Loade (psf) | Maximum span (inches) | ||
With edge supporte | Without edge support | Total load | Live load | |||
16 o.c. | 1/2, 19/32, 5/8 | 24 | 24 | 50 | 40 | 16g |
20 o.c. | 19/32, 5/8, 3/4 | 32 | 32 | 40 | 30 | 20g,h |
24 o.c. | 23/32, 3/4 | 48 | 36 | 35 | 25 | 24 |
32 o.c. | 7/8, 1 | 48 | 40 | 50 | 40 | 32 |
48 o.c. | 13/32, 11/8 | 60 | 48 | 50 | 40 | 48 |
For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kN/m2.
- Applies to panels 24 inches or wider.
- Uniform load deflection limitations 1/180 of span under live load plus dead load, 1/240 under live load only.
- Panel edges shall have approved tongue-and-groove joints or shall be supported with blocking unless 1/4-inch minimum thickness underlayment or 11/2 inches of approved cellular or lightweight concrete is placed over the subfloor, or finish floor is 3/4-inch wood strip. Allowable uniform load based on deflection of 1/360 of span is 100 pounds per square foot except the span rating of 48 inches on center is based on a total load of 65 pounds per square foot.
- Allowable load at maximum span.
- Tongue-and-groove edges, panel edge clips (one midway between each support, except two equally spaced between supports 48 inches on center), lumber blocking or other. Only lumber blocking shall satisfy blocked diaphragm requirements.
- For 1/2-inch panel, maximum span shall be 24 inches.
- Span is permitted to be 24 inches on center where 3/4-inch wood strip flooring is installed at right angles to joist.
- Span is permitted to be 24 inches on center for floors where 11/2 inches of cellular or lightweight concrete is applied over the panels.
ALLOWABLE SPAN FOR WOOD STRUCTURAL PANEL COMBINATION SUBFLOOR-UNDERLAYMENT (SINGLE FLOOR)a (Panels Continuous Over Two or More Spans and Strength Axis Perpendicular to Supports)
IDENTIFICATION | MAXIMUM SPACING OF JOISTS (inches) | ||||
16 | 20 | 24 | 32 | 48 | |
Species groupb | Thickness (inches) | ||||
1 | 1/2 | 5/8 | 3/4 | — | — |
2, 3 | 5/8 | 3/4 | 7/8 | — | — |
4 | 3/4 | 7/8 | 1 | — | — |
Single floor span ratingc | 16 o.c. | 20 o.c. | 24 o.c. | 32 o.c. | 48 o.c. |
For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kN/m2.
- Spans limited to value shown because of possible effects of concentrated loads. Allowable uniform loads based on deflection of 1/360 of span is 100 pounds per square foot except allowable total uniform load for 11/8-inch wood structural panels over joists spaced 48 inches on center is 65 pounds per square foot. Panel edges shall have approved tongue-and-groove joints or shall be supported with blocking, unless 1/4-inch minimum thickness underlayment or 11/2 inches of approved cellular or lightweight concrete is placed over the subfloor, or finish floor is 3/4-inch wood strip.
- Applicable to all grades of sanded exterior-type plywood. See DOC PS 1 for plywood species groups.
- Applicable to Underlayment grade, C-C (Plugged) plywood, and Single Floor grade wood structural panels.
ALLOWABLE LOAD (PSF) FOR WOOD STRUCTURAL PANEL ROOF SHEATHING CONTINUOUS OVER TWO OR MORE SPANS AND STRENGTH AXIS PARALLEL TO SUPPORTS (Plywood structural panels are five-ply, five-layer unless otherwise noted)a
PANEL GRADE | THICKNESS (inch) | MAXIMUM SPAN (inches) | LOAD AT MAXIMUM SPAN (psf) | |
Live | Total | |||
Structural I sheathing | 7/16 | 24 | 20 | 30 |
15/32 | 24 | 35b | 45b | |
1/2 | 24 | 40b | 50b | |
19/32, 5/8 | 24 | 70 | 80 | |
23/32, 3/4 | 24 | 90 | 100 | |
Sheathing, other grades covered in DOC PS 1 or DOC PS 2 | 7/16 | 16 | 40 | 50 |
15/32 | 24 | 20 | 25 | |
1/2 | 24 | 25 | 30 | |
19/32 | 24 | 40b | 50b | |
5/8 | 24 | 45b | 55b | |
23/32, 3/4 | 24 | 60b | 65b |
For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kN/m2.
Structural floor sheathing shall be designed in accordance with the general provisions of this code.
Floor sheathing conforming to the provisions of Table 2304.8(1), 2304.8(2), 2304.8(3) or 2304.8(4) shall be deemed to meet the requirements of this section.
Structural roof sheathing shall be designed in accordance with the general provisions of this code and the special provisions in this section.
Roof sheathing conforming to the provisions of Table 2304.8(1), 2304.8(2), 2304.8(3) or 2304.8(5) shall be deemed to meet the requirements of this section. Wood structural panel roof sheathing shall be of a type manufactured with exterior glue (Exposure 1 or Exterior).
The decking shall extend across not fewer than three spans. End joints of pieces within 6 inches (152 mm) of the end joints of the adjacent pieces in either direction shall be separated by not fewer than two intervening courses. In the end bays, each piece shall bear on one support or more. Where an end joint occurs in an end bay, the next piece in the same course shall continue over the first inner support for not less than 24 inches (610 mm). The details of the controlled random pattern shall be as specified for each decking material in Section 2304.9.3.3, 2304.9.4.3 or 2304.9.5.3.
Decking that cantilevers beyond a support for a horizontal distance greater than 18 inches (457 mm), 24 inches (610 mm) or 36 inches (914 mm) for 2-inch (51 mm), 3-inch (76 mm) and 4-inch (102 mm) nominal thickness decking, respectively, shall comply with the following:
- The maximum cantilevered length shall be 30 percent of the length of the first adjacent interior span.
- A structural fascia shall be fastened to each decking piece to maintain a continuous, straight line.
- End joints shall not be in the decking between the cantilevered end of the decking and the centerline of the first adjacent interior span.
MINIMUM NAIL SIZE (Length x Diameter) (inches) | MAXIMUM SPACING BETWEEN FACE NAILS a, b (inches) | NUMBER OF TOENAILS INTO SUPPORTSc | |
Decking Supports ≤ 48 inches o.c. | Decking Supports > 48 inches o.c. | ||
4 × 0.192 | 30 | 18 | 1 |
4 × 0.162 | 24 | 14 | 2 |
4 × 0.148 | 22 | 13 | 2 |
31/2 × 0.162 | 20 | 12 | 2 |
31/2 × 0.148 | 19 | 11 | 2 |
31/2 × 0.135 | 17 | 10 | 2 |
3 × 0.148 | 11 | 7 | 2 |
3 × 0.128 | 9 | 5 | 2 |
23/4 × 0.148 | 10 | 6 | 2 |
23/4 × 0.131 | 9 | 6 | 3 |
23/4 × 0.120 | 8 | 5 | 3 |
- Nails shall be driven perpendicular to the lamination face, alternating between top and bottom edges.
- Where nails penetrate through two laminations and into the third, they shall be staggered one-third of the spacing in adjacent laminations. Otherwise, nails shall be staggered one-half of the spacing in adjacent laminations.
- Where supports are 48 inches on center or less, alternate laminations shall be toenailed to alternate supports; where supports are spaced more than 48 inches on center, alternate laminations shall be toenailed to every support.
DESCRIPTION OF BUILDING ELEMENTS | NUMBER AND TYPE OF FASTENER | SPACING AND LOCATION | |
Roof | |||
1. Blocking between ceiling joists, rafters or trusses to top plate or other framing below | 3-8d common (21/2" × 0.131"); or 3-10d box (3" × 0.128"); or 3-3" × 0.131" nails; or 3-3"14 gage staples, 7/16" crown |
Each end, toenail | |
Blocking between rafters or truss not at the wall top plate, to rafter or truss | 2-8d common (21/2" × 0.131") 2-3" × 0.131" nails 2-3" 14 gage staples |
Each end, toenail | |
2-16 d common (31/2" × 0.162") 3-3" × 0.131" nails 3-3" 14 gage staples |
End nail | ||
Flat blocking to truss and web filler | 16d common (31/2" × 0.162") @ 6" o.c. 3" × 0.131" nails @ 6" o.c. 3" × 14 gage staples @ 6" o.c |
Face nail | |
2. Ceiling joists to top plate | 3-8d common (21/2" × 0.131"); or 3-10d box (3" × 0.128"); or 3-3" × 0.131" nails; or 3-3" 14 gage staples, 7/16" crown |
Each joist, toenail | |
3. Ceiling joist not attached to parallel rafter, laps over partitions (no thrust) (see Section 2308.7.3.1, Table 2308.7.3.1) |
3-16d common (31/2" × 0.162"); or 4-10d box (3" × 0.128"); or 4-3" × 0.131" nails; or 4-3" 14 gage staples, 7/16" crown |
Face nail | |
4. Ceiling joist attached to parallel rafter (heel joint) (see Section 2308.7.3.1, Table 2308.7.3.1) |
Per Table 2308.7.3.1 | Face nail | |
5. Collar tie to rafter | 3-10d common (3" × 0.148"); or 4-10d box (3" × 0.128"); or 4-3" × 0.131" nails; or 4-3" 14 gage staples, 7/16" crown |
Face nail | |
6. Rafter or roof truss to top plate (See Section 2308.7.5, Table 2308.7.5) |
3-10 common (3" × 0.148"); or 3-16d box (31/2" × 0.135"); or 4-10d box (3" × 0.128"); or 4-3" × 0.131 nails; or 4-3" 14 gage staples, 7/16" crown |
Toenailc | |
7. Roof rafters to ridge valley or hip rafters; or roof rafter to 2-inch ridge beam | 2-16d common (31/2" × 0.162"); or 3-10d box (3" × 0.128"); or 3-3" × 0.131" nails; or 3-3" 14 gage staples, 7/16" crown; or |
End nail | |
3-10d common (3" × 0.148"); or 4-16d box (31/2" × 0.135"); or 4-10d box (3" × 0.128"); or 4-3" × 0.131" nails; or 4-3" 14 gage staples, 7/16" crown |
Toenail | ||
Wall | |||
8. Stud to stud (not at braced wall panels) | 16d common (31/2" × 0.162"); | 24" o.c. face nail | |
10d box (3" × 0.128"); or 3" × 0.131" nails; or 3-3" 14 gage staples, 7/16" crown |
16" o.c. face nail | ||
9. Stud to stud and abutting studs at intersecting wall corners (at braced wall panels) | 16d common (31/2" × 0.162"); or | 16" o.c. face nail | |
16d box (31/2" × 0.135"); or | 12" o.c. face nail | ||
3" × 0.131" nails; or 3-3" 14 gage staples, 7/16" crown |
12" o.c. face nail | ||
10. Built-up header (2" to 2" header) | 16d common (31/2" × 0.162"); or | 16" o.c. each edge, face nail | |
16d box (31/2" × 0.135") | 12" o.c. each edge, face nail | ||
11. Continuous header to stud | 4-8d common (21/2" × 0.131"); or 4-10d box (3" × 0.128") |
Toenail | |
12. Top plate to top plate | 16d common (31/2" × 0.162"); or | 16" o.c. face nail | |
10d box (3" × 0.128"); or 3" × 0.131" nails; or 3" 14 gage staples, 7/16" crown |
12" o.c. face nail | ||
13. Top plate to top plate, at end joints | 8-16d common (31/2" × 0.162"); or 12-10d box (3" × 0.128"); or 12-3" × 0.131" nails; or 12-3" 14 gage staples, 7/16" crown |
Each side of end joint, face nail (minimum 24" lap splice length each side of end joint) | |
14. Bottom plate to joist, rim joist, band joist or blocking (not at braced wall panels) | 16d common (31/2" × 0.162"); or | 16" o.c. face nail | |
16d box (31/2" × 0.135"); or 3" × 0.131" nails; or 3" 14 gage staples, 7/16" crown |
12" o.c. face nail | ||
15. Bottom plate to joist, rim joist, band joist or blocking at braced wall panels | 2-16d common (31/2" × 0.162"); or 3-16d box (31/2" × 0.135"); or 4-3" × 0.131" nails; or 4-3" 14 gage staples, 7/16" crown |
16" o.c. face nail | |
16. Stud to top or bottom plate | 4-8d common (21/2" × 0.131"); or 4-10d box (3" × 0.128"); or 4-3" × 0.131" nails; or 4-3" 14 gage staples, 7/16" crown; or |
Toenail | |
2-16d common (31/2" × 0.162"); or 3-10d box (3" × 0.128"); or 3-3" × 0.131" nails; or 3-3" 14 gage staples, 7/16" crown |
End nail | ||
17. Top plates, laps at corners and intersections | 2-16d common (31/2" × 0.162"); or 3-10d box (3" × 0.128"); or 3-3" × 0.131" nails; or 3-3" 14 gage staples, 7/16" crown |
Face nail | |
18. 1" brace to each stud and plate | 2-8d common (21/2" × 0.131"); or 2-10d box (3" × 0.128"); or 2-3" × 0.131" nails; or 2-3" 14 gage staples, 7/16" crown |
Face nail | |
19. 1" × 6" sheathing to each bearing | 2-8d common (21/2" × 0.131"); or 2-10d box (3" × 0.128") |
Face nail | |
20. 1" × 8" and wider sheathing to each bearing | 3-8d common (21/2" × 0.131"); or 3-10d box (3" × 0.128") |
Face nail | |
Floor | |||
21. Joist to sill, top plate, or girder | 3-8d common (21/2" × 0.131"); or floor 3-10d box (3" × 0.128"); or 3-3" × 0.131" nails; or 3-3" 14 gage staples, 7/16" crown |
Toenail | |
22. Rim joist, band joist, or blocking to top plate, sill or other framing below | 8d common (21/2" × 0.131"); or 10d box (3" × 0.128"); or 3" × 0.131" nails; or 3" 14 gage staples, 7/16" crown |
6" o.c., toenail | |
23. 1" × 6" subfloor or less to each joist | 2-8d common (21/2" × 0.131"); or 2-10d box (3" × 0.128") |
Face nail | |
24. 2" subfloor to joist or girder | 2-16d common (31/2" × 0.162") | Face nail | |
25. 2" planks (plank & beam — floor & roof) | 2-16d common (31/2" × 0.162") | Each bearing, face nail | |
26. Built-up girders and beams, 2" lumber layers | 20d common (4" × 0.192") | 32" o.c., face nail at top and bottom staggered on opposite sides | |
10d box (3" × 0.128"); or 3" × 0.131" nails; or 3" 14 gage staples, 7/16" crown |
24" o.c. face nail at top and bottom staggered on opposite sides | ||
And: 2-20d common (4" × 0.192"); or 3-10d box (3" × 0.128"); or 3-3" × 0.131" nails; or 3-3" 14 gage staples, 7/16" crown |
Ends and at each splice, face nail | ||
27. Ledger strip supporting joists or rafters | 3-16d common (31/2" × 0.162"); or 4-10d box (3" × 0.128"); or 4-3" × 0.131" nails; or 4-3" 14 gage staples, 7/16" crown |
Each joist or rafter, face nail | |
28. Joist to band joist or rim joist | 3-16d common (31/2" × 0.162"); or 4-10d box (3" × 0.128"); or 4-3" × 0.131" nails; or 4-3" 14 gage staples, 7/16" crown |
End nail | |
29. Bridging or blocking to joist, rafter or truss | 2-8d common (21/2" × 0.131"); or 2-10d box (3" × 0.128"); or 2-3" × 0.131" nails; or 2-3" 14 gage staples, 7/16" crown |
Each end, toenail | |
Wood structural panels (WSP), subfloor, roof and interior wall sheathing to framing and particleboard wall sheathing to framinga | |||
Edges (inches) |
Intermediate supports (inches) |
||
30. 3/8" — 1/2" | 6d common or deformed (2" × 0.113") (subfloor and wall) | 6 | 12 |
8d common or deformed (21/2" × 0.131") (roof) or RSRS-01 (23/8" × 0.113") nail (roof)d | 6 | 12 | |
23/8" × 0.113" nail (subfloor and wall) | 6 | 12 | |
13/4" 16 gage staple, 7/16" crown (subfloor and wall) |
4 | 8 | |
23/8" × 0.113" nail (roof) | 4 | 8 | |
13/4" 16 gage staple, 7/16" crown (roof) | 3 | 6 | |
31. 19/32" — 3/4" | 8d common (21/2" × 0.131"); or 6d deformed (2" × 0.113") (subfloor and wall) |
6 | 12 |
8d common or deformed (21/2" × 0.131") (roof) or RSRS-01 (23/8" × 0.113") nail (roof)d |
6 | 12 | |
23/8" × 0.113" nail; or 2" 16 gage staple, 7/16" crown |
4 | 8 | |
32. 7/8" — 11/4" | 10d common (3" × 0.148"); or 8d deformed (21/2" × 0.131") |
6 | 12 |
Other exterior wall sheathing | |||
33. 1/2" fiberboard sheathingb | 11/2" galvanized roofing nail (7/16" head diameter); or 11/4" 16 gage staple with 7/16" or 1" crown |
3 | 6 |
34. 25/32" fiberboard sheathingb | 13/4" galvanized roofing nail (7/16" diameter head); or 11/2" 16 gage staple with 7/16" or 1" crown |
3 | 6 |
Wood structural panels, combination subfloor underlayment to framing | |||
35. 3/4" and less | 8d common (21/2" × 0.131"); or 6d deformed (2" × 0.113") |
6 | 12 |
36. 7/8" — 1" | 8d common (21/2" × 0.131"); or 8d deformed (21/2" × 0.131") |
6 | 12 |
37. 11/8" — 11/4" | 10d common (3" × 0.148"); or 8d deformed (21/2" × 0.131") |
6 | 12 |
Panel siding to framing | |||
38. 1/2" or less | 6d corrosion-resistant siding (17/8" × 0.106"); or 6d corrosion-resistant casing (2" × 0.099") |
6 | 12 |
39. 5/8" | 8d corrosion-resistant siding (23/8" × 0.128"); or 8d corrosion-resistant casing (21/2" × 0.113") |
6 | 12 |
Interior paneling | |||
40. 1/4" | 4d casing (11/2" × 0.080"); or 4d finish (11/2" × 0.072") |
6 | 12 |
41. 3/8" | 6d casing (2" × 0.099"); or 6d finish (Panel supports at 24 inches) |
6 | 12 |
- Nails spaced at 6 inches at intermediate supports where spans are 48 inches or more. For nailing of wood structural panel and particleboard diaphragms and shear walls, refer to Section 2305. Nails for wall sheathing are permitted to be common, box or casing.
