CRC · California Residential Code

Where does Chapter 5 (Floors) apply?

For a homeowner: Chapter 5 of the California Residential Code applies to every floor in your home — including attics used for HVAC or plumbing and exterior decks — and requires those floors to be designed and built to carry the loads specified in the code (see **§ R501.1** and **§ R301**). If you rely on the code’s prescriptive tables (joist spans, panel spans, deck footings), make sure the project matches the tables’ load and deflection assumptions; otherwise an engineered design is required. **§ R501.1**

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Last reviewed: July 6, 2026

What the code requires — plain English

The California Residential Code says Chapter 5 governs the design and construction of all floor systems in residential buildings — this explicitly includes attic spaces used to house mechanical or plumbing fixtures and equipment. See § R501.1 for the chapter application and § R501.2 for the general requirement that floors must be capable of carrying the design loads in § R301 and transmit those loads to the supports. § R501.1 § R501.2

The single most important rule: Chapter 5 applies to the floors of the building — including attics used for equipment — and those floors must be designed to carry the loads required by § R301. § R501.1

Requirements in detail

Scope — what "floors" means here

  • Chapter 5 covers raised floor framing (wood and cold-formed steel), floors on the ground (pressure-preservative-treated wood and concrete slabs), and wood-framed exterior decks and their attachments. See the Chapter 5 overview and table of contents. § R502, § R504, § R505, § R506, § R507

Design loads and performance

  • Floor systems must be designed to carry the applicable design live, dead and snow loads in § R301 and to transmit those loads to supporting elements per § R501.2. § R501.2
  • Typical CRC design assumptions shown elsewhere in Chapter 5 and related tables include: second-floor live load = 40 psf, third-floor live load = 30 psf, attic live load = 10 psf, and a common dead-load assumption of 10 psf for floors. Deflection criteria commonly used are L/360 for live loads and L/240 for total load. § R301 (design criteria)

Prescriptive tables and when to use them

  • Chapter 5 provides allowable-span and sheathing tables (e.g., Table R503.2.1.1(1) for wood structural panels) and prescriptive rules for wood floor framing, on-ground floors, cold‑formed steel framing, concrete slabs, and decks. Use those tables only where the prescriptive conditions and load assumptions match your project. § R503, Table R503.2.1.1(1)

Decision-relevant dimensions / values (quick reference table)

Item (decision dimension) Typical value / threshold Code Reference
Chapter applicability (includes attics with equipment) Applies to all floors, including attic spaces used for mechanical/plumbing § R501.1
Requirement to carry & transfer loads Must accommodate loads per § R301 § R501.2; see § R301
Typical second-floor live load (design assumption) 40 psf Table assumptions, Chapter 5 / R301 design assumptions (see tables)
Typical attic live load (uninhabitable / limited storage) 10 psf Design assumption notes (Chapter 5 / R301)
Deflection limits L/360 (live), L/240 (total) Deflection criteria in Chapter 5 tables / notes
Floors on ground — minimum granular base 4 in. granular base under preservative-treated wood sleepers § R504.2.1
Vapour retarder for slabs-on-grade 6 mil polyethylene where required § R506.3.3
Decks — design load Design per § R301.5 or ground snow load, whichever is greater § R507.1

(Whenever you apply a prescriptive table, confirm the table’s listed load/deflection assumptions match your design — the table notes contain the assumptions cited above.)

Exceptions & special cases

  • Attics used to house mechanical or plumbing equipment: explicitly included in Chapter 5 applicability (not excluded). § R501.1
  • Free‑standing decks may be exempt from footings when they fully bear on grade or meet limited size/height rules — see the exceptions in § R507.3 (e.g., free-standing deck area ≤ 200 ft² and walking surface ≤ 20 in. above grade within 36 in.). § R507.3
  • Wood floors on ground have site limitations: wood basement floors are limited where differential fill against opposite foundation walls exceeds 2 ft unless specially designed. § R504.1.1
  • Vapor retarder exceptions for slabs-on-grade (garages, small unheated storage < 70 ft², carports, etc.) are in § R506.3.3. § R506.3.3

If a given floor condition does not meet the prescriptive assumptions in the tables, the code requires an engineered design in accordance with § R301 (see design criteria and load declaration requirements). § R301

Common mistakes

  • Assuming Chapter 5 only governs raised (framed) floors — it also governs floors on the ground (R504, R506) and decks (R507). § R504, § R506, § R507
  • Using span/sheathing tables without checking the table’s stated live‑load / dead‑load / deflection assumptions (tables include design assumptions in notes). Always verify table notes before choosing member sizes. Table notes show 40 psf second-floor live load, deflection limits L/360, etc.
  • Forgetting attic areas that contain equipment are treated as floors and must be designed to carry the required loads — Chapter 5 explicitly includes such attic spaces. § R501.1
  • Treating deck prescriptive rules as universal: prescriptive deck provisions only apply where the deck construction, materials and loads match the section; otherwise, design per § R301 is required. § R507.1

Worked example — which parts of Chapter 5 apply and how to start the design

Scenario: You are designing a typical second‑floor living room in a two‑story house. The room will be supported on wood joists, subfloor will be wood structural panels, and the attic above is separate.

  1. Applicability check:

    • This is a floor in a residential building → Chapter 5 applies per § R501.1. § R501.1

  2. Design loads to use:

    • Use the CRC design assumptions for second floors: 40 psf live load and a typical floor dead load of 10 psf (table notes). Use deflection criteria L/360 for live load. (See Chapter 5 / R301 notes.)

  3. Convert area load to line load (example numbers):

    • If joists are spaced 16 in. o.c. (1.333 ft tributary width), the uniform load on one joist = (live + dead) × tributary width = (40 + 10) psf × 1.333 ft = ~66.7 plf.
    • For a 12‑ft clear span, that is the design uniform load the joist must support (for bending and deflection checks). (Load assumptions and deflection criteria are from Chapter 5 notes / R301.)

  4. Next step:

    • Use the prescriptive joist span tables in § R502 (wood floor framing) and the subfloor panel spans in § R503 (Table R503.2.1.1) to choose joist size and subfloor thickness only if the project conditions match the table assumptions (loads, spacing, material grade). If they do not match, obtain an engineered design per § R301. § R502, § R503, § R301

Related provisions (useful cross‑references)

  • § R301 — Design criteria and loads used for floor design.
  • § R502 — Wood floor framing (prescriptive framing rules and span tables).
  • § R503 — Floor sheathing rules and allowable panel spans (Tables R503.2.1.1).
  • § R504 — Pressure preservative‑treated wood floors (floors on ground).
  • § R505 — Cold‑formed steel floor framing.
  • § R506 — Concrete slabs on ground (slab vapor retarders, capillary break).
  • § R507 — Exterior decks (prescriptive deck rules and footings).

