ADOPTS WITH AMENDMENTS:

International Building Code 2018 (IBC 2018)

Heads up: There are no amended sections in this chapter.

The provisions of this chapter shall govern the materials, design, construction and quality of wood members and their fasteners.

Exception: Buildings and structures located within the high-velocity hurricane zone shall comply with the provisions of Sections 2302, 2303.1 through 2303.1.4, 2303.1.8, 2303.2, 2303.5, 2303.5.1, 2303.5.2, 2304.12, 2304.12.9 and Sections 2314 through 2330.

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:

  1. Allowable stress design in accordance with Sections 2304, 2305 and 2306.
  2. Load and resistance factor design in accordance with Sections 2304, 2305 and 2307.
  3. Conventional light-frame construction in accordance with Section 2304.
  4. AWC WFCM in accordance with Section 2309.
  5. The design and construction of log structures in accordance with the provisions of ICC 400.
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).
Structural sawn lumber; end-jointed lumber; prefabricated wood I-joists; structural glued-laminated timber; wood structural panels; fiberboard sheathing (when used structurally); hardboard siding (when used structurally); particleboard; preservative-treated wood; structural log members; structural composite lumber; round timber poles and piles; fire-retardant-treated wood; hardwood plywood; wood trusses; joist hangers; nails; and staples shall conform to the applicable provisions of this section.
Sawn lumber used for load-supporting purposes, including end-jointed or edge-glued lumber, machine stress-rated or machine-evaluated lumber, shall be identified by the grade mark of a lumber grading or inspection agency that has been approved by an accreditation body that complies with DOC PS 20 or equivalent. Grading practices and identification shall comply with rules published by an agency approved in accordance with the procedures of DOC PS 20 or equivalent procedures.
In lieu of a grade mark on the material, a certificate of inspection as to species and grade issued by a lumber grading or inspection agency meeting the requirements of this section is permitted to be accepted for precut, remanufactured or rough-sawn lumber and for sizes larger than 3 inches (76 mm) nominal thickness.
Approved end-jointed lumber is permitted to be used interchangeably with solid-sawn members of the same species and grade. End-jointed lumber used in an assembly required to have a fire-resistance rating shall have the designation "Heat Resistant Adhesive" or "HRA" included in its grade mark.
Structural capacities and design provisions for prefabricated wood I-joists shall be established and monitored in accordance with ASTM D5055.
Glued-laminated timbers shall be manufactured and identified as required in ANSI/AITC A190.1 and ASTM D3737.
Cross-laminated timbers shall be manufactured and identified in accordance with ANSI/APA PRG 320.
Wood structural panels, when used structurally (including those used for siding, roof and wall sheathing, subflooring, diaphragms and built-up members), shall conform to the requirements for their type in DOC PS 1, DOC PS 2 or ANSI/APA PRP 210. Each panel or member shall be identified for grade, bond classification, and Performance Category by the trademarks of an approved testing and grading agency. The Performance Category value shall be used as the "nominal panel thickness" or "panel thickness" whenever referenced in this code. Wood structural panel components shall be designed and fabricated in accordance with the applicable standards listed in Section 2306.1 and identified by the trademarks of an approved testing and inspection agency indicating conformance to the applicable standard. In addition, wood structural panels when permanently exposed in outdoor applications shall be of Exterior type, except that wood structural panel roof sheathing exposed to the outdoors on the underside is permitted to be Exposure 1 type.
Fiberboard for its various uses shall conform to ASTM C208. Fiberboard sheathing, when used structurally, shall be identified by an approved agency as conforming to ASTM C208.
To ensure tight-fitting assemblies, edges shall be manufactured with square, shiplapped, beveled, tongue-and-groove or U-shaped joints.
Where used as roof insulation in all types of construction, fiberboard shall be protected with an approved roof covering.
Where installed and fire-blocked to comply with Chapter 7, fiberboards are permitted as wall insulation in all types of construction. In fire walls and fire barriers, unless treated to comply with Section 803.1 for Class A materials, the boards shall be cemented directly to the concrete, masonry or other noncombustible base and shall be protected with an approved noncombustible veneer anchored to the base without intervening airspaces.
Fiberboard wall insulation applied on the exterior of foundation walls shall be protected below ground level with a bituminous coating.
Hardboard siding shall conform to the requirements of ANSI A135.6 and, where used structurally, shall be identified by the label of an approved agency. Hardboard underlayment shall meet the strength requirements of 7/32-inch (5.6 mm) or 1/4-inch (6.4 mm) service class hardboard planed or sanded on one side to a uniform thickness of not less than 0.200 inch (5.1 mm). Prefinished hardboard paneling shall meet the requirements of ANSI A135.5. Other basic hardboard products shall meet the requirements of ANSI A135.4. Hardboard products shall be installed in accordance with manufacturer's recommendations.
Particleboard shall conform to ANSI A208.1. Particleboard shall be identified by the grade mark or certificate of inspection issued by an approved agency. Particleboard shall not be utilized for applications other than indicated in this section unless the particleboard complies with the provisions of Section 2306.3.
Particleboard floor underlayment shall conform to Type PBU of ANSI A208.1. Type PBU underlayment shall not be less than 1/4-inch (6.4 mm) thick and shall be installed in accordance with the instructions of the Composite Panel Association.
Lumber, timber, plywood, piles and poles supporting permanent structures required by Section 2304.12 to be preservative treated shall conform to AWPA U1 and M4. Lumber and plywood used in permanent wood foundation systems shall conform to Chapter 18.

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:

  1. Identification of treating manufacturer.
  2. Type of preservative used.
  3. Minimum preservative retention (pcf).
  4. End use for which the product is treated.
  5. AWPA standard to which the product was treated.
  6. Identity of the accredited inspection agency.
Where preservative-treated wood is used in enclosed locations where drying in service cannot readily occur, such wood shall be at a moisture content of 19 percent or less before being covered with insulation, interior wall finish, floor covering or other materials.
Structural capacities for structural composite lumber shall be established and monitored in accordance with ASTM D5456.
Stress grading of structural log members of nonrectangular shape, as typically used in log buildings, shall be in accordance with ASTM D3957. Such structural log members shall be identified by the grade mark of an approved lumber grading or inspection agency. In lieu of a grade mark on the material, a certificate of inspection as to species and grade issued by a lumber grading or inspection agency meeting the requirements of this section shall be permitted.
Round timber poles and piles shall comply with ASTM D3200 and ASTM D25, respectively.
Engineered wood rim boards shall conform to ANSI/APA PRR 410 or shall be evaluated in accordance with ASTM D7672. Structural capacities shall be in accordance with ANSI/APA PRR 410 or established in accordance with ASTM D7672. Rim boards conforming to ANSI/APA PRR 410 shall be marked in accordance with that standard.
Fire-retardant-treated wood is any wood product which, when impregnated with chemicals by a pressure process or other means during manufacture, shall have, when tested in accordance with ASTM E84 or UL 723, a listed flame spread index of 25 or less and show no evidence of significant progressive combustion when the test is continued for an additional 20-minute period. Additionally, the flame front shall not progress more than 101/2 feet (3200 mm) beyond the centerline of the burners at any time during the test.
For wood products impregnated with chemicals by a pressure process, the process shall be performed in closed vessels under pressures not less than 50 pounds per square inch gauge (psig) (345 kPa).
For wood products impregnated with chemicals by other means during manufacture, the treatment shall be an integral part of the manufacturing process of the wood product. The treatment shall provide permanent protection to all surfaces of the wood product. The use of paints, coating, stains or other surface treatments is not an approved method of protection as required in this section.
For wood products produced by other means during manufacture, other than a pressure process, all sides of the wood product shall be tested in accordance with and produce the results required in Section 2303.2. Wood structural panels shall be permitted to test only the front and back faces.

