CRC · California Residential Code
Material identification and requirements for lumber and engineered floor members
For homeowners: The California Residential Code requires that any wood members carrying floor loads must be plainly identified — sawn lumber needs a recognized grade mark or certificate, I‑joists must meet ASTM D5055, and structural composite lumber must meet ASTM D5456. Always check product stamps/labels and follow manufacturer installation guidance.
Last reviewed: July 6, 2026
What the code requires — 2–4 sentences
In plain English: all sawn lumber and wood-based floor members used for load‑supporting purposes must be identified and have certified design values or be manufactured and monitored to the referenced standards. Key rules are in § R502.1.1, § R502.1.2, and § R502.1.5 of the California Residential Code. § R502.1.1 requires a grade mark or an accepted certificate for sawn lumber; § R502.1.2 and § R502.1.5 require prefabricated I‑joists and structural composite lumber to have structural capacities established and monitored to specific ASTM standards.
All load‑bearing wood members must carry the appropriate grade/identification and have capacities documented by the code‑required grading agency or ASTM/ANSI standard. (short plain‑English rule)
Requirements in detail
Sawn lumber — identification and acceptance
Defined term to note: sawn lumber.
Requirement: sawn lumber must be identified by a grade mark from an accredited lumber grading or inspection agency and must have design values certified by an accreditation body that complies with DOC PS 20. In lieu of a grade mark, a certificate of inspection from a qualifying grading/inspection agency is permitted. See § R502.1.1.
Preservative‑treated dimension lumber must be identified as required by § R304.2 (see § R502.1.1.1). The code reference in R502.1.1.1 points to R304.2 for the specific required identification.
End‑jointed lumber that is identified in conformance with § R502.1.1 is permitted to be used interchangeably with solid‑sawn members of the same species and grade. If used in an assembly that requires a fire‑resistance rating, the grade mark for end‑jointed lumber must include the designation “Heat‑Resistant Adhesive” or “HRA”. See § R502.1.1.2.
Prefabricated wood I‑joists
Defined term: prefabricated wood I‑joists.
Requirement: Structural capacities and design provisions for prefabricated wood I‑joists shall be established and monitored in accordance with ASTM D5055. See § R502.1.2. Confirm the product documentation and manufacturer’s stamp/label that shows compliance with ASTM D5055.
Note: lateral support and cutting/notching restrictions for I‑joists are governed elsewhere (manufacturer’s instructions and R502.7.1 / R502.8); the code explicitly allows manufacturer recommendations for lateral support of I‑joists.
Structural composite lumber (SCL)
- Defined term: structural composite lumber (SCL; e.g., LVL, PSL).
- Requirement: Structural capacities for SCL must be established and monitored in accordance with ASTM D5456. See § R502.1.5. Verify factory stamps/labels or evaluation reports showing conformance to ASTM D5456.
Quick reference table (decision‑relevant items)
| Material / product | Identification / marking required | Standard / method for capacities | Notes (decision‑relevant) | Code Reference |
|---|---|---|---|---|
| Sawn lumber | Grade mark by accredited grading/inspection agency, or certificate of inspection | Design values certified by an accreditation body complying with DOC PS 20 | Accept certificate in lieu of grade mark for some precut/remanufactured pieces | § R502.1.1 |
| Preservative‑treated lumber | Identification per preservative labeling requirements | See R304.2 for labeling specifics | Must bear required label/stamp for treated use | § R502.1.1.1 |
| End‑jointed lumber | Grade mark conforming to R502.1.1; if used in fire‑rated assembly, HRA required in grade mark | Same design values as solid‑sawn of same species/grade | Permitted to be used interchangeably with solid‑sawn | § R502.1.1.2 |
| Prefabricated wood I‑joists | Manufacturer identification; product documentation showing compliance | ASTM D5055 for capacity and design monitoring | Follow manufacturer for lateral bracing, cutting/notching rules | § R502.1.2 |
| Structural composite lumber (SCL) | Manufacturer marking / product identification | ASTM D5456 for capacities | Verify evaluation reports or third‑party monitoring | § R502.1.5 |
Exceptions & special cases
End‑jointed lumber is allowed to substitute for solid‑sawn lumber of the same species and grade — but when the assembly is required to have a fire‑resistance rating the “HRA” designation must appear in the grade mark. § R502.1.1.2 explains this special requirement.
Manufacturer guidance governs modifications for many engineered products: I‑joists, SCL, glulam, and trusses often prohibit field cutting/notching except per the manufacturer or RDP (registered design professional). See § R502.8.2 for the prohibition on altering engineered members except as allowed by the manufacturer or RDP and the lateral support exception in § R502.7.1 for I‑joists and other engineered members.