Code references

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

  • CRC § 5-1 High 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 § 4-6 High relevance — show source text

    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

    Floors (On Ground) . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14

    R505 Cold-Formed Steel Floor Framing . . . . . . . . . . . . . . . 5-14

    R506 Concrete Floors (On Ground) . . . . . . . . . . . . . . . . . . . 5-26

    R507 Exterior Decks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26

    CHAPTER 6 WALL CONSTRUCTION. . . . . . . . . . . . . . . . . . . 6-3

    R601 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3

    R602 Wood Wall Framing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3

    R603 Cold-Formed Steel Wall Framing. . . . . . . . . . . . . . . . 6-53

    R604 Wood Structural Panels . . . . . . . . . . . . . . . . . . . . . . . . 6-93

    R605 Particleboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-93

    R606 General Masonry Construction. . . . . . . . . . . . . . . . . . 6-93

  • California Residential Code High relevance — show source text

    Chapter 1 Scope and Administration.

    Chapter 1 establishes the limits of applicability of the code and describes how the code is to be applied and enforced. The provisions of Chapter 1 establish the authority and duties of the code official appointed by the authority having jurisdiction and also establish the rights and privileges of the design professional, contractor and property owner.

    Chapter 2 Definitions.

    Chapter 2 is the repository of the definitions of terms used in the body of the code. The user of the code should be familiar with and consult this chapter because the definitions are essential to the correct interpretation of the code and because the user may not be aware that a term is defined.

    Chapter 3 Building Planning.

    Chapter 3 provides guidelines for a minimum level of structural integrity, life safety, fire safety and livability for inhabitants of dwelling units regulated by this code. Chapter 3 is a compilation of the code requirements specific to the building planning sector of the design and construction process. This chapter sets forth code requirements dealing with light, ventilation, sanitation, minimum room size, ceiling height and environmental comfort. Chapter 3 establishes life-safety provisions including limitations on glazing used in hazardous areas, specifications on stairways, use of guards at elevated surfaces, window and fall protection, and rules for means of egress. Snow, wind and seismic design live and dead loads and flood-resistant construction, as well as solar energy systems are addressed in this chapter.

    Chapter 4 Foundations.

    Chapter 4 provides the requirements for the design and construction of foundation systems for buildings regulated by this code. Provisions for seismic load, flood load and frost protection are contained in this chapter. A foundation system consists of two interdependent components: the foundation structure itself and the supporting soil.

    The prescriptive provisions of this chapter provide requirements for constructing footings and walls for foundations of wood, masonry, concrete and precast concrete. In addition to a foundation’s ability to support the required design loads, this chapter addresses several other factors that can affect foundation performance. These include controlling surface water and subsurface drainage, requiring soil tests where conditions warrant and evaluating proximity to slopes and minimum depth requirements. The chapter also provides requirements to minimize adverse effects of moisture, decay and pests in basements and crawl spaces.

    Chapter 5 Floors.

    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 four different types: 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.

    Chapter 6 Wall Construction.

    Chapter 6 contains provisions that regulate the design and construction of walls. The wall construction covered in Chapter 6 consists of five different types: wood framed, cold-formed steel framed, masonry, concrete and structural insulated panel (SIP). The primary concern of this chapter is the structural integrity of wall construction and transfer of all imposed loads to the supporting structure. This chapter provides the requirements for the design and construction of wall systems that are capable of supporting the minimum design vertical loads (dead, live and snow loads) and lateral loads (wind or seismic loads). This chapter contains the prescriptive requirements for wall bracing and/or shear walls to resist t

  • CRC § 3-82 High 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 § 916-574 High relevance — show source text

    Note: Contact information for the California Department of Water Resources and the Department’s Directory of Flood Officials, which includes levee and reclamation district boundary maps, is available on-line at the following website: www.water.ca.gov/ BuildingCodes. The Department of Water Resources Building Code Project Engineer can be contacted at 916-574-1451. The Central Valley Flood Control Board Chief Engineer can be contacted at 916-574-0609. The California Emergency Management Agency Inland Region Program Manager can be contacted at 916-845-8488.

    CK109.2 Appeals. When a request for an alternate means of protection has been denied by the building official, the applicant may file a written appeal with the board of appeals. In considering such appeal, the board of appeals may provide additional information to, and request additional written statements from the Central Valley Flood Protection Board, the California Department of Water Resources and the California Emergency Management Agency. If such additional written statements are provided, the board of appeals shall consider those statements.

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    APPENDIX CK — AREAS PROTECTED BY THE FACILITIES OF THE CENTRAL VALLEY FLOOD PROTECTION PLAN

    APPENDIX CK-6 2025 CALIFORNIA RESIDENTIAL CODE

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    APPENDIX CK — AREAS PROTECTED BY THE FACILITIES OF THE CENTRAL VALLEY FLOOD PROTECTION PLAN

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    APPENDIX CK-8 2025 CALIFORNIA RESIDENTIAL CODE

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    Concrete Capillary break R506.2.3.1 Compressive strength R402.2 Floors (on ground) R506 Tile (roof) R905.3 Weathering Figure R301.2(1), R402.2 Construction

    3D-printed Appendix BM Cavity wall masonry R608 Cob Appendix BK Extended plate walls Appendix BN Flood-resistant R306

    Floors Chapter 5 Footings R403 Foundation material R402

    Foundation walls R404

    Foundations Chapter 4 Hemp-lime Appendix BL Masonry R606, R607, R608, R610 Pollutant control R340 Roofs Chapter 8 Steel framing R505, R603, R804 Strawbale Appendix BJ Straw-clay Appendix BI Walls Chapter 6 Waste R334.1 Wood framing R502, R602, R802 Construction Documents R106, R306.3.9

  • CRC § 1.5 Medium relevance — show source text

    Exception: Under-floor spaces that meet the requirements of FEMA TB 11.

    R408.8 Under-floor vapor retarder. In Climate Zones 1A, 2A and 3A below the warm-humid line, a continuous Class I or II vapor retarder shall be provided on the exposed face of air-permeable insulation installed between the floor joists and exposed to the grade in the under-floor space. The vapor retarder shall have a maximum water vapor permeance of 1.5 perms when tested in accordance with Procedure B of ASTM E96.

    Exception: The vapor retarder shall not be required in unvented crawl spaces constructed in accordance with Section R408.3.

    Note: The International Energy Conservation Code (IECC) climate zones used by this section differ from those used by the California Energy Code to determine applicability of energy efficiency measures. Comparison of IECC and California Energy Code climate zones is shown in Table R702.7.3.

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    CALIFORNIA RESIDENTIAL CODE – MATRIX ADOPTION TABLE

    CHAPTER 5 – FLOORS

    (Matrix Adoption Tables are nonregulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)

    Adopting agency BSC BSC-
    CG    		 SFM HCD Col6 Col7 DSA Col9 Col10 OSHPD Col12 Col13 Col14 Col15 Col16 BSCC DPH AGR DWR CEC CA SL SLC
    Adopting agency BSC BSC-
    CG    		 SFM 1 2 1/AC AC SS SS/CC 1 1R 2 3 4 5 5 5 5 5 5 5 5 5
    Adopt entire chapter
    Adopt entire chapter as
    amended (amended
    sections listed below)    		 X
    Adopt only those sections
    that are listed below
    Chapter / Section
    R502.1.1 X
    R502.12.1 X
    R506.3.3.1 X

    The state agency does not adopt sections identified with the following symbol: †

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  • CRC § 1.9.1. Medium relevance — show source text

    Sections of this code identified by the abbreviation “HCD 1-AC” require specific accommodations for persons with disabilities as defined in Chapter 2 of the California Building Code. The application of such provisions shall be in conjunction with other require- ments of the Building Standards Code and apply only to newly constructed covered multifamily dwellings as defined in Chapter 2 of the California Building Code. “HCD 1-AC” applications include, but are not limited to, the following: 1. All newly constructed covered multifamily dwellings as defined in Chapter 2 of the California Building Code. 2. New common use areas as defined in Chapter 2 of the California Building Code serving existing covered multifamily dwellings. 3. Additions to existing buildings, where the addition alone meets the definition of covered multifamily dwellings as defined in Chapter 2 of the California Building Code. 4. New common use areas serving new covered multifamily dwellings. 5. Where any portion of a building’s exterior is preserved, but the interior of the building is removed, including all structural portions of floors and ceilings, the building is considered a new building for determining the application of California Build- ing Code, Chapter 11A.

