CRC · California Residential Code
What loads and load paths apply to residential floors?
Your floors must be sized for the CRC-prescribed loads (e.g., 40 psf first-floor, 30 psf upper floors, and about 10 psf dead load in many tables) and must provide a continuous, verifiable path to transfer those loads through the framing to the foundation; check § R501.2 and the design assumptions in § R301.
Last reviewed: July 6, 2026
What the code requires — 2-4 sentences
Floors must be designed to carry all applicable loads and to provide a continuous load path that transfers those loads to the supporting elements and foundation — this is the fundamental rule in § R501.2 (floors must accommodate loads per § R301) and § R301.1 (buildings must be constructed to safely support dead, live, snow, wind and seismic loads). § R501.2 and § R301.1 together require that the designer identify the governing loads and provide members and connections sized and arranged to transmit those loads to the foundation.
The single most important rule: floors must be designed for the loads listed in § R301 and must have a continuous, verifiable path to transfer those loads to the foundation (see § R501.2 and § R301.1).
Requirements in detail
What "loads" apply to residential floors
- Dead load — the weight of the permanent materials of the floor assembly (framing, sheathing, finish). See § R301.4 for the dead-load requirement reference.
- Live load — the imposed (occupancy) load the floor must carry. Typical prescriptive values used in CRC tables include 40 psf for first-floor living areas and 30 psf for second/upper floors; 10 psf is used for attics (storage/no-storage distinctions appear in other tables). These numeric assumptions appear in CRC design-assumption tables referenced by § R301.
- Snow, wind and seismic effects — where applicable these loads must be included per § R301 (snow loads and ground-snow maps, wind and seismic design criteria). Floors may be affected by snow (as tributary loads, drift), and must participate in lateral load-resisting systems (diaphragms/collectors) as required by R301/ASCE references.
- Concentrated loads and special loads — e.g., concentrated mechanical equipment, built-in tubs, stair openings; trusses and engineered members must have their controlling concentrated loads shown on truss drawings. See R502 truss design requirements.
What "load path" means for floors
- A continuous load path is required from the point where a load acts on the floor (decking, furniture, guardrail reaction, etc.) through joists/girders, to supporting walls or beams, to foundations. This continuous-path requirement is mandated by § R301.1 and reiterated for floors by § R501.2.
- Guard and deck loads must be transferred into the deck framing and to the joists/beams with connections that do not rely on end-grain withdrawal alone; see § R507.10 for guard loading and attachment specifics.
- Trussed members must show reactions and design loads on shop drawings to allow verification of the load path into bearing supports and connections (see R502.12.4).
Decision‑relevant numeric values (quick reference)
| Load or limit | Typical value (prescriptive) | Why it matters | Code Reference |
|---|---|---|---|
| First-floor live load | 40 psf | Governs sizing of joists/girders for living areas | § R301 (design assumptions in CRC tables) — |
| Upper-floor live load | 30 psf | Used for second-story living areas in prescriptive tables | § R301 (design assumptions in CRC tables) — |
| Attic live load (storage/no-storage) | 10 psf | Applies to attics where storage is expected | § R301 (design assumptions) — |
| Typical floor dead load (assumption) | 10 psf | Used in many prescriptive tables for member sizing | § R301 (design assumptions) — |
| Deflection guidance (common table value) | L/240 (max deflection used in many tables) | Limits serviceability; varies by table and member type | CRC tables with design assumptions — |
| Continuous load path required | — | Always required; required by § R301.1 and § R501.2 | § R301.1, § R501.2 — |
(These values are the CRC prescriptive design assumptions visible in the code tables. For engineered designs, use the specific loads and combinations required by the engineer and ASCE/IBC references invoked by the code.)
Exceptions & special cases
- Prescriptive tables supply typical load assumptions and deflection limits, but where loads exceed those assumptions (heavy equipment, concentrated loads, rooftop structures, unusual occupancies), the code requires engineered design — see § R301.1 for alternative/engineered provisions.