Preservation labeling for treated lumber is referenced from § R502.1.1.1 to § R304.2 (R502 calls R304.2 for the identification requirement). The R502 text points to R304.2 for the specifics. If you need the exact treated‑wood label content, consult § R304.2 directly (this section is the controlling reference for treated‑wood identification).
Common mistakes
- Assuming undocumented or unstamped lumber is code‑compliant. The code explicitly requires a grade mark or acceptable certificate for sawn lumber (§ R502.1.1).
- Using end‑jointed stock in a fire‑rated assembly without verifying the grade mark contains “HRA”. § R502.1.1.2 requires this marking.
- Installing I‑joists or SCL without product data showing compliance with ASTM D5055 or ASTM D5456 respectively, or failing to follow manufacturer lateral‑support instructions (the code defers to manufacturer directions for lateral bracing of these members). §§ R502.1.2, R502.1.5, R502.7.1.
- Field cutting, notching, or boring engineered members (I‑joists, SCL, glulams, CLT) contrary to the manufacturer’s instructions or without RDP design — R502.8.2 prohibits such alterations except as allowed by the manufacturer or RDP.
Worked example — verifying compliance for a proposed 2×10 floor system
Scenario: You (designer/contractor) propose to use 2×10 floor joists for a living‑area floor. You consider two options: (A) sawn No.‑2 lumber (solid‑sawn) or (B) prefabricated wood I‑joists.
Checklist and application of the CRC requirements:
Option A — Sawn lumber:
- Verify each bundle or stick has a grade mark from an accredited grading agency or obtain a certificate of inspection acceptable to the building official. This satisfies § R502.1.1. If the joists are preservative treated, check for the treated‑wood label per § R502.1.1.1 (which points you to § R304.2 for labeling specifics).
- If a manufacturer supplies end‑jointed 2×10s, confirm the grade mark and, if the assembly needs a fire‑resistance rating, look for “HRA” in the mark as required by § R502.1.1.2.
Option B — Prefabricated wood I‑joists:
- Require product documentation (label, spec sheet, or evaluation report) showing the joists’ structural capacities are established and monitored in accordance with ASTM D5055 as required by § R502.1.2. Do not accept undocumented performance claims.
- Confirm the manufacturer’s installation instructions for lateral bracing and allowable field cuts/notches are followed (R502.7.1 and R502.8.2 govern bracing and cutting of engineered members — manufacturer guidance controls).
Bottom line for the owner/designer: choose either material only when the product carries the required grade/labeling or conforming ASTM/ANSI identification and when manufacturer guidance is available for installation details; the CRC requires those verifications.
Related provisions
- § R502.1.1.1 — Preservative‑treated lumber identification (referenced to § R304.2)
- § R502.1.1.2 — End‑jointed lumber and “HRA” marking requirement for fire‑rated assemblies
- § R502.1.2 — Prefabricated wood I‑joists (ASTM D5055)
- § R502.1.5 — Structural composite lumber (ASTM D5456)
- § R502.7.1 — Bridging / lateral support; exception directing engineered members to manufacturer recommendations
- § R502.8 (and R502.8.2) — Cutting, drilling and notching restrictions for sawn vs. engineered members
If you need the exact preservative‑treatment label content (the code calls out § R304.2 from § R502.1.1.1), I can retrieve § R304.2 text for the exact label elements on request; it is referenced by R502.1.1.1 but the full R304.2 text is not reproduced here.
Code references
Grounded in the retrieved California Residential Code — click a citation to read the verbatim passage:
CRC § 0.42. High relevance — show source text
Portions of connections of wood-framed floor systems not noted in the figures shall be in accordance with Section R502, or AWC WFCM, if applicable. Wood framing members shall be of a species having a specific gravity equal to or greater than 0.42. 2. For floor systems of cold-formed steel construction, the provisions of Section R608.9.1 and the prescriptive details of Figures R608.9(5) through R608.9(8), where permitted by the tables accompanying those figures. Portions of connections of coldformed steel-framed floor systems not noted in the figures shall be in accordance with Section R505, or AISI S230, if applicable. 3. Proprietary connectors selected to resist loads and load combinations in accordance with Appendix A (ASD) or Appendix B (LRFD) of PCA 100. 4. An engineered design using loads and load combinations in accordance with Appendix A (ASD) or Appendix B (LRFD) of PCA 100.
- An engineered design using loads and material design provisions in accordance with this code, or in accordance with ASCE 7, ACI 318, and AWC NDS for wood-framed construction or AISI S100 for cold-formed steel frame construction.