    “HCD 1-AC” building standards generally do not apply to public use areas or public accommodations such as hotels and motels and public housing. Public use areas, public accommodations and public housing, as defined in Chapter 2 of the California Build- ing Code, are subject to the Division of the State Architect (DSA-AC) in Chapter 11B and are referenced in California Building Code Section 1.9.1.

    Enforcing agency— Local building department or the Department of Housing and Community Development.

    Authority cited— Health and Safety Code Sections 17040, 17920.9, 17921, 17921.5, 17921.6, 17921.10, 17922, 17922.6, 17922.12, 17922.14, 17926, 17927, 17928, 17958.12, 18938.3, 18944.11 and 19990; and Government Code Sections 12955.1 and 12955.1.1.

    Reference— Health and Safety Code Sections 17000 through 17062.5, 17910 through 17995.5, 18200 through 18700, 18860 through 18874, 18938.6, 18941, 19890, 19891, 19892 and 19960 through 19997; Civil Code Sections 1101.4, 1101.5, 1954.201 and 1954.202; Government Code Sections 12955.1 and 12955.1.1; and California Code of Regulations, Title 20, Sections 1605.1, 1605.3 and 1607.

    1.8.2.1.3 Permanent buildings in mobilehome parks and special occupancy parks.

    Application— Permanent buildings, and permanent accessory buildings or structures, constructed within mobilehome parks and special occupancy parks that are under the control and ownership of the park operator. Sections of this code which pertain to applications listed in this section are identified using the abbreviation “HCD 2.”

  • CRC § 4.420 Medium relevance — show source text

    410|≥4.420|NA|AHRI
    550/590| |Water
    source
    electri-
    cally
    operated
    positive
    displace-
    ment|<75|≤0.7885
    FL
    ≤0.6316
    IPLV.IP|≤0.7875
    FL
    ≤0.5145
    IPLV.IP|75/655|NA|NA|NA|≥3.550|NA|NA|NA|6.150|6.150| |Water
    source
    electri-
    cally
    operated
    positive
    displace-
    ment|≥75
    and
    <150|≤0.7579
    FL
    ≤0.5895
    IPLV.IP|≤0.7140
    FL
    ≤0.4620
    IPLV.IP|54/445|≥4.640|≥3.680|≥2.680|NA|≥8.330|≥6.410|≥4.420|NA|NA| |Water
    source
    electri-
    cally
    operated
    positive
    displace-
    ment|≥75
    and
    <150|≤0.7579
    FL
    ≤0.5895
    IPLV.IP|≤0.7140
    FL
    ≤0.4620
    IPLV.IP|75/655|NA|NA|NA|≥3.550|NA|NA|NA|6.150|6.150| |Water
    source
    electri-
    cally
    operated
    positive
    displace-
    ment|≥150
    and
    <300|≤0.6947
    FL
    ≤0.5684
    IPLV.IP|≤0.7140
    FL
    ≤0.4620
    IPLV.IP|54/445|≥4.640|≥3.680|≥2.680|NA|≥8.330|≥6.410|≥4.420|NA|NA| |Water
    source
    electri-
    cally
    operated
    positive
    displace-
    ment|≥150
    and
    <300|≤0.6947
    FL
    ≤0.5684
    IPLV.IP|≤0.7140
    FL
    ≤0.4620
    IPLV.IP|75/655|NA|NA|NA|≥3.550|NA|NA|NA|6.150|6.150| |Water
    source
    electri-
    cally
    operated
    positive
    displace-
    ment|≥300
    and
    <600|≤0.6421
    FL
    ≤0.5474
    IPLV.IP|≤0.6563
    FL
    ≤0.4305
    IPLV.IP|54/445|≥4.930|≥3.960|≥2.970|NA|≥8.900|≥6.

  • CRC § 233.3.4 Medium relevance — show source text

    11B- 233.3.4 Alterations. Alterations shall comply with Section 11B- 233.3.4.

    Exception: Where compliance with Section 11B- 809.2, 11B- 809.3 or 11B- 809.4 is technically infeasible, or where it is technically infeasible to provide an accessible route to a residential dwelling unit, the entity shall be permitted to alter or construct a comparable residential dwelling unit to comply with Sections 11B- 809.2 through 11B- 809.4 provided that the minimum number of residential dwelling units required by Sections 11B- 233.3.1.1 and 11B-233.3.1.3, as applicable, is satisfied.

    11B- 233.3.4.1 Alterations to vacated buildings. Where a building is vacated for the purposes of alteration, and the altered building contains more than 15 residential dwelling units, at least 5 percent of the residential dwelling units shall comply with Sections 11B- 809.2 through 11B- 809.4 and shall be on an accessible route as required by Section 11B- 206. In addition, at least 2 percent of the residential dwelling units shall comply with Section 11B- 809.5.

    11B- 233.3.4.2 Alterations to individual residential dwelling units. In individual residential dwelling units, where a bathroom or a kitchen is substantially altered, and at least one other room is altered, the requirements of Section 11B- 233.3.1 shall apply to the altered residential dwelling units until the total number of residential dwelling units complies with the minimum number required by Sections 11B- 233.3.1.1 and 11B-233.3.1.3. Residential dwelling units required to comply with Section 11B- 233.3.1.1 shall be on an accessible route as required by Section 11B- 206 .

    Exception: Where facilities contain 15 or fewer residential dwelling units, the requirements of Sections 11B- 233.3.1.1 and 11B-233.3.1.3 shall apply to the total number of residential dwelling units that are altered under a single contract, or are developed as a whole, whether or not located on a common site.

    11B-233.3.4.3 Alterations to residential dwelling units with adaptable features. The building standards for residential dwell- ing units with adaptable features do not apply to the alteration, repair, rehabilitation or maintenance of residential dwelling units constructed for first occupancy on or prior to March 13, 1991. Multifamily dwelling units with adaptable features constructed for first occupancy after March 13, 1991 shall be maintained in compliance with the accessibility standards in effect at the time of construction.

    Exception: Where any portion of a building’s exterior is preserved, but the interior of the building is removed, including all struc- tural portions of floors and ceilings and a new building is constructed behind the existing exterior, the building is considered a new building for determining the application of this chapter.