- Decks and guards: deck guard loads must be carried to joists with a continuous path; specific hold-downs and attachment details are provided in § R507.10 for deck guard support. If guard posts are 4×4 wood posts supporting top-of-guard loads, notching is restricted.
- Trusses and prefabricated members: truss drawings must show all design loads and reactions (top/bottom chord live & dead, concentrated loads) so the bearing and connections can be designed and verified. See R502.12.4.
Common mistakes
- Relying on finish materials (tile, cabinetry) to carry or distribute structural load instead of sizing the framing for the specified live/dead loads listed in the CRC tables. The CRC's load assumptions (e.g., 40 psf first-floor live) are the baseline — see § R301 tables.
- Breaking the load path at a ledger, unsupported overhang, or by using fasteners in end grain only. The code requires a verifiable continuous path per § R301.1 and § R501.2.
- Applying live‑load reduction incorrectly (or not at all) — CRC prescriptive tables use conservative uniform live loads (40/30 psf); reduction rules (from the CBC/ASCE references) should only be used where permitted and shown on design documents. (See the building-code live-load provisions that CRC references.)
- Forgetting concentrated or imposed loads (HVAC, tubs) when sizing members — truss/girder drawings and shop drawings must show concentrated loads and reactions (R502.12.4).
Worked example — two‑story living room bearing wall load
Scenario: A simple two-story town house. A continuous bearing interior wall supports the ends of 12‑ft joists on the second floor. The living room above is 20 ft × 15 ft; the joists run the 15‑ft span and bear on the wall along a 15‑ft line.
- Use CRC prescriptive loads (from design-assumption tables): second-floor live load = 30 psf, second-floor dead load = 10 psf.
- Tributary area to the bearing wall: the wall supports joist ends for half the span on each side. If the joists are spaced 16 inches o.c. and the wall supports joists along its length, compute load per linear foot. Simpler approach: calculate total uniform load on the 20×15 room, then find portion carried by the wall (half the tributary width per joist).
- Total uniform load on second-floor area = (dead + live) × area = (10 + 30) psf × (20 ft × 15 ft) = 40 psf × 300 ft² = 12,000 lb.
- If the wall is continuous under all joist ends and carries half the tributary area (i.e., half the floor area tributary to that wall line), assume the wall carries roughly half the load = 6,000 lb. (Exact tributary-area method depends on joist layout; verify in project framing plan.)
- Design implication: that 6,000 lb vertical reaction must be transferred down through studs or posts and into the foundation — connections at the framing, any girder or beam sizing, and foundation bearing must be checked. This is the required continuous load path per § R501.2 and § R301.1.
Notes: this numeric example uses CRC prescriptive loads; actual projects may require load reductions, concentrated-load checks, or engineered verification if nonstandard loading or longer spans exist. The code tables and truss/engineered documents must be checked for exact reactions.
Related provisions
- § R501.2 — Floor construction shall accommodate loads per § R301 and transmit resulting loads to supports.
- § R301.1 — Buildings and parts shall be constructed to safely support dead, live, snow, wind and seismic loads; complete load path required.
- § R301.4 — Dead loads (index/reference to dead‑load provisions).
- § R301 (design assumptions and tables) — prescriptive values (e.g., 40 psf first-floor live, 30 psf second-floor live, 10 psf floor dead) used in CRC tables.
- § R502.12.4 — Truss design drawing requirements (must show design loads, reactions).
- § R503 — Floor sheathing and allowable spans (affects load distribution and deflection).
- § R507.10 — Deck guard support and transfer of guard loads to deck framing and joists.
