Treated Wood & Durability

Grounded in the retrieved California Building Code — click a citation to read the verbatim passage:

• CBC § 2304.12.2 Medium relevance — show source text

  2304.12.2 Other locations. Wood used in the locations specified in Sections 2304.12.2.1 through 2304.12.2.8 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 waterborne preservatives are used. Prior to application of the protective finish, the wood shall be dried in accordance with the manufacturer’s recommendations. 2304.12.2.1 Girder ends. 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.

  2304.12.2.2 Posts or columns. 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 projected not less than 1 inch (25 mm) above the slab or deck and are separated from the concrete pier by an impervious moisture barrier.

  3. Are located not less than 8 inches (203 mm) above exposed earth.

  2304.12.2.3 Supporting member for permanent appurtenances. 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: Sawn lumber in buildings located in a geographical region where experience has demonstrated that climatic conditions preclude the need to use durable materials where the structure is exposed to the weather.

  2304.12.2.4 Supporting members for permeable floors and roofs. 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.

  2304.12.2.5 Ventilation beneath balcony or elevated walking surfaces. Enclosed framing in exterior balconies and elevated walking surfaces that have weather-exposed surfaces 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.

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  2304.12.2.6 Wood in contact with the ground or fresh water. 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 freshwater use.

  Exception: Untreated wood is permitted where such wood is continuously and entirely below the ground-water level or submerged in fresh water.

• CBC § 2304.12.1.3 Medium relevance — show source text

  Exception: [DSA-SS and OSHPD 1, 1R, 2, 4 & 5] At exterior walls where the earth is paved with an asphalt or concrete slab at least 18 inches (457 mm) wide and draining away from the building, the bottom of sills are permitted to be 6 inches (152 mm) above the top of such slab. Other equivalent means of termite and decay protection may be accepted by the enforcement agency.

  2304.12.1.3 Exterior walls below grade. 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.

  2304.12.1.4 Sleepers and sills. 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.

  2304.12.1.4.1 Additional requirements. [DSA-SS and OSHPD 1, 1R, 2, 4 & 5] Stud walls or partitions at shower or toilet rooms with more than two plumbing fixtures, excluding floor drains, and stud walls adjacent to unroofed paved areas shall rest on a concrete curb extending at least 6 inches (152 mm) above finished floor and pavement level.

  2304.12.1.5 Wood siding. Clearance between wood siding and earth on the exterior of a building shall be not 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 preservativetreated wood.

  2304.12.2 Other locations. Wood used in the locations specified in Sections 2304.12.2.1 through 2304.12.2.8 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 waterborne preservatives are used. Prior to application of the protective finish, the wood shall be dried in accordance with the manufacturer’s recommendations. 2304.12.2.1 Girder ends. 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.

  2304.12.2.2 Posts or columns. 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 projected not less than 1 inch (25 mm) above the slab or deck and are separated from the concrete pier by an impervious moisture barrier.

  3. Are located not less than 8 inches (203 mm) above exposed earth.

• CBC § 2304.10.2.1 Medium relevance — show source text

  2304.10.2.1 Additional requirements. [DSA-SS and OSHPD 1, 1R, 2, 4 & 5] Fasteners used for the attachment of exterior wall coverings shall be of hot-dipped zinc-coated galvanized steel, mechanically deposited zinc-coated steel, stainless steel, silicon bronze or copper. The coating weights for hot-dipped zinc-coated fasteners shall be in accordance with ASTM A153. The coating weights for mechanically deposited zinc coated fasteners shall be in accordance with ASTM B695, Class 55 minimum.

  2304.10.3 Sheathing fasteners. Sheathing nails or other approved sheathing connectors shall be driven so that their head or crown is flush with the surface of the sheathing.

  2304.10.4 Joist hangers and framing anchors. 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.

  2304.10.5 Other fasteners. Clips, staples, glues and other approved methods of fastening are permitted where approved.

  2304.10.6 Fasteners and connectors in contact with preservative-treated and fire-retardant-treated wood. Fasteners, including nuts and washers, and connectors in contact with preservative-treated and fire-retardant-treated wood shall be in accordance with Sections 2304.10.6.1 through 2304.10.6.4. The coating weights for zinc-coated fasteners shall be in accordance

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  with ASTM A153. The coating weight for zinc-coated nails shall be in accordance with ASTM A153 Class D or ASTM A641 Class 3S [1 ounce per square foot (305 g/m [2] )]. Stainless steel driven fasteners shall be in accordance with the material requirements of ASTM F1667.