R608.9.3 Connections between concrete walls and light-frame ceiling and roof systems. Connections between concrete walls and light-frame ceiling and roof systems shall be in accordance with one of the following:
- For ceiling and roof systems of wood-framed construction, the provisions of Section R608.9.1 and the prescriptive details of Figures R608.9(9) and R608.9(10), where permitted by the tables accompanying those figures. Portions of connections of wood-framed ceiling and roof systems not noted in the figures shall be in accordance with Section R802, or AWC WFCM, if applicable. Wood framing members shall be of a species having a specific gravity equal to or greater than 0.42.
- For ceiling and roof systems of cold-formed steel construction, the provisions of Section R608.9.1 and the prescriptive details of Figures R608.9(11) and R608.9(12), where permitted by the tables accompanying those figures. Portions of
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WALL CONSTRUCTION
connections of cold-formed steel-framed ceiling and roof systems not noted in the figures shall be in accordance with Section R804, or AISI S230, if applicable. 3. Proprietary connectors selected to resist loads and load combinations in accordance with Appendix A (ASD) or Appendix B (LRFD) of PCA 100. 4. An engineered design using loads and load combinations in accordance with Appendix A (ASD) or Appendix B (LRFD) of PCA 100.
- An engineered design using loads and material design provisions in accordance with this code, or in accordance with ASCE 7, ACI 318, and AWC NDS for wood-framed construction or AISI S100 for cold-formed steel-framed construction.
CRC § 3-82 Medium relevance — show source text
R336 Large Family Day-Care Homes . . . . . . . . . . . . . . . . . . . 3-82
R337 Materials and Construction Methods for Exterior
Wildfire Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-83
R338 Electric Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-83
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CONTENTS
R339 Reserved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-84
R340 Pollutant Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-84
CHAPTER 4 FOUNDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
R401 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
R402 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
R403 Footings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
R404 Foundation and Retaining Walls . . . . . . . . . . . . . . . . 4-24
R405 Foundation Drainage . . . . . . . . . . . . . . . . . . . . . . . . . . 4-42
R406 Foundation Waterproofing and Dampproofing . . . 4-43
R407 Columns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-44
R408 Under-Floor Space . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-44
CHAPTER 5 FLOORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
R501 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
R502 Wood Floor Framing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
R503 Floor Sheathing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12
R504 Pressure Preservative-Treated Wood
CRC § 1.1.1 Medium relevance — show source text
Note: See Section R301.1.1.1 for limited-density owner- built rural dwellings.
R502.1.1.1 Preservative-treated lumber. Preservative treated dimension lumber shall be identified as required by Section R304.2.
R502.1.1.2 End-jointed lumber. Approved end-jointed lumber identified by a grade mark conforming to Section R502.1.1 shall be permitted to be used interchangeably with solid-sawn members of the same species and grade. End-jointed lumber used in an assembly required elsewhere in this code to have a fire-resistance rating shall have the designation “Heat-Resistant Adhesive” or “HRA” included in its grade mark.
R502.1.2 Prefabricated wood I-joists. Structural capacities and design provisions for prefabricated wood I-joists shall be established and monitored in accordance with ASTM D5055.
R502.1.3 Structural glued-laminated timbers. Glued-laminated timbers shall be manufactured and identified as required in ANSI A190.1, ANSI 117 and ASTM D3737.
R502.1.4 Structural log members. Structural log members shall comply with the provisions of ICC 400.
R502.1.5 Structural composite lumber. Structural capacities for structural composite lumber shall be established and monitored in accordance with ASTM D5456.
R502.1.6 Cross-laminated timber. Cross-laminated timber shall be manufactured and identified as required by ANSI/APA PRG 320.
R502.1.7 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.
R502.2 Design and construction. Floors shall be designed and constructed in accordance with the provisions of this chapter, Figure R502.2 and Sections R304 and R305 or in accordance with ANSI AWC NDS.