- Spacing shall be 6 inches on center on the edges and 12 inches on center at intermediate supports for nonstructural applications. Panel supports at 16 inches (20 inches if strength axis in the long direction of the panel, unless otherwise marked).
- Where a rafter is fastened to an adjacent parallel ceiling joist in accordance with this schedule and the ceiling joist is fastened to the top plate in accordance with this schedule, the number of toenails in the rafter shall be permitted to be reduced by one nail.
- RSRS-01 is a Roof Sheathing Ring Shank nail meeting the specifications in ASTM F1667. Staples shall not be used to resist or transfer seismic forces in structures assigned to Seismic Design Category D, E or F.
Fasteners, including nuts and washers, in contact with preservative-treated wood shall be of hot-dipped zinc-coated galvanized steel, stainless steel, silicon bronze or copper. Staples shall be of stainless steel. Fasteners other than nails, staples, timber rivets, wood screws and lag screws shall be permitted to be of mechanically deposited zinc-coated steel with coating weights in accordance with ASTM B695, Class 55 minimum. Connectors that are used in exterior applications and in contact with preservative-treated wood shall have coating types and weights in accordance with the treated wood or connector manufacturer's recommendations. In the absence of manufacturer's recommendations, not less than ASTM A653, Type G185 zinc-coated galvanized steel, or equivalent, shall be used.
Exception: Plain carbon steel fasteners, including nuts and washers, in SBX/DOT and zinc borate preservative-treated wood in an interior, dry environment shall be permitted.
Where a structure, portion thereof or individual structural elements are required by provisions of this code to be of heavy timber, the building elements therein shall comply with the applicable provisions of Sections 2304.11.1 through 2304.11.4. Minimum dimensions of heavy timber shall comply with the applicable requirements in Table 2304.11 based on roofs or floors supported and the configuration of each structural element, or in Sections 2304.11.2 through 2304.11.4. Lumber decking shall be in accordance with Section 2304.9.
MINIMUM DIMENSIONS OF HEAVY TIMBER STRUCTURAL MEMBERS
MINIMUM NOMINAL
SOLID SAWN SIZE
|
MINIMUM GLUED-
LAMINATED NET SIZE
|
MINIMUM STRUCTURAL
COMPOSITE LUMBER NET SIZE
|
|||||
SUPPORTING | HEAVY TIMBER STRUCTURAL
ELEMENTS
|
Width, inch | Depth, inch | Width, inch | Depth, inch | Width, inch | Depth, inch |
Floor loads only
or combined floor
and roof loads |
Columns;
Framed sawn or glued-laminated
timber arches that spring from the
floor line;
Framed timber trusses |
8 | 8 | 63/4 | 81/4 | 7 | 71/2 |
Wood beams and girders | 6 | 10 | 5 | 101/2 | 51/4 | 91/2 | |
Roof loads only | Columns (roof and ceiling loads);
Lower half of: wood-frame
or glued-laminated arches
that spring from the floor
line or from grade |
6 | 8 | 5 | 81/4 | 51/4 | 71/2 |
Upper half of: wood-frame
or glued-laminated arches
that spring from the floor
line or from grade
|
6 | 6 | 5 | 6 | 51/4 | 51/2 | |
Framed timber trusses and other
roof framing; a
Framed or glued-laminated
arches that spring from the top
of walls or wall abutments |
4b | 6 | 3b | 67/8 | 31/2b | 51/2 |
For SI: 1 inch = 25.4 mm.
- Spaced members shall be permitted to be composed of two or more pieces not less than 3 inches nominal in thickness where blocked solidly throughout their intervening spaces or where spaces are tightly closed by a continuous wood cover plate of not less than 2 inches nominal in thickness secured to the underside of the members. Splice plates shall be not less than 3 inches nominal in thickness.
- Where protected by approved automatic sprinklers under the roof deck, framing members shall be not less than 3 inches nominal in width.
Sawn or glued-laminated plank floors shall be one of the following:
- Sawn or glued-laminated planks, splined or tongue-and-groove, of not less than 3 inches (76 mm) nominal in thickness covered with 1-inch (25 mm) nominal dimension tongue-and-groove flooring, laid crosswise or diagonally, 15/32-inch (12 mm) wood structural panel or 1/2-inch (12.7 mm) particleboard.
- Planks not less than 4 inches (102 mm) nominal in width set on edge close together and well spiked and covered with 1-inch (25 mm) nominal dimension flooring or 15/32-inch (12 mm) wood structural panel or 1/2-inch (12.7 mm) particleboard.
The lumber shall be laid so that continuous lines of joints will occur only at points of support. Floors shall not extend closer than 1/2 inch (12.7 mm) to walls. Such 1/2-inch (12.7 mm) space shall be covered by a molding fastened to the wall and so arranged that it will not obstruct the swelling or shrinkage movements of the floor. Corbelling of masonry walls under the floor shall be permitted to be used in place of molding.
Sawn, wood structural panel, or glued-laminated plank roofs shall be one of the following:
- Sawn or glued laminated, splined or tongue-and-groove plank, not less than 2 inches (51 mm) nominal in thickness.
- 11/8-inch-thick (32 mm) wood structural panel (exterior glue).
- Planks not less than 3 inches (76 mm) nominal in width, set on edge close together and laid as required for floors.
Posts or columns supporting permanent structures and supported by a concrete or masonry slab or footing that is in direct contact with the earth shall be of naturally durable or preservative-treated wood.
Exception: Posts or columns that meet all of the following:
- Are not exposed to the weather, or are protected by a roof, eave, overhang, or other covering if exposed to the weather.
- Are supported by concrete piers or metal pedestals projected not less than 1 inch (25 mm) above the slab or deck and are separated from the concrete pier by an impervious moisture barrier.
- Are located not less than 8 inches (203 mm) above exposed earth.
Naturally durable or preservative-treated wood shall be utilized for those portions of wood members that form the structural supports of buildings, balconies, porches or similar permanent building appurtenances where such members are exposed to the weather without adequate protection from a roof, eave, overhang or other covering to prevent moisture or water accumulation on the surface or at joints between members.
Exception: Buildings located in a geographical region where experience has demonstrated that climatic conditions preclude the need to use durable materials where the structure is exposed to the weather.
Wood used in contact with exposed earth shall be naturally durable for both decay and termite resistance or preservative treated in accordance with AWPA U1 for soil or fresh water use.
Exception: Untreated wood is permitted where such wood is continuously and entirely below the ground-water level or submerged in fresh water.
Wood members supporting concrete, masonry or similar materials shall be checked for the effects of long-term loading using the provisions of the ANSI/AWC NDS. The total deflection, including the effects of long-term loading, shall be limited in accordance with Section 1604.3.1 for these supported materials.
Exception: Horizontal wood members supporting masonry or concrete nonstructural floor or roof surfacing not more than 4 inches (102 mm) thick need not be checked for long-term loading.
For SI: Δdia = 0.052vL3/EAW + vL/4Gt + Len/1627 + Σ(xΔc)/2W
where: | ||
A | = | Area of chord cross section, in square inches (mm2). |
E | = | Modulus of elasticity of diaphragm chords, in pounds per square inch (N/mm2). |
en | = | Staple slip, in inches (mm) [see Table 2305.2(1)]. |
Gt | = | Panel rigidity through the thickness, in pounds per inch (N/mm) of panel width or depth [see Table 2305.2(2)]. |
L | = | Diaphragm length (dimension perpendicular to the direction of the applied load), in feet (mm). |
v | = | Induced unit shear in pounds per linear foot (plf) (N/mm). |
W | = | Diaphragm width [in the direction of applied force, in feet (mm)]. |
x | = | Distance from chord splice to nearest support, in feet (mm). |
Δc | = | Diaphragm chord splice slip at the induced unit shear, in inches (mm). |
Δdia | = | Maximum mid-span diaphragm deflection determined by elastic analysis, in inches (mm). |
LOAD PER FASTENERb (pounds) | FASTENER DESIGNATIONS |
14-Ga staple × 2 inches long | |
60 | 0.011 |
80 | 0.018 |
100 | 0.028 |
120 | 0.04 |
140 | 0.053 |
160 | 0.068 |
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound = 4.448 N.
PANEL TYPE | SPAN RATING | VALUES OF Gt (lb/in. panel depth or width) | |||||||
Structural Sheathing | Structural I | ||||||||
Plywood | OSB | Plywood | OSB | ||||||
3-ply | 4-ply | 5-plya | 3-ply | 4-ply | 5-plya | ||||
Sheathing | 24/0 | 25,000 | 32,500 | 37,500 | 77,500 | 32,500 | 42,500 | 41,500 | 77,500 |
24/16 | 27,000 | 35,000 | 40,500 | 83,500 | 35,000 | 45,500 | 44,500 | 83,500 | |
32/16 | 27,000 | 35,000 | 40,500 | 83,500 | 35,000 | 45,500 | 44,500 | 83,500 | |
40/20 | 28,500 | 37,000 | 43,000 | 88,500 | 37,000 | 48,000 | 47,500 | 88,500 | |
48/24 | 31,000 | 40,500 | 46,500 | 96,000 | 40,500 | 52,500 | 51,000 | 96,000 | |
Single Floor | 16 o.c. | 27,000 | 35,000 | 40,500 | 83,500 | 35,000 | 45,500 | 44,500 | 83,500 |
20 o.c. | 28,000 | 36,500 | 42,000 | 87,000 | 36,500 | 47,500 | 46,000 | 87,000 | |
24 o.c. | 30,000 | 39,000 | 45,000 | 93,000 | 39,000 | 50,500 | 49,500 | 93,000 | |
32 o.c. | 36,000 | 47,000 | 54,000 | 110,000 | 47,000 | 61,000 | 59,500 | 110,000 | |
48 o.c. | 50,500 | 65,500 | 76,000 | 155,000 | 65,500 | 85,000 | 83,500 | 155,000 |
Structural Sheathing | Structural I | ||||||
Thickness (in.) | A-A, A-C | Marine | All Other Grades | A-A, A-C | Marine | All Other Grades | |
Sanded Plywood | 1/4 | 24,000 | 31,000 | 24,000 | 31,000 | 31,000 | 31,000 |
11/32 | 25,500 | 33,000 | 25,500 | 33,000 | 33,000 | 33,000 | |
3/8 | 26,000 | 34,000 | 26,000 | 34,000 | 34,000 | 34,000 | |
15/32 | 38,000 | 49,500 | 38,000 | 49,500 | 49,500 | 49,500 | |
1/2 | 38,500 | 50,000 | 38,500 | 50,000 | 50,000 | 50,000 | |
19/32 | 49,000 | 63,500 | 49,000 | 63,500 | 63,500 | 63,500 | |
5/8 | 49,500 | 64,500 | 49,500 | 64,500 | 64,500 | 64,500 | |
23/32 | 50,500 | 65,500 | 50,500 | 65,500 | 65,500 | 65,500 | |
3/4 | 51,000 | 66,500 | 51,000 | 66,500 | 66,500 | 66,500 | |
7/8 | 52,500 | 68,500 | 52,500 | 68,500 | 68,500 | 68,500 | |
1 | 73,500 | 95,500 | 73,500 | 95,500 | 95,500 | 95,500 | |
11/8 | 75,000 | 97,500 | 75,000 | 97,500 | 97,500 | 97,500 |
where: | ||
A | = | Area of end-post cross section in square inches (mm2). |
b | = | Shear wall length, in feet (mm). |
da | = | Total vertical elongation of wall anchorage system (such as fastener slip, device elongation, rod elongation) at the induced unit shear in the shear wall (v). |
E | = | Modulus of elasticity of end posts, in pounds per square inch (N/mm2). |
en | = | Staple slip, in inches (mm) [see Table 2305.2(1)]. |
Gt | = | Panel rigidity through the thickness, in pounds per inch (N/mm) of panel width or depth [see Table 2305.2(2)]. |
h | = | Shear wall height, in feet (mm). |
v | = | Induced unit shear, in pounds per linear foot (N/mm). |
Δsw | = | Maximum shear wall deflection determined by elastic analysis, in inches (mm). |
The design and construction of wood elements in structures using allowable stress design shall be in accordance with the following applicable standards:
American Wood Council.