  • CRC § 6.980 Medium relevance — show source text

    900|≥6.980|≥5.000|NA|NA| |Water
    source
    electri-
    cally
    operated
    positive
    displace-
    ment|≥300
    and
    <600|≤0.6421
    FL
    ≤0.5474
    IPLV.IP|≤0.6563
    FL
    ≤0.4305
    IPLV.IP|75/655|NA|NA|NA|≥3.900|NA|NA|NA|6.850|6.850| |Water
    source
    electri-
    cally
    operated
    positive
    displace-
    ment|≥600|≤0.5895
    FL
    ≤0.5263
    IPLV.IP|≤0.6143
    FL
    ≤0.3990
    IPLV.IP|54/445|≥4.930|≥3.960|≥2.970|NA|≥8.900|≥6.980|≥5.000|NA|NA| |Water
    source
    electri-
    cally
    operated
    positive
    displace-
    ment|≥600|≤0.5895
    FL
    ≤0.5263
    IPLV.IP|≤0.6143
    FL
    ≤0.3990
    IPLV.IP|75/655|NA|NA|NA|≥3.900|NA|NA|NA|6.850|6.850| |Water
    source
    electri-
    cally
    operated
    centrifu-
    gal|<75|≤0.6421
    FL
    ≤0.5789
    IPLV.IP|≤0.7316
    FL
    ≤0.4632
    IPLV.IP|54/445|≥4.640|≥3.680|≥2.680|NA|≥8.330|≥6.410|≥4.420|NA|AHRI
    550/590| |Water
    source
    electri-
    cally
    operated
    centrifu-
    gal|<75|≤0.6421
    FL
    ≤0.5789
    IPLV.IP|≤0.7316
    FL
    ≤0.4632
    IPLV.IP|75/655|NA|NA|NA|≥3.550|NA|NA|NA|≥6.150|≥6.150| |Water
    source
    electri-
    cally
    operated
    centrifu-
    gal|≥75
    and
    <150|≤0.5895
    FL
    ≤0.5474
    IPLV.IP|≤0.6684
    FL
    ≤0.4211
    IPLV.IP|54/445|≥4.640|≥3.680|≥2.680|NA|≥8.330|≥6.410|≥4.

  • CRC § 2-2 Medium relevance — show source text

    ceiling and
    two center-bearing
    floors|2-2 × 10|6-0|2|4-9|2|4-0|2|5-8|2|4-6|2|3-10|3|5-5|2|4-3|2|3-8|3| |Roof, ceiling and
    two center-bearing
    floors|2-2 × 12|7-0|2|5-7|2|4-9|3|6-8|2|5-4|3|4-6|3|6-4|2|5-0|3|4-3|3| |Roof, ceiling and
    two center-bearing
    floors|3-2 × 8|6-4|1|5-0|2|4-3|2|6-0|1|4-9|2|4-1|2|5-8|2|4-6|2|3-10|2| |Roof, ceiling and
    two center-bearing
    floors|3-2 × 10|7-6|2|5-11|2|5-1|2|7-1|2|5-8|2|4-10|2|6-9|2|5-4|2|4-7|2| |Roof, ceiling and
    two center-bearing
    floors|3-2 × 12|8-10|2|7-0|2|5-11|2|8-5|2|6-8|2|5-8|3|8-0|2|6-4|2|5-4|3| |Roof, ceiling and
    two center-bearing
    floors|4-2 × 8|7-3|1|5-9|1|4-11|2|6-11|1|5-6|2|4-8|2|6-7|1|5-2|2|4-5|2| |Roof, ceiling and
    two center-bearing
    floors|4-2 × 10|8-8|1|6-10|2|5-10|2|8-3|2|6-6|2|5-7|2|7-10|2|6-2|2|5-3|2| |Roof, ceiling and
    two center-bearing
    floors|4-2 × 12|10-2|2|8-1|2|6-10|2|9-8|2|7-8|2|6-7|2|9-2|2|7-3|2|6-2|2|

    6-18 2025 CALIFORNIA RESIDENTIAL CODE

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

    WALL CONSTRUCTION

    |TABLE R602.7(1)—GIRDER SPANSa AND HEADER SPANSa FOR EXTERIOR BEARING WALLS
    (Maximum spans for Douglas fir-larch, hem-fir, Southern pine and spruce-pine-firb and required number of jack

  • CRC § 17062.5 Medium relevance — show source text

    Reference— Business and Professions Code, Division 5; Health and Safety Code Sections 17000 through 17062.5, 17910 through 17995.5, 18200 through 18700, 18860 through 18874, 18938.6, 18941, 19890, 19891, 19892 and 19960 through 19997; Civil Code Sections 832, 1101.4, 1101.5, 1954.201, 1954.202 and 5551; Government Code Sections 8698.4, 12955.1 and 12955.1.1; and California Code of Regulations, Title 20, Sections 1605.1, 1605.3 and 1607.

    1.8.2.1.2 Housing accessibility.

    Application— Covered multifamily dwellings as defined in Chapter 2 of the California Building Code including, but not limited to, lodg- ing houses, dormitories, timeshares, condominiums, shelters for homeless persons, congregate residences, apartments, dwellings, employee housing, factory-built housing and other types of dwellings containing sleeping accommodations with or without common toilet or cooking facilities.

    Sections of this code identified by the abbreviation “HCD 1-AC” require specific accommodations for persons with disabilities as defined in Chapter 2 of the California Building Code. The application of such provisions shall be in conjunction with other require- ments of the Building Standards Code and apply only to newly constructed covered multifamily dwellings as defined in Chapter 2 of the California Building Code. “HCD 1-AC” applications include, but are not limited to, the following: 1. All newly constructed covered multifamily dwellings as defined in Chapter 2 of the California Building Code. 2. New common use areas as defined in Chapter 2 of the California Building Code serving existing covered multifamily dwellings. 3. Additions to existing buildings, where the addition alone meets the definition of covered multifamily dwellings as defined in Chapter 2 of the California Building Code. 4. New common use areas serving new covered multifamily dwellings. 5. Where any portion of a building’s exterior is preserved, but the interior of the building is removed, including all structural portions of floors and ceilings, the building is considered a new building for determining the application of California Build- ing Code, Chapter 11A.

    “HCD 1-AC” building standards generally do not apply to public use areas or public accommodations such as hotels and motels and public housing. Public use areas, public accommodations and public housing, as defined in Chapter 2 of the California Build- ing Code, are subject to the Division of the State Architect (DSA-AC) in Chapter 11B and are referenced in California Building Code Section 1.9.1.

    Enforcing agency— Local building department or the Department of Housing and Community Development.

  • CRC § 12.4 Medium relevance — show source text

    D = Dead load.

    D i = Weight of ice in accordance with Chapter 10 of ASCE 7.

    E = Combined effect of horizontal and vertical earthquake induced forces as defined in Section 12.4 of ASCE 7.

    F = Load due to fluids with well-defined pressures and maximum heights.

    F a = Flood load in accordance with Chapter 5 of ASCE 7.

    H = Load due to lateral earth pressures, ground water pressure or pressure of bulk materials.

    L = Live load.

    L r = Roof live load. p g(asd) = Allowable stress design ground snow load. p g = Ground snow load determined from Figures 1608.2(1) through 1608.2(4) and Table 1608.2.

    2025 CALIFORNIA BUILDING CODE 16-3

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

    STRUCTURAL DESIGN

    R = Rain load.

    S = Snow load.