Code references
Grounded in the retrieved California Residential Code — click a citation to read the verbatim passage:
CRC § 4-8 High 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
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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, dCol2 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 load1 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 load1 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 load1 story—plus basement 19 × 6 14 × 6 12 × 6 12 × 6 12 × 6 12 × 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 § 2.3.1 Medium relevance — show source text
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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
Court Emergency escape and rescue openings R319.1, R319.2.4 Means of egress R318.1 Natural light R325.1.1 Covering Exterior R703
Interior R702 Roof Chapter 9 Wall Chapter 7 Crawl Space R408
Access R408.4
Damper Fireplace R1001.7.1 Dampproofing R406 Day Care Appendix BD Defined R202 Large family day-care homes R336 Dead Loads R301.4
Decay Protection against R304 Deck
Attachment R318.5 Supported by exterior wall R507 Wood/plastic composite boards R507.2.2
Definitions Building R202 Mechanical system R202 Plumbing R202 Design Criteria R301 Alternative provisions R301.1.1 Application R301.1 Climatic and geographic R301.2 Dead load R301.4
Deflection R301.6 Engineered design R301.1.3
Accessibility R322 Accessory Dwelling Unit R202 Authority to Enforce Automatic Fire Sprinkler Systems 1.8.9.1, R313.2 Accessory Structure Elevations R306.3.2
Energy R330.5 Exterior walls R302.1
Scope R101.2 Addition (see also Existing Buildings) Carbon monoxide alarms R311.2.2 Change of occupancy R110.1 Construction R302.2.3
CRC § 14-0 Medium relevance — show source text
pinef
Red pinef|6 × 6|14-0|14-0|14-0|14-0|14-0|9-9|NP|NP| |60 ground
snow load|Redwoodf
Western cedarsf
Ponderosa pinef
Red pinef|8 × 8|14-0|14-0|14-0|14-0|14-0|14-0|14-0|14-0|5-30 2025 CALIFORNIA RESIDENTIAL CODE
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FLOORS
TABLE R507.4—DECK POST HEIGHT—continued Col2 Col3 Col4 Col5 Col6 Col7 Col8 Col9 Col10 Col11 LOADS
(psf)****bPOST SPECIESc POST
SIZEdTRIBUTARY AREA (ft2)g, h TRIBUTARY AREA (ft2)g, h TRIBUTARY AREA (ft2)g, h TRIBUTARY AREA (ft2)g, h TRIBUTARY AREA (ft2)g, h TRIBUTARY AREA (ft2)g, h TRIBUTARY AREA (ft2)g, h TRIBUTARY AREA (ft2)g, h LOADS
(psf)****bPOST SPECIESc POST
SIZEd20 40 60 80 100 120 140 160 LOADS
(psf)****bPOST SPECIESc POST
SIZEdMAXIMUM DECK POST HEIGHTa (feet-inches) MAXIMUM DECK POST HEIGHTa (feet-inches) MAXIMUM DECK POST HEIGHTa (feet-inches) MAXIMUM DECK POST HEIGHTa (feet-inches) MAXIMUM DECK POST HEIGHTa (feet-inches) MAXIMUM DECK POST HEIGHTa (feet-inches) MAXIMUM DECK POST HEIGHTa (feet-inches) MAXIMUM DECK POST HEIGHTa (feet-inches) 70 ground
snow loadSouthern pine 4 × 4 14-0 10-2 8-2 6-11 5-11 5-2 4-4 3-4 70 ground
snow loadSouthern pine 4 × 6 14-0 12-11 10-5 8-11 7-10 7-1 6-5 5-10 70 ground
snow loadSouthern pine 6 × 6 14-0 14-0 14-0 14-0 14-0 12-9 10-11 8-7 70 ground
snow loadSouthern pine 8 × CRC § 12.3 Medium relevance — show source text
R502.12.3 Alterations to trusses. Truss members and components shall not be cut, notched, spliced or otherwise altered in any way without the approval of a registered design professional. Alterations resulting in the addition of load that exceeds the design load for the truss, shall not be permitted without verification that the truss is capable of supporting the additional loading.