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FLOORS
FIGURE R502.2—FLOOR CONSTRUCTION
SILL PLATE
BAND, RIM OR HEADER JOIST
BOTTOM WALL STUDS
PLATE
OPTIONAL FINISH
FLOOR
SUBFLOOR OR FLOOR SHEATHING– JOISTS–SEE TABLES SEE SECTION R503 R502.3.1(1) AND R502.3.1(2)
Col1 Col2 Col3 Col4 Col5 Col6 Col7 Col8 Col9 Col10 Col11 Col12 Col13 Col14 Col15 2 IN. CLEARANCE
SEE SECTION
R1001.11
FIREPLACE
SOLID
BLOCKING–SEE
SECTION R502.7
SILL PLATE
FOUNDATION
CRC § 5-1 Medium relevance — show source text
The state agency does not adopt sections identified with the following symbol: †
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5 FLOORS
User notes:
About this chapter: Chapter 5 provides the requirements for the design and construction of floor systems that will be capable of supporting minimum required design loads. This chapter covers wood floor framing, wood floors on the ground, cold-formed steel floor framing and concrete slabs on the ground. Allowable span tables are provided that greatly simplify the determination of joist, girder and sheathing sizes for raised floor systems of wood framing and cold-formed steel framing. This chapter also contains prescriptive requirements for wood-framed exterior decks and their attachment to the main building.
SECTION R501—GENERAL
R501.1 Application. The provisions of this chapter shall control the design and construction of the floors for buildings, including the floors of attic spaces used to house mechanical or plumbing fixtures and equipment.
R501.2 Requirements. Floor construction shall be capable of accommodating all loads in accordance with Section R301 and of transmitting the resulting loads to the supporting structural elements.
SECTION R502—WOOD FLOOR FRAMING
R502.1 General. Wood and wood-based products used for load-supporting purposes shall conform to the applicable provisions of this section.
R502.1.1 Sawn lumber. Sawn lumber shall be identified by a grade mark of an accredited lumber grading or inspection agency and have design values certified by an accreditation body that complies with DOC PS 20. In lieu of a grade mark, a certificate of inspection issued by a lumber grading or inspection agency meeting the requirements of this section shall be accepted.
Note: See Section R301.1.1.1 for limited-density owner- built rural dwellings.
R502.1.1.1 Preservative-treated lumber. Preservative treated dimension lumber shall be identified as required by Section R304.2.
R502.1.1.2 End-jointed lumber. Approved end-jointed lumber identified by a grade mark conforming to Section R502.1.1 shall be permitted to be used interchangeably with solid-sawn members of the same species and grade. End-jointed lumber used in an assembly required elsewhere in this code to have a fire-resistance rating shall have the designation “Heat-Resistant Adhesive” or “HRA” included in its grade mark.
R502.1.2 Prefabricated wood I-joists. Structural capacities and design provisions for prefabricated wood I-joists shall be established and monitored in accordance with ASTM D5055.
R502.1.3 Structural glued-laminated timbers. Glued-laminated timbers shall be manufactured and identified as required in ANSI A190.1, ANSI 117 and ASTM D3737.
R502.1.4 Structural log members. Structural log members shall comply with the provisions of ICC 400.
R502.1.5 Structural composite lumber. Structural capacities for structural composite lumber shall be established and monitored in accordance with ASTM D5456.
R502.1.6 Cross-laminated timber. Cross-laminated timber shall be manufactured and identified as required by ANSI/APA PRG 320.
CRC § 0.131 Medium relevance — show source text
At top and bottom plates where the wood structural panel is in direct contact with the framing, 8d common nail (21/2 inches × 0.131 inch) shall be permitted.
b. Full round head nail with minimum head diameter of 0.281 inch (7 mm).
c. Nails are in accordance with ASTM F1667.|For SI: 1 inch = 25.4 mm.
a. At top and bottom plates where the wood structural panel is in direct contact with the framing, 8d common nail (21/2 inches × 0.131 inch) shall be permitted.
b. Full round head nail with minimum head diameter of 0.281 inch (7 mm).
c. Nails are in accordance with ASTM F1667.|For SI: 1 inch = 25.4 mm.
a. At top and bottom plates where the wood structural panel is in direct contact with the framing, 8d common nail (21/2 inches × 0.131 inch) shall be permitted.
b. Full round head nail with minimum head diameter of 0.281 inch (7 mm).
c. Nails are in accordance with ASTM F1667.|BN102.3 Wall bracing. Wall bracing for EPW construction shall comply with the requirements for WSP or CS-WSP or CS-G bracing methods in Section R602.10, except that the sheathing fasteners shall comply with Table BN102.2.
BN102.3.1 Simplified wall bracing. With the exception of Section R602.12.2, Item 2, provisions of Section R602.12 shall be applicable to EPW construction. The fastening schedule for wood structural panels shall comply with Table BN102.2.
BN102.4 Rim joists. Rim joists supporting an EPW shall comply with Figure BN102.4(1) or BN102.4(2). Sawn 2× lumber or engineered wood rim board shall be used to construct rim (band) joists. Engineered wood rim board shall comply with Section R602.1.7. The minimum bearing length requirements for the floor joists shall be satisfied or joists shall be supported with metal hangers.