ANSI/AWC NDS | National Design Specification for Wood Construction |
SDPWS | Special Design Provisions for Wind and Seismic |
American Society of Agricultural and Biological Engineers.
ASABE EP 484.3 | Diaphragm Design of Metal-clad, Wood-Frame Rectangular Buildings |
ASABE EP 486.2 | Shallow Post Foundation Design |
ASABE EP 559.1 | Design Requirements and Bending Properties for Mechanically Laminated Wood Assemblies |
APA—The Engineered Wood Association.
ANSI 117 Standard Specifications for Structural Glued Laminated Timber of Softwood Species | |
ANSI A190.1 Structural Glued Laminated Timber | |
Panel Design Specification | |
Plywood Design Specification Supplement 1— | |
Plywood Design Specification Supplement 2—
Design & Fabrication of Glued Plywood-lumber Beams
|
|
Plywood Design Specification Supplement 3— | |
Plywood Design Specification Supplement 4— | |
Plywood Design Specification Supplement 5—
Design & Fabrication of All-plywood Beams
|
|
APA T300 | Glulam Connection Details |
APA S560 | Field Notching and Drilling of Glued
Laminated Timber Beams
|
APA S475 | Glued Laminated Beam Design Tables |
APA X450 | Glulam in Residential Construction |
APA X440 | Product and Application Guide: Glulam |
APA R540 | Builders Tips: Proper Storage and Handling of Glulam Beams |
Truss Plate Institute, Inc.
TPI 1 | National Design Standard for Metal Plate Connected Wood Truss Construction |
West Coast Lumber Inspection Bureau
AITC 104 | Typical Construction Details | |
AITC 110 | Standard Appearance Grades for Structural Glued Laminated Timber | |
AITC 113 | Standard for Dimensions of Structural Glued Laminated Timber | |
AITC 119 | Standard Specifications for Structural Glued Laminated Timber of Hardwood Species | |
AITC 200 | Inspection Manual |
The allowable unit stresses for preservative-treated wood need not be adjusted for treatment, but are subject to other adjustments.
The allowable unit stresses for fire-retardant-treated wood, including fastener values, shall be developed from an approved method of investigation that considers the effects of anticipated temperature and humidity to which the fire-retardant-treated wood will be subjected, the type of treatment and the redrying process. Other adjustments are applicable except that the impact load duration shall not apply.
The capacity of lumber decking arranged according to the patterns described in Section 2304.9.2 shall be the lesser of the capacities determined for flexure and deflection according to the formulas in Table 2306.1.4.
ALLOWABLE LOADS FOR LUMBER DECKING
PATTERN | ALLOWABLE AREA LOADa, b | |
Flexure | Deflection | |
Simple span | ||
Two-span continuous | ||
Combination simple- and two-span continuous | ||
Cantilevered pieces intermixed | ||
Controlled random layup | ||
Mechanically laminated decking | ||
2-inch decking | ||
3-inch and 4-inch decking |
- σb = Allowable total uniform load limited by bending.
σΔ = Allowable total uniform load limited by deflection. - d = Actual decking thickness.
l = Span of decking.
Fb' = Allowable bending stress adjusted by applicable factors.
E' = Modulus of elasticity adjusted by applicable factors.
The allowable shear values of CBC Tables 2306.2(1) and 2306.2(2) are permitted to be increased 40% for wind design.
Wood structural panel diaphragms used to resist seismic forces in structures assigned to Seismic Design Category D, E or F shall be applied directly to the framing members.
ALLOWABLE SHEAR VALUES (POUNDS PER FOOT) FOR WOOD STRUCTURAL PANEL DIAPHRAGMS UTILIZING STAPLES WITH FRAMING OF DOUGLAS FIR-LARCH, OR SOUTHERN PINEa FOR WIND OR SEISMIC LOADINGf
PANEL GRADE |
STAPLE LENGTH AND GAGEd |
MINIMUM FASTENER PENETRATION IN FRAMING (inches) |
MINIMUM NOMINAL PANEL THICKNESS (inch) |
MINIMUM NOMINAL WIDTH OF FRAMING MEMBERS AT ADJOINING PANEL EDGES AND BOUNDARIESe (inches) |
BLOCKED DIAPHRAGMS |
UNBLOCKED DIAPHRAGMS |
||||||
Fastener spacing (inches) at diaphragm boundaries (all cases) at continuous panel edges parallel to load (Cases 3, 4), and at all panel edges (Cases 5, 6)b |
Fasteners spaced 6 max. at supported edgesb |
|||||||||||
6 | 4 | 21/2c | 2c | Case 1 (No unblocked edges or continuous joints parallel to load) |
All other configurations (Cases 2, 3, 4, 5 and 6) |
|||||||
Fastener spacing (inches) at other panel edges (Cases 1, 2, 3 and 4)b |
||||||||||||
6 | 6 | 4 | 3 | |||||||||
Structural I | 11/2
16 gage
|
1 | 3/8 | 2 | 175 | 235 | 350 | 400 | 155 | 115 | ||
3 | 200 | 265 | 395 | 450 | 175 | 130 | ||||||
15/32 | 2 | 175 | 235 | 350 | 400 | 155 | 120 | |||||
3 | 200 | 265 | 395 | 450 | 175 | 130 | ||||||
Sheathing,
single floor
and other
covered in
DOC PS 1
and PS 2 |
11/2
16 gage
|
1 | 3/8 | 2 | 160 | 210 | 315 | 360 | 140 | 105 | ||
3 | 180 | 235 | 355 | 400 | 160 | 120 | ||||||
7/16 | 2 | 165 | 225 | 335 | 380 | 150 | 110 | |||||
3 | 190 | 250 | 375 | 425 | 165 | 125 | ||||||
15/32 | 2 | 160 | 210 | 315 | 360 | 140 | 105 | |||||
3 | 180 | 235 | 355 | 405 | 160 | 120 | ||||||
19/32 | 2 | 175 | 235 | 350 | 400 | 155 | 115 | |||||
3 | 200 | 265 | 395 | 450 | 175 | 130 |
For SI: 1 inch = 25.4 mm, 1 pound per foot = 14.5939 N/m.
- For framing of other species: (1) Find specific gravity for species of lumber in ANSI/AWC NDS. (2) For staples find shear value from table for Structural I panels (regardless of actual grade) and multiply value by 0.82 for species with specific gravity of 0.42 or greater, or 0.65 for all other species.
- Space fasteners maximum 12 inches on center along intermediate framing members (6 inches on center where supports are spaced 48 inches on center).
- Framing at adjoining panel edges shall be 3 inches nominal or wider.
- Staples shall have a minimum crown width of 7/16 inch and shall be installed with their crowns parallel to the long dimension of the framing members.
- The minimum nominal width of framing members not located at boundaries or adjoining panel edges shall be 2 inches.
- For shear loads of normal or permanent load duration as defined by the ANSI/AWC NDS, the values in the table shall be multiplied by 0.63 or 0.56, respectively.
TABLE 2306.2(2)
ALLOWABLE SHEAR VALUES (POUNDS PER FOOT) FOR WOOD STRUCTURAL PANEL BLOCKED DIAPHRAGMS UTILIZING MULTIPLE ROWS OF STAPLES (HIGH-LOAD DIAPHRAGMS) WITH FRAMING OF DOUGLAS FIR-LARCH OR SOUTHERN PINEa FOR WIND OR SEISMIC LOADINGb, g, h
PANEL GRADEc | STAPLE GAGEf |
MINIMUM FASTENER PENETRATION IN FRAMING (inches) |
MINIMUM NOMINAL PANEL THICKNESS (inch) |
MINIMUM NOMINAL WIDTH OF FRAMING MEMBER AT ADJOINING PANEL EDGES AND BOUNDARIESe |
LINES OF FASTENERS |
BLOCKED DIAPHRAGMS | |||||
Cases 1 and 2d | |||||||||||
Fastener Spacing Per Line at Boundaries (inches) |
|||||||||||
4 | 21/2 | 2 | |||||||||
Fastener Spacing Per Line at Other Panel Edges (inches) |
|||||||||||
6 | 4 | 4 | 3 | 3 | 2 | ||||||
Structural I grades | 14 gage
staples
|
2 | 15/32 | 3 | 2 | 600 | 600 | 860 | 960 | 1,060 | 1,200 |
4 | 3 | 860 | 900 | 1,160 | 1,295 | 1,295 | 1,400 | ||||
19/32 | 3 | 2 | 600 | 600 | 875 | 960 | 1,075 | 1,200 | |||
4 | 3 | 875 | 900 | 1,175 | 1,440 | 1,475 | 1,795 | ||||
Sheathing single
floor and other
grades covered in
DOC PS 1 and PS 2
|
14 gage
staples
|
2 | 15/32 | 3 | 2 | 540 | 540 | 735 | 865 | 915 | 1,080 |
4 | 3 | 735 | 810 | 1,005 | 1,105 | 1,105 | 1,195 | ||||
19/32 | 3 | 2 | 600 | 600 | 865 | 960 | 1,065 | 1,200 | |||
4 | 3 | 865 | 900 | 1,130 | 1,430 | 1,370 | 1,485 | ||||
23/32 | 4 | 3 | 865 | 900 | 1,130 | 1,490 | 1,430 | 1,545 |
For SI: 1 inch = 25.4 mm, 1 pound per foot = 14.5939 N/m.
- For framing of other species: (1) Find specific gravity for species of framing lumber in ANSI/AWC NDS. (2) For staples, find shear value from table for Structural I panels (regardless of actual grade) and multiply value by 0.82 for species with specific gravity of 0.42 or greater, or 0.65 for all other species.
- Fastening along intermediate framing members: Space fasteners not greater than 12 inches on center, except 6 inches on center for spans greater than 32 inches.
- Panels conforming to PS 1 or PS 2.
- This table gives shear values for Cases 1 and 2 as shown in Table 2306.2(1). The values shown are applicable to Cases 3, 4, 5 and 6 as shown in Table 2306.2(1), providing fasteners at all continuous panel edges are spaced in accordance with the boundary fastener spacing.
- The minimum nominal depth of framing members shall be 3 inches nominal. The minimum nominal width of framing members not located at boundaries or adjoining panel edges shall be 2 inches.
- Staples shall have a minimum crown width of 7/16 inch, and shall be installed with their crowns parallel to the long dimension of the framing members.
- High-load diaphragms shall be subject to special inspection in accordance with Section 1705.5.1.
- For shear loads of normal or permanent load duration as defined by the ANSI/AWC NDS, the values in the table shall be multiplied by 0.63 or 0.56, respectively.
TABLE 2306.2(2)—continued
ALLOWABLE SHEAR VALUES (POUNDS PER FOOT) FOR WOOD STRUCTURAL PANEL BLOCKED DIAPHRAGMS UTILIZING MULTIPLE ROWS OF STAPLES (HIGH-LOAD DIAPHRAGMS) WITH FRAMING OF DOUGLAS FIR-LARCH OR SOUTHERN PINE FOR WIND OR SEISMIC LOADING
- Wood structural panel thickness for shear walls shall not be less than 3/8 inch (9.525 mm) thick, and studs shall not be spaced at more than 16 inches (406.4 mm) on center.
- The maximum nominal unit shear capacities for three-ply plywood resisting seismic forces in structures assigned to Seismic Design Category D, E or F is 400 pounds per linear foot (plf) (181.43 kg per meter).
- Where shear design values using allowable stress design (ASD) exceed 350 plf or load and resistance factor design (LRFD) exceed 500 plf, all framing members receiving edge nailing from abutting panels shall not be less than a single 3 inch (76.19 mm) nominal member, or two 2 inch (50.8 mm) nominal members fastened together in accordance with CBC Section 2306.1 to transfer the design shear value between framing members. Wood structural panel joint and sill plate nailing shall be staggered at all panel edges. See Sections 4.3.6.1 and 4.3.6.4.3 of AWC SDPWS for sill plate size and anchorage requirements.
- Nails shall be placed not less than 1/2 inch (12.7 mm) in from the panel edges and not less than 3/8 inch (9.525 mm) from the edge of the connecting members for shear greater than 350 plf using ASD or 500 plf using LRFD. Nails shall be placed not less than 3/8 inch (9.525 mm) from panel edges and not less than 1/4 inch (6.35 mm) from the edge of the connecting members for shears of 350 plf or less using ASD or 500 plf or less using LRFD.
- Table 4.3B of AWC SDPWS application is not allowed for structures assigned to Seismic design category D, E or F.
Where panels are fastened to framing members with staples, requirements and limitations of AWC SDPWS shall be met and the allowable shear values set forth in CBC Tables 2306.3(1), 2306.3(2) or 2306.3(3) shall only be permitted for structures assigned to Seismic Design Category A, B or C.
The allowable shear values in CBC Tables 2306.3(1) and 2306.3(2) are permitted to be increased 40% for wind design. Panels complying with ANSI/APA PRP-210 shall be permitted to use design values for Plywood Siding in the AWC SDPWS.