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:

  1. The identification mark of an approved agency in accordance with Section 1703.5.
  2. Identification of the treating manufacturer.
  3. The name of the fire-retardant treatment.
  4. The species of wood treated.
  5. Flame spread and smoke-developed index.
  6. Method of drying after treatment.
  7. Conformance with appropriate standards in accordance with Sections 2303.2.5 through 2303.2.8.
  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).
Design values for untreated lumber and wood structural panels, as specified in Section 2303.1, shall be adjusted for fire-retardant-treated wood. Adjustments to design values shall be based on an approved method of investigation that takes into consideration the effects of the anticipated temperature and humidity to which the fire-retardant-treated wood will be subjected, the type of treatment and redrying procedures.
The effect of treatment and the method of redrying after treatment, and exposure to high temperatures and high humidities on the flexure properties of fire-retardant-treated softwood plywood shall be determined in accordance with ASTM D5516. The test data developed by ASTM D5516 shall be used to develop adjustment factors, maximum loads and spans, or both, for untreated plywood design values in accordance with ASTM D6305. Each manufacturer shall publish the allowable maximum loads and spans for service as floor and roof sheathing for its treatment.
For each species of wood that is treated, the effects of the treatment, the method of redrying after treatment and exposure to high temperatures and high humidities on the allowable design properties of fire-retardant-treated lumber shall be determined in accordance with ASTM D5664. The test data developed by ASTM D5664 shall be used to develop modification factors for use at or near room temperature and at elevated temperatures and humidity in accordance with ASTM D6841. Each manufacturer shall publish the modification factors for service at temperatures of not less than 80°F (27°C) and for roof framing. The roof framing modification factors shall take into consideration the climatological location.
Where fire-retardant-treated wood is exposed to weather, or damp or wet locations, it shall be identified as "Exterior" to indicate there is no increase in the listed flame spread index as defined in Section 2303.2 when subjected to ASTM D2898.
Interior fire-retardant-treated wood shall have moisture content of not over 28 percent when tested in accordance with ASTM D3201 procedures at 92-percent relative humidity. Interior fire-retardant-treated wood shall be tested in accordance with Section 2303.2.5.1 or 2303.2.5.2. Interior fire-retardant-treated wood designated as Type A shall be tested in accordance with the provisions of this section.
Fire-retardant-treated wood shall be dried to a moisture content of 19 percent or less for lumber and 15 percent or less for wood structural panels before use. For wood kiln-dried after treatment (KDAT), the kiln temperatures shall not exceed those used in kiln drying the lumber and plywood submitted for the tests described in Section 2303.2.5.1 for plywood and 2303.2.5.2 for lumber.
See Section 603.1 for limitations on the use of fire-retardant-treated wood in buildings of Type I or II construction.
Hardwood and decorative plywood shall be manufactured and identified as required in HPVA HP-1.
Wood trusses shall comply with Sections 2303.4.1 through 2303.4.7.
Wood trusses shall be designed in accordance with the provisions of this code and accepted engineering practice. Members are permitted to be joined by nails, glue, bolts, timber connectors, metal connector plates or other approved framing devices.

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 also be provided with the shipment of trusses delivered to the job site. Truss design drawings shall include, at a minimum, the information specified below:

  1. Slope or depth, span and spacing;
  2. Location of all joints and support locations;
  3. Number of plies if greater than one;
  4. Required bearing widths;
  5. Design loads as applicable, including;

    1. 5.1. Top chord live load;
    2. 5.2. Top chord dead load;
    3. 5.3. Bottom chord live load;
    4. 5.4. Bottom chord dead load;
    5. 5.5. Additional loads and locations; and
    6. 5.6. Environmental design criteria and loads (wind, rain, snow, seismic, etc.).
  6. Other lateral loads, including drag strut loads;
  7. Adjustments to wood member and metal connector plate design value for conditions of use;
  8. Maximum reaction force and direction, including maximum uplift reaction forces where applicable;
  9. Metal-connector-plate type, size and thickness or gage, and the dimensioned location of each metal connector plate except where symmetrically located relative to the joint interface;
  10. Size, species and grade for each wood member;
  11. Truss-to-truss connections and truss field assembly requirements;
  12. Calculated span-to-deflection ratio and maximum vertical and horizontal deflection for live and total load as applicable;
  13. Maximum axial tension and compression forces in the truss members;
  14. 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:

  1. 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.
  2. The trusses shall be designed so that the buckling of any individual truss member is resisted internally by the individual truss through suitable means (i.e., buckling reinforcement by T-reinforcement or L-reinforcement, proprietary reinforcement, etc.). 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.
  3. A project-specific permanent individual truss member restraint/bracing design shall be permitted to be specified by any registered design professional.
The owner or the owner's authorized agent shall contract with any qualified registered design professional for the design of the temporary installation restraint/bracing and the permanent individual truss member restraint/bracing for all trusses with clear spans 60 feet (18 288 mm) or greater.
The individual or organization responsible for the design of trusses.

Where required by the registered design professional, the building official or the statutes of the jurisdiction in which the project is to be constructed, each individual truss design drawing shall bear the seal and signature of the truss designer.

Exceptions:

  1. 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.
  2. When 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.
The truss manufacturer shall provide a truss placement diagram that identifies the proposed location for each individually designated truss and references the corresponding truss design drawing. The truss placement diagram shall be provided as part of the truss submittal package, and with the shipment of trusses delivered to the job site. Truss placement diagrams that serve only as a guide for installation and do not deviate from the permit submittal drawings shall not be required to bear the seal or signature of the truss designer.
The truss submittal package provided by the truss manufacturer shall consist of each individual truss design drawing, the truss placement diagram, the permanent individual truss member restraint/bracing method and details and any other structural details germane to the trusses; and, as applicable, the cover/truss index sheet.
The design for the transfer of loads and anchorage of each truss to the supporting structure is the responsibility of the registered design professional.
Truss members and components shall not be cut, notched, drilled, spliced or otherwise altered in any way without written concurrence and approval of a registered design professional. Alterations resulting in the addition of loads to any member (e.g., HVAC equipment, piping, additional roofing or insulation, etc.) shall not be permitted without verification that the truss is capable of supporting such additional loading.
In addition to Sections 2303.4.1 through 2303.4.5, the design, manufacture and quality assurance of metal-plate-connected wood trusses shall be in accordance with TPI 1. Job-site inspections shall be in compliance with Section 110.4, as applicable.
Trusses not part of a manufacturing process in accordance with either Section 2303.4.6 or a referenced standard, which provides requirements for quality control done under the supervision of a third-party quality control agency, shall be manufactured in compliance with Sections 1704.2.5 and 1705.5, as applicable.
Allowable loads for joist hangers shall be in accordance with ASTM D7147.

Allowable loads for other premanufactured connectors shall be established using the procedure in ASTM D7147. A maximum of two connectors shall be tested simultaneously when establishing loads for one connector.

Exception: Allowable loads for connectors that are flat and are not loaded eccentrically, such as straps, are permitted to be determined by calculations in accordance with the standards listed in this code.

Nails and staples shall conform to requirements of ASTM F1667. Nails used for framing and sheathing connections shall have minimum average bending yield strengths as follows: 80 kips per square inch (ksi) (551 MPa) for shank diameters larger than 0.177 inch (4.50 mm) but not larger than 0.254 inch (6.45 mm), 90 ksi (620 MPa) for shank diameters larger than 0.142 inch (3.61 mm) but not larger than 0.177 inch (4.50 mm) and 100 ksi (689 MPa) for shank diameters of at least 0.099 inch (2.51 mm) but not larger than 0.142 inch (3.61 mm).
Consideration shall be given in design to the possible effect of cross-grain dimensional changes considered vertically which may occur in lumber fabricated in a green condition.
The provisions of this section apply to design methods specified in Section 2301.2.
Computations to determine the required sizes of members shall be based on the net dimensions (actual sizes) and not nominal sizes.
The framing of exterior and interior walls shall be in accordance with the provisions specified in Section 2301.2 unless a specific design is furnished.
Studs shall have full bearing on a 2-inch-thick (actual 11/2-inch, 38 mm) or larger plate or sill having a width at least equal to the width of the studs.
Headers, double joists, trusses or other approved assemblies that are of adequate size to transfer loads to the vertical members shall be provided over window and door openings in load-bearing walls and partitions.
Wood walls and bearing partitions shall not support more than two floors and a roof unless an analysis satisfactory to the building official shows that shrinkage of the wood framing will not have adverse effects on the structure or any plumbing, electrical or mechanical systems or other equipment installed therein due to excessive shrinkage or differential movements caused by shrinkage. The analysis shall also show that the roof drainage system and the foregoing systems or equipment will not be adversely affected or, as an alternate, such systems shall be designed to accommodate the differential shrinkage or movements.
Gable endwalls shall be structurally continuous between points of lateral support.
Gable endwalls adjacent to cathedral ceilings shall be structurally continuous from the uppermost floor to the ceiling diaphragm or to the roof diaphragm.
Full height studs may be sized using the bracing at a ceiling diaphragm for determining stud length requirements.
The framing of wood-joisted floors and wood-framed roofs shall be in accordance with the provisions specified in Section 2301.2 unless a specific design is furnished.
Combustible framing shall be a minimum of 2 inches (51 mm), but shall not be less than the distance specified in Sections 2111 and 2113 and the Florida Building Code, Mechanical, from flues, chimneys and fireplaces, and 6 inches (152 mm) away from flue openings.
Wall sheathing on the outside of exterior walls, including gables, and the connection of the sheathing to framing shall be designed in accordance with the general provisions of this code and shall be capable of resisting wind pressures in accordance with Section 1609.