    T = Cumulative effects of self-straining load forces and effects.

    V asd = Allowable stress design wind speed, mph (m/s) where applicable.

    V = Basic wind speed, V, mph (m/s) determined from Figures 1609.3(1) through 1609.3(4) or ASCE 7.

    V T = Tornado speed, mph (m/s) determined from Chapter 32 of ASCE 7.

    W = Load due to wind pressure.

    W i = Wind-on-ice in accordance with Chapter 10 of ASCE 7.

    SECTION 1603—CONSTRUCTION DOCUMENTS

    1603.1 General. Construction documents shall show the material, size, section and relative locations of structural members with floor levels, column centers and offsets dimensioned. The design loads and other information pertinent to the structural design required by Sections 1603.1.1 through 1603.1.9 shall be indicated on the construction documents.

    Exception: Construction documents for buildings constructed in accordance with the conventional light-frame construction provisions of Section 2308 shall indicate the following structural design information:

    1. Floor and roof dead and live loads.

    2. Ground snow load, p g, and allowable stress design ground snow load, p g(asd) .

    3. Basic wind speed, V, mph (m/s), and allowable stress design wind speed, V asd , as determined in accordance with Section 1609.3.1 and wind exposure.

    4. Seismic design category and site class.

    5. Flood design data, if located in flood hazard areas established in Section 1612.3.

    6. Design load-bearing values of soils.

    7. Rain load data.

    [OSHPD 1R, 2 & 5] Additional requirements are included in Sections 7-115 and 7-125 of the California Administrative Code (Part 1, Title 24, C.C.R).

    1603.1.1 Floor live load. The uniformly distributed, concentrated and impact floor live load used in the design shall be indicated for floor areas. Use of live load reduction in accordance with Section 1607.13 shall be indicated for each type of live load used in the design.

  • CRC § 4-7 Medium relevance — show source text

    Linear interpolation of footing width is permitted between the soil bearing pressures in the table. Extrapolation is not permitted.
    b. The table is based on the following conditions and loads: building width, 32 feet; wall height, 9 feet; basement wall height, 8 feet; dead loads, 15 psf roof and ceiling assembly,
    10 psf floor assembly, 12 psf wall assembly; live loads, roof and ground snow loads as listed, 40 psf first floor, 30 psf second and third floors. Footing sizes are calculated
    assuming a clear span roof/ceiling assembly and an interior bearing wall or beam at each floor.
    c. Where the building width perpendicular to the wall footing is greater than 32 feet, the footing width shall be increased by 2 inches and footing depth shall be increased by 1
    inch for every 4 feet of increase in building width.
    d. Where the building width perpendicular to the wall footing is less than 32 feet, a 2-inch decrease in footing width and 1-inch decrease in footing depth is permitted for every 4
    feet of decrease in building width provided that the minimum width is 12 inches and minimum depth is 6 inches.
    SLAB
    ON GRADE
    BASEMENT
    CRAWL
    SPACE|

    2025 CALIFORNIA RESIDENTIAL CODE 4-7

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

    FOUNDATIONS

    TABLE R403.1(2)—MINIMUM WIDTH AND THICKNESS FOR CONCRETE FOOTINGS FOR
    LIGHT-FRAME CONSTRUCTION WITH BRICK VENEER OR LATH AND PLASTER (inches)a, b, c, d    		 Col2 Col3 Col4 Col5 Col6 Col7 Col8
    ** GROUND SNOW LOAD OR**
    ROOF LIVE LOAD    		 ** STORY AND TYPE OF**
    STRUCTURE WITH BRICK
    VENEER    		 ** LOAD-BEARING VALUE OF SOIL (psf)** ** LOAD-BEARING VALUE OF SOIL (psf)** ** LOAD-BEARING VALUE OF SOIL (psf)** ** LOAD-BEARING VALUE OF SOIL (psf)** ** LOAD-BEARING VALUE OF SOIL (psf)** ** LOAD-BEARING VALUE OF SOIL (psf)**
    ** GROUND SNOW LOAD OR**
    ROOF LIVE LOAD    		 ** STORY AND TYPE OF**
    STRUCTURE WITH BRICK
    VENEER    		 ** 1,500** ** 2,000** ** 2,500** ** 3,000** ** 3,500** ** 4,000**
    20 psf roof live load or 25 psf
    ground snow load    		 1 story—slab-on-grade 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
    20 psf roof live load or 25 psf
    ground snow load    		 1 story—with crawl space 15 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
    20 psf roof live load or 25 psf
    ground snow load    		 1 story—plus basement 18 × 6 14 × 6 12 ×
  • CRC § 5-12 Medium relevance — show source text

    5-12 2025 CALIFORNIA RESIDENTIAL CODE

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

    FLOORS

    TABLE R503.2.1.1(1)—ALLOWABLE SPANS AND LOADS FOR WOOD STRUCTURAL
    PANELS FOR ROOF AND SUBFLOOR SHEATHING AND COMBINATION SUBFLOOR UNDERLAYMENTa, b, c    		 Col2 Col3 Col4 Col5 Col6 Col7 Col8 Col9
    SPAN
    RATING    		 MINIMUM
    NOMINAL
    PANEL
    THICKNESS
    (inch)    		 ALLOWABLE LIVE LOAD
    (psf)h, I    		 ALLOWABLE LIVE LOAD
    (psf)h, I    		 MAXIMUM SPAN
    (inches)    		 MAXIMUM SPAN
    (inches)    		 LOAD
    (pounds per square foot,
    at maximum span)    		 LOAD
    (pounds per square foot,
    at maximum span)    		 MAXIMUM SPAN
    (inches)
    SPAN
    RATING    		 MINIMUM
    NOMINAL
    PANEL
    THICKNESS
    (inch)    		 Span
    @ 16″ o.c.    		 Span
    @ 24″ o.c.    		 With edge
    supportd    		 Without edge
    support    		 Total load Live load Live load
    Sheathinge Sheathinge Rooff Rooff Rooff Rooff Subfloorj
    16/0 3/8 30 — 16 16 40 30 0
    20/0 3/8 50 — 20 20 40 30 0
    24/0 3/8 100 30 24 20g 40 30 0
    24/16 7/16 100 40 24 24 50 40 16
    32/16 15/32, 1/2 180 70 32 28 40 30 16h
    40/20 19/32, 5/8 305 130 40 32 40 30 20h, i
    48/24 23/32, 3/4 — 175 48 36 45 35 24
    60/32 7/8 — 305 60 48 45 35 32
    Underlayment,
    C-C plugged, single floore    		 Underlayment,
    **C-C plugged,
  • CRC § 0.0254 Medium relevance — show source text