TABLE 2306.3(1)
ALLOWABLE SHEAR VALUES (POUNDS PER FOOT) FOR WOOD STRUCTURAL PANEL SHEAR WALLS UTILIZING STAPLES WITH FRAMING OF DOUGLAS FIR-LARCH OR SOUTHERN PINEa FOR WIND OR SEISMIC LOADINGb, f, g, i
PANEL GRADE | MINIMUM NOMINAL PANEL THICKNESS (inch) |
MINIMUM FASTENER PENETRATION IN FRAMING (inches) |
PANELS APPLIED DIRECT TO FRAMING | PANELS APPLIED OVER 1/2" OR 5/8" GYPSUM SHEATHING |
||||||||
Staple length and gageh (inches) |
Fastener spacing at panel edges (inches) |
Staple length and gageh (inches) |
Fastener spacing at panel edges (inches) |
|||||||||
6 | 4 | 3 | 2d | 6 | 4 | 3 | 2d | |||||
Structural I
sheathing
|
3/8 | 1 | 11/2 16
Gage
|
155 | 235 | 315 | 400 | 2 16 Gage | 155 | 235 | 310 | 400 |
7/16 | 170 | 260 | 345 | 440 | 155 | 235 | 310 | 400 | ||||
15/32 | 185 | 280 | 375 | 475 | 155 | 235 | 300 | 400 | ||||
Sheathing,
plywood sidinge
except Group 5
Species,
ANSI/APA PRP 210
sidinge
|
5/16c or 1/4c | 1 | 11/2 16
Gage
|
145 | 220 | 295 | 375 | 2 16 Gage | 110 | 165 | 220 | 285 |
3/8 | 140 | 210 | 280 | 360 | 140 | 210 | 280 | 360 | ||||
7/16 | 155 | 230 | 310 | 395 | 140 | 210 | 280 | 360 | ||||
15/32 | 170 | 255 | 335 | 430 | 140 | 210 | 280 | 360 | ||||
19/32 | 13/4 16
Gage
|
185 | 280 | 375 | 475 | — | — | — | — | — |
For SI: 1 inch = 25.4 mm, 1 pound per foot = 14.5939 N/m.
- For framing of other species: (1) Find specific gravity for species of lumber in ANSI/AWC NDS. (2) For staples find shear value from table for Structural I panels (regardless of actual grade) and multiply value by 0.82 for species with specific gravity of 0.42 or greater, or 0.65 for all other species.
- Panel edges backed with 2-inch nominal or wider framing. Install panels either horizontally or vertically. Space fasteners maximum 6 inches on center along intermediate framing members for 3/8-inch and 7/16-inch panels installed on studs spaced 24 inches on center. For other conditions and panel thickness, space fasteners maximum 12 inches on center on intermediate supports.
- 3/8-inch panel thickness or siding with a span rating of 16 inches on center is the minimum recommended where applied directly to framing as exterior siding. For grooved panel siding, the nominal panel thickness is the thickness of the panel measured at the point of fastening.
- Framing at adjoining panel edges shall be 3 inches nominal or wider.
- Values apply to all-veneer plywood. Thickness at point of fastening on panel edges governs shear values.
- Where panels are applied on both faces of a wall and fastener spacing is less than 6 inches on center on either side, panel joints shall be offset to fall on different framing members, or framing shall be 3 inches nominal or thicker at adjoining panel edges.
- In Seismic Design Category D, E or F, where shear design values exceed 350 pounds per linear foot, all framing members receiving edge fastening from abutting panels shall be not less than a single 3-inch nominal member, or two 2-inch nominal members fastened together in accordance with Section 2306.1 to transfer the design shear value between framing members. Wood structural panel joint and sill plate nailing shall be staggered at all panel edges. See AWC SDPWS for sill plate size and anchorage requirements.
- Staples shall have a minimum crown width of 7/16 inch and shall be installed with their crowns parallel to the long dimension of the framing members.
- For shear loads of normal or permanent load duration as defined by the ANSI/AWC NDS, the values in the table shall be multiplied by 0.63 or 0.56, respectively.
TABLE 2306.3(2)
ALLOWABLE SHEAR VALUES (plf) FOR WIND OR SEISMIC LOADING ON SHEAR WALLS OF FIBERBOARD SHEATHING BOARD CONSTRUCTION UTILIZING STAPLES FOR TYPE V CONSTRUCTION ONLYa, b, c, d, e
THICKNESS AND GRADE (inches) |
STAPLE GAGE AND DIMENSIONS | ALLOWABLE SHEAR VALUE (pounds per linear foot) STAPLE SPACING AT PANEL EDGES (inches)a |
||
4 | 3 | 2 | ||
1/2 or 25/32 Structural | No. 16 gage galvanized staple, 7/16" crown 13/4 inch long | 150 | 200 | 225 |
No. 16 gage galvanized staple, 1" crown 13/4 inch long | 220 | 290 | 325 |
For SI: 1 inch = 25.4 mm, 1 pound per foot = 14.5939 N/m.
- Fiberboard sheathing shall not be used to brace concrete or masonry walls.
- Panel edges shall be backed with 2-inch or wider framing of Douglas Fir-larch or Southern Pine. For framing of other species: (1) Find specific gravity for species of framing lumber in ANSI/AWC NDS. (2) For staples, multiply the shear value from the table by 0.82 for species with specific gravity of 0.42 or greater, or 0.65 for all other species.
- Values shown are for fiberboard sheathing on one side only with long panel dimension either parallel or perpendicular to studs.
- Fastener shall be spaced 6 inches on center along intermediate framing members.
- Values are not permitted in Seismic Design Category D, E or F.
TABLE 2306.3(3)
ALLOWABLE SHEAR VALUES FOR WIND OR SEISMIC FORCES FOR SHEAR WALLS OF LATH AND PLASTER OR GYPSUM BOARD WOOD FRAMED WALL ASSEMBLIES UTILIZING STAPLES
TYPE OF MATERIAL | THICKNESS OF MATERIAL |
WALL CONSTRUCTION |
STAPLE SPACINGb MAXIMUM (inches) |
SHEAR VALUEa, c (plf) |
MINIMUM STAPLE SIZE f, g |
1. Expanded metal or woven wire
lath and Portland cement plaster
|
7/8" | Unblocked | 6 | 180 | No. 16 gage galv. staple, 7/8" legs |
2. Gypsum lath, plain or perforated | 3/8" lath and
1/2" plaster
|
Unblocked | 5 | 100 | No. 16 gage galv. staple, 11/8" long |
3. Gypsum sheathing | 1/2" × 2' × 8' | Unblocked | 4 | 75 | No. 16 gage galv. staple, 13/4" long |
1/2" ×4' | Blockedd
Unblocked
|
4
7
|
175
100
|
||
4. Gypsum board, gypsum veneer
base or water-resistant gypsum
backing board |
1/2" | Unblockedd | 7 | 75 | No. 16 gage galv. staple, 11/2" long |
Unblockedd | 4 | 110 | |||
Unblocked | 7 | 100 | |||
Unblocked | 4 | 125 | |||
Blockede | 7 | 125 | |||
Blockede | 4 | 150 | |||
5/8" | Unblockedd | 7 | 115 | No. 16 gage galv. staple, 11/2"
legs,15/8" long
|
|
4 | 145 | ||||
Blockede | 7 | 145 | |||
4 | 175 | ||||
Blockede
Two-ply
|
Base ply: 9
Face ply: 7
|
250 | No. 16 gage galv. staple 15/8" long
No. 15 gage galv. staple, 21/4" long
|
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per foot = 14.5939 N/m.
- These shear walls shall not be used to resist loads imposed by masonry or concrete walls (see AWC SDPWS). Values shown are for short-term loading due to wind or seismic loading. Walls resisting seismic loads shall be subject to the limitations in Section 12.2.1 of ASCE 7. Values shown shall be reduced 25 percent for normal loading.
- Applies to fastening at studs, top and bottom plates and blocking.
- Except as noted, shear values are based on a maximum framing spacing of 16 inches on center.
- Maximum framing spacing of 24 inches on center.
- All edges are blocked, and edge fastening is provided at all supports and all panel edges.
- Staples shall have a minimum crown width of 7/16 inch, measured outside the legs, and shall be installed with their crowns parallel to the long dimension of the framing members.
- Staples for the attachment of gypsum lath and woven-wire lath shall have a minimum crown width of 3/4 inch, measured outside the legs.
Shear walls sheathed with lath, plaster or gypsum board shall not be used below the top level in a multi-level building for structures assigned to Seismic Design Category D.
Structures of conventional light-frame construction shall be limited in story height in accordance with Table 2308.2.1.
ALLOWABLE STORY HEIGHT
SEISMIC DESIGN CATEGORY | ALLOWABLE STORY ABOVE GRADE PLANE |
A and B | Three stories |
C | Two stories |
D and Ea | One story |
For SI: 1 inch = 25.4 mm.
- For the purposes of this section, for buildings assigned to Seismic Design Category D or E, cripple walls shall be considered to be a story unless cripple walls are solid blocked and do not exceed 14 inches in height.
Loads shall be in accordance with Chapter 16 and shall not exceed the following:
Average dead loads shall not exceed 15 psf (718 N/m2) for combined roof and ceiling, exterior walls, floors and partitions.
Exceptions:
- Subject to the limitations of Section 2308.6.10, stone or masonry veneer up to the lesser of 5 inches (127 mm) thick or 50 psf (2395 N/m2) and installed in accordance with Chapter 14 is permitted to a height of 30 feet (9144 mm) above a noncombustible foundation, with an additional 8 feet (2438 mm) permitted for gable ends.
- Concrete or masonry fireplaces, heaters and chimneys shall be permitted in accordance with the provisions of this code.
Live loads shall not exceed 40 psf (1916 N/m2) for floors.
Exception: Live loads for concrete slab-on-ground floors in Risk Categories I and II shall be not more than 125 psf.
- Ground snow loads shall not exceed 50 psf (2395 N/m2).
V shall not exceed 130 miles per hour (57 m/s) (3-second gust).
Exceptions:
- V shall not exceed 140 mph (61.6 m/s) (3-second gust) for buildings in Exposure Category B that are not located in a hurricane-prone region.
- Where V exceeds 130 mph (3-second gust), the provisions of either AWC WFCM or ICC 600 are permitted to be used.
- The design and construction shall also comply with Section 2304 and Section 2305.
- In conjunction with the use of provisions in Section 2308.6 (Wall bracing), engineering analysis shall be furnished that demonstrates compliance of lateral-force-resisting systems with Section 2305.
- In addition to the use of provisions in Section 2308.4 (Floor framing), engineering analysis shall be furnished that demonstrates compliance of floor framing elements and connections with Section 2302.1, Item 1 or 2.
- In addition to the use of provisions in Section 2308.5 (Wall construction), engineering analysis shall be furnished that demonstrates compliance of wall framing elements and connections with Section 2302.1, Item 1 or 2.
- In addition to the use of provisions in Section 2308.7 (Roof and Ceiling Framing), engineering analysis shall be furnished demonstrating compliance of roof and ceiling framing elements and connections with Section 2302.1, Item 1 or 2.
Girders for single-story construction or girders supporting loads from a single floor shall be not less than 4 inches by 6 inches (102 mm by 152 mm) for spans 6 feet (1829 mm) or less, provided that girders are spaced not more than 8 feet (2438 mm) on center. Other girders shall be designed to support the loads specified in this code. Girder end joints shall occur over supports.
Where a girder is spliced over a support, an adequate tie shall be provided. The ends of beams or girders supported on masonry or concrete shall not have less than 3 inches (76 mm) of bearing.
The allowable spans of girders that are fabricated of dimension lumber shall not exceed the values set forth in Table 2308.4.1.1(1) or 2308.4.1.1(2).