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.

TABLE 2304.6.1

MAXIMUM NOMINAL 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 THICKNESS
(inches)
MAXIMUM
WALL STUD
SPACING
(inches)
PANEL NAIL
SPACING
MAXIMUM NOMINAL
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.

  1. 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.
  2. 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 Section 2301.2.
  3. 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 a maximum of 16 inches on center.
  4. Vasd shall be determined in accordance with Section 1609.3.1.
Softwood wood structural panels used for interior paneling shall conform to the provisions of Chapter 8 and shall be installed in accordance with Table 2304.10.1. Panels shall comply with DOC PS 1, DOC PS 2 or ANSI/APA PRP 210. Prefinished hardboard paneling shall meet the requirements of CPA/ANSI A135.5. Hardwood plywood shall conform to HPVA HP-1.

Structural floor sheathing and structural roof sheathing shall comply with Sections 2304.8.1 and 2304.8.2, respectively.

TABLE 2304.8(1)

ALLOWABLE SPANS FOR LUMBER FLOOR AND ROOF SHEATHINGa

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.

  1. Maximum 19-percent moisture content.

TABLE 2304.8(2)

SHEATHING LUMBER, MINIMUM GRADE REQUIREMENTS: BOARD GRADE

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

TABLE 2304.8(3)

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 ROOFc FLOORc
Panel span rating Panel thickness
(inches)
Maximum span (inches) Loadd (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.

  1. Applies to panels 24 inches or wider.
  2. Uniform load deflection limitations 1/180 of span under live load plus dead load, 1/240 under live load only.
  3. 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.
  4. Allowable load at maximum span.
  5. 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.
  6. For 1/2-inch panel, maximum span shall be 24 inches.
  7. Span is permitted to be 24 inches on center where 3/4-inch wood strip flooring is installed at right angles to joist.
  8. 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.

TABLE 2304.8(4)

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.

  1. 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.
  2. Applicable to all grades of sanded exterior-type plywood. See DOC PS 1 for plywood species groups.
  3. Applicable to Underlayment grade, C-C (Plugged) plywood, and Single Floor grade wood structural panels.

TABLE 2304.8(5)

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, b

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.

  1. Uniform load deflection limitations 1/180 of span under live load plus dead load, 1/240 under live load only. Edges shall be blocked with lumber or other approved type of edge supports.
  2. For composite and four-ply plywood structural panel, load shall be reduced by 15 pounds per square foot.

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).

Lumber decking shall be designed and installed in accordance with the general provisions of this code and Sections 2304.9.1 through 2304.9.5.3.
Each piece of lumber decking shall be square-end trimmed. When random lengths are furnished, each piece shall be square end trimmed across the face so that at least 90 percent of the pieces are within 0.5 degrees (0.00873 rad) of square. The ends of the pieces shall be permitted to be beveled up to 2 degrees (0.0349 rad) from the vertical with the exposed face of the piece slightly longer than the opposite face of the piece. Tongue-and-groove decking shall be installed with the tongues up on sloped or pitched roofs with pattern faces down.
Lumber decking is permitted to be laid up following one of five standard patterns as defined in Sections 2304.9.2.1 through 2304.9.2.5. Other patterns are permitted to be used provided they are substantiated through engineering analysis.
All pieces shall be supported on their ends (i.e., by two supports).
All pieces shall be supported by three supports, and all end joints shall occur in line on alternating supports. Supporting members shall be designed to accommodate the load redistribution caused by this pattern.
Courses in end spans shall be alternating simple-span pattern and two-span continuous pattern. End joints shall be staggered in adjacent courses and shall bear on supports.
The decking shall extend across a minimum of three spans. Pieces in each starter course and every third course shall be simple span pattern. Pieces in other courses shall be cantilevered over the supports with end joints at alternating quarter or third points of the spans. Each piece shall bear on at least one support.

The decking shall extend across a minimum of 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 at least two intervening courses. In the end bays, each piece shall bear on at least one support. Where an end joint occurs in an end bay, the next piece in the same course shall continue over the first inner support for at least 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:

  1. The maximum cantilevered length shall be 30 percent of the length of the first adjacent interior span.
  2. A structural fascia shall be fastened to each decking piece to maintain a continuous, straight line.
  3. There shall be no end joints in the decking between the cantilevered end of the decking and the centerline of the first adjacent interior span.
Mechanically laminated decking shall comply with Sections 2304.9.3.1 through 2304.9.3.3.
Mechanically laminated decking consists of square-edged dimension lumber laminations set on edge and nailed to the adjacent pieces and to the supports.

The length of nails connecting laminations shall be not less than two and one-half times the net thickness of each lamination. Where decking supports are 48 inches (1219 mm) on center or less, side nails shall be installed not more than 30 inches (762 mm) on center alternating between top and bottom edges, and staggered one-third of the spacing in adjacent laminations. Where supports are spaced more than 48 inches (1219 mm) on center, side nails shall be installed not more than 18 inches (457 mm) on center alternating between top and bottom edges and staggered one-third of the spacing in adjacent laminations. For mechanically laminated decking constructed with laminations of 2-inch (51 mm) nominal thickness, nailing in accordance with Table 2304.9.3.2 shall be permitted. Two side nails shall be installed at each end of butt-jointed pieces.

Laminations shall be toenailed to supports with 20d or larger common nails. Where the supports are 48 inches (1219 mm) on center or less, alternate laminations shall be toenailed to alternate supports; where supports are spaced more than 48 inches (1219 mm) on center, alternate laminations shall be toenailed to every support. For mechanically laminated decking constructed with laminations of 2-inch (51 mm) nominal thickness, toenailing at supports in accordance with Table 2304.9.3.2 shall be permitted.

TABLE 2304.9.3.2

FASTENING SCHEDULE FOR MECHANICALLY LAMINATED DECKING USING LAMINATIONS OF 2-INCH NOMINAL THICKNESS

MINIMUM NAIL SIZE
(Length × diameter)
MAXIMUM SPACING BETWEEN FACE NAILSa, 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

For SI: 1 inch = 25.4 mm.

  1. Nails shall be driven perpendicular to the lamination face, alternating between top and bottom edges.
  2. 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.
  3. Where supports are 48 inches (1219 mm) on center or less, alternate laminations shall be toenailed to alternate supports; where supports are spaced more than 48 inches (1219 mm) on center, alternate laminations shall be toenailed to every support.
There shall be a minimum distance of 24 inches (610 mm) between end joints in adjacent courses. The pieces in the first and second courses shall bear on at least two supports with end joints in these two courses occurring on alternate supports. A maximum of seven intervening courses shall be permitted before this pattern is repeated.
Two-inch (51 mm) sawn tongue-and-groove decking shall comply with Sections 2304.9.4.1 through 2304.9.4.3.
Two-inch (51 mm) decking shall have a maximum moisture content of 15 percent. Decking shall be machined with a single tongue-and-groove pattern. Each decking piece shall be nailed to each support.
Each piece of decking shall be toe-nailed at each support with one 16d common nail through the tongue and face-nailed with one 16d common nail.
There shall be a minimum distance of 24 inches (610 mm) between end joints in adjacent courses. The pieces in the first and second courses shall bear on at least two supports with end joints in these two courses occurring on alternate supports. A maximum of seven intervening courses shall be permitted before this pattern is repeated.
Three- and four-inch (76 mm and 102 mm) sawn tongue-and-groove decking shall comply with Sections 2304.9.5.1 through 2304.9.5.3.
Three-inch (76 mm) and four-inch (102 mm) decking shall have a maximum moisture content of 19 percent. Decking shall be machined with a double tongue-and-groove pattern. Decking pieces shall be interconnected and nailed to the supports.
Each piece shall be toenailed at each support with one 40d common nail and face-nailed with one 60d common nail. Courses shall be spiked to each other with 8-inch (203 mm) spikes at maximum intervals of 30 inches (762 mm) through predrilled edge holes penetrating to a depth of approximately 4 inches (102 mm). One spike shall be installed at a distance not exceeding 10 inches (254 mm) from the end of each piece.
There shall be a minimum distance of 48 inches (1219 mm) between end joints in adjacent courses. Pieces not bearing on a support are permitted to be located in interior bays provided the adjacent pieces in the same course continue over the support for at least 24 inches (610 mm). This condition shall not occur more than once in every six courses in each interior bay.
Connectors and fasteners shall comply with the applicable provisions of Sections 2304.10.1 through 2304.10.7.