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For SI: 1 inch = 25.4 mm.
For SI: 1 inch = 25.4 mm.
APPENDIX BN — EXTENDED PLATE WALL CONSTRUCTION
FIGURE BN102.4(1)—RIM JOIST CONSTRUCTION FOR EPW—DOUBLE MEMBER
FIGURE BN102.4(2)—RIM JOIST CONSTRUCTION FOR EPW—INSET DOUBLE MEMBER
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APPENDIX BN — EXTENDED PLATE WALL CONSTRUCTION
BN102.4.1 Rim joist used as rim header. Wood rim boards, or band joists, that serve as rim board headers shall be constructed in accordance with Section R602.7.2.
CRC § 2.1 Medium relevance — show source text
R507.2 Materials. Materials used for the construction of decks shall comply with this section.
R507.2.1 Wood materials. Wood structural members shall be protected from decay where required by Sections R304.1 and R304.1.2, and protected from termites where required by Section R305.1. Where design in accordance with Section R301 is provided, wood structural members shall be designed using the wet service factor defined in AWC NDS. Sawn lumber for joists, beams and posts shall be No. 2 or better. Cuts, notches and drilled holes of preservative-treated wood members shall be treated in accordance with Section R304.1.1.
R507.2.1.1 Engineered wood products. Engineered wood products shall be in accordance with Section R502.
R507.2.2 Plastic composite deck boards, stair treads, guards or handrails. Plastic composite exterior deck boards, stair treads, guards and handrails shall comply with the requirements of ASTM D7032 and this section.
R507.2.2.1 Labeling. Plastic composite deck boards and stair treads, or their packaging, shall bear a label that indicates compliance with ASTM D7032 and includes the allowable load and maximum allowable span determined in accordance with ASTM D7032. Plastic or composite handrails and guards, or their packaging, shall bear a label that indicates compliance with ASTM D7032 and includes the maximum allowable span determined in accordance with ASTM D7032.
R507.2.2.2 Flame spread index. Plastic composite deck boards, stair treads, guards, and handrails shall exhibit a flame spread index not exceeding 200 when tested in accordance with ASTM E84 or UL 723 with the test specimen remaining in place during the test.
Exception: Plastic composites determined to be noncombustible.
R507.2.2.3 Decay resistance. Plastic composite deck boards, stair treads, guards and handrails containing wood, cellulosic or other biodegradable materials shall be decay resistant in accordance with ASTM D7032.
R507.2.2.4 Termite resistance. Where required by Section 305, plastic composite deck boards, stair treads, guards and handrails containing wood, cellulosic or other biodegradable materials shall be termite resistant in accordance with ASTM D7032.
R507.2.2.5 Installation of plastic composites. Plastic composite deck boards, stair treads, guards and handrails shall be installed in accordance with this code and the manufacturer’s instructions.
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R507.2.3 Fasteners and connectors. Metal fasteners and connectors used for all decks shall be in accordance with Section R304.3 and Table R507.2.3. Holes for through bolts shall be drilled to a diameter of [1] / 32 inch to [1] / 16 inch larger than the bolt diameter. Connectors shall be installed in accordance with the manufacturer’s approved instructions.
|TABLE R507.2.3—FASTENER AND CONNECTOR SPECIFICATIONS FOR DECKSa,
CRC § 5.7 Medium relevance — show source text
FRAMING AND 6-INCH SCREW SPACING ON THE PERIMETER OF EACH PANEL OF STRUCTURAL SHEATHING—continued Col2 Col3 Col4 Col5 Col6 Col7 Col8 Col9 Col10 ** SEISMIC**
DESIGN
CATEGORY** STORY** ** BRACED WALL LINE LENGTH**
(feet)** BRACED WALL LINE LENGTH**
(feet)** BRACED WALL LINE LENGTH**
(feet)** BRACED WALL LINE LENGTH**
(feet)** BRACED WALL LINE LENGTH**
(feet)** BRACED WALL LINE LENGTH**
(feet)** SINGLE-
STORY
HOLD-
DOWN
FORCE
(pounds)**** CUMULATIVE**
HOLD-DOWN
FORCE
(pounds)** SEISMIC**
DESIGN
CATEGORY** STORY** ** 10** ** 20** ** 30** ** 40** ** 50** ** 60** ** 60** ** 60** ** SEISMIC**
DESIGN
CATEGORY** STORY** ** Minimum total length of braced wall panels required along each braced wall line**
(feet)** Minimum total length of braced wall panels required along each braced wall line**
(feet)** Minimum total length of braced wall panels required along each braced wall line**
(feet)** Minimum total length of braced wall panels required along each braced wall line**
(feet)** Minimum total length of braced wall panels required along each braced wall line**
(feet)** Minimum total length of braced wall panels required along each braced wall line**
(feet)** Minimum total length of braced wall panels required along each braced wall line**
(feet)** Minimum total length of braced wall panels required along each braced wall line**
(feet)D2 5.7 8.2 10.6 13.0 15.4 17.8 3,360 — D2 9.2 15.1 21.1 27.0 32.9 38.8 3,360 6,720 D2 12.7 22.1 31.5 40.9 50.3 59.7 3,360 10,080 For SI: 1 mil = 0.0254 mm, 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound-force = 4.448 N. For SI: 1 mil = 0.0254 mm, 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound-force = 4.448 N. For SI: 1 mil = 0.0254 mm, 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound-force = 4.448 N. CRC § 7.1.1 Medium relevance — show source text
For intermediate values of endwall length and roof slope, use the next higher value or determine by interpolation.