HEADER AND GIRDER SPANSa, b FOR EXTERIOR BEARING WALLS (Maximum spans for Douglas fir-larch, hem-fir, Southern pine and spruce-pine-fir and required number of jack studs)
GIRDERS AND HEADERS SUPPORTING | SIZE | GROUND SNOW LOAD (psf)e | |||||||||||||||||
30 | 50 | 70 | |||||||||||||||||
Building widthc (feet) | |||||||||||||||||||
12 | 24 | 36 | 12 | 24 | 36 | 12 | 24 | 36 | |||||||||||
Spanf | NJd | Spanf | NJd | Spanf | NJd | Spanf | NJd | Spanf | NJd | Spanf | NJd | Spanf | NJd | Spanf | NJd | Spanf | NJd | ||
Roof and ceiling | 1-2 × 6 | 4-0 | 1 | 3-1 | 2 | 2-7 | 2 | 3-5 | 1 | 2-8 | 2 | 2-3 | 2 | 3-0 | 2 | 2-4 | 2 | 2-0 | 2 |
1-2 × 8 | 5-1 | 2 | 3-11 | 2 | 3-3 | 2 | 4-4 | 2 | 3-4 | 2 | 2-10 | 2 | 3-10 | 2 | 3-0 | 2 | 2-6 | 3 | |
1-2 × 10 | 6-0 | 2 | 4-8 | 2 | 3-11 | 2 | 5-2 | 2 | 4-0 | 2 | 3-4 | 3 | 4-7 | 2 | 3-6 | 3 | 3-0 | 3 | |
1-2 × 12 | 7-1 | 2 | 5-5 | 2 | 4-7 | 3 | 6-1 | 2 | 4-8 | 3 | 3-11 | 3 | 5-5 | 2 | 4-2 | 3 | 3-6 | 3 | |
2-2 × 4 | 4-0 | 1 | 3-1 | 1 | 2-7 | 1 | 3-5 | 1 | 2-7 | 1 | 2-2 | 1 | 3-0 | 1 | 2-4 | 1 | 2-0 | 1 | |
2-2 × 6 | 6-0 | 1 | 4-7 | 1 | 3-10 | 1 | 5-1 | 1 | 3-11 | 1 | 3-3 | 2 | 4-6 | 1 | 3-6 | 2 | 2-11 | 2 | |
2-2 × 8 | 7-7 | 1 | 5-9 | 1 | 4-10 | 2 | 6-5 | 1 | 5-0 | 2 | 4-2 | 2 | 5-9 | 1 | 4-5 | 2 | 3-9 | 2 | |
2-2 × 10 | 9-0 | 1 | 6-10 | 2 | 5-9 | 2 | 7-8 | 2 | 5-11 | 2 | 4-11 | 2 | 6-9 | 2 | 5-3 | 2 | 4-5 | 2 | |
2-2 × 12 | 10-7 | 2 | 8-1 | 2 | 6-10 | 2 | 9-0 | 2 | 6-11 | 2 | 5-10 | 2 | 8-0 | 2 | 6-2 | 2 | 5-2 | 3 | |
3-2 × 8 | 9-5 | 1 | 7-3 | 1 | 6-1 | 1 | 8-1 | 1 | 6-3 | 1 | 5-3 | 2 | 7-2 | 1 | 5-6 | 2 | 4-8 | 2 | |
3-2 × 10 | 11-3 | 1 | 8-7 | 1 | 7-3 | 2 | 9-7 | 1 | 7-4 | 2 | 6-2 | 2 | 8-6 | 1 | 6-7 | 2 | 5-6 | 2 | |
3-2 × 12 | 13-2 | 1 | 10-1 | 2 | 8-6 | 2 | 11-3 | 2 | 8-8 | 2 | 7-4 | 2 | 10-0 | 2 | 7-9 | 2 | 6-6 | 2 | |
4-2 × 8 | 10-11 | 1 | 8-4 | 1 | 7-0 | 1 | 9-4 | 1 | 7-2 | 1 | 6-0 | 1 | 8-3 | 1 | 6-4 | 1 | 5-4 | 2 | |
4-2 × 10 | 12-11 | 1 | 9-11 | 1 | 8-4 | 1 | 11-1 | 1 | 8-6 | 1 | 7-2 | 2 | 9-10 | 1 | 7-7 | 2 | 6-4 | 2 | |
4-2 × 12 | 15-3 | 1 | 11-8 | 1 | 9-10 | 2 | 13-0 | 1 | 10-0 | 2 | 8-5 | 2 | 11-7 | 1 | 8-11 | 2 | 7-6 | 2 | |
Roof, ceiling and one center-bearing floor | 1-2 × 6 | 3-3 | 1 | 2-7 | 2 | 2-2 | 2 | 3-0 | 2 | 2-4 | 2 | 2-0 | 2 | 2-9 | 2 | 2-2 | 2 | 1-10 | 2 |
1-2 × 8 | 4-1 | 2 | 3-3 | 2 | 2-9 | 2 | 3-9 | 2 | 3-0 | 2 | 2-6 | 3 | 3-6 | 2 | 2-9 | 2 | 2-4 | 3 | |
1-2 × 10 | 4-11 | 2 | 3-10 | 2 | 3-3 | 3 | 4-6 | 2 | 3-6 | 3 | 3-0 | 3 | 4-1 | 2 | 3-3 | 3 | 2-9 | 3 | |
1-2 × 12 | 5-9 | 2 | 4-6 | 3 | 3-10 | 3 | 5-3 | 2 | 4-2 | 3 | 3-6 | 3 | 4-10 | 3 | 3-10 | 3 | 3-3 | 4 | |
2-2 × 4 | 3-3 | 1 | 2-6 | 1 | 2-2 | 1 | 3-0 | 1 | 2-4 | 1 | 2-0 | 1 | 2-8 | 1 | 2-2 | 1 | 1-10 | 1 | |
2-2 × 6 | 4-10 | 1 | 3-9 | 1 | 3-3 | 2 | 4-5 | 1 | 3-6 | 2 | 3-0 | 2 | 4-1 | 1 | 3-3 | 2 | 2-9 | 2 | |
2-2 × 8 | 6-1 | 1 | 4-10 | 2 | 4-1 | 2 | 5-7 | 2 | 4-5 | 2 | 3-9 | 2 | 5-2 | 2 | 4-1 | 2 | 3-6 | 2 | |
2-2 × 10 | 7-3 | 2 | 5-8 | 2 | 4-10 | 2 | 6-8 | 2 | 5-3 | 2 | 4-5 | 2 | 6-1 | 2 | 4-10 | 2 | 4-1 | 2 | |
2-2 × 12 | 8-6 | 2 | 6-8 | 2 | 5-8 | 2 | 7-10 | 2 | 6-2 | 2 | 5-3 | 3 | 7-2 | 2 | 5-8 | 2 | 4-10 | 3 | |
3-2 × 8 | 7-8 | 1 | 6-0 | 1 | 5-1 | 2 | 7-0 | 1 | 5-6 | 2 | 4-8 | 2 | 6-5 | 1 | 5-1 | 2 | 4-4 | 2 | |
3-2 × 10 | 9-1 | 1 | 7-2 | 2 | 6-1 | 2 | 8-4 | 1 | 6-7 | 2 | 5-7 | 2 | 7-8 | 2 | 6-1 | 2 | 5-2 | 2 | |
3-2 × 12 | 10-8 | 2 | 8-5 | 2 | 7-2 | 2 | 9-10 | 2 | 7-8 | 2 | 6-7 | 2 | 9-0 | 2 | 7-1 | 2 | 6-1 | 2 | |
4-2 × 8 | 8-10 | 1 | 6-11 | 1 | 5-11 | 1 | 8-1 | 1 | 6-4 | 1 | 5-5 | 2 | 7-5 | 1 | 5-11 | 1 | 5-0 | 2 | |
4-2 × 10 | 10-6 | 1 | 8-3 | 2 | 7-0 | 2 | 9-8 | 1 | 7-7 | 2 | 6-5 | 2 | 8-10 | 1 | 7-0 | 2 | 6-0 | 2 | |
4-2 × 12 | 12-4 | 1 | 9-8 | 2 | 8-3 | 2 | 11-4 | 2 | 8-11 | 2 | 7-7 | 2 | 10-4 | 2 | 8-3 | 2 | 7-0 | 2 | |
Roof, ceiling and one clear span floor | 1-2 × 6 | 2-11 | 2 | 2-3 | 2 | 1-11 | 2 | 2-9 | 2 | 2-1 | 2 | 1-9 | 2 | 2-7 | 2 | 2-0 | 2 | 1-8 | 2 |
1-2 × 8 | 3-9 | 2 | 2-10 | 2 | 2-5 | 3 | 3-6 | 2 | 2-8 | 2 | 2-3 | 3 | 3-3 | 2 | 2-6 | 3 | 2-2 | 3 | |
1-2 × 10 | 4-5 | 2 | 3-5 | 3 | 2-10 | 3 | 4-2 | 2 | 3-2 | 3 | 2-8 | 3 | 3-11 | 2 | 3-0 | 3 | 2-6 | 3 | |
1-2 × 12 | 5-2 | 2 | 4-0 | 3 | 3-4 | 3 | 4-10 | 3 | 3-9 | 3 | 3-2 | 4 | 4-7 | 3 | 3-6 | 3 | 3-0 | 4 | |
2-2 × 4 | 2-11 | 1 | 2-3 | 1 | 1-10 | 1 | 2-9 | 1 | 2-1 | 1 | 1-9 | 1 | 2-7 | 1 | 2-0 | 1 | 1-8 | 1 | |
2-2 × 6 | 4-4 | 1 | 3-4 | 2 | 2-10 | 2 | 4-1 | 1 | 3-2 | 2 | 2-8 | 2 | 3-10 | 1 | 3-0 | 2 | 2-6 | 2 | |
2-2 × 8 | 5-6 | 2 | 4-3 | 2 | 3-7 | 2 | 5-2 | 2 | 4-0 | 2 | 3-4 | 2 | 4-10 | 2 | 3-9 | 2 | 3-2 | 2 | |
2-2 × 10 | 6-7 | 2 | 5-0 | 2 | 4-2 | 2 | 6-1 | 2 | 4-9 | 2 | 4-0 | 2 | 5-9 | 2 | 4-5 | 2 | 3-9 | 3 | |
2-2 × 12 | 7-9 | 2 | 5-11 | 2 | 4-11 | 3 | 7-2 | 2 | 5-7 | 2 | 4-8 | 3 | 6-9 | 2 | 5-3 | 3 | 4-5 | 3 | |
3-2 × 8 | 6-11 | 1 | 5-3 | 2 | 4-5 | 2 | 6-5 | 1 | 5-0 | 2 | 4-2 | 2 | 6-1 | 1 | 4-8 | 2 | 4-0 | 2 | |
3-2 × 10 | 8-3 | 2 | 6-3 | 2 | 5-3 | 2 | 7-8 | 2 | 5-11 | 2 | 5-0 | 2 | 7-3 | 2 | 5-7 | 2 | 4-8 | 2 | |
3-2 × 12 | 9-8 | 2 | 7-5 | 2 | 6-2 | 2 | 9-0 | 2 | 7-0 | 2 | 5-10 | 2 | 8-6 | 2 | 6-7 | 2 | 5-6 | 3 | |
4-2 × 8 | 8-0 | 1 | 6-1 | 1 | 5-1 | 2 | 7-5 | 1 | 5-9 | 2 | 4-10 | 2 | 7-0 | 1 | 5-5 | 2 | 4-7 | 2 | |
4-2 × 10 | 9-6 | 1 | 7-3 | 2 | 6-1 | 2 | 8-10 | 1 | 6-10 | 2 | 5-9 | 2 | 8-4 | 1 | 6-5 | 2 | 5-5 | 2 | |
4-2 × 12 | 11-2 | 2 | 8-6 | 2 | 7-2 | 2 | 10-5 | 2 | 8-0 | 2 | 6-9 | 2 | 9-10 | 2 | 7-7 | 2 | 6-5 | 2 | |
Roof, ceiling and two center-bearing floors | 1-2 × 6 | 2-8 | 2 | 2-1 | 2 | 1-10 | 2 | 2-7 | 2 | 2-0 | 2 | 1-9 | 2 | 2-5 | 2 | 1-11 | 2 | 1-8 | 2 |
1-2 × 8 | 3-5 | 2 | 2-8 | 2 | 2-4 | 3 | 3-3 | 2 | 2-7 | 2 | 2-2 | 3 | 3-1 | 2 | 2-5 | 3 | 2-1 | 3 | |
1-2 × 10 | 4-0 | 2 | 3-2 | 3 | 2-9 | 3 | 3-10 | 2 | 3-1 | 3 | 2-7 | 3 | 3-8 | 2 | 2-11 | 3 | 2-5 | 3 | |
1-2 × 12 | 4-9 | 3 | 3-9 | 3 | 3-2 | 4 | 4-6 | 3 | 3-7 | 3 | 3-1 | 4 | 4-3 | 3 | 3-5 | 3 | 2-11 | 4 | |
2-2 × 4 | 2-8 | 1 | 2-1 | 1 | 1-9 | 1 | 2-6 | 1 | 2-0 | 1 | 1-8 | 1 | 2-5 | 1 | 1-11 | 1 | 1-7 | 1 | |
2-2 × 6 | 4-0 | 1 | 3-2 | 2 | 2-8 | 2 | 3-9 | 1 | 3-0 | 2 | 2-7 | 2 | 3-7 | 1 | 2-10 | 2 | 2-5 | 2 | |
2-2 × 8 | 5-0 | 2 | 4-0 | 2 | 3-5 | 2 | 4-10 | 2 | 3-10 | 2 | 3-3 | 2 | 4-7 | 2 | 3-7 | 2 | 3-1 | 2 | |
2-2 × 10 | 6-0 | 2 | 4-9 | 2 | 4-0 | 2 | 5-8 | 2 | 4-6 | 2 | 3-10 | 3 | 5-5 | 2 | 4-3 | 2 | 3-8 | 3 | |
2-2 × 12 | 7-0 | 2 | 5-7 | 2 | 4-9 | 3 | 6-8 | 2 | 5-4 | 3 | 4-6 | 3 | 6-4 | 2 | 5-0 | 3 | 4-3 | 3 | |
3-2 × 8 | 6-4 | 1 | 5-0 | 2 | 4-3 | 2 | 6-0 | 1 | 4-9 | 2 | 4-1 | 2 | 5-8 | 2 | 4-6 | 2 | 3-10 | 2 | |
3-2 × 10 | 7-6 | 2 | 5-11 | 2 | 5-1 | 2 | 7-1 | 2 | 5-8 | 2 | 4-10 | 2 | 6-9 | 2 | 5-4 | 2 | 4-7 | 2 | |
3-2 × 12 | 8-10 | 2 | 7-0 | 2 | 5-11 | 2 | 8-5 | 2 | 6-8 | 2 | 5-8 | 3 | 8-0 | 2 | 6-4 | 2 | 5-4 | 3 | |
4-2 × 8 | 7-3 | 1 | 5-9 | 1 | 4-11 | 2 | 6-11 | 1 | 5-6 | 2 | 4-8 | 2 | 6-7 | 1 | 5-2 | 2 | 4-5 | 2 | |
4-2 × 10 | 8-8 | 1 | 6-10 | 2 | 5-10 | 2 | 8-3 | 2 | 6-6 | 2 | 5-7 | 2 | 7-10 | 2 | 6-2 | 2 | 5-3 | 2 | |
4-2 × 12 | 10-2 | 2 | 8-1 | 2 | 6-10 | 2 | 9-8 | 2 | 7-8 | 2 | 6-7 | 2 | 9-2 | 2 | 7-3 | 2 | 6-2 | 2 | |
Roof, ceiling and two clear span floors | 1-2 × 6 | 2-3 | 2 | 1-9 | 2 | 1-5 | 2 | 2-3 | 2 | 1-9 | 2 | 1-5 | 3 | 2-2 | 2 | 1-8 | 2 | 1-5 | 3 |
1-2 × 8 | 2-10 | 2 | 2-2 | 3 | 1-10 | 3 | 2-10 | 2 | 2-2 | 3 | 1-10 | 3 | 2-9 | 2 | 2-1 | 3 | 1-10 | 3 | |
1-2 × 10 | 3-4 | 2 | 2-7 | 3 | 2-2 | 3 | 3-4 | 3 | 2-7 | 3 | 2-2 | 4 | 3-3 | 3 | 2-6 | 3 | 2-2 | 4 | |
1-2 × 12 | 4-0 | 3 | 3-0 | 3 | 2-7 | 4 | 4-0 | 3 | 3-0 | 4 | 2-7 | 4 | 3-10 | 3 | 3-0 | 4 | 2-6 | 4 | |
2-2 × 4 | 2-3 | 1 | 1-8 | 1 | 1-4 | 1 | 2-3 | 1 | 1-8 | 1 | 1-4 | 1 | 2-2 | 1 | 1-8 | 1 | 1-4 | 2 | |
2-2 × 6 | 3-4 | 1 | 2-6 | 2 | 2-2 | 2 | 3-4 | 2 | 2-6 | 2 | 2-2 | 2 | 3-3 | 2 | 2-6 | 2 | 2-1 | 2 | |
2-2 × 8 | 4-3 | 2 | 3-3 | 2 | 2-8 | 2 | 4-3 | 2 | 3-3 | 2 | 2-8 | 2 | 4-1 | 2 | 3-2 | 2 | 2-8 | 3 | |
2-2 × 10 | 5-0 | 2 | 3-10 | 2 | 3-2 | 3 | 5-0 | 2 | 3-10 | 2 | 3-2 | 3 | 4-10 | 2 | 3-9 | 3 | 3-2 | 3 | |
2-2 × 12 | 5-11 | 2 | 4-6 | 3 | 3-9 | 3 | 5-11 | 2 | 4-6 | 3 | 3-9 | 3 | 5-8 | 2 | 4-5 | 3 | 3-9 | 3 | |
3-2 × 8 | 5-3 | 1 | 4-0 | 2 | 3-5 | 2 | 5-3 | 2 | 4-0 | 2 | 3-5 | 2 | 5-1 | 2 | 3-11 | 2 | 3-4 | 2 | |
3-2 × 10 | 6-3 | 2 | 4-9 | 2 | 4-0 | 2 | 6-3 | 2 | 4-9 | 2 | 4-0 | 2 | 6-1 | 2 | 4-8 | 2 | 4-0 | 3 | |
3-2 × 12 | 7-5 | 2 | 5-8 | 2 | 4-9 | 3 | 7-5 | 2 | 5-8 | 2 | 4-9 | 3 | 7-2 | 2 | 5-6 | 3 | 4-8 | 3 | |
4-2 × 8 | 6-1 | 1 | 4-8 | 2 | 3-11 | 2 | 6-1 | 1 | 4-8 | 2 | 3-11 | 2 | 5-11 | 1 | 4-7 | 2 | 3-10 | 2 | |
4-2 × 10 | 7-3 | 2 | 5-6 | 2 | 4-8 | 2 | 7-3 | 2 | 5-6 | 2 | 4-8 | 2 | 7-0 | 2 | 5-5 | 2 | 4-7 | 2 | |
4-2 × 12 | 8-6 | 2 | 6-6 | 2 | 5-6 | 2 | 8-6 | 2 | 6-6 | 2 | 5-6 | 2 | 8-3 | 2 | 6-4 | 2 | 5-4 | 3 |
For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kPa.