Connections for wood members shall be designed in accordance with the appropriate methodology in Section 2301.2. The number and size of fasteners connecting wood members shall not be less than that set forth in Table 2304.10.1.

TABLE 2304.10.1

FASTENING SCHEDULE

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
2-16d 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 2301.2)
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 2301.2) Per Section 2301.2 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 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 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. Reserved
18. 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
19. 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
20. 1" × 6" sheathing to each bearing 2-8d common (21/2" × 0.131"); or
2-10d box (3" × 0.128")
Face nail
21. 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
22. 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
23. 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
24. 1" × 6" subfloor or less to each joist 2-8d common (21/2" × 0.131"); or
2-10d box (3" × 0.128")
Face nail
25. 2" subfloor to joist or girder 2-16d common (31/2" × 0.162") Face nail
26. 2" planks (plank & beam — floor & roof) 2-16d common (31/2" × 0.162") Each bearing, face nail
27. 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
28. 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
29. 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
30. 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)
31. 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
32. 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
33. 7/8" — 11/4" 10d common (3" × 0.148"); or
8d deformed (21/2" × 0.131")
6 12
Other exterior wall sheathing
34. 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
35. 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
36. 3/4" and less 8d common (21/2" × 0.131"); or
6d deformed (2" × 0.113")
6 12
37. 7/8" — 1" 8d common (21/2" × 0.131"); or
8d deformed (21/2" × 0.131")
6 12
38. 11/8" — 11/4" 10d common (3" × 0.148"); or
8d deformed (21/2" × 0.131")
6 12
Panel siding to framing
39. 1/2" or less 6d corrosion-resistant siding
(17/8" × 0.106"); or
6d corrosion-resistant casing (2" × 0.099")
6 12
40. 5/8" 8d corrosion-resistant siding
(23/8" × 0.128"); or
8d corrosion-resistant casing
(21/2" × 0.113")
6 12
Interior paneling
41. 1/4" 4d casing (11/2" × 0.080"); or
4d finish (11/2" × 0.072")
6 12
42. 3/8" 6d casing (2" × 0.099"); or
6d finish (Panel supports at 24 inches)
6 12

For SI: 1 inch = 25.4 mm.

  1. 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.
  2. 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).
  3. 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.
  4. RSRS-01 is a Roof Sheathing Ring Shank nail meeting the specifications in ASTM F1667.
Sheathing nails or other approved sheathing connectors shall be driven so that their head or crown is flush with the surface of the sheathing.
Connections depending on joist hangers or framing anchors, ties and other mechanical fastenings not otherwise covered are permitted where approved. The vertical load-bearing capacity, torsional moment capacity and deflection characteristics of joist hangers shall be determined in accordance with ASTM D7147.
Clips, staples, glues and other approved methods of fastening are permitted where approved.
Fasteners, including nuts and washers, and connectors in contact with preservative-treated and fire-retardant-treated wood shall be in accordance with Sections 2304.10.5.1 through 2304.10.5.4. The coating weights for zinc-coated fasteners shall be in accordance with ASTM A153. Stainless steel driven fasteners shall be in accordance with the material requirements of ASTM F1667.

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, a minimum of 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.

Fastenings, including nuts and washers, for wood foundations shall be as required in AWC PWF.
Fasteners, including nuts and washers, for fire-retardant-treated wood used in exterior applications or wet or damp locations 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.
Fasteners, including nuts and washers, for fire-retardant-treated wood used in interior locations shall be in accordance with the manufacturer's recommendations. In the absence of manufacturer's recommendations, Section 2304.10.5.3 shall apply.
Where wall framing members are not continuous from the foundation sill to the roof, the members shall be secured to ensure a continuous load path. Where required, sheet metal clamps, ties or clips shall be formed of galvanized steel or other approved corrosion-resistant material not less than 0.0329-inch (0.836 mm) base metal thickness.
Wood columns and posts shall be framed to provide full end bearing. Alternatively, column-and-post end connections shall be designed to resist the full compressive loads, neglecting end-bearing capacity. Column-and-post end connections shall be fastened to resist lateral and net induced uplift forces.

Where a structure, portion thereof or individual structural elements are required to be of heavy timber by provisions of this code, 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 as applicable in Table 2304.11 based on roofs or floors supported and the configuration of each structural element, or as applicable in Sections 2304.11.2 through 2304.11.4. Lumber decking shall also be in accordance with Section 2304.9.

TABLE 2304.11

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 (inches) Depth (inches) Width (inches) Depth (inches) Width (inches) Depth (inches)
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.

  1. Spaced members shall be permitted to be composed of two or more pieces not less than 3 inches (76 mm) 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 (51 mm) nominal in thickness secured to the underside of the members. Splice plates shall be not less than 3 inches (76 mm) nominal in thickness.
  2. Where protected by approved automatic sprinklers under the roof deck, framing members shall be not less than 3 inches (76 mm) nominal in width.
Heavy timber structural members shall be detailed and constructed in accordance with Sections 2304.11.1.1 through 2304.11.1.3.
Minimum dimensions of columns shall be in accordance with Table 2304.11. Columns shall be continuous or superimposed throughout all stories and connected in an approved manner. Girders and beams at column connections shall be closely fitted around columns and adjoining ends shall be cross tied to each other, or intertied by caps or ties, to transfer horizontal loads across joints. Wood bolsters shall not be placed on tops of columns unless the columns support roof loads only. Where traditional heavy timber detailing is used, connections shall be permitted to be by means of reinforced concrete or metal caps with brackets, or shall be connected by properly designed steel or iron caps, with pintles and base plates, or by timber splice plates affixed to the columns by metal connectors housed within the contact faces, or by other approved methods.
Minimum dimensions of floor framing shall be in accordance with Table 2304.11. Approved wall plate boxes or hangers shall be provided where wood beams, girders or trusses rest on masonry or concrete walls. Where intermediate beams are used to support a floor, they shall rest on top of girders, or shall be supported by an approved metal hanger into which the ends of the beams shall be closely fitted. Where traditional heavy timber detailing is used, these connections shall be permitted to be supported by ledgers or blocks securely fastened to the sides of the girders.
Minimum dimensions of roof framing shall be in accordance with Table 2304.11. Every roof girder and at least every alternate roof beam shall be anchored to its supporting member; forces shall be as required in Chapter 16.
Exterior walls shall be permitted to be cross-laminated timber meeting the requirements of Section 2303.1.4.
Interior walls and partitions shall be of solid wood construction formed by not less than two layers of 1-inch (25 mm) matched boards or laminated construction 4 inches (102 mm) thick, or of 1-hour fire-resistance-rated construction.
Floors shall be without concealed spaces. Wood floors shall be constructed in accordance with Section 2304.11.3.1 or 2304.11.3.2.
Cross-laminated timber shall be not less than 4 inches (102 mm) in actual thickness. Cross-laminated timber shall be continuous from support to support and mechanically fastened to one another. Cross-laminated timber shall be permitted to be connected to walls without a shrinkage gap providing swelling or shrinking is considered in the design. Corbelling of masonry walls under the floor shall be permitted to be used.

Sawn or glued-laminated plank floors shall be one of the following:

  1. 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.
  2. 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 no continuous line of joints will occur except 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.

Roofs shall be without concealed spaces and roof decks shall be constructed in accordance with Section 2304.11.4.1 or 2304.11.4.2. Other types of decking shall be permitted to be used where equivalent fire resistance and structural properties are being provided. Where supported by a wall, roof decks shall be anchored to walls to resist forces determined in accordance with Chapter 16. Such anchors shall consist of steel bolts, lags, screws or approved hardware of sufficient strength to resist prescribed forces.
Cross-laminated timber roofs shall be not less than 3 inches (76 mm) in actual thickness and shall be continuous from support to support and mechanically fastened to one another.