c. Tabulated values in Tables R608.7.1.1(1) and R608.7.1.1(3) for “one story or top story of two story” are based on a floor-to-ceiling height of 10 feet. Tabulated values in Tables
R608.7.1.1(2) and R608.7.1.1(3) for “first story of two story” are based on floor-to-ceiling heights of 10 feet each for the first and second story. For floor to ceiling heights
between those shown in this table and those assumed in Table R608.7.1.1(1), R608.7.1.1(2) or R608.7.1.1(3), use the solid wall lengths in Table R608.7.1.1(1), R608.7.1.1(2) or
R608.7.1.1(3), or determine the reduction factor by interpolating between 1.0 and the factor shown in this table.|For SI: 1 foot = 304.8 mm.
a. See Section R608.7.1.1 and Note d to Table R608.7.1.1(1) for application of reduction factors in this table.
b. For intermediate values of endwall length and roof slope, use the next higher value or determine by interpolation.
c. Tabulated values in Tables R608.7.1.1(1) and R608.7.1.1(3) for “one story or top story of two story” are based on a floor-to-ceiling height of 10 feet. Tabulated values in Tables
R608.7.1.1(2) and R608.7.1.1(3) for “first story of two story” are based on floor-to-ceiling heights of 10 feet each for the first and second story. For floor to ceiling heights
between those shown in this table and those assumed in Table R608.7.1.1(1), R608.7.1.1(2) or R608.7.1.1(3), use the solid wall lengths in Table R608.7.1.1(1), R608.7.1.1(2) or
R608.7.1.1(3), or determine the reduction factor by interpolating between 1.0 and the factor shown in this table.|For SI: 1 foot = 304.8 mm.
a. See Section R608.7.1.1 and Note d to Table R608.7.1.1(1) for application of reduction factors in this table.
b. For intermediate values of endwall length and roof slope, use the next higher value or determine by interpolation.
c. Tabulated values in Tables R608.7.1.1(1) and R608.7.1.1(3) for “one story or top story of two story” are based on a floor-to-ceiling height of 10 feet. Tabulated values in Tables
R608.7.1.1(2) and R608.7.1.1(3) for “first story of two story” are based on floor-to-ceiling heights of 10 feet each for the first and second story.CRC § 2.5 Medium relevance — show source text
Parapet construction R302.2.5 Scope R101.2 Separation R302.2 Structural independence R302.2.6 Trusses
Steel R505.1.3, R804.3.6 Wood R502.12, R802.10 Tubular Daylighting Device (TDD) (see Skylights) Two-Family Dwellings R302.3
Under Floor
Space R408
Vapor Retarders R702.7 Capillary break R506.2.3.1 Under floor R408.8 Vehicular Gates Appendix BH Veneer
Masonry R703.7 Ventilation Adjoining rooms R325.1.3 Bathroom and kitchen R325.2
Habitable rooms R325.1
Roof R806
Under floor R408.1 Venting (Mechanical) Chimney and vent connectors R1006 Fireplace R1006 General R325.3
Violations R113 Visible Transmittance (VT)
Wall Furnace (see Appliance) Wallboard (see Gypsum) Walls
Bathtub compartments R327.2 Bracing, steel R603.9 Bracing, wood R602.10 Construction Chapter 6 Covering Chapter 7 Crawl space R202 Cripple R602.9
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INDEX
Deflection R301.7
Exterior, defined R202 Exterior covering R703 Finishes R327.2, R702 Fireplace R1001.5 Foundation R404 Insulating concrete form R608.3, R608.4, R608.5.3 Steel framing R603 Structural insulated panels (SIP) R610 Thickness, masonry chimneys R1003.10 Wood framing R602 Waste
Construction waste R334
Water Closet R326.1, R327 Clearances for R327.1 Waterproofing And dampproofing R406 Wells (see Individual Water Supply) Whirlpool Bathtubs R324.3.1, P2720 Wind
Design criteria R301.2, R301.2.1 Speed maps Figure R301.2(2) Window R609 Emergency Escape and Rescue Openings R319, R321.2.2 Fall protection R321.2 Glazing R324 Light and ventilation R325 Opening limiting devices R321.2.2 Wood
Floor construction R502
Foundation walls R404.2 Protection against decay R304 Roof-ceiling construction R802 Shakes R905.8 Shingles R905.7 Trusses R502.12, R802.10 Walls R602