    Deflection criteria:L/360 for live loads,L/240 for total loads.
    b. Design load assumptions:
    Second-floor dead load is 10 psf.
    Roof/ceiling dead load is 12 psf.
    Second-floor live load is 40 psf.
    Third floor live load is 30 psf.
    Attic live load is 10 psf.
    c. Building width is in the direction of horizontal framing members supported by the header.
    d. Minimum Grade 33 ksi steel shall be used for 33 mil and 43 mil thicknesses. Minimum Grade 50 ksi steel shall be used for 54 and 68 mil thicknesses.|For SI: 1 mil = 0.0254 mm, 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 pound per square inch = 6.895 kPa, 1 ksi = 1,000 psi = 6.895 MPa.
    a. Deflection criteria:L/360 for live loads,L/240 for total loads.
    b. Design load assumptions:
    Second-floor dead load is 10 psf.
    Roof/ceiling dead load is 12 psf.
    Second-floor live load is 40 psf.
    Third floor live load is 30 psf.
    Attic live load is 10 psf.
    c. Building width is in the direction of horizontal framing members supported by the header.
    d. Minimum Grade 33 ksi steel shall be used for 33 mil and 43 mil thicknesses. Minimum Grade 50 ksi steel shall be used for 54 and 68 mil thicknesses.|For SI: 1 mil = 0.0254 mm, 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 pound per square inch = 6.895 kPa, 1 ksi = 1,000 psi = 6.895 MPa.
    a. Deflection criteria:L/360 for live loads,L/240 for total loads.
    b. Design load assumptions:
    Second-floor dead load is 10 psf.
    Roof/ceiling dead load is 12 psf.
    Second-floor live load is 40 psf.
    Third floor live load is 30 psf.
    Attic live load is 10 psf.
    c. Building width is in the direction of horizontal framing members supported by the header.
    d. Minimum Grade 33 ksi steel shall be used for 33 mil and 43 mil thicknesses. Minimum Grade 50 ksi steel shall be used for 54 and 68 mil thicknesses.|

    2025 CALIFORNIA RESIDENTIAL CODE 6-83

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

    WALL CONSTRUCTION

    TRACK

    TRACK

    TRACK

    TRACK OR C-SHAPE ATTACH WITH NO. 8 SCREWS (MINIMUM DEPTH = HEADER DEPTH MINUS ½ INCH)

    KING STUD(S)

    JACK STUD(S)

    NO. 8 SCREWS THROUGH SHEATHING TO EACH JACK AND KING STUD

    AT 12 ON CENTER ˝

    STRUCTURAL SHEATHING

    FIGURE R603.6(1)—BOX BEAM HEADER

    For SI: 1 inch = 25.4 mm.

  • CRC § 25.4 Medium relevance — show source text

    Applicable to all grades of sanded exterior-type plywood.|For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kPa.
    a. Plywood continuous over two or more spans and face grain perpendicular to supports. Unsupported edges shall be tongue-and-groove or blocked except where nominal1/4-
    inch-thick wood panel-type underlayment, fiber-cement underlayment or3/4-inch wood finish floor is used. Fiber-cement underlayment shall comply with ASTM C1288 or ISO
    8336 Category C. Allowable uniform live load at maximum span based on deflection of1/360 of span is 100 psf.
    b. Applicable to all grades of sanded exterior-type plywood.|

    2025 CALIFORNIA RESIDENTIAL CODE 5-13

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

    FLOORS

    R503.2.2 Allowable spans. The maximum allowable span for wood structural panels used as subfloor or combination subfloor underlayment shall be as set forth in Table R503.2.1.1(1), or APA E30. The maximum span for sanded plywood combination subfloor underlayment shall be as set forth in Table R503.2.1.1(2).

    R503.2.3 Installation. Wood structural panels used as subfloor or combination subfloor underlayment shall be attached to wood framing in accordance with Table R602.3(1) and shall be attached to cold-formed steel framing in accordance with Table R505.3.1(2).

    R503.3 Particleboard.

    R503.3.1 Identification and grade. Particleboard shall conform to ANSI A208.1 and shall be so identified by a grade mark or certificate of inspection issued by an approved agency. R503.3.2 Floor underlayment. Particleboard floor underlayment shall conform to Type PBU and shall be not less than [1] / 4 inch (6.4 mm) in thickness.

    R503.3.3 Installation. Particleboard underlayment shall be installed in accordance with the recommendations of the manufacturer and attached to framing in accordance with Table R602.3(1).

    SECTION R504—PRESSURE PRESERVATIVE-TREATED WOOD FLOORS (ON GROUND)

    R504.1 General. Pressure preservative-treated wood basement floors and floors on ground shall be designed to withstand axial forces and bending moments resulting from lateral soil pressures at the base of the exterior walls and floor live and dead loads. Floor framing shall be designed to meet joist deflection requirements in accordance with Section R301.

    R504.1.1 Unbalanced soil loads. Unless special provision is made to resist sliding caused by unbalanced lateral soil loads, wood basement floors shall be limited to applications where the differential depth of fill on opposite exterior foundation walls is 2 feet (610 mm) or less.

    R504.1.2 Construction. Joists in wood basement floors shall bear tightly against the narrow face of studs in the foundation wall or directly against a band joist that bears on the studs. Plywood subfloor shall be continuous over lapped joists or over butt joints between in-line joists. Sufficient blocking shall be provided between joists to transfer lateral forces at the base of the end walls into the floor system.

  • CRC § 4-8 Medium relevance — show source text

    Extrapolation is not permitted.
    b. The table is based on the following conditions and loads: building width, 32 feet; wall height, 9 feet; basement wall height, 8 feet; dead loads, 15 psf roof and ceiling assembly,
    10 psf floor assembly, 12 psf wall assembly; live loads, roof and ground snow loads as listed, 40 psf first floor, 30 psf second and third floors. Footing sizes are calculated
    assuming a clear span roof/ceiling assembly and an interior bearing wall or beam at each floor.
    c. Where the building width perpendicular to the wall footing is greater than 32 feet, the footing width shall be increased by 2 inches and footing depth shall be increased by 1
    inch for every 4 feet of increase in building width.
    d. Where the building width perpendicular to the wall footing is less than 32 feet, a 2-inch decrease in footing width and 1-inch decrease in footing depth is permitted for every 4
    feet of decrease in building width provided that the minimum width is 12 inches and minimum depth is 6 inches.
    SLAB
    ON GRADE
    BASEMENT
    CRAWL
    SPACE|

    4-8 2025 CALIFORNIA RESIDENTIAL CODE

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

    FOUNDATIONS

    TABLE R403.1(3)—MINIMUM WIDTH AND THICKNESS FOR CONCRETE FOOTINGS WITH
    CAST-IN-PLACE CONCRETE OR PARTIALLY GROUTED MASONRY WALL CONSTRUCTION (inches)a, b, c, d    		 Col2 Col3 Col4 Col5 Col6 Col7 Col8
    ** GROUND SNOW LOAD OR**
    ROOF LIVE LOAD    		 ** STORY AND TYPE OF**
    STRUCTURE WITH CMU OR
    CONCRETE    		 ** LOAD-BEARING VALUE OF SOIL (psf)** ** LOAD-BEARING VALUE OF SOIL (psf)** ** LOAD-BEARING VALUE OF SOIL (psf)** ** LOAD-BEARING VALUE OF SOIL (psf)** ** LOAD-BEARING VALUE OF SOIL (psf)** ** LOAD-BEARING VALUE OF SOIL (psf)**
    ** GROUND SNOW LOAD OR**
    ROOF LIVE LOAD    		 ** STORY AND TYPE OF**
    STRUCTURE WITH CMU OR
    CONCRETE    		 ** 1,500** ** 2,000** ** 2,500** ** 3,000** 3,500 ** 4,000**
    20 psf roof live load or 25 psf
    ground snow load    		 1 story—slab-on-grade 13 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
    20 psf roof live load or 25 psf
    ground snow load    		 1 story—with crawl space 16 × 6 12 × 6 12 × 6 12 × 6 12 × 6 12 × 6
    20 psf roof live load or 25 psf
    ground snow load    		 1 story—plus basement 19 × 6 14 × 6 12 × 6 12 × 6 12 × 6 12 ×
  • CRC § 1608.2 Medium relevance — show source text

    L = Live load.