Sawn, wood structural panel or glued-laminated plank roofs shall be one of the following:

  1. Sawn or glued laminated, splined or tongue-and-groove plank, not less than 2 inches (51 mm) nominal in thickness.
  2. 11/8-inch-thick (29 mm) wood structural panel (exterior glue).
  3. Planks not less than 3 inches (76 mm) nominal in width, set on edge close together and laid as required for floors.
Wood shall be protected from decay and termites in accordance with the applicable provisions of Sections 2304.12.1 through 2304.12.7.
Wood used above ground in the locations specified in Sections 2304.12.1.1 through 2304.12.1.5, 2304.12.3 and 2304.12.5 shall be naturally durable wood or preservative-treated wood using water-borne preservatives, in accordance with AWPA U1 for above-ground use.
Wood joists or wood structural floors that are closer than 18 inches (457 mm) or wood girders that are closer than 12 inches (305 mm) to the exposed ground in crawl spaces or unexcavated areas located within the perimeter of the building foundation shall be of naturally durable or preservative-treated wood.
Wood framing members, including wood sheathing, that are in contact with exterior foundation walls and are less than 8 inches (203 mm) from exposed earth shall be of naturally durable or preservative-treated wood.
Wood framing members and furring strips in direct contact with the interior of exterior masonry or concrete walls below grade shall be of naturally durable or preservative-treated wood.
Sleepers and sills on a concrete or masonry slab that is in direct contact with earth shall be of naturally durable or preservative-treated wood.
Clearance between wood siding and earth on the exterior of a building shall not be less than 6 inches (152 mm) or less than 2 inches (51 mm) vertical from concrete steps, porch slabs, patio slabs and similar horizontal surfaces exposed to the weather except where siding, sheathing and wall framing are of naturally durable or preservative-treated wood.
Wood used in the locations specified in Sections 2304.12.2.1 through 2304.12.2.5 shall be naturally durable wood or preservative-treated wood in accordance with AWPA U1. Preservative-treated wood used in interior locations shall be protected with two coats of urethane, shellac, latex epoxy or varnish unless water-borne preservatives are used. Prior to application of the protective finish, the wood shall be dried in accordance with the manufacturer's recommendations.
The ends of wood girders entering exterior masonry or concrete walls shall be provided with a 1/2-inch (12.7 mm) airspace on top, sides and end, unless naturally durable or preservative-treated wood is used.

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:

  1. Are not exposed to the weather, or are protected by a roof, eave, overhang or other covering if exposed to the weather.
  2. Are supported by concrete piers or metal pedestals projecting at least 1 inch (25 mm) above the slab or deck and are separated from the concrete pier by an impervious moisture barrier.
  3. Are located at least 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: When a building is located in a geo-graphical region where experience has demonstrated that climatic conditions preclude the need to use durable materials where the structure is exposed to the weather.

The portions of glued-laminated timbers that form the structural supports of a building or other structure and are exposed to weather and not fully protected from moisture by a roof, eave or similar covering shall be pressure treated with preservative or be manufactured from naturally durable or preservative-treated wood.
Wood structural members that support moisture-permeable floors or roofs that are exposed to the weather, such as concrete or masonry slabs, shall be of naturally durable or preservative-treated wood unless separated from such floors or roofs by an impervious moisture barrier. The impervious moisture barrier system protecting the structure-supporting floors shall provide positive drainage of water that infiltrates the moisture-permeable floor topping.
In new construction, enclosed framing in exterior balconies and elevated walking surfaces that are exposed to rain, snow or drainage from irrigation shall be provided with openings that provide a net free cross ventilation area not less than 1/150 of the area of each separate space.

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.

Posts and columns that are supporting permanent structures and embedded in concrete that is exposed to the weather or in direct contact with the earth shall be of preservative-treated wood.

Decks, fences, patios, planters, or other wooden building components that directly abut the sidewall of the foundation or structure shall be constructed so as to provide:

  1. Eighteen-inch (457 mm) clearance beneath or,
  2. Six-inch (152 mm) clearance between the top of the component and the exterior wall covering or,
  3. Have components that are easily removable by screws or hinges to allow access for inspection of the foundation sidewall and treatment for termites.
Wood floor framing in the locations specified in Section 2304.12.2.1 and exposed framing of exterior decks or balconies shall be of naturally durable species (termite resistant) or preservative treated in accordance with AWPA U1 for the species, product preservative and end use or provided with approved methods of termite protection.
Wood installed in retaining or crib walls shall be preservative treated in accordance with AWPA U1 for soil and fresh water use.

The provisions of Section 2603.8 shall apply to the installation of foam plastic insulation in close proximity to the ground.

Exception: Materials which are of naturally durable wood or are pressure treated for ground contact, and which are installed with at least 6 inches (152 mm) clear space from the structure to allow for inspection and treatment for termites.

In order to reduce chances of termite infestation, no wood, vegetation, stumps, dead roots, cardboard, trash, or other cellulose-containing material shall be buried on the building lot within 15 feet (4.6 m) of any building or the position of any building proposed to be built.

All building sites shall be graded to provide drainage under all portions of the building not occupied by basements.
The foundation and the area encompassed within 1 foot (305 mm) therein shall have all vegetation, stumps, dead roots, cardboard, trash, and foreign material removed and the fill material shall be free of vegetation and foreign material. The fill shall be compacted to assure adequate support of the foundation.
After all work is completed, loose wood and debris shall be completely removed from under the building and within 1 foot (305 mm) thereof. All wood forms and supports shall be completely removed. This includes, but is not limited to: wooden grade stakes, forms, contraction spacers, tub trap boxes, plumbing supports, bracing, shoring, forms, or other cellulose-containing material placed in any location where such materials are not clearly visible and readily removable prior to completion of the work. Wood shall not be stored in contact with the ground under any building.

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.

Structures using wood-frame shear walls or wood-frame diaphragms to resist wind, seismic or other lateral loads shall be designed and constructed in accordance with AWC SDPWS and the applicable provisions of Sections 2305, 2306 and 2307.
Openings in shear panels that materially affect their strength shall be detailed on the plans and shall have their edges adequately reinforced to transfer all shearing stresses.

The deflection of wood-frame diaphragms shall be determined in accordance with AWC SDPWS. The deflection (Δdia) of a blocked wood structural panel diaphragm uniformly fastened throughout with staples is permitted to be calculated in accordance with Equation 23-1.

  1. If not uniformly fastened, the constant 0.188 (For SI: 1/1627) in the third term shall be modified by an approved method.

(Equation 23-1)

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 = Maximum induced unit shear, in pounds per linear foot (plf) (N/mm).

W = Diaphragm width (in the direction of applied force), in feet (mm).

Δdia = The calculated maximum midspan diaphragm deflection determined by elastic analysis, in inches (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)

TABLE 2305.2(1)

en VALUES (inches) FOR USE IN CALCULATING DIAPHRAGM AND SHEAR WALL DEFLECTION DUE TO FASTENER SLIP (Structural I)a, c

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.

  1. Increase en values 20 percent for plywood grades other than Structural I.
  2. Load per fastener = maximum shear per foot divided by the number of fasteners per foot at interior panel edges.
  3. Decrease en values 50 percent for seasoned lumber (moisture content < 19 percent).

TABLE 2305.2(2)

VALUES OF Gt FOR USE IN CALCULATING DEFLECTION OF WOOD STRUCTURAL PANEL SHEAR WALLS AND DIAPHRAGMS

PANEL
TYPE
SPAN
RATING
VALUES OF Gt (lb/in. panel depth or width)
Structural Sheathing Structural I
Plywood Plywood
3-ply 4-ply 5-plya OSB 3-ply 4-ply 5-plya OSB
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 A-A,
A-C
Marine All Other
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

For SI: 1 inch = 25.4 mm, 1 pound/inch = 0.1751 N/mm.

  1. 5-ply applies to plywood with five or more layers. For 5-ply plywood with three layers, use values for 4-ply panels.

The deflection of wood-frame shear walls shall be determined in accordance with AWC SDPWS. The deflection (Δsw) of a blocked wood structural panel shear wall uniformly fastened throughout with staples is permitted to be calculated in accordance with Equation 23-2.