- Spans are given in feet and inches.
- Spans are based on minimum design properties for No. 2 grade lumber of Douglas fir-larch, hem-fir, Southern pine and spruce-pine fir.
- Building width is measured perpendicular to the ridge. For widths between those shown, spans are permitted to be interpolated.
- NJ = Number of jack studs required to support each end. Where the number of required jack studs equals one, the header is permitted to be supported by an approved framing anchor attached to the full-height wall stud and to the header.
- Use 30 psf ground snow load for cases in which ground snow load is less than 30 psf and the roof live load is equal to or less than 20 psf.
- Spans are calculated assuming the top of the header or girder is laterally braced by perpendicular framing. Where the top of the header or girder is not laterally braced (for example, cripple studs bearing on the header), tabulated spans for headers consisting of 2 × 8, 2 × 10, or 2 × 12 sizes shall be multiplied by 0.70 or the header or girder shall be designed.
HEADER AND GIRDER SPANSa, b FOR INTERIOR BEARING WALLS (Maximum spans for Douglas fir-larch, hem-fir, Southern pine and spruce-pine-fir and required number of jack studs)
HEADERS AND GIRDERS SUPPORTING | SIZE | BUILDING WIDTHc (feet) | |||||
12 | 24 | 36 | |||||
Spane | NJd | Spane | NJd | Spane | NJd | ||
One floor only | 2-2 × 4 | 4-1 | 1 | 2-10 | 1 | 2-4 | 1 |
2-2 × 6 | 6-1 | 1 | 4-4 | 1 | 3-6 | 1 | |
2-2 × 8 | 7-9 | 1 | 5-5 | 1 | 4-5 | 2 | |
2-2 × 10 | 9-2 | 1 | 6-6 | 2 | 5-3 | 2 | |
2-2 × 12 | 10-9 | 1 | 7-7 | 2 | 6-3 | 2 | |
3-2 × 8 | 9-8 | 1 | 6-10 | 1 | 5-7 | 1 | |
3-2 × 10 | 11-5 | 1 | 8-1 | 1 | 6-7 | 2 | |
3-2 × 12 | 13-6 | 1 | 9-6 | 2 | 7-9 | 2 | |
4-2 × 8 | 11-2 | 1 | 7-11 | 1 | 6-5 | 1 | |
4-2 × 10 | 13-3 | 1 | 9-4 | 1 | 7-8 | 1 | |
4-2 × 12 | 15-7 | 1 | 11-0 | 1 | 9-0 | 2 | |
Two floors | 2-2 × 4 | 2-7 | 1 | 1-11 | 1 | 1-7 | 1 |
2-2 × 6 | 3-11 | 1 | 2-11 | 2 | 2-5 | 2 | |
2-2 × 8 | 5-0 | 1 | 3-8 | 2 | 3-1 | 2 | |
2-2 × 10 | 5-11 | 2 | 4-4 | 2 | 3-7 | 2 | |
2-2 × 12 | 6-11 | 2 | 5-2 | 2 | 4-3 | 3 | |
3-2 × 8 | 6-3 | 1 | 4-7 | 2 | 3-10 | 2 | |
3-2 × 10 | 7-5 | 1 | 5-6 | 2 | 4-6 | 2 | |
3-2 × 12 | 8-8 | 2 | 6-5 | 2 | 5-4 | 2 | |
4-2 × 8 | 7-2 | 1 | 5-4 | 1 | 4-5 | 2 | |
4-2 × 10 | 8-6 | 1 | 6-4 | 2 | 5-3 | 2 | |
4-2 × 12 | 10-1 | 1 | 7-5 | 2 | 6-2 | 2 |
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
- Spans are given in feet and inches.
- Spans are based on minimum design properties for No. 2 grade lumber of Douglas fir-larch, hem-fir, Southern pine and spruce-pine fir.
- Building width is measured perpendicular to the ridge. For widths between those shown, spans are permitted to be interpolated.
- NJ = Number of jack studs required to support each end. Where the number of required jack studs equals one, the header is permitted to be supported by an approved framing anchor attached to the full-height wall stud and to the header.
- Spans are calculated assuming the top of the header or girder is laterally braced by perpendicular framing. Where the top of the header or girder is not laterally braced (for example, cripple studs bearing on the header), tabulated spans for headers consisting of 2 × 8, 2 × 10, or 2 × 12 sizes shall be multiplied by 0.70 or the header or girder shall be designed.
Spans for floor joists shall be in accordance with Table 2308.4.2.1(1) or 2308.4.2.1(2) or the AWC STJR.
FLOOR JOIST SPANS FOR COMMON LUMBER SPECIES (Residential sleeping areas, live load = 30 psf, L/Δ = 360)
JOIST SPACING (inches) | SPECIES AND GRADE | DEAD LOAD = 10 psf | DEAD LOAD = 20 psf | |||||||
2 × 6 | 2 × 8 | 2 × 10 | 2 × 12 | 2 × 6 | 2 × 8 | 2 × 10 | 2 × 12 | |||
Maximum floor joist spans | ||||||||||
(ft. - in.) | (ft. - in.) | (ft. - in.) | (ft. - in.) | (ft. - in.) | (ft. - in.) | (ft. - in.) | (ft. - in.) | |||
12 | Douglas Fir-Larch | SS | 12-6 | 16-6 | 21-0 | 25-7 | 12-6 | 16-6 | 21-0 | 25-7 |
Douglas Fir-Larch | #1 | 12-0 | 15-10 | 20-3 | 24-8 | 12-0 | 15-7 | 19-0 | 22-0 | |
Douglas Fir-Larch | #2 | 11-10 | 15-7 | 19-10 | 23-0 | 11-6 | 14-7 | 17-9 | 20-7 | |
Douglas Fir-Larch | #3 | 9-8 | 12-4 | 15-0 | 17-5 | 8-8 | 11-0 | 13-5 | 15-7 | |
Hem-Fir | SS | 11-10 | 15-7 | 19-10 | 24-2 | 11-10 | 15-7 | 19-10 | 24-2 | |
Hem-Fir | #1 | 11-7 | 15-3 | 19-5 | 23-7 | 11-7 | 15-2 | 18-6 | 21-6 | |
Hem-Fir | #2 | 11-0 | 14-6 | 18-6 | 22-6 | 11-0 | 14-4 | 17-6 | 20-4 | |
Hem-Fir | #3 | 9-8 | 12-4 | 15-0 | 17-5 | 8-8 | 11-0 | 13-5 | 15-7 | |
Southern Pine | SS | 12-3 | 16-2 | 20-8 | 25-1 | 12-3 | 16-2 | 20-8 | 25-1 | |
Southern Pine | #1 | 11-10 | 15-7 | 19-10 | 24-2 | 11-10 | 15-7 | 18-7 | 22-0 | |
Southern Pine | #2 | 11-3 | 14-11 | 18-1 | 21-4 | 10-9 | 13-8 | 16-2 | 19-1 | |
Southern Pine | #3 | 9-2 | 11-6 | 14-0 | 16-6 | 8-2 | 10-3 | 12-6 | 14-9 | |
Spruce-Pine-Fir | SS | 11-7 | 15-3 | 19-5 | 23-7 | 11-7 | 15-3 | 19-5 | 23-7 | |
Spruce-Pine-Fir | #1 | 11-3 | 14-11 | 19-0 | 23-0 | 11-3 | 14-7 | 17-9 | 20-7 | |
Spruce-Pine-Fir | #2 | 11-3 | 14-11 | 19-0 | 23-0 | 11-3 | 14-7 | 17-9 | 20-7 | |
Spruce-Pine-Fir | #3 | 9-8 | 12-4 | 15-0 | 17-5 | 8-8 | 11-0 | 13-5 | 15-7 | |
16 | Douglas Fir-Larch | SS | 11-4 | 15-0 | 19-1 | 23-3 | 11-4 | 15-0 | 19-1 | 23-0 |
Douglas Fir-Larch | #1 | 10-11 | 14-5 | 18-5 | 21-4 | 10-8 | 13-6 | 16-5 | 19-1 | |
Douglas Fir-Larch | #2 | 10-9 | 14-1 | 17-2 | 19-11 | 9-11 | 12-7 | 15-5 | 17-10 | |
Douglas Fir-Larch | #3 | 8-5 | 10-8 | 13-0 | 15-1 | 7-6 | 9-6 | 11-8 | 13-6 | |
Hem-Fir | SS | 10-9 | 14-2 | 18-0 | 21-11 | 10-9 | 14-2 | 18-0 | 21-11 | |
Hem-Fir | #1 | 10-6 | 13-10 | 17-8 | 20-9 | 10-4 | 13-1 | 16-0 | 18-7 | |
Hem-Fir | #2 | 10-0 | 13-2 | 16-10 | 19-8 | 9-10 | 12-5 | 15-2 | 17-7 | |
Hem-Fir | #3 | 8-5 | 10-8 | 13-0 | 15-1 | 7-6 | 9-6 | 11-8 | 13-6 | |
Southern Pine | SS | 11-2 | 14-8 | 18-9 | 22-10 | 11-2 | 14-8 | 18-9 | 22-10 | |
Southern Pine | #1 | 10-9 | 14-2 | 18-0 | 21-4 | 10-9 | 13-9 | 16-1 | 19-1 | |
Southern Pine | #2 | 10-3 | 13-3 | 15-8 | 18-6 | 9-4 | 11-10 | 14-0 | 16-6 | |
Southern Pine | #3 | 7-11 | 10-10 | 12-1 | 14-4 | 7-1 | 8-11 | 10-10 | 12-10 | |
Spruce-Pine-Fir | SS | 10-6 | 13-10 | 17-8 | 21-6 | 10-6 | 13-10 | 17-8 | 21-4 | |
Spruce-Pine-Fir | #1 | 10-3 | 13-6 | 17-2 | 19-11 | 9-11 | 12-7 | 15-5 | 17-10 | |
Spruce-Pine-Fir | #2 | 10-3 | 13-6 | 17-2 | 19-11 | 9-11 | 12-7 | 15-5 | 17-10 | |
Spruce-Pine-Fir | #3 | 8-5 | 10-8 | 13-0 | 15-1 | 7-6 | 9-6 | 11-8 | 13-6 | |
19.2 | Douglas Fir-Larch | SS | 10-8 | 14-1 | 18-0 | 21-10 | 10-8 | 14-1 | 18-0 | 21-0 |
Douglas Fir-Larch | #1 | 10-4 | 13-7 | 16-9 | 19-6 | 9-8 | 12-4 | 15-0 | 17-5 | |
Douglas Fir-Larch | #2 | 10-1 | 12-10 | 15-8 | 18-3 | 9-1 | 11-6 | 14-1 | 16-3 | |
Douglas Fir-Larch | #3 | 7-8 | 9-9 | 11-10 | 13-9 | 6-10 | 8-8 | 10-7 | 12-4 | |
Hem-Fir | SS | 10-1 | 13-4 | 17-0 | 20-8 | 10-1 | 13-4 | 17-0 | 20-7 | |
Hem-Fir | #1 | 9-10 | 13-0 | 16-4 | 19-0 | 9-6 | 12-0 | 14-8 | 17-0 | |
Hem-Fir | #2 | 9-5 | 12-5 | 15-6 | 17-1 | 8-11 | 11-4 | 13-10 | 16-1 | |
Hem-Fir | #3 | 7-8 | 9-9 | 11-10 | 13-9 | 6-10 | 8-8 | 10-7 | 12-4 | |
Southern Pine | SS | 10-6 | 13-10 | 17-8 | 21-6 | 10-6 | 13-10 | 17-8 | 21-6 | |
Southern Pine | #1 | 10-1 | 13-4 | 16-5 | 19-6 | 9-11 | 12-7 | 14-8 | 17-5 | |
Southern Pine | #2 | 9-6 | 12-1 | 14-4 | 16-10 | 8-6 | 10-10 | 12-10 | 15-1 | |
Southern Pine | #3 | 7-3 | 9-1 | 11-0 | 13-1 | 6-5 | 8-2 | 9-10 | 11-8 | |
Spruce-Pine-Fir | SS | 9-10 | 13-0 | 16-7 | 20-2 | 9-10 | 13-0 | 16-7 | 19-6 | |
Spruce-Pine-Fir | #1 | 9-8 | 12-9 | 15-8 | 18-3 | 9-1 | 11-6 | 14-1 | 16-3 | |
Spruce-Pine-Fir | #2 | 9-8 | 12-9 | 15-8 | 18-3 | 9-1 | 11-6 | 14-1 | 16-3 | |
Spruce-Pine-Fir | #3 | 7-8 | 9-9 | 11-10 | 13-9 | 6-10 | 8-8 | 10-7 | 12-4 | |
24 | Douglas Fir-Larch | SS | 9-11 | 13-1 | 16-8 | 20-3 | 9-11 | 13-1 | 16-2 | 18-9 |
Douglas Fir-Larch | #1 | 9-7 | 12-4 | 15-0 | 17-5 | 8-8 | 11-0 | 13-5 | 15-7 | |
Douglas Fir-Larch | #2 | 9-1 | 11-6 | 14-1 | 16-3 | 8-1 | 10-3 | 12-7 | 14-7 | |
Douglas Fir-Larch | #3 | 6-10 | 8-8 | 10-7 | 12-4 | 6-2 | 7-9 | 9-6 | 11-0 | |
Hem-Fir | SS | 9-4 | 12-4 | 15-9 | 19-2 | 9-4 | 12-4 | 15-9 | 18-5 | |
Hem-Fir | #1 | 9-2 | 12-0 | 14-8 | 17-0 | 8-6 | 10-9 | 13-1 | 15-2 | |
Hem-Fir | #2 | 8-9 | 11-4 | 13-10 | 16-1 | 8-0 | 10-2 | 12-5 | 14-4 | |
Hem-Fir | #3 | 6-10 | 8-8 | 10-7 | 12-4 | 6-2 | 7-9 | 9-6 | 11-0 | |
Southern Pine | SS | 9-9 | 12-10 | 16-5 | 19-11 | 9-9 | 12-10 | 16-5 | 19-8 | |
Southern Pine | #1 | 9-4 | 12-4 | 14-8 | 17-5 | 8-10 | 11-3 | 13-1 | 15-7 | |
Southern Pine | #2 | 8-6 | 10-10 | 12-10 | 15-1 | 7-7 | 9-8 | 11-5 | 13-6 | |
Southern Pine | #3 | 6-5 | 8-2 | 9-10 | 11-8 | 5-9 | 7-3 | 8-10 | 10-5 | |
Spruce-Pine-Fir | SS | 9-2 | 12-1 | 15-5 | 18-9 | 9-2 | 12-1 | 15-0 | 17-5 | |
Spruce-Pine-Fir | #1 | 8-11 | 11-6 | 14-1 | 16-3 | 8-1 | 10-3 | 12-7 | 14-7 | |
Spruce-Pine-Fir | #2 | 8-11 | 11-6 | 14-1 | 16-3 | 8-1 | 10-3 | 12-7 | 14-7 | |
Spruce-Pine-Fir | #3 | 6-10 | 8-8 | 10-7 | 12-4 | 6-2 | 7-9 | 9-6 | 11-0 |
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
Note: Check sources for availability of lumber in lengths greater than 20 feet.