    L r = Roof live load.

    p g(asd) = Allowable stress design ground snow load.

    p g = Ground snow load determined from Figures 1608.2(1) through 1608.2(4) and Table 1608.2.

    R = Rain load.

    S = Snow load.

    T = Cumulative effects of self-straining load forces and effects.

    V asd = Allowable stress design wind speed, mph (m/s) where applicable.

    V = Basic wind speed, V, mph (m/s) determined from Figures 1609 A .3(1) through 1609 A .3(4) or ASCE 7.

    V T = Tornado speed, mph (m/s) determined from Chapter 32 of ASCE 7.

    W = Load due to wind pressure.

    W i = Wind-on-ice in accordance with Chapter 10 of ASCE 7.

    2025 CALIFORNIA BUILDING CODE 16A-3

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

    STRUCTURAL DESIGN

    SECTION 1603 A —CONSTRUCTION DOCUMENTS

    1603 A .1 General. Construction documents shall show the material, size, section and relative locations of structural members with floor levels, column centers and offsets dimensioned. The design loads and other information pertinent to the structural design required by Sections 1603 A .1.1 through 1603 A .1.10 shall be indicated on the construction documents.

    Exception: Construction documents for buildings constructed in accordance with the conventional light-frame construction provisions of Section 2308 shall indicate the following structural design information:

    1. Floor and roof dead and live loads.

    2. Ground snow load, p g, and allowable stress design ground snow load, p g(asd) .

    3. Basic wind speed, V, mph (m/s), and allowable stress design wind speed, V asd , as determined in accordance with Section 1609 A .3.1 and wind exposure.

    4. Seismic design category and site class.

    5. Flood design data, if located in flood hazard areas established in Section 1612 A .3.

    6. Design load-bearing values of soils.

    7. Rain load data.

    [DSA-SS] Additional requirements are included in Section 4-210 and 4-317 of the California Administrative Code (Part 1, Title 24, C.C.R).

    [OSHPD 1] Additional requirements are included in Section 7-115 and 7-125 of the California Administrative Code.

    1603 A .1.1 Floor live load. The uniformly distributed, concentrated and impact floor live load used in the design shall be indicated for floor areas. Use of live load reduction in accordance with Section 1607 A .13 shall be indicated for each type of live load used in the design.

  • CRC § 0.0254 Medium relevance — show source text

    Building width is in the direction of horizontal framing members supported by the header.
    d. Minimum Grade 33 ksi steel shall be used for 33 mil and 43 mil thicknesses. Minimum Grade 50 ksi steel shall be used for 54 and 68 mil thicknesses.|For SI: 1 mil = 0.0254 mm, 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 pound per square inch = 6.895 kPa, 1 ksi = 1,000 psi = 6.895 MPa.
    a. Deflection criteria:L/360 for live loads,L/240 for total loads.
    b. Design load assumptions:
    Second-floor dead load is 10 psf.
    Roof/ceiling dead load is 12 psf.
    Second-floor live load is 40 psf.
    Third floor live load is 30 psf.
    Attic live load is 10 psf.
    c. Building width is in the direction of horizontal framing members supported by the header.
    d. Minimum Grade 33 ksi steel shall be used for 33 mil and 43 mil thicknesses. Minimum Grade 50 ksi steel shall be used for 54 and 68 mil thicknesses.|

    6-82 2025 CALIFORNIA RESIDENTIAL CODE

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

    WALL CONSTRUCTION

    TABLE R603.6(6)—BOX-BEAM AND BACK-TO-BACK HEADER SPANS
    (HEADERS SUPPORTING TWO FLOORS, ROOF AND CEILING)a, b, d    		 Col2 Col3 Col4 Col5 Col6 Col7 Col8 Col9 Col10 Col11
    MEMBER
    DESIGNATION    		 GROUND SNOW LOAD
    (50 psf)    		 GROUND SNOW LOAD
    (50 psf)    		 GROUND SNOW LOAD
    (50 psf)    		 GROUND SNOW LOAD
    (50 psf)    		 GROUND SNOW LOAD
    (50 psf)    		 GROUND SNOW LOAD
    (70 psf)    		 GROUND SNOW LOAD
    (70 psf)    		 GROUND SNOW LOAD
    (70 psf)    		 GROUND SNOW LOAD
    (70 psf)    		 GROUND SNOW LOAD
    (70 psf)
    MEMBER
    DESIGNATION    		 Building widthc
    (feet)    		 Building widthc
    (feet)    		 Building widthc
    (feet)    		 Building widthc
    (feet)    		 Building widthc
    (feet)    		 Building widthc
    (feet)    		 Building widthc
    (feet)    		 Building widthc
    (feet)    		 Building widthc
    (feet)    		 Building widthc
    (feet)
    MEMBER
    DESIGNATION    		 24 **28
  • CRC § 3.1 Medium relevance — show source text

    Exception: Construction documents for buildings constructed in accordance with the conventional light-frame construction provisions of Section 2308 shall indicate the following structural design information:

    1. Floor and roof dead and live loads.

    2. Ground snow load, p g, and allowable stress design ground snow load, p g(asd) .

    3. Basic wind speed, V, mph (m/s), and allowable stress design wind speed, V asd , as determined in accordance with Section 1609 A .3.1 and wind exposure.

    4. Seismic design category and site class.

    5. Flood design data, if located in flood hazard areas established in Section 1612 A .3.

    6. Design load-bearing values of soils.

    7. Rain load data.

    [DSA-SS] Additional requirements are included in Section 4-210 and 4-317 of the California Administrative Code (Part 1, Title 24, C.C.R).

    [OSHPD 1] Additional requirements are included in Section 7-115 and 7-125 of the California Administrative Code.

    1603 A .1.1 Floor live load. The uniformly distributed, concentrated and impact floor live load used in the design shall be indicated for floor areas. Use of live load reduction in accordance with Section 1607 A .13 shall be indicated for each type of live load used in the design.

    1603 A .1.2 Roof live load. The roof live load used in the design shall be indicated for roof areas. 1603 A .1.3 Roof snow load data. The ground snow load, p g, shall be indicated. In areas where the ground snow load, p g , exceeds 15 pounds per square foot (psf) (0.72 kN/m [2] ), the following additional information shall also be provided, regardless of whether snow loads govern the design of the roof:

    1. Flat-roof snow load, p f .
    2. Snow exposure factor, C e .
    3. Risk category.
    4. Thermal factor, C t .
    5. Slope factor(s), C s .
    6. Drift surcharge load(s), p d , where the sum of p d and p f exceeds 30 psf (1.44 kN/m [2] ) .
    7. Width of snow drift(s), w .
    8. Winter wind parameter for snow drift, W 2 .