Yard R318.1, R319.1, R319.2.4, R325.1.1
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HISTORY NOTE APPENDIX
CRC § 2303.1.1 Medium relevance — show source text
2303.1.1 Sawn lumber. 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.
2303.1.1.1 Certificate of inspection. 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.
2303.1.1.2 End-jointed lumber. 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.
2303.1.2 Prefabricated wood I-joists. Structural capacities and design provisions for prefabricated wood I-joists shall be established and monitored in accordance with ASTM D5055.
2303.1.3 Structural glued-laminated timber. Glued-laminated timbers shall be manufactured and identified as required in ANSI/APA 190.1 and ASTM D3737.
2303.1.3.1 Additional requirements. [DSA-SS, DSA-SS/CC and OSHPD 1, 1R, 2, 4 & 5] The construction documents shall indicate the following: 1. Dry or wet service conditions. 2. Laminating combinations and stress requirements. 3. Species group. 4. Preservative material and retention, when preservative treatment is required. 5. Provisions for protection during shipping and field handling, such as sealing and wrapping in accordance with AITC 111.
When mechanical reinforcement such as radial tension reinforcement is required, such reinforcement shall comply with AITC 404 and shall be detailed accordingly in the construction documents. Construction documents shall specify that the moisture content of laminations at the time of manufacture shall not exceed 12 percent for dry conditions of use.
The design of fasteners and connections shall comply with AITC 117, Section I, Item 6 (Connection Design), and NDS Appendix E.
2303.1.4 Cross-laminated timber. Cross-laminated timbers shall be manufactured and identified in accordance with ANSI/APA PRG 320.
2303.1.4.1 Additional requirements. [DSA-SS & DSA-SS/CC & OSHPD 1, 1R, 2, 4 & 5] Requirements in Section 2303.1.3.1 shall apply to cross-laminated timber.
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WOOD
**2303.1.5 Wood structural panels.
CRC § 2.2.2. Medium relevance — show source text
Dead load limits for townhouses in Seismic Design Category C and all structures in Seismic Design Categories D0, D1, and D2 shall be determined in accordance with Section
R301.2.2.2.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
Note: Check sources for availability of lumber in lengths greater than 20 feet.
a. End bearing length shall be increased to 2 inches.
b. Dead load limits for townhouses in Seismic Design Category C and all structures in Seismic Design Categories D0, D1, and D2 shall be determined in accordance with Section
R301.2.2.2.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
Note: Check sources for availability of lumber in lengths greater than 20 feet.
a. End bearing length shall be increased to 2 inches.
b. Dead load limits for townhouses in Seismic Design Category C and all structures in Seismic Design Categories D0, D1, and D2 shall be determined in accordance with Section
R301.2.2.2.|R502.3.2 Other floor joists. Table R502.3.1(2) shall be used to determine the maximum allowable span of floor joists that support other areas of the building, other than sleeping areas and attics, provided that the design live load does not exceed 40 pounds per square foot (1.92 kPa) and the design dead load does not exceed 20 pounds per square foot (0.96 kPa).
R502.3.3 Floor cantilevers. Floor cantilever spans shall not exceed the nominal depth of the wood floor joist. Floor cantilevers constructed in accordance with Table R502.3.3(1) shall be permitted where supporting a light-frame bearing wall and roof only. Floor cantilevers constructed in accordance with Table R502.3.3(2) shall be permitted where supporting an exterior balcony. A full-depth rim joist shall be provided at the unsupported end of the cantilever joists. Solid blocking shall be provided at the support for the cantilever. Where the cantilever length is 24 inches (610 mm) or less and the building is assigned to Seismic Design Category A, B or C, solid blocking at the support for the cantilever shall not be required.