(Equation 23-2)

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 (including fastener slip, device elongation, rod elongation, etc.) 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.
NDS National Design Specification for Wood Construction
SDPWS Special Design Provisions for Wind and Seismic
American Institute of Timber Construction.
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
American Society of Agricultural and Biological Engineers.
ASABE EP 484.2 Diaphragm Design of Metal-clad, Post-Frame Rectangular Buildings
ASABE EP 486.2 Shallow Post Foundation Design
ASABE 559.1 Design Requirements and Bending Properties for Mechanically Laminated Columns
APA—The Engineered Wood Association.
ANSI 117 Glued Laminated Timber of Softwood Species
ANSI A190.1 Structural Glued Laminated Timber
Panel Design Specification
Plywood Design Specification Supplement 1—Design & Fabrication of Plywood Curved Panel
Plywood Design Specification Supplement 2—Design & Fabrication of Glued Plywood-lumber Beams
Plywood Design Specification Supplement 3—Design & Fabrication of Plywood Stressed-skin Panels
Plywood Design Specification Supplement 4—Design & Fabrication of Plywood Sandwich Panels
Plywood Design Specification Supplement 5—Design & Fabrication of All-plywood Beams
EWS APA T300 Glulam Connection Details
EWS APA S560 Field Notching and Drilling of Glued Laminated Timber Beams
EWS APA S475 Glued Laminated Beam Design Tables
EWS APA X450 Glulam in Residential Building Construction Guide
EWS APA X440 Product and Application Guide: Glulam
EWS 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
The design of rafter spans is permitted to be in accordance with the AWC STJR.
The design of plank and beam flooring is permitted to be in accordance with the AWC Wood Construction Data No. 4.

The allowable unit stresses for preservative-treated wood need no adjustment 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.

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

For SI: 1 inch = 25.4 mm.

  1. σb = Allowable total uniform load limited by bending.

    σΔ = Allowable total uniform load limited by deflection.

  2. d = Actual decking thickness.

    l = Span of decking.

    Fb' = Allowable bending stress adjusted by applicable factors.

    E' = Modulus of elasticity adjusted by applicable factors.

Wood-frame diaphragms shall be designed and constructed in accordance with AWC SDPWS. 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 Table 2306.2(1) or 2306.2(2) shall be permitted. The allowable shear values in Tables 2306.2(1) and 2306.2(2) are permitted to be increased 40 percent for wind design.

TABLE 2306.2(1)

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 STAPLE LENGTH
AND GAGEd
MINIMUM
FASTENER
PENETRATION
IN FRAMING
(inches)
MINIMUM PANEL
THICKNESS
(inch)
MINIMUM NOMINAL
WIDTH OF
FRAMING
MEMBERS AT
ADJOINING PANEL
EDGES AND
BOUNDARIESe
(inches)
BLOCKED UNBLOCKED
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 grades 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
grades 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.

  1. 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 above 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.
  2. Space fasteners maximum 12 inches on center along intermediate framing members (6 inches on center where supports are spaced 48 inches on center).
  3. Framing at adjoining panel edges shall be 3 inches nominal or wider.
  4. 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.
  5. The minimum nominal width of framing members not located at boundaries or adjoining panel edges shall be 2 inches.
  6. For shear loads of normal or permanent load duration as defined by the ANSI/AWC NDS, the values in the table above 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 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.

  1. 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 above 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.
  2. Fastening along intermediate framing members: Space fasteners a maximum of 12 inches on center, except 6 inches on center for spans greater than 32 inches.
  3. Panels conforming to PS 1 or PS 2.
  4. 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.
  5. 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.
  6. 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.
  7. Reserved.
  8. For shear loads of normal or permanent load duration as defined by the ANSI/AWC NDS, the values in the table above 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-frame shear walls shall be designed and constructed in accordance with AWC SDPWS. 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 Table 2306.3(1), 2306.3(2) or 2306.3(3) shall be permitted. The allowable shear values in Tables 2306.3(1) and 2306.3(2) are permitted to be increased 40 percent 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 sizeh Fastener spacing at panel
edges (inches)
Staple sizeh 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
siding
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.

  1. 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 above 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.
  2. 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. 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.
  4. Framing at adjoining panel edges shall be 3 inches nominal or wider.
  5. Values apply to all-veneer plywood. Thickness at point of fastening on panel edges governs shear values.
  6. 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.
  7. 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 ANSI/AWC SDPWS for sill plate size and anchorage requirements.
  8. 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.
  9. For shear loads of normal or permanent load duration as defined by the ANSI/AWC NDS, the values in the table above 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 FASTENER SIZE ALLOWABLE SHEAR VALUE
(pounds per linear foot)
STAPLE SPACING AT PANEL EDGES (inches)a
4 3 2
1/2" or 25/32" Structural 16 gage galvanized staple, 7/16" crown, 13/4 inch long 150 200 225
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.

  1. Fiberboard sheathing shall not be used to brace concrete or masonry walls.
  2. 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 above by 0.82 for species with specific gravity of 0.42 or greater, or 0.65 for all other species.
  3. Values shown are for fiberboard sheathing on one side only with long panel dimension either parallel or perpendicular to studs.
  4. Fastener shall be spaced 6 inches on center along intermediate framing members.
  5. 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 SIZEf, 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 sheating 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.

  1. 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.
  2. Applies to fastening at studs, top and bottom plates and blocking.
  3. Except as noted, shear values are based on a maximum framing spacing of 16 inches on center.
  4. Maximum framing spacing of 24 inches on center.
  5. All edges are blocked, and edge fastening is provided at all supports and all panel edges.
  6. 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.
  7. 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.
The design and construction of wood elements and structures using load and resistance factor design shall be in accordance with ANSI/AWC NDS and AWC SDPWS.
Structural design in accordance with the AWC WFCM shall be permitted for buildings assigned to Risk Category I or II subject to the limitations of Section 1.1.3 of the AWC WFCM and the load assumptions contained therein. Structural elements beyond these limitations shall be designed in accordance with accepted engineering practice.
Wood members and their fastenings shall be designed to comply with ASCE 7 by methods based on rational analysis or approved laboratory testing procedures, both performed in accordance with fundamental principles of theoretical and applied mechanics.
Wood members shall be framed, anchored, tied and braced to develop the strength and rigidity necessary for the purposes for which they are used and to resist the loads imposed as set forth in this code. Wood construction shall be in conformance with the tolerances, quality and methods of construction as prescribed by the standards in Chapter 35 of this code.
Preparation, fabrication and installation of wood members and the glues, connectors and mechanical devices for fastening shall conform to good engineering practice.
Any person desiring to manufacture or fabricate wood truss assemblies shall obtain a certificate of competency from the authority having jurisdiction.
The following standards, as set forth in Chapter 35 of this code, are hereby adopted for the design and quality of wood members and their fastenings:

American Hardboard Products Association, 887-B Wilmette Road, Palatine, IL 60067 AHA.

  1. Basic Hardboard ANSI/AHA A135.4—1982.
  2. Prefinished Hardboard Paneling ANSI/AHA A135.5—1982.
  3. Hardboard Siding ANSI/AHA A135.6—1990.
  4. Cellulosic Fiberboard ANSI/AHA A194.1—1985.
  5. Recommended Product and Application Specification—Structural Insulating Roof Deck, I.B. Spec. No. 1.
  6. Recommended Product and Application Specification—1/2-inch Fiberboard Nail-Base-Sheathing I.B. Spec. No. 2.
  7. Recommended Product and Application Specification—1/2-inch Intermediate Fiberboard Sheathing I.B. Spec. No. 3.

American Institute of Timber Construction, 333 West Hampden Avenue, Englewood, CO 80110 AITC.

  1. Typical Construction Details, AITC 104.
  2. Code of Suggested Practices, AITC 106.
  3. Standard for Heavy Timber Construction, AITC 108.
  4. Standard for Preservative Treatment for Structural Glued Laminated Timber, AITC 109.
  5. Standard Appearance Grades for Structural Glued Laminated Timber, AITC 110.
  6. Standard for Tongue and Groove Heavy Timber Roof Decking, AITC 112.
  7. Standard for Dimensions of Glued Laminated Structural Members, AITC 113.
  8. Standard Specifications for Hardwood Glued Laminated Timber, AITC 119.
  9. Technical Report No. 7, Calculation of Fire Resistance of Glued Laminated Timber.

APA The Engineered Wood Association (formerly APA American Plywood Association), 7011 South 19th Street, Tacoma, WA 98466.