FLOOR JOIST SPANS FOR COMMON LUMBER SPECIES (Residential living areas, live load = 40 psf, L/Δ = 360)
JOIST SPACING (inches) | SPECIES AND GRADE | DEAD LOAD = 10 psf | DEAD LOAD = 20 psf | |||||||
2 × 6 | 2 × 8 | 2 × 10 | 2 × 12 | 2 × 6 | 2 × 8 | 2 × 10 | 2 × 12 | |||
Maximum floor joist spans | ||||||||||
(ft. - in.) | (ft. - in.) | (ft. - in.) | (ft. - in.) | (ft. - in.) | (ft. - in.) | (ft. - in.) | (ft. - in.) | |||
12 | Douglas Fir-Larch | SS | 11-4 | 15-0 | 19-1 | 23-3 | 11-4 | 15-0 | 19-1 | 23-3 |
Douglas Fir-Larch | #1 | 10-11 | 14-5 | 18-5 | 22-0 | 10-11 | 14-2 | 17-4 | 20-1 | |
Douglas Fir-Larch | #2 | 10-9 | 14-2 | 17-9 | 20-7 | 10-6 | 13-3 | 16-3 | 18-10 | |
Douglas Fir-Larch | #3 | 8-8 | 11-0 | 13-5 | 15-7 | 7-11 | 10-0 | 12-3 | 14-3 | |
Hem-Fir | SS | 10-9 | 14-2 | 18-0 | 21-11 | 10-9 | 14-2 | 18-0 | 21-11 | |
Hem-Fir | #1 | 10-6 | 13-10 | 17-8 | 21-6 | 10-6 | 13-10 | 16-11 | 19-7 | |
Hem-Fir | #2 | 10-0 | 13-2 | 16-10 | 20-4 | 10-0 | 13-1 | 16-0 | 18-6 | |
Hem-Fir | #3 | 8-8 | 11-0 | 13-5 | 15-7 | 7-11 | 10-0 | 12-3 | 14-3 | |
Southern Pine | SS | 11-2 | 14-8 | 18-9 | 22-10 | 11-2 | 14-8 | 18-9 | 22-10 | |
Southern Pine | #1 | 10-9 | 14-2 | 18-0 | 21-11 | 10-9 | 14-2 | 16-11 | 20-1 | |
Southern Pine | #2 | 10-3 | 13-6 | 16-2 | 19-1 | 9-10 | 12-6 | 14-9 | 17-5 | |
Southern Pine | #3 | 8-2 | 10-3 | 12-6 | 14-9 | 7-5 | 9-5 | 11-5 | 13-6 | |
Spruce-Pine-Fir | SS | 10-6 | 13-10 | 17-8 | 21-6 | 10-6 | 13-10 | 17-8 | 21-6 | |
Spruce-Pine-Fir | #1 | 10-3 | 13-6 | 17-3 | 20-7 | 10-3 | 13-3 | 16-3 | 18-10 | |
Spruce-Pine-Fir | #2 | 10-3 | 13-6 | 17-3 | 20-7 | 10-3 | 13-3 | 16-3 | 18-10 | |
Spruce-Pine-Fir | #3 | 8-8 | 11-0 | 13-5 | 15-7 | 7-11 | 10-0 | 12-3 | 14-3 | |
16 | Douglas Fir-Larch | SS | 10-4 | 13-7 | 17-4 | 21-1 | 10-4 | 13-7 | 17-4 | 21-0 |
Douglas Fir-Larch | #1 | 9-11 | 13-1 | 16-5 | 19-1 | 9-8 | 12-4 | 15-0 | 17-5 | |
Douglas Fir-Larch | #2 | 9-9 | 12-7 | 15-5 | 17-10 | 9-1 | 11-6 | 14-1 | 16-3 | |
Douglas Fir-Larch | #3 | 7-6 | 9-6 | 11-8 | 13-6 | 6-10 | 8-8 | 10-7 | 12-4 | |
Hem-Fir | SS | 9-9 | 12-10 | 16-5 | 19-11 | 9-9 | 12-10 | 16-5 | 19-11 | |
Hem-Fir | #1 | 9-6 | 12-7 | 16-0 | 18-7 | 9-6 | 12-0 | 14-8 | 17-0 | |
Hem-Fir | #2 | 9-1 | 12-0 | 15-2 | 17-7 | 8-11 | 11-4 | 13-10 | 16-1 | |
Hem-Fir | #3 | 7-6 | 9-6 | 11-8 | 13-6 | 6-10 | 8-8 | 10-7 | 12-4 | |
Southern Pine | SS | 10-2 | 13-4 | 17-0 | 20-9 | 10-2 | 13-4 | 17-0 | 20-9 | |
Southern Pine | #1 | 9-9 | 12-10 | 16-1 | 19-1 | 9-9 | 12-7 | 14-8 | 17-5 | |
Southern Pine | #2 | 9-4 | 11-10 | 14-0 | 16-6 | 8-6 | 10-10 | 12-10 | 15-1 | |
Southern Pine | #3 | 7-1 | 8-11 | 10-10 | 12-10 | 6-5 | 8-2 | 9-10 | 11-8 | |
Spruce-Pine-Fir | SS | 9-6 | 12-7 | 16-0 | 19-6 | 9-6 | 12-7 | 16-0 | 19-6 | |
Spruce-Pine-Fir | #1 | 9-4 | 12-3 | 15-5 | 17-10 | 9-1 | 11-6 | 14-1 | 16-3 | |
Spruce-Pine-Fir | #2 | 9-4 | 12-3 | 15-5 | 17-10 | 9-1 | 11-6 | 14-1 | 16-3 | |
Spruce-Pine-Fir | #3 | 7-6 | 9-6 | 11-8 | 13-6 | 6-10 | 8-8 | 10-7 | 12-4 | |
19.2 | Douglas Fir-Larch | SS | 9-8 | 12-10 | 16-4 | 19-10 | 9-8 | 12-10 | 16-4 | 19-2 |
Douglas Fir-Larch | #1 | 9-4 | 12-4 | 15-0 | 17-5 | 8-10 | 11-3 | 13-8 | 15-11 | |
Douglas Fir-Larch | #2 | 9-1 | 11-6 | 14-1 | 16-3 | 8-3 | 10-6 | 12-10 | 14-10 | |
Douglas Fir-Larch | #3 | 6-10 | 8-8 | 10-7 | 12-4 | 6-3 | 7-11 | 9-8 | 11-3 | |
Hem-Fir | SS | 9-2 | 12-1 | 15-5 | 18-9 | 9-2 | 12-1 | 15-5 | 18-9 | |
Hem-Fir | #1 | 9-0 | 11-10 | 14-8 | 17-0 | 8-8 | 10-11 | 13-4 | 15-6 | |
Hem-Fir | #2 | 8-7 | 11-3 | 13-10 | 16-1 | 8-2 | 10-4 | 12-8 | 14-8 | |
Hem-Fir | #3 | 6-10 | 8-8 | 10-7 | 12-4 | 6-3 | 7-11 | 9-8 | 11-3 | |
Southern Pine | SS | 9-6 | 12-7 | 16-0 | 19-6 | 9-6 | 12-7 | 16-0 | 19-6 | |
Southern Pine | #1 | 9-2 | 12-1 | 14-8 | 17-5 | 9-0 | 11-5 | 13-5 | 15-11 | |
Southern Pine | #2 | 8-6 | 10-10 | 12-10 | 15-1 | 7-9 | 9-10 | 11-8 | 13-9 | |
Southern Pine | #3 | 6-5 | 8-2 | 9-10 | 11-8 | 5-11 | 7-5 | 9-0 | 10-8 | |
Spruce-Pine-Fir | SS | 9-0 | 11-10 | 15-1 | 18-4 | 9-0 | 11-10 | 15-1 | 17-9 | |
Spruce-Pine-Fir | # | 8-9 | 11-6 | 14-1 | 16-3 | 8-3 | 10-6 | 12-10 | 14-10 | |
Spruce-Pine-Fir | #2 | 8-9 | 11-6 | 14-1 | 16-3 | 8-3 | 10-6 | 12-10 | 14-10 | |
Spruce-Pine-Fir | #3 | 6-10 | 8-8 | 10-7 | 12-4 | 6-3 | 7-11 | 9-8 | 11-3 | |
24 | Douglas Fir-Larch | SS | 9-0 | 11-11 | 15-2 | 18-5 | 9-0 | 11-11 | 14-9 | 17-1 |
Douglas Fir-Larch | #1 | 8-8 | 11-0 | 13-5 | 15-7 | 7-11 | 10-0 | 12-3 | 14-3 | |
Douglas Fir-Larch | #2 | 8-1 | 10-3 | 12-7 | 14-7 | 7-5 | 9-5 | 11-6 | 13-4 | |
Douglas Fir-Larch | #3 | 6-2 | 7-9 | 9-6 | 11-0 | 5-7 | 7-1 | 8-8 | 10-1 | |
Hem-Fir | SS | 8-6 | 11-3 | 14-4 | 17-5 | 8-6 | 11-3 | 14-4 | 16-10a | |
Hem-Fir | #1 | 8-4 | 10-9 | 13-1 | 15-2 | 7-9 | 9-9 | 11-11 | 13-10 | |
Hem-Fir | #2 | 7-11 | 10-2 | 12-5 | 14-4 | 7-4 | 9-3 | 11-4 | 13-1 | |
Hem-Fir | #3 | 6-2 | 7-9 | 9-6 | 11-0 | 5-7 | 7-1 | 8-8 | 10-1 | |
Southern Pine | SS | 8-10 | 11-8 | 14-11 | 18-1 | 8-10 | 11-8 | 14-11 | 18-0 | |
Southern Pine | #1 | 8-6 | 11-3 | 13-1 | 15-7 | 8-1 | 10-3 | 12-0 | 14-3 | |
Southern Pine | #2 | 7-7 | 9-8 | 11-5 | 13-6 | 7-0 | 8-10 | 10-5 | 12-4 | |
Southern Pine | #3 | 5-9 | 7-3 | 8-10 | 10-5 | 5-3 | 6-8 | 8-1 | 9-6 | |
Spruce-Pine-Fir | SS | 8-4 | 11-0 | 14-0 | 17-0 | 8-4 | 11-0 | 13-8 | 15-11 | |
Spruce-Pine-Fir | #1 | 8-1 | 10-3 | 12-7 | 14-7 | 7-5 | 9-5 | 11-6 | 13-4 | |
Spruce-Pine-Fir | #2 | 8-1 | 10-3 | 12-7 | 14-7 | 7-5 | 9-5 | 11-6 | 13-4 | |
Spruce-Pine-Fir | #3 | 6-2 | 7-9 | 9-6 | 11-0 | 5-7 | 7-1 | 8-8 | 10-1 |
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
Note: Check sources for availability of lumber in lengths greater than 20 feet.
- End bearing length shall be increased to 2 inches.
Openings in horizontal diaphragms in Seismic Design Categories B, C, D and E with a dimension that is greater than 4 feet (1219 mm) shall be constructed with metal ties and blocking in accordance with this section and Figure 2308.4.4.1(1). Metal ties shall be not less than 0.058 inch [1.47 mm (16 galvanized gage)] in thickness by 11/2 inches (38 mm) in width and shall have a yield stress not less than 33,000 psi (227 Mpa). Blocking shall extend not less than the dimension of the opening in the direction of the tie and blocking. Ties shall be attached to blocking in accordance with the manufacturer's instructions but with not less than eight 16d common nails on each side of the header-joist intersection.
Openings in floor diaphragms in Seismic Design Categories D and E shall not have any dimension exceeding 50 percent of the distance between braced wall lines or an area greater than 25 percent of the area between orthogonal pairs of braced wall lines [see Figure 2308.4.4.1(2)]; or the portion of the structure containing the opening shall be designed in accordance with accepted engineering practice to resist the forces specified in Chapter 16, to the extent such irregular opening affects the performance of the conventional framing system.
OPENINGS IN FLOOR AND ROOF DIAPHRAGMS
OPENING LIMITATIONS FOR FLOOR AND ROOF DIAPHRAGMS
In Seismic Design Categories D and E, portions of a floor level shall not be vertically offset such that the framing members on either side of the offset cannot be lapped or tied together in an approved manner in accordance with Figure 2308.4.4.2 unless the portion of the structure containing the irregular offset is designed in accordance with accepted engineering practice.
Exception: Framing supported directly by foundations need not be lapped or tied directly together.
PORTIONS OF FLOOR LEVEL OFFSET VERTICALLY
The size, height and spacing of studs shall be in accordance with Table 2308.5.1.
Studs shall be continuous from a support at the sole plate to a support at the top plate to resist loads perpendicular to the wall. The support shall be a foundation or floor, ceiling or roof diaphragm or shall be designed in accordance with accepted engineering practice.
Exception: Jack studs, trimmer studs and cripple studs at openings in walls that comply with Table 2308.4.1.1(1) or 2308.4.1.1(2).
SIZE, HEIGHT AND SPACING OF WOOD STUDSc
STUD SIZE (inches) | BEARING WALLS | NONBEARING WALLS | ||||
Laterally unsupported stud heighta (feet) | Supporting roof and ceiling only | Supporting one floor, roof and ceiling | Supporting two floors, roof and ceiling | Laterally unsupported stud heighta (feet) | Spacing (inches) | |
Spacing (inches) | ||||||
2 × 3b | — | — | — | — | 10 | 16 |
2 × 4 | 10 | 24 | 16 | — | 14 | 24 |
3 × 4 | 10 | 24 | 24 | 16 | 14 | 24 |
2 × 5 | 10 | 24 | 24 | — | 16 | 24 |
2 × 6 | 10 | 24 | 24 | 16 | 20 | 24 |
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
- Listed heights are distances between points of lateral support placed perpendicular to the plane of the wall. Increases in unsupported height are permitted where justified by an analysis.