  2304.10.6.1 Fasteners and connectors for preservative-treated wood. Fasteners, including nuts and washers, in contact with preservative-treated wood shall be of hot-dipped zinc-coated galvanized steel, stainless steel, silicon bronze or copper. Staples shall be of stainless steel. Fasteners other than nails, staples, timber rivets, wood screws and lag screws shall be permitted to be of mechanically deposited zinc-coated steel with coating weights in accordance with ASTM B695, Class 55 minimum. Connectors that are used in exterior applications and in contact with preservative-treated wood shall have coating types and weights in accordance with the treated wood or connector manufacturer’s recommendations. In the absence of manufacturer’s recommendations, not less than ASTM A653, Type G185 zinc-coated galvanized steel, or equivalent, shall be used.

  Exception: Plain carbon steel fasteners, including nuts and washers, in SBX/DOT and zinc borate preservative-treated wood in an interior, dry environment shall be permitted.

  2304.10.6.2 Fastenings for wood foundations. Fastenings, including nuts and washers, for wood foundations shall be as required in AWC PWF.

• CBC § 2304.10.6.3 Medium relevance — show source text

  2304.10.6.3 Fasteners for fire-retardant-treated wood used in exterior applications or wet or damp locations. 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 zinccoated steel with coating weights in accordance with ASTM B695, Class 55 minimum.

  2304.10.6.4 Fasteners for fire-retardant-treated wood used in interior applications. 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 2304.10.6.3 shall apply.

  2304.10.7 Load path. 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.

  2304.10.8 Framing requirements. Wood columns and posts shall be framed to provide full end bearing. Alternatively, columnand-post end connections shall be designed to resist the full compressive loads, neglecting end-bearing capacity. Column-andpost end connections shall be fastened to resist lateral and net induced uplift forces.

  2304.11 Heavy timber construction. Where a structure, portion thereof or individual structural elements are required by provisions of this code to be of heavy timber, the building elements therein shall comply with the applicable provisions of Sections 2304.11.1 through 2304.11.4. Minimum dimensions of heavy timber shall comply with the applicable requirements in Table 2304.11 based on roofs or floors supported and the configuration of each structural element, or in Sections 2304.11.2 through 2304.11.4. Lumber decking shall be in accordance with Section 2304.9.

  TABLE 2304.11—MINIMUM DIMENSIONS OF HEAVY TIMBER STRUCTURAL MEMBERS	Col2	Col3	Col4	Col5	Col6	Col7	Col8
  		MINIMUM NOMI- NAL SOLID SAWN SIZE	MINIMUM NOMI- NAL SOLID SAWN SIZE	MINIMUM GLUED- LAMINATED NET SIZE	MINIMUM GLUED- LAMINATED NET SIZE	MINIMUM STRUC- TURAL COMPOSITE LUMBER NET SIZE	MINIMUM STRUC- TURAL COMPOSITE LUMBER NET SIZE
  SUPPORTING	HEAVY TIMBER STRUCTURAL ELEMENTS	Width, inch	Depth, inch	Width, inch	Depth, inch	Width, inch	**Depth,

• CBC § 2303.2.6.3 Medium relevance — show source text

  Each manufacturer shall publish the treatment adjustment factors for service at maximum 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.

  2303.2.6.3 Fire-retardant-treated laminated veneer lumber. The effect of treatment and redrying after treatment and any treatment-based effects due to exposure to high temperatures and high humidities on the allowable design properties of fireretardant-treated laminated veneer lumber shall be determined in accordance with ASTM D8223. Each manufacturer shall publish reference design values and treatment-based design value adjustment factors in accordance with ASTM D8223, taking into account the climatological location.

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  [BF] 2303.2.7 Exposure to weather, damp or wet locations. 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.

  2303.2.8 Interior applications. 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 2303.2.6.1 or 2303.2.6.2. Interior fire-retardant-treated wood designated as Type A shall be tested in accordance with the provisions of this section.