R502.12.4 Truss design drawings. Truss design drawings, prepared in compliance with Section R502.12.1, shall be submitted to the building official and approved prior to installation. Truss design drawings shall be provided with the shipment of trusses delivered to the job site. Truss design drawings shall include, at a minimum, the information specified as follows:
- Slope or depth, span and spacing.
- Location of all joints.
- Required bearing widths.
- Design loads as applicable: 4.1. Top chord live load. 4.2. Top chord dead load.
4.3. Bottom chord live load.
4.4. Bottom chord dead load.
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FLOORS
4.5. Concentrated loads and their points of application. 4.6. Controlling wind and earthquake loads. 5. Adjustments to lumber and joint connector design values for conditions of use.
Each reaction force and direction.
Joint connector type and description, such as size, thickness or gage, and the dimensioned location of each joint connector except where symmetrically located relative to the joint interface.
Lumber size, species and grade for each member.
Connection requirements for: 9.1. Truss-to-girder-truss. 9.2. Truss ply-to-ply. 9.3. Field splices.
Calculated deflection ratio, maximum description for live and total load, or both.
Maximum axial compression forces in the truss members to enable the building designer to design the size, connections and anchorage of the permanent continuous lateral bracing. Forces shall be shown on the truss drawing or on supplemental documents.
Required permanent truss member bracing location.
R502.13 Draftstopping required. Draftstopping shall be provided in accordance with Section R302.12.
R502.14 Fireblocking required. Fireblocking shall be provided in accordance with Section R302.11.
SECTION R503—FLOOR SHEATHING
R503.1 Lumber sheathing. Maximum allowable spans for lumber used as floor sheathing shall conform to Tables R503.1, R503.2.1.1(1) and R503.2.1.1(2).
CRC § 14-0 Medium relevance — show source text
pine|4 × 6|14-0|14-0|12-6|10-9|9-6|8-7|7-10|7-3| |50 ground
snow load|Southern pine|6 × 6|14-0|14-0|14-0|14-0|14-0|14-0|14-0|13-4| |50 ground
snow load|Southern pine|8 × 8|14-0|14-0|14-0|14-0|14-0|14-0|14-0|14-0| |50 ground
snow load|Douglas fire Hem-
fireSpruce-pine-fire|4 × 4|14-0|12-1|9-8|8-2|7-1|6-2|5-3|4-2| |50 ground
snow load|Douglas fire Hem-
fireSpruce-pine-fire|4 × 6|14-0|14-0|12-4|10-7|9-4|8-4|7-7|6-11| |50 ground
snow load|Douglas fire Hem-
fireSpruce-pine-fire|6 × 6|14-0|14-0|14-0|14-0|14-0|14-0|14-0|12-10| |50 ground
snow load|Douglas fire Hem-
fireSpruce-pine-fire|8 × 8|14-0|14-0|14-0|14-0|14-0|14-0|14-0|14-0| |50 ground
snow load|Redwoodf
Western cedarsf-
Ponderosa pinef
Red pinef|4 × 4|14-0|11-8|9-0|6-10|3-7|NP|NP|NP| |50 ground
snow load|Redwoodf
Western cedarsf-
Ponderosa pinef
Red pinef|4 × 6|14-0|14-0|12-0|10-0|8-6|7-0|5-3|NP| |50 ground
snow load|Redwoodf
Western cedarsf-
Ponderosa pinef
Red pinef|6 × 6|14-0|14-0|14-0|14-0|14-0|14-0|10-8|2-4| |50 ground
snow load|Redwoodf
Western cedarsf-
Ponderosa pinef
Red pinef|8 × 8|14-0|14-0|14-0|14-0|14-0|14-0|14-0|14-0| |60 ground
snow load|Southern pine|4 × 4|14-0|11-1|8-11|7-7|6-7|5-10|5-2|4-6| |60 ground
snow load|Southern pine|4 × 6|14-0|14-0|11-4|9-9|8-7|7-9|7-1|6-6| |60 ground
snow load|Southern pine|6 × 6|14-0|14-0|14-0|14-0|14-0|14-0|12-9|11-2| |60 ground
snow load|Southern pine|8 ×CRC § 5-42 Medium relevance — show source text
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FLOORS
FIGURE R507.9.2(1)—DECK ATTACHMENT FOR LATERAL LOADS
WATER-PROTECTIVE BARRIER
LAPPED OVER FLASHING
"Z" FLASHING (SHOWN) OR "L" FLASHING (OPTIONAL)
HOLD-DOWN OR SIMILAR DEVICE
ATTACHED TO ADJACENT JOISTS
PER MANUFACTURER
LAG SCREWS OR BOLTS STAGGARED
APPROVED JOIST HANGER
For SI: 1 inch = 25.4 mm.