  1. APA Design Construction Guide, E30.
  2. Plywood Design Specification Y510J.
  3. Plywood Design Specification—Design and Fabrication of Plywood Beams, Supplement No. 1 S811.
  4. Plywood Design Specification—Design and Fabrication of Plywood Beams, Supplement No. 2 S812.
  5. Plywood Design Specification-Design and Fabrication of Plywood Stressed—Skin Panels, Supplement No. 3 U813.
  6. Plywood Design Specifications—Design and Fabrication of Plywood Sandwich Panels Supplement No. 4 U814.
  7. Plywood Design Specifications—Design and Fabrication of All-Plywood Beams, Supplement No. 5 H815.
  8. Plywood Folded Plate, Laboratory Report 21 V910.
  9. APA Design/Construction Guide Diaphragms L350.
  10. Performance Standards and Policies for Structural-Use Panels PRP-108.
  11. 303 Siding Manufacturing Specifications B840.
  12. Standard Specifications for Structural Glued Laminated Timber of Softwood Species, ANSI 117.
  13. Structural Glued Laminated Timber, ANSI A190.1.

ASTM International, 1916 Race Street, Philadelphia, PA 19103-1187 ASTM.

  1. Standard Test Methods for Mechanical Fasteners in Wood, ASTM D1761.
  2. Accelerated Weathering on Fire-Retardant Treated Wood for Fire Testing, ASTM D2898.
  3. Surface Burning Characteristics of Building Materials, ASTM E84.
  4. Hygroscopic Properties of Fire-Retardant Wood and Wood-Base Products, ASTM D3201.
  5. Standard Specifications for Adhesives for Field-Gluing Plywood to Lumber Framing for Floor Systems, ASTM D3498.

American Wood Preservers Association, P.O. Box 361784, Birmingham, AL 35236-1784.

  1. AWPA Use Category Systems Standard U1.
  2. AWPA Standard M4 Care of Pressure Treated Wood Products.

National Institute for Standards and Technology Standard Development Services Section, Standards Application and Analysis Division, Washington, D.C. 20234 NIST.

  1. Mat-Formed Particleboard CS236.
  2. Structural Glued Laminated Timber PS56.
  3. Construction and Industrial Plywood PS1.
  4. American Softwood Lumber Standard PS20.
  5. Performance Standard for Wood Based Structural Use Panels PS2{*}.

{*} All wood-based structural panels except plywood shall have product approval and shall be tested in accordance with High-Velocity Hurricane Zone Testing Protocols.

American Wood Council, 222 Catoctin Circle SE, Suite 201, Leesburg, VA 20175.

  1. ANSI/AWC NDS—2018: National Design Specification for Wood Construction with 2018 NDS Supplement.
  2. AWC Wood Structural Design Data.
  3. AWC ST JR—2015: Span Tables for Joists and Rafters.
  4. AWC 2015 Design Values for Joists and Rafters.
  5. AWC WCD No. 1—Wood Construction Data No. 1, Details for Conventional Wood Frame Construction.
  6. AWC WCD No. 4—Wood Construction Data No. 4, Plank-and-Beam Framing for Residential Building.
  7. AWC WCD No. 5—Wood Construction Data No. 5, Heavy Timber Construction.
  8. AWC WCD No. 6—Wood Construction Data No. 6, Design of Wood Frame Structures for Permanence.
  9. ANSI/AWC PWF—2015: Permanent Wood Foundation (PWF) Design Specification.
  10. ANSI/AWC WFCM—2018: Wood Frame Construction Manual for One- and Two-Family Dwellings.
  11. ANSI/AWC SDPWS-2015: Special Design Provisions for Wind and Seismic.

Timber Company, Inc., 2402 Daniels Street, Madison, WI 53704.

TECO Performance Standards and Policies for Structural use Panels. PRP-133.

Truss Plate Institute, 218 N. Lee Street, Suite 312, Alexandria, VA 22314.

  1. National Design Standard for Metal Plate Connected Wood Truss Construction (excluding Chapter 2).
  2. Building Component Safety Information (BCSI 1) Guide to Good Practice for Handling, Installing & Bracing of Metal Plate Connected Wood Trusses. [A joint publication with the Wood Truss Council of America (WTCA).]
Wood shingles and/or shakes shall be identified by the grademark of an approved grading or inspection bureau or agency.

All wood-based structural panels, including those made of fiberboard, hardboard and particleboard shall have product approval. Product approval shall be given upon certification by an approved independent testing laboratory that the product:

  1. Complies with the applicable standards set forth above.
  2. Complies with the manufacturer's published design properties before and after a wet-dry, wet-dry cycle.
  3. When tested dry, maintains a safety factor of 2:1 and when tested after the cycles specified in Section 2315.1.11(2) above maintains a safety factor of 1.5:1. Testing shall be as specified in the testing protocol.
All lumber 2 inches (51 mm) or less in thickness shall contain not more than 19-percent moisture at the time of permanent incorporation in a building or structure and/or at the time of treatment with a wood preservative.
All structural wood members not limited by other sections of this chapter shall be of sufficient size and capacity to carry all loads as required by the high-velocity hurricane provisions of Chapter 16 without exceeding the allowable design stresses specified in the National Design Specification for Wood Construction and in compliance with Section 2317.
Lumber used for joists, rafters, trusses, columns, beams and/or other structural members shall be of no less strength than No. 2 grade of Southern Pine, Douglas Fir-Larch, Hem-Fir or Spruce-Pine-Fir. Joists and rafters shall be sized according to AF&PA Span Tables for Joists and Rafters adopted in Section 2314.4.
Lumber used for studs in exterior walls and interior bearing walls shall be of no less strength than stud grade of Southern Pine, Douglas Fir-Larch, Hem-Fir or Spruce-Pine-Fir and capable of resisting all loads determined in accordance with Chapter 16 (High-Velocity Hurricane Zones). The unbraced height of the wall shall be no more than 8 feet 6 inches (2.6 m) (including top and bottom plates). Heights may be increased where justified by rational analysis prepared by a registered professional engineer or registered architect proficient in structural design.
The designer shall specify on the design drawings the size, spacing, species and grade of all load supporting members.
Allowable stress design value may be modified for repetitive, duration, etc., factors where design is by a registered professional engineer or registered architect proficient in structural design or where such modified values are reflected in the tables of the standards in Section 2314.4.
Studs in walls framing over 8 feet 6 inches (2.6 m) (including top and bottom plates) or supporting floor and roof loads shall be designed by rational analysis prepared by a registered professional engineer or registered architect proficient in structural design.
Studs shall be not less than nominal 2 × 6 for exterior walls or 2 × 4 for interior bearing or load resisting walls unless designed by rational analysis by a registered professional engineer or registered architect proficient in structural design.
Studs shall be spaced not more than 16 inches (406 mm) on center unless designed by rational analysis as a system of columns and beams by a registered professional engineer or registered architect proficient in structural design.
Studs in exterior and bearing walls shall be placed with the longer dimension perpendicular to the wall.
Studs in exterior walls and in bearing walls shall be supported by foundation plates, sills, or girders or floor framing directly over supporting walls or girders. Stud bearing walls when perpendicular to supporting joists may be offset from supporting walls or girders not more than the depth of the joists unless such joists are designed for the extra loading conditions.
Stud walls framing into base plates of exterior walls and interior bearing walls resting on masonry or concrete shall be anchored past the plate to the masonry or concrete, or shall be anchored to a sill plate which is anchored in accordance with Section 2318.1.4.1 when the net wind uplift is up to 500 pounds per foot (7297 N/m).
Sills and/or base plates, where provided in contact with masonry or concrete, shall be of an approved durable species or be treated with an approved preservative and shall be attached to the masonry or concrete with 1/2-inch (13 mm) diameter bolts with oversized washer spaced not over 2 feet (610 mm) apart and embedded not less than 7 inches (178 mm) into a grout filled cell of masonry or into concrete. Base plates shall be placed in a recess 3/4 inch (19 mm) deep and the width of the base plate at the edge of a concrete slab, beam/slab or any other type of construction which uses a masonry surface or concrete slab, or be provided with an alternate waterstop method as approved by the building official. Alternate methods of anchorage may be designed by rational analysis by a registered professional engineer or a registered architect proficient in structural design.
Where the base plate of a bearing wall is supported on joists or trusses running perpendicular to the wall and the studs from the wall above do not fall directly over a joist or truss, a double base plate or a single base plate supported by a minimum 2 × 4 inset ribbon shall be used to support the upper stud wall.
The top plate of stud bearing walls shall be doubled and lapped at each intersection of walls and partitions.
Joints shall be lapped not less than 4 feet (1219 mm).
Corners of stud walls and partitions shall be framed solid by not less than three studs.
Studs, other than end-jointed lumber, shall be spliced only at points where lateral support is provided.
Wood framing may be any one, or a combination, of the following types: platform, balloon, plank and beam or pole type.