  2303.2.9 Moisture content. 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 2303.2.6.1 for plywood and 2303.2.6.2 for lumber.

  2303.2.10 Types I and II construction applications. See Section 603.1 for limitations on the use of fire-retardant-treated wood in buildings of Type I or II construction.

  2303.3 Hardwood and plywood. Hardwood and decorative plywood shall be manufactured and identified as required in HPVA HP-1.

  2303.4 Trusses. Wood trusses shall comply with Sections 2303.4.1 through 2303.4.7.

  2303.4.1 Design. 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.

• CBC § 15.3 Medium relevance — show source text

  R302.15.3 Testing. For fire-retardant-treated wood products, the front and back faces of the wood product shall be tested in accordance with and produce the results required in Section R302.15.

  R302.15.3.1 Fire testing of fire-retardant-treated wood structural panels. Fire-retardant-treated wood structural panels shall be tested with a ripped or cut longitudinal gap of [1] / 8 inch (3.2 mm).

  302.15.4 Labeling. In addition to the labels required by Section R802.1.1 for sawn lumber and Section R803.2.1 for wood structural panels, each piece of fire-retardant-treated lumber and fire-retardant-treated wood structural panel shall be labeled. The label shall contain:

  1. The identification mark of an approved agency in accordance with Section 1703.5 of the California Building Code.

  2. Identification of the treating manufacturer.

  3. The name of the fire-retardant treatment.

  4. The species of wood treated.

  5. Flame spread index and smoke-developed index.

  6. Method of drying after treatment.

  7. Conformance to applicable standards in accordance with Sections R302.15.5 through R302.15.10.

  8. For FRTW exposed to weather, or a damp or wet location, the words “No increase in the listed classification when subjected to the Standard Rain Test” (ASTM D2898).

  R302.15.5 Strength adjustments. Design values for untreated lumber and wood structural panels as specified in Section R802.1 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.

  R302.15.6 Fire-retardant-treated wood structural panels. 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 their treatment.

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  R302.15.7 Fire-retardant-treated lumber. For each species of wood treated, the effect of the treatment and 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.

• CBC § 2303.1.8.1 Medium relevance — show source text

  2303.1.8.1 Floor underlayment. Particleboard floor underlayment shall conform to Type PBU of ANSI A208.1. Type PBU underlayment shall be not less than [1] / 4 -inch (6.4 mm) thick and shall be installed in accordance with the instructions of the Composite Panel Association.

  2303.1.9 Preservative-treated wood. 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.

  2303.1.9.1 Identification. 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.

  2303.1.9.2 Moisture content. 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.

  2303.1.10 Structural composite lumber. Structural capacities for structural composite lumber shall be established and monitored in accordance with ASTM D5456.

  2303.1.11 Structural log members. 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.

  2303.1.12 Round timber poles and piles. Round timber poles and piles shall comply with ASTM D3200 and ASTM D25, respectively.

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  2303.1.13 Engineered wood rim board. 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.

• CBC § 2304.11.4.1 Medium relevance — show source text

  2304.11.4.1 Cross-laminated timber roofs. Cross-laminated timber roofs shall be not less than 3 inches (76 mm) in thickness and shall be continuous from support to support and mechanically fastened to one another.

  2304.11.4.2 Sawn, wood structural panel, or glued-laminated plank roofs. 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. 1 [1] / 8 -inch-thick (32 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.

  2304.12 Protection against decay and termites. Wood shall be protected from decay and termites in accordance with the applicable provisions of Sections 2304.12.1 through 2304.12.4.

  2304.12.1 Locations requiring waterborne preservatives or naturally durable wood. Wood used above ground in the locations specified in Sections 2304.12.1.1 through 2304.12.1.5 shall be naturally durable wood or preservative-treated wood using waterborne preservatives, in accordance with AWPA U1 for above-ground use.

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  2304.12.1.1 Joists, girders and subfloor. 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.

  2304.12.1.1.1 [SPCB] There shall be a clearance of at least 18 inches (457 mm) between the underside of wood floor joists and the finished surface of the ground, and at least 12 inches (305 mm) between the underside of any other wood horizontal framing member and the finished surface of the ground. The ground underneath floor joists shall be leveled or smoothed off so as to maintain a reasonably even surface.