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FLOORS
TABLE R502.3.3(1)—CANTILEVER SPANS FOR FLOOR JOISTS
SUPPORTING LIGHT-FRAME EXTERIOR BEARING WALL AND ROOF ONLYa, b, c, f, g
(Floor live load ≤ 40 psf, roof live load ≤ 20 psf)Col2 Col3 Col4 Col5 Col6 Col7 Col8 Col9 Col10 Col11 Col12 Col13 MEMBER & SPACING MAXIMUM CANTILEVER SPAN
**(uplift force at backspan support in lb)d,CRC § 9.1.1 Medium relevance — show source text
R608.9.1.1 Anchor bolts. Anchor bolts used to connect light-frame floor, ceiling and roof systems to concrete walls in accordance with Figures R608.9(1) through R608.9(12) shall have heads, or shall be rods with threads on both ends with a hex or square nut on the end embedded in the concrete. Bolts and threaded rods shall comply with Section R608.5.2.2. Anchor bolts with J- or L-hooks shall not be used where the connection details in these figures are used.
R608.9.1.2 Removal of stay-in-place form material at bolts. Holes in stay-in-place forms for installing bolts for attaching facemounted wood ledger boards to the wall shall be not less than 4 inches (102 mm) in diameter for forms not greater than 1 [1] / 2 inches (38 mm) in thickness, and increased 1 inch (25 mm) in diameter for each [1] / 2 -inch (12.7 mm) increase in form thickness. Holes in stayin-place forms for installing bolts for attaching face-mounted cold-formed steel tracks to the wall shall be not less than 4 inches (102 mm) square. The wood ledger board or steel track shall be in direct contact with the concrete at each bolt location. Exception: A vapor retarder or other material less than or equal to [1] / 16 inch (1.6 mm) in thickness is permitted to be installed between the wood ledger or cold-formed track and the concrete.
R608.9.2 Connections between concrete walls and light-frame floor systems. Connections between concrete walls and lightframe floor systems shall be in accordance with one of the following:
For floor systems of wood-framed construction, the provisions of Section R608.9.1 and the prescriptive details of Figures R608.9(1) through R608.9(4), where permitted by the tables accompanying those figures. Portions of connections of wood-framed floor systems not noted in the figures shall be in accordance with Section R502, or AWC WFCM, if applicable. Wood framing members shall be of a species having a specific gravity equal to or greater than 0.42.
For floor systems of cold-formed steel construction, the provisions of Section R608.9.1 and the prescriptive details of Figures R608.9(5) through R608.9(8), where permitted by the tables accompanying those figures. Portions of connections of coldformed steel-framed floor systems not noted in the figures shall be in accordance with Section R505, or AISI S230, if applicable.
Proprietary connectors selected to resist loads and load combinations in accordance with Appendix A (ASD) or Appendix B (LRFD) of PCA 100.
An engineered design using loads and load combinations in accordance with Appendix A (ASD) or Appendix B (LRFD) of PCA 100.
An engineered design using loads and material design provisions in accordance with this code, or in accordance with ASCE 7, ACI 318, and AWC NDS for wood-framed construction or AISI S100 for cold-formed steel frame construction.
R608.9.3 Connections between concrete walls and light-frame ceiling and roof systems. Connections between concrete walls and light-frame ceiling and roof systems shall be in accordance with one of the following:
- For ceiling and roof systems of wood-framed construction, the provisions of Section R608.9.1 and the prescriptive details of Figures R608.9(9) and R608.9(10), where permitted by the tables accompanying those figures.
Frequently asked questions
What counts as an acceptable grade mark for sawn lumber?
An accredited lumber grading or inspection agency grade mark is required; alternatively a certificate of inspection from an approved grading/inspection agency is acceptable under § R502.1.1.
Can I use end‑jointed lumber for floor joists?
Yes — provided the end‑jointed lumber is identified by a grade mark conforming to § R502.1.1. If the member is used in a fire‑rated assembly, the grade mark must include “HRA” as required by § R502.1.1.2.
Do engineered I‑joists need a special stamp?
I‑joists must have their structural capacities established and monitored per ASTM D5055, and you should have product documentation showing compliance as required by § R502.1.2. Follow the manufacturer’s installation instructions.
Are field cuts and notches allowed in engineered members?
Field cutting, notching or boring of engineered members (I‑joists, SCL, glulam, CLT, trusses) is generally prohibited except where allowed by the manufacturer’s recommendations or by a registered design professional, per § R502.8.2.
What standard governs structural composite lumber (SCL)?
SCL structural capacities must be established and monitored in accordance with ASTM D5456, per § R502.1.5. Verify the product label/evaluation showing that compliance.
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