- Shall not be used in exterior walls.
- Utility-grade studs shall not be spaced more than 16 inches on center or support more than a roof and ceiling, or exceed 8 feet in height for exterior walls and load-bearing walls or 10 feet for interior nonload-bearing walls.
Studs shall be placed with their wide dimension perpendicular to the wall. Not less than three studs shall be installed at each corner of an exterior wall.
Exceptions:
- In interior nonbearing walls and partitions, studs are permitted to be set with the long dimension parallel to the wall.
- At corners, two studs are permitted, provided that wood spacers or backup cleats of 3/8-inch-thick (9.5 mm) wood structural panel, 3/8-inch (9.5 mm) Type M "Exterior Glue" particleboard, 1-inch-thick (25 mm) lumber or other approved devices that will serve as an adequate backing for the attachment of facing materials are used. Where fire-resistance ratings or shear values are involved, wood spacers, backup cleats or other devices shall not be used unless specifically approved for such use.
Bearing and exterior wall studs shall be capped with double top plates installed to provide overlapping at corners and at intersections with other partitions. End joints in double top plates shall be offset not less than 48 inches (1219 mm), and shall be nailed in accordance with Table 2304.10.1. Plates shall be a nominal 2 inches (51 mm) in depth and have a width not less than the width of the studs.
Exception: A single top plate is permitted, provided that the plate is adequately tied at corners and intersecting walls by not less than the equivalent of 3-inch by 6-inch (76 mm by 152 mm) by 0.036-inch-thick (0.914 mm) galvanized steel plate that is nailed to each wall or segment of wall by six 8d [21/2" × 0.113" (64-mm by 2.87 mm)] box nails or equivalent on each side of the joint. For the butt-joint splice between adjacent single top plates, not less than the equivalent of a 3-inch by 12-inch (76 mm by 304 mm) by 0.036-inch-thick (0.914 mm) galvanized steel plate that is nailed to each wall or segment of wall by 12 8d [21/2-inch × 0.113-inch (64 mm by 2.87 mm)] box nails on each side of the joint shall be required, provided that the rafters, joists or trusses are centered over the studs with a tolerance of not more than 1 inch (25 mm). The top plate shall not be required over headers that are in the same plane and in line with the upper surface of the adjacent top plates and are tied to adjacent wall sections as required for the butt joint splice between adjacent single top plates.
Where bearing studs are spaced at 24-inch (610 mm) intervals, top plates are less than two 2-inch by 6-inch (51 mm by 152 mm) or two 3-inch by 4-inch (76 mm by 102 mm) members and the floor joists, floor trusses or roof trusses that they support are spaced at more than 16-inch (406 mm) intervals, such joists or trusses shall bear within 5 inches (127 mm) of the studs beneath or a third plate shall be installed.
Headers shall be provided over each opening in exterior bearing walls. The size and spans in Table 2308.4.1.1(1) are permitted to be used for one- and two-family dwellings. Headers for other buildings shall be designed in accordance with Section 2301.2, Item 1 or 2. Headers of two or more pieces of nominal 2-inch (51 mm) framing lumber set on edge shall be permitted in accordance with Table 2308.4.1.1(1) and nailed together in accordance with Table 2304.10.1 or of solid lumber of equivalent size.
Single-member headers of nominal 2-inch (51 mm) thickness shall be framed with a single flat 2-inch-nominal (51 mm) member or wall plate not less in width than the wall studs on the top and bottom of the header in accordance with Figures 2308.5.5.1(1) and 2308.5.5.1(2) and face nailed to the top and bottom of the header with 10d box nails [3 inches × 0.128 inches (76 mm × 3.3 mm)] spaced 12 inches (305 mm) on center.
Wall studs shall support the ends of the header in accordance with Table 2308.4.1.1(1). Each end of a lintel or header shall have a bearing length of not less than 11/2 inches (38 mm) for the full width of the lintel.
SINGLE-MEMBER HEADER IN EXTERIOR BEARING WALL
ALTERNATIVE SINGLE-MEMBER HEADER WITHOUT CRIPPLE
Except where stucco construction that complies with Section 2510 is installed, the outside of exterior walls, including gables, of enclosed buildings shall be sheathed with one of the materials of the nominal thickness specified in Table 2308.5.11 with fasteners in accordance with the requirements of Section 2304.10 or fasteners designed in accordance with accepted engineering practice. Alternatively, sheathing materials and fasteners complying with Section 2304.6 shall be permitted.
MINIMUM THICKNESS OF WALL SHEATHING
SHEATHING TYPE | MINIMUM THICKNESS | MAXIMUM WALL STUD SPACING |
Diagonal wood boards | 5/8 inch | 24 inches on center |
Structural fiberboard | 1/2 inch | 16 inches on center |
Wood structural panel | In accordance with Tables 2308.6.3(2) and 2308.6.3(3) | — |
M-S "Exterior Glue" and M-2 "Exterior Glue" | In accordance with Section 2306.3 and Table 2308.6.3(4) | — |
Gypsum sheathing | 1/2 inch | 16 inches on center |
Reinforced cement mortar | 1 inch | 24 inches on center |
Hardboard panel siding | In accordance with Table 2308.6.3(5) | — |
For SI: 1 inch = 25.4 mm.
Wall framing to which sheathing used for bracing is applied shall be nominal 2 inch wide [actual 1-1/2 inch (38 mm)] or larger members. Braced wall panel construction types shall not be mixed within a braced wall line. Braced wall panels required by LAMC Section 91.2308.6.1 may be eliminated when all of the following requirements are met:
- One story detached Group U occupancies are not more than 25 feet (7.62 m) in depth or length.
- The roof and three enclosing walls are solid sheathed with 1/2 inch (12.7 mm) nominal thickness wood structural panels with 8d common nails placed 3/8 inches (9.525 mm) from panel edges and spaced not more than 6 inches (152.4 mm) on center along all panel edges and 12 inches (304.8 mm) on center along intermediate framing members. Wall openings for doors or windows are permitted provided a minimum 4 foot (1219.2 mm) wide wood structural braced panel with a minimum height to length ratio of 2 to 1 is provided at each end of the wall line and that the wall line be sheathed for 50% of its length.
BASIC COMPONENTS OF THE LATERAL BRACING SYSTEM
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, GBGbc, 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, f, g, h |
SDS < 0.50: Each end and ≤25'- 0" o.c. (minimum 43% of wall length)e, f, g, h |
8'- 0" | |
0.5 ≤SDS < 0.75: Each end and ≤ 25'- 0" o.c. (minimum 32% of wall length)e, f, g, h |
0.5 ≤SDS< 0.75: Each end and ≤ 25'- 0" o.c. (minimum 59% of wall length)e, f, g, h |
|||||
0.75 ≤SDS ≤ 1.00: Each end and ≤ 25'- 0" o.c. (minimum 37% of wall length)e, f, g, h |
0.75 ≤SDS ≤ 1.00: Each end and ≤ 25'- 0" o.c. (minimum 75% of wall length)e, f, g, h |
|||||
SDS > 1.00: Each end and ≤25'- 0" o.c. (minimum 48% of wall length)e, f, g, h |
SDS > 1.00: Each end and ≤25'- 0" o.c. (minimum 100% of wall length)e, f, g, h |
NP = Not Permitted.
- This table specifies minimum requirements for braced wall panels along interior or exterior braced wall lines.
- See Section 2308.6.3 for full description of bracing methods.
- For Method GB, gypsum wallboard applied to framing supports that are spaced at 16 inches on center.
- The required lengths shall be doubled for gypsum board applied to only one face of a braced wall panel.
- Percentage shown represents the minimum amount of bracing required along the building length (or wall length if the structure has an irregular shape).
- Minimum length of panel bracing of one face of the wall for WSP sheathing shall be at least 4'-0" long or both feces of the wall for GB sheathing shall be at least 8'-0" long; h/w ratio shall not exceed 2:1. For WSP panel bracing of the same material on two faces of the wall, the minimum length is permitted to be one-half of the tabulated value, but the h/w ratio shall not exceed 2:1 and design for uplift is required. The 2:1 h/w ratio limitation does not apply to alternate braced wall panels constructed in accordance with Section 2308.6.5.1 or 2308.6.5.2.
- Nailing as specified below shall occur at all panel edges at studs, at top and bottom plates and, where occurring, at blocking:
For 1/2-inch gypsum board, 5d (0.113-inch diameter) cooler nails at 7 inches on center;
For 5/8-inch gypsum board, No. 11 gage (0.120-inch diameter) at 7 inches on center;
For gypsum sheathing board, 1-3/4 inches long by 7/l6-inch head, diamond point galvanized nails at 4 inches on center;
For gypsum lath, No. 13 gage (0.092 inch) by 1-1/8 inches long, 19/64-inch head, plasterboard at 5 inches on center; and
For Portland cement plaster, No. 11 gage (0.120 inch) by 1-1/2 inches long, 7/l6-inch head at 6 inches on center. - WSP sheathing shall be a minimum of 15/32" thick nailed with 8d common placed 3/8 inch from panel edges and spaced not more than 6 inches on center and 12 inches on center along intermediate framing members.
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.
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 2304.10.1 | 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 | 3/4" thick (1" nominal) × 6" minimum width to studs at maximum of 24" o.c. | Table 2304.10.1 | Per stud | |
WSP Wood structural | 3/8" in accordance with 2308.6.3(3) |
| Table 2304.10.1 | 6" edges 12" field |
SFB Structural fiberboard sheathing | 1/2" in accordance with Table 2304.10.1 to studs at maximum 16" o.c. |
| Table 2304.10.1 | 3" edges 6" field |
GB (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, 7/16" dia. head nails or 7/8" long, 16 gage staples | 6" o.c. on all framing members |
HPS | 7/16" in accordance with |
| Table 2304.10.1 | 4" edges 8" field |
ABW Alternate braced wall | 3/8" | Figure 2308.6.5.1 and | Figure 2308.6.5.1 | |
PFH Portal frame with hold- downs | 3/8" | Figure 2308.6.5.2 and | Figure 2308.6.5.2 |
For SI: 1 foot = 304.8 mm, 1 degree = 0.01745 rad.
- Method LIB shall have gypsum board fastened to one or more side(s) with nails or screws
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.
- Thickness of grooved panels is measured at bottom of grooves.
- 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.
- Plywood shall consist of four or more plies.
- 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.
- Nails shall be corrosion resistant.
- Minimum acceptable nail dimensions:
Where used to comply with Section 2308.6.
Panel Siding (inch) Lap Siding (inch) Shank diameter 0.092 0.099 Head diameter 0.225 0.240 - Nail length must accommodate the sheathing and penetrate framing 11/2 inches.
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.
Where the ABW is installed at the first story of a two-story buildings, the wood structural panel sheathing shall be provided on both faces, three anchor bolts shall be placed at one-quarter points, and tie-down device uplift capacity shall be not less than 3,000 pounds (13 344 N).
In one-story buildings, each panel shall have a length of not less than 16 inches (406 mm) and a height of not more than 10 feet (3048 mm). Each panel shall be sheathed on one face with a single layer of 3/8- 15/32 inch (9.511.9 mm) minimum-thickness wood structural panel sheathing nailed with 8d common or galvanized box nails in accordance with CBC Figure 2308.6.5.2. The wood structural panel sheathing shall extend up over the solid sawn or glued-laminated header and shall be nailed in accordance with CBC Figure 2308.6.5.2. A built-up header consisting of not fewer than at least two 2- inch by 12- inch (51 mm by 305 mm) boards, fastened in accordance with Item 24 of LAMC Table 2304.10.1 shall be permitted to be used. A spacer, if used, shall be placed on the side of the built-up beam opposite the wood structural panel sheathing. The header shall extend between the inside faces of the first full-length outer studs of each panel. The clear span of the header between the inner studs of each panel shall be not less than 6 feet (1829 mm) and not more than 18 feet (5486 mm) in length. A strap with an uplift capacity of not less than 1,000 pounds (4,400 N) shall fasten the header to the inner studs opposite the sheathing. One anchor bolt not less than 5/8 inch (15.9 mm) in diameter and installed in accordance with CBC Section 2308.3.1 shall be provided in the center of each sill plate. The studs at each end of the panel shall have a hold-down device fastened to the foundation with an uplift capacity of not less than 3,500 pounds (15 570 N).
Where a panel is located on one side of the opening, the header shall extend between the inside face of the first full-length stud of the panel and the bearing studs at the other end of the opening. A strap with an uplift capacity of not less than 1,000 pounds (4400 N) shall fasten the header to the bearing studs. The bearing studs shall also have a hold-down device fastened to the foundation with an uplift capacity of not less than 1,000 pounds (4400 N). The hold-down devices shall be an embedded strap type, installed in accordance with the manufacturer's recommendations. The PFH panels shall be supported directly on a foundation that is continuous across the entire length of the braced wall line. This foundation shall be reinforced with not less than one No. 4 bar top and bottom. Where the continuous foundation is required to have a depth greater than 12 inches (305 mm), a minimum 12- inch by 12- inch (305 mm by 305 mm) continuous footing or turned-down slab edge is permitted at door openings in the braced wall line. This continuous footing or turned-down slab edge shall be reinforced with not less than one No. 4 bar top and bottom. This reinforcement shall be lapped not less than 15 inches (381 mm) with the reinforcement required in the continuous foundation located directly under the braced wall line.
Where a PFH is installed at the first story of a two-story buildings, each panel shall have a length of not less than 24 inches (610 mm).
PORTAL FRAME WITH HOLD-DOWNS (PFH)
Where joists or rafters are used, braced wall line top plates shall be fastened over the full length of the braced wall line to joists, rafters, rim boards or full-depth blocking above in accordance with Table 2304.10.1, as applicable, based on the orientation of the joists or rafters to the braced wall line. Blocking shall be not less than 2 inches (51 mm) in nominal thickness and shall be fastened to the braced wall line top plate as specified in Table 2304.10.1. Notching or drilling of holes in blocking in accordance with the requirements of Section 2308.4.2.4 or 2308.7.4 shall be permitted.
At exterior gable end walls, braced wall panel sheathing in the top story shall be extended and fastened to the roof framing where the spacing between parallel exterior braced wall lines is greater than 50 feet (15 240 mm).
Where roof trusses are used and are installed perpendicular to an exterior braced wall line, lateral forces shall be transferred from the roof diaphragm to the braced wall over the full length of the braced wall line by blocking of the ends of the trusses or by other approved methods providing equivalent lateral force transfer. Blocking shall be not less than 2 inches (51 mm) in nominal thickness and equal to the depth of the truss at the wall line and shall be fastened to the braced wall line top plate as specified in Table 2304.10.1. Notching or drilling of holes in blocking in accordance with the requirements of Section 2308.4.2.4 or 2308.7.4 shall be permitted.
Exc