  Exception: For purposes of structural pest control inspection, a minimum of 12 inches (305 mm) of clearance under-floor joists shall be considered adequate except that such clearance shall not be necessary where the subarea soil is of such a nature as to prevent excavation or where excavation would create a hazard from shifting soil or other causes.

  2304.12.1.2 Wood supported by exterior foundation walls. 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.

  Exception: [DSA-SS and OSHPD 1, 1R, 2, 4 & 5] At exterior walls where the earth is paved with an asphalt or concrete slab at least 18 inches (457 mm) wide and draining away from the building, the bottom of sills are permitted to be 6 inches (152 mm) above the top of such slab. Other equivalent means of termite and decay protection may be accepted by the enforcement agency.

• CBC § 2303.1.6.3 Medium relevance — show source text

  2303.1.6.3 Wall insulation. Where installed and fireblocked 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.

  2303.1.6.3.1 Protection. Fiberboard wall insulation applied on the exterior of foundation walls shall be protected below ground level with a bituminous coating.

  2303.1.7 Hardboard. 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 manufacture’s recommendations.

  2303.1.8 Particleboard. 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.

  2303.1.8.1 Floor underlayment. Particleboard floor underlayment shall conform to Type PBU of ANSI A208.1. Type PBU underlayment shall be not less than [1] / 4 -inch (6.4 mm) thick and shall be installed in accordance with the instructions of the Composite Panel Association.

  2303.1.9 Preservative-treated wood. 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.

  2303.1.9.1 Identification. 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.

  2303.1.9.2 Moisture content. 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.

• CBC § 23-27 Medium relevance — show source text

  **|Truss Plate Institute, Inc.| ||TPI 1|National Design Standard for Metal Plate Connected Wood Truss Construction|

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  TABLE 2306.1—STANDARDS FOR DESIGN AND CONSTRUCTION OF WOOD ELEMENTS IN STRUCTURES USING ALLOWABLE STRESS DESIGN—continued	Col2	Col3
  STANDARDS PROMULGATOR	STANDARD	TITLE
  West Coast Lumber Inspection Bureau	West Coast Lumber Inspection Bureau	West Coast Lumber Inspection Bureau
  	AITC 104	Typical Construction Details
  	AITC 110	Standard Appearance Grades for Structural Glued Laminated Timber
  	AITC 113	Standard for Dimensions of Structural Glued Laminated Timber
  	AITC 119	Standard Specifications for Structural Glued Laminated Timber of Hardwood Species
  	AITC 200	Inspection Manual

  2306.1.1 Joists and rafters. The design of rafter spans is permitted to be in accordance with the AWC STJR.

  2306.1.2 Plank and beam flooring. The design of plank and beam flooring is permitted to be in accordance with the AWC Wood Construction Data No. 4.

  2306.1.3 Preservative-treated wood allowable stresses. The allowable unit stresses for preservative-treated wood conforming to AWPA U1 need not be adjusted for treatment, but are subject to other adjustments. Load duration factors greater than 1.6 shall not be used in the structural design of preservative-treated wood members.

  2306.1.4 Fire-retardant-treated wood allowable stresses. The allowable unit stresses for fire-retardant-treated wood, including connection design values, shall be developed in accordance with the provisions of Section 2303.2.6. Load duration factors greater than 1.6 shall not be used in the structural design of fire-retardant-treated wood members.

  2306.1.5 Lumber decking. 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 moment and deflection according to the formulas in Table 2306.1.5.

  TABLE 2306.1.5—ALLOWABLE LOADS FOR LUMBER DECKING	Col2	Col3
  PATTERN	ALLOWABLE AREA LOADa	ALLOWABLE AREA LOADa
  PATTERN	Moment	Deflection
  Simple span	w_b_ 8_Fb_ ′_d_2 _l_26 -------------- =	wΔ 384Δ_E_′ 5_l_4 ----------------- _d_3 12 ----- =
  Two-span continuous	w_b_ 8_Fb_ ′_d_2 _l_26 ------------- =	wΔ 185Δ_E_′ _l_4 ----------------- _d_3 12 ----- =
  Combination simple- and two-span continuous	w_b_ 8_Fb_

• CBC § 23-21 Medium relevance — show source text

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  with ASTM A153. The coating weight for zinc-coated nails shall be in accordance with ASTM A153 Class D or ASTM A641 Class 3S [1 ounce per square foot (305 g/m [2] )]. Stainless steel driven fasteners shall be in accordance with the material requirements of ASTM F1667.