FIGURE R507.9.2(2)—DECK ATTACHMENT FOR LATERAL LOADS
WATER-RESISTING BARRIER
LAPPED OVER FLASHING
"L" FLASHING (SHOWN) OR "Z" FLASHING (OPTIONAL)
APPROVED JOIST HANGERS
LAG SCREWS OR BOLTS STAGGERED
HOLD-DOWN DEVICE MIN 750 LB. CAPACITY AT 4 LOCATIONS, EVENLY DISTRIBUTED ALONG DECK AND ONE WITHIN 24" OF EACH
END OF THE LEDGER. HOLD-DOWN DEVICES
SHALL FULLY ENGAGE DECK JOIST PER
HOLD-DOWN MANUFACTURER. ATTACHED TO
TOP PLATE STUDS OR HEADER WITH A FULLY
THREADED 3/8" DIAMETER LAG SCREW
PREDRILLED W/ MIN. 3" PENETRATION
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
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FLOORS
R507.10 Exterior guards. Guards shall be constructed to meet the requirements of Sections R301.5 and R321, and this section.
R507.10.1 Support of guards. Where guards are supported on deck framing, guard loads shall be transferred to the deck framing with a continuous load path to the deck joists.
R507.10.1.1 Guards supported by side of deck framing. Where guards are connected to the interior or exterior side of a deck joist or beam, the joist or beam shall be connected to the adjacent joists to prevent rotation of the joist or beam. Connections relying only on fasteners in end grain withdrawal are not permitted.
R507.10.1.2 Guards supported on top of deck framing. Where guards are mounted on top of the decking, the guards shall be connected to the deck framing or blocking and installed in accordance with manufacturer’s instructions to transfer the guard loads to the adjacent joists.
R507.10.2 Wood posts at deck guards. Where 4-inch by 4-inch (102 mm by 102 mm) wood posts support guard loads applied to the top of the guard, such posts shall not be notched at the connection to the supporting structure.
R507.10.3 Plastic composite guards. Plastic composite guards shall comply with the provisions of Section R507.2.2.
R507.10.4 Other guards. Other guards shall be in accordance with either manufacturer’s instructions or accepted engineering principles.