    1603 A .1.4 Wind and tornado design data. The following information related to wind loads and, where required by Section 1609 A .5, tornado loads shall be shown, regardless of whether wind or tornado loads govern the design of the lateral force-resisting system of the structure:

    1. Basic wind speed, V, mph (m/s), tornado speed, V T, mph (m/s), and allowable stress design wind speed, V asd, mph (m/s), as determined in accordance with Section 1609 A .3.1.
  • CRC § 2.5 Medium relevance — show source text

    R507.2.5 Alternate materials. Alternative materials, including glass and metals, shall be permitted.

    R507.3 Footings. Decks shall be supported on concrete footings or other approved structural systems designed to accommodate all loads in accordance with Section R301. Deck footings shall be sized to carry the imposed loads from the deck structure to the ground as shown in Figure R507.3.

    Exceptions:

    1. Footings shall not be required for free-standing decks consisting of joists directly supported on grade over their entire length.
    2. Footings shall not be required for free-standing decks that meet all of the following criteria: 2.1. The joists bear directly on precast concrete pier blocks at grade without support by beams or posts. 2.2. The area of the deck does not exceed 200 square feet (18.6 m [2] ). 2.3. The walking surface is not more than 20 inches (508 mm) above grade at any point within 36 inches (914 mm) measured horizontally from the edge.

    2025 CALIFORNIA RESIDENTIAL CODE 5-27

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

    FLOORS

    FIGURE R507.3—DECK POSTS TO DECK FOOTING CONNECTION

    MANUFACTURED POST CONNECTOR

    4″ GRAVEL

    NOTE:

    POSTS MUST BE CENTERED ON OR IN FOOTING
    For SI: 1 inch = 25.4 mm.
    R507.3.1 Minimum size. The minimum size of deck footings shall be in accordance with Table R507.3.1, based on the tributary
    area and allowable soil-bearing pressure in accordance with Table R401.4.1(1).    		 Col2 Col3 Col4 Col5 Col6 Col7 Col8 Col9 Col10 Col11
    TABLE R507.3.1—MINIMUM FOOTING SIZE FOR DECKS TABLE R507.3.1—MINIMUM FOOTING SIZE FOR DECKS TABLE R507.3.1—MINIMUM FOOTING SIZE FOR DECKS TABLE R507.3.1—MINIMUM FOOTING SIZE FOR DECKS TABLE R507.3.1—MINIMUM FOOTING SIZE FOR DECKS TABLE R507.3.1—MINIMUM FOOTING SIZE FOR DECKS TABLE R507.3.1—MINIMUM FOOTING SIZE FOR DECKS TABLE R507.3.1—MINIMUM FOOTING SIZE FOR DECKS TABLE R507.3.1—MINIMUM FOOTING SIZE FOR DECKS TABLE R507.3.1—MINIMUM FOOTING SIZE FOR DECKS TABLE R507.3.1—MINIMUM FOOTING SIZE FOR DECKS
    LIVE OR
    GROUND
    SNOW
    LOADb
    (psf)
    TRIBUTARY
    AREAe
    (ft2)    		 LOAD-BEARING VALUE OF SOILSa, c, d (psf) LOAD-BEARING VALUE OF SOILSa, c, d (psf) LOAD-BEARING VALUE OF SOILS**_a, c,
  • CRC § 7.2.1 Medium relevance — show source text

    BJ106.10 Support of plaster skins. Plaster skins on strawbale structural walls shall be continuously supported along their bottom edge. Acceptable supports include: a concrete or masonry stem wall, a concrete slab-on-grade, a wood-framed floor in accordance with Figure BJ105.1(2) and an approved engineered design or a steel angle anchored with an approved engineered design. A weep screed as described in Section R703.7.2.1 is not an acceptable support.

    BJ106.11 Transfer of loads to and from plaster skins. Where plastered strawbale walls are used to support superimposed vertical loads, such loads shall be transferred to the plaster skins by continuous direct bearing in accordance with Figure BJ105.1(3) or by an approved engineered design. Where plastered strawbale walls are used to resist in-plane lateral loads, such loads shall be transferred to the reinforcing mesh from the structural member or assembly above in accordance with Figure BJ105.1(3) or BJ105.1(4) and to the sill plate in accordance with Figure BJ105.1(1) or BJ105.1(2) and with Table BJ106.13(1).

    APPENDIX BJ-12 2025 CALIFORNIA RESIDENTIAL CODE

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

    APPENDIX BJ — STRAWBALE CONSTRUCTION

    BJ106.12 Load-bearing walls. Bearing capacities for plastered strawbale walls used as load-bearing walls in one-story buildings to support vertical loads imposed in accordance with Section R301 shall be in accordance with Table BJ106.12.

    TABLE BJ106.12—ALLOWABLE SUPERIMPOSED VERTICAL LOADS (LBS/FOOT) FOR PLASTERED LOAD-BEARING STRAWBALE WALLS Col2 Col3 Col4 Col5 Col6
    WALL
    DESIGNATION    		 ** PLASTERa (both sides)** ** PLASTERa (both sides)** MESHb STAPLESc ALLOWABLE
    BEARING CAPACITYd
    (plf)
    WALL
    DESIGNATION    		 Type Thickness
    (minimum in inches each side)    		 Thickness
    (minimum in inches each side)    		 Thickness
    (minimum in inches each side)    		 Thickness
    (minimum in inches each side)
    A Clay 11/2 None required None required 400
    B Soil-cement 1 Required Required 800
    C Limee 7/8 Required Required 500
    D Cement-Lime 7/8 Required Required 800
    E Cement 7/8 Required Required 800
    For SI: 1 inch = 25.4 mm, 1 pound per foot = 14.5939 N/m.
    a. Plasters shall conform to Sections BJ104.4.3 through BJ104.4.9, BJ106.7 and BJ106.10.
    b. Any metal mesh allowed by this appendix and installed in accordance with Section BJ106.9.
    c. In accordance with Section BJ106.9.2, except as required to transfer roof loads to the plaster skins in accordance with Section BJ106.11.
    d.

Frequently asked questions

When does Chapter 5 NOT apply?

Chapter 5 applies to building floors as stated in § R501.1; if your condition is atypical (special materials, unusual loads, or conditions outside the tables’ assumptions), you must use an engineered design per § R301 rather than the prescriptive Chapter 5 tables. § R501.1, § R301

Are attic spaces always excluded from Chapter 5?

No — attics that are used to house mechanical or plumbing fixtures and equipment are explicitly included in Chapter 5 applicability. § R501.1

Can I always use the span tables in Chapter 5 to size joists and sheathing?

Only when your project matches the table’s stated assumptions (loads, spacing, materials and deflection limits). The tables include notes with those assumptions — verify them before using the table; otherwise provide engineered calculations. § R503

Do decks fall under Chapter 5?

Yes — wood‑framed exterior decks and their attachment to the building are in Chapter 5 (Section R507). Decks must be designed for the loading requirements in § R301.5 or the ground snow load, whichever controls. § R507.1

What if my floor sits directly on grade (on‑ground floor)?

Floors on the ground are covered (see § R504 for pressure‑preservative treated wood floors and § R506 for concrete slabs). There are specific site preparation, moisture and base requirements in those sections. § R504, § R506

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