  2304.10.6.1 Fasteners and connectors for preservative-treated wood. Fasteners, including nuts and washers, in contact with preservative-treated wood shall be of hot-dipped zinc-coated galvanized steel, stainless steel, silicon bronze or copper. Staples shall be of stainless steel. Fasteners other than nails, staples, timber rivets, wood screws and lag screws shall be permitted to be of mechanically deposited zinc-coated steel with coating weights in accordance with ASTM B695, Class 55 minimum. Connectors that are used in exterior applications and in contact with preservative-treated wood shall have coating types and weights in accordance with the treated wood or connector manufacturer’s recommendations. In the absence of manufacturer’s recommendations, not less than ASTM A653, Type G185 zinc-coated galvanized steel, or equivalent, shall be used.

  Exception: Plain carbon steel fasteners, including nuts and washers, in SBX/DOT and zinc borate preservative-treated wood in an interior, dry environment shall be permitted.

  2304.10.6.2 Fastenings for wood foundations. Fastenings, including nuts and washers, for wood foundations shall be as required in AWC PWF.

  2304.10.6.3 Fasteners for fire-retardant-treated wood used in exterior applications or wet or damp locations. 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 zinccoated steel with coating weights in accordance with ASTM B695, Class 55 minimum.

  2304.10.6.4 Fasteners for fire-retardant-treated wood used in interior applications. 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 2304.10.6.3 shall apply.

  2304.10.7 Load path. 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.

  2304.10.8 Framing requirements. Wood columns and posts shall be framed to provide full end bearing. Alternatively, columnand-post end connections shall be designed to resist the full compressive loads, neglecting end-bearing capacity. Column-andpost end connections shall be fastened to resist lateral and net induced uplift forces.

• CBC § 3.4 Medium relevance — show source text

  3.4_||||||||X|X|X|X|X||X|X|||||||||| |2304.4.1||||||||X|X|X|X|X|||X|||||||||| |2304.10.2.1||||||||X||X|X|X||X|X|||||||||| |2304.12.1.1.1||||||||||||||||||||||X||| |2304.12.1.2||||||||X||X|X|X||X|X|||||||||| |2304.12.1.4.1||||||||X||X|X|X||X|X|||||||||| |2304.12.8||||||||||||||||||||||X||| |2304.12.9||||||||||||||||||||||X||| |2305.1.2||||||||X|X|X|X|X||X|X|||||||||| |2308.2.7||||||||X|X||X|X|||X|||||||||| |2309.1.1||||||||X|X||X|X|||X||||||||||

  The state agency does not adopt sections identified with the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.

  2025 CALIFORNIA BUILDING CODE 23-1

  on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

  23-2 2025 CALIFORNIA BUILDING CODE

  on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

  23 WOOD

  User notes:

  About this chapter: Chapter 23 provides minimum requirements for the design of buildings and structures that use wood and wood-based products. The chapter is organized around three design methodologies: allowable stress design (ASD), load and resistance factor design (LRFD) and conventional light-frame construction. In addition it allows the use of the American Wood Council Wood Frame Construction Manual for a limited range of structures. Included in the chapter are references to design and manufacturing standards for various wood and wood-based products; general construction requirements; design criteria for lateral force-resisting systems and specific requirements for the application of the three design methods.

  ICC code development note: Code change proposals to sections preceded by the designation [BF] will be considered by a code development committee meeting during the 2024 (Group A) Code Development Cycle. All other code change proposals will be considered by a code development committee meeting during the 2025 (Group B) Code Development Cycle.

  SECTION 2301—GENERAL

  2301.1 Scope. The provisions of this chapter shall govern the materials, design, construction and quality of wood members and their fasteners.

  [HCD 1] For limited-density owner-built rural dwellings, owner-produced or used materials and appliances may be utilized unless found not to be of sufficient strength or durability to perform the intended function; owner-produced or used lumber, or shakes and shingles may be utilized unless found to contain dry rot, excessive splitting or other defects obviously rendering the material unfit in strength or durability for the intended purpose.

  2301.1.1 _**Application.