Exterior stud walls of two-story buildings shall be balloon-framed with studs continuous from foundation to second floor ceiling and with second floor joists supported as indicated in Section 2319.3.3. Gable endwalls in wood frame buildings shall be balloon framed with studs continuous from foundation to roof.

Exception: Platform framing is allowed in buildings over one story in height provided an additional mandatory inspection for floor level connectors is made before the framing/firestopping inspection. Gable endwalls shall be balloon framed with studs continuous from top floor to roof.

Studs that carry loads in excess of 75 percent of their capacity shall not be notched or cut.
Studs that carry loads 75 percent or less of their capacity may be notched to one-third of the depth without limit of the number of consecutive studs.
Stud walls and partitions containing pipes shall be framed to give proper clearance for the piping.
Where walls and partitions containing piping are parallel to floor joists, the joists shall be doubled and may be spaced to allow vertical passage of pipes.
Where vertical pipe positions necessitate the cutting of plates, a metal tie not less than 1 inch by 1/8 inch (25 mm by 3 mm) shall be placed on each side of the plate across the opening and nailed with not less than two 16d or three 8d nails at each end.
All headers in bearing walls shall be designed by rational analysis.
Headers or lintels over stud wall openings shall have not less than nominal 2-inch (51 mm) bearings.
Where stud walls or partitions join masonry or concrete walls, such studs shall be secured against lateral movement by bolting to the masonry or concrete with 1/2- inch (13 mm) diameter anchor bolts with oversized washers spaced not more than 4 feet (1219 mm) apart and embedded not less than 5 inches (127 mm) into a grout filled cell or into concrete or as designed by a registered professional engineer or registered architect proficient in structural design using rational analysis.
Exterior stud walls shall be effectively wind-braced in accordance with Section 2322.3. Such bracing shall be designed by a registered professional engineer or registered architect proficient in structural design.
The intermixing of wall framing described in this chapter with other types of structural wall systems as provided in this code shall not be permitted unless such wall framing and connections are designed by a registered professional engineer or registered architect proficient in structural design.
Columns and posts shall be framed to true end bearing, shall be securely anchored against lateral and vertical forces, and shall be designed by a registered professional engineer or registered architect proficient in structural design.
Columns and posts shall be spliced only in regions where lateral support is adequately provided about both axes and is designed by rational analysis. Such design shall be prepared, signed and sealed by a registered professional engineer or registered architect proficient in structural design.
Design dimensions of columns and posts shall not be reduced by notching, cutting or boring.
The minimum size of joists and rafters shall be as set forth in Section 2317.
The design of horizontal framing other than joists and rafters shall be as set forth in Section 2317.1.1.
Joists and rafters shall have not less than 3 inches of bearing, on wood, metal, grout-filled masonry or concrete, except as provided in Sections 2319.3.2, 2319.3.3 and 2319.3.4.
Joists and rafters may bear on and be anchored by steel strap anchor embedded into a grout-filled cell of the masonry or reinforced concrete, as described in Section 2321.5.1, to a wood plate provided such wood plate is of an approved durable species or pressure treated with an approved preservative and such plate shall be not less than 2 inch by 4 inch (51 mm by 102 mm) and attached in accordance with Section 2318.1.4.1. The net uplift on the plate shall be limited to 300 pounds per foot (4378 N/m).
Joists and rafters may bear on a product approved channel-shaped metal saddle and fastened to the masonry by a steel strap anchor embedded into a grout-filled cell of the masonry or concrete.
Joists and rafters may bear on masonry, provided that each joist or rafter in contact with masonry is of an approved durable species or pressure treated with an approved preservative and anchored as in Section 2319.3.2.2 above.
Floor joists may butt into a header beam if effectively toenailed and if an approved metal hanger providing not less than 3 inches (76 mm) of bearing transmits the vertical load to the top of the header, provided, however, that approved devices or other approved means of support may be used in lieu of such bearing. All hangers and devices shall have product approval.
Ceiling joists may butt into a header beam, as set forth for floor joists, or approved devices or other approved means of support may be used in lieu of such bearing. All devices shall have product approval.
In lieu of the above, bearing and anchorage may be designed by rational analysis by a registered professional engineer or registered architect proficient in structural design.
Horizontal members shall not be spliced between supports except that properly designed splices or approved end-jointed lumber may be used.
Unless local unit stresses are calculated on the basis of reduced size, wood members in bending shall not be cut, notched or bored except as provided in Sections 2319.5.1.1 and 2319.5.1.2.
Notches may be cut in the top or bottom not deeper than one-sixth of the depth not longer than one-third of the depth of the member and shall not be located in the middle one-third of the span. Where members are notched at the ends, over bearing points, the notch depth shall not exceed one-fourth the member depth.
Holes may be bored in the middle one-third of the depth and length and not larger than one-sixth of the depth. Space between any two holes in the same joist shall be not less than the depth of the joist.
Where necessary to run service pipes in the space between the ceiling and floor larger than can be accommodated by the above provision, such ceilings shall be furred or provision made for headers or beams and/or for changing direction of the joists where the design permits.
Joists shall be doubled adjacent to openings where more than one joist is cut out or shall be so increased in size or number as may be needed to meet the stress requirements.
Headers shall be of the same size as the joists and where supporting more than one joist shall be double members.
Headers shall be supported by approved metal hangers or ledgers or other approved members.
Wood joists, beams or girders which frame into masonry or reinforced concrete shall have a minimum of 1/2-inch (12.7 mm) air space at the top, end and sides or shall be preservative pressure treated or of an approved durable species.
Where masonry extends above such wood members, joists shall be fire-cut so the top edge does not enter the masonry more than 1 inch (25 mm) or shall be provided with wall plate boxes of self-releasing type or approved hangers.
In buildings with pitched roofs the ceiling joists, where practicable, shall be nailed to the rafters and shall be designed to carry all imposed loads including but not limited to lateral thrust.
Ceiling joists spanning more than 10 feet (3 m) shall be laterally supported at midspan.
Ceiling joists shall not be used to support rafter loads unless the joists and connections are properly designed for the total load being imposed.
The permit documents shall include roof framing plans showing spacing and spans of all roof members indicating any fabricated elements to be designed and furnished by others and shall include the details for support and bearing of the roof structural system, for the permanent cross/lateral/diagonal bracing and anchorage required to resist dead, live and wind loads as set forth in Chapter 16 (High-Velocity Hurricane Zones). The framing plans shall also indicate the uplift forces applied on the roof, sheathing type, thickness and nailing requirements for the sheathing. The roof framing plans shall be prepared by, and bear the sign and seal of, a registered professional engineer or registered architect of record proficient in structural design.
Roof joists may cantilever over exterior walls as limited by the allowable stress, but the length of such cantilever shall not exceed one-half the length of the portion of the joist inside the building; and where the cantilever of tail joists exceeds 3 feet (914 mm), the roof joist acting as a header shall be doubled.
Hip rafters, valley rafters and ridge boards shall be provided and shall be not less in size than the largest rafter framing thereto nor less than required to support the loads.
Collar ties and their connections shall be provided to resist the thrust of rafters and shall be designed by a registered engineer or registered architect proficient in structural design.
Collar ties shall not be required if the ridge is designed as a supporting beam. Such design shall be done by a registered professional engineer or registered architect proficient in structural design.
Ceiling joists may serve as collar ties when properly designed by a registered professional engineer or registered architect proficient in structural design.
The actual roof and ceiling dead loads may be used to resist uplift loads, but the maximum combined dead load used to resist uplift loads shall not exceed 10 pounds per square foot (479 Pa).
Heavy timber construction of floors or roofs shall comply with the standards in Section 2314.4. All heavy timber construction shall be designed by methods based on rational analysis performed in accordance with ASCE 7 to withstand the loads required in Chapter 16 (High-Velocity Hurricane Zones).
Vertically laminated built-up beams shall be designed and made up of members continuous from bearing to bearing.
Glued-laminated members shall be designed to comply with applicable AITC standards adopted by this code.
Trussed rafters shall be designed by methods admitting of rational analysis by a registered professional engineer or registered architect proficient in structural d