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CRC § 1.5 Medium relevance — show source text
18)||| |4.|Assembly areas_c, e_|Stadiums and arenas with fixed seats
(fastened to the floor)|60a (See Section 1607_A_.18)||| |4.|Assembly areas_c, e_|Other assembly areas|100a||| |5.|Balconies and decks|Balconies and decks|1.5 times the live load for the area
served, not required to exceed 100|—|—| |6.|Catwalks for maintenance and service access|Catwalks for maintenance and service access|40|300|—| |7.|Cornices|Cornices|60|—|—| |8.|Corridors|First floor|100|—|—| |8.|Corridors|Other floors|Same as occupancy
served except as indicated|Same as occupancy
served except as indicated|Same as occupancy
served except as indicated| |9.|Dining rooms and restaurants|Dining rooms and restaurants|100a|—|—| |10.|Dwellings (see residential)|Dwellings (see residential)|—|—|—| |11.|Elevator machine room and control room grating
(on area of 2 inches by 2 inches)|Elevator machine room and control room grating
(on area of 2 inches by 2 inches)|—|300|—| |12.|Finish light floor plate construction (on area of 1 inch by 1 inch)|Finish light floor plate construction (on area of 1 inch by 1 inch)|—|200|—|2025 CALIFORNIA BUILDING CODE 16A-11
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STRUCTURAL DESIGN
TABLE 1607A.1—MINIMUM UNIFORMLY DISTRIBUTED LIVE LOADS, L, AND MINIMUM CONCENTRATED LIVE LOADS—continued
0Col2 Col3 Col4 Col5 Col6 OCCUPANCY OR USE OCCUPANCY OR USE OCCUPANCY OR USE UNIFORM
(psf)CONCENTRATE
D (pounds)ALSO SEE
SECTION13. Fire escapes Fire escapes 100 — — 13. On single-family dwellings only 40 40 40 14. Fixed ladders Fixed ladders See Section 1607_A_.10 See Section 1607_A_.10 — 15. Garages and vehicle
floorsPassenger vehicle garages 40c See Section
1607_A_.7— 15. Garages and vehicle
floorsTrucks and buses See Section 1607_A_.8 See Section 1607_A_.8 See Section 1607_A_.8 15. Garages and vehicle
floorsFire trucks and emergency vehicles See Section 1607_A_.8 See Section 1607_A_.8 See Section 1607_A_.8 15. Garages and vehicle
floorsForklifts and movable equipment See Section 1607_A_.8 See Section 1607_A_.8 See Section 1607_A_.8 16. Handrails, guards and grab bars Handrails, guards and grab bars See Section 1607_A_. CRC § 1607A.1 Medium relevance — show source text
SECTION 1607 A —LIVE LOADS
1607 A .1 General. Buildings, structures, and parts thereof shall be designed to resist the effects of live loads.
TABLE 1607A.1—MINIMUM UNIFORMLY DISTRIBUTED LIVE LOADS, L, AND MINIMUM CONCENTRATED LIVE LOADS
0Col2 Col3 Col4 Col5 Col6 OCCUPANCY OR USE OCCUPANCY OR USE OCCUPANCY OR USE UNIFORM
(psf)CONCENTRATE
D (pounds)ALSO SEE
SECTION1. Apartments (see residential) Apartments (see residential) — — — 2. Access floor systems Office use 50 2,000 — 2. Access floor systems Computer use 100 2,000 — 3. Armories and drill rooms Armories and drill rooms 150a — — 4. Assembly areas_c, e_ Fixed seats (fastened to floor) 60a — — 4. Assembly areas_c, e_ Lobbies 100a 4. Assembly areas_c, e_ Movable seats 100a 4. Assembly areas_c, e_ Stage floors 150a 4. Assembly areas_c, e_ Platforms (assembly) 100a 4. Assembly areas_c, e_ Bleachers, folding and telescopic seat-
ing and grandstands_g_100a (See Section 1607_A_.18) 4. Assembly areas_c, e_ Stadiums and arenas with fixed seats
(fastened to the floor)60a (See Section 1607_A_.18) 4. Assembly areas_c, e_ Other assembly areas 100a 5. Balconies and decks Balconies and decks 1.5 times the live load for the area
served, not required to exceed 100— — 6. Catwalks for maintenance and service access Catwalks for maintenance and service access 40 300 — 7. Cornices Cornices 60 — — 8. Corridors First floor 100 — — 8. Corridors Other floors Same as occupancy
served except as indicatedSame as occupancy
served except as indicatedSame as occupancy
served except as indicated9. Dining rooms and restaurants Dining rooms and restaurants 100a — — 10. Dwellings (see residential) Dwellings (see residential) — — — 11. Elevator machine room and control room grating
(on area of 2 inches by 2 inches)Elevator machine room and control room grating
(on area of 2 inches by 2 inches)— 300 — 12. Finish light floor plate construction (on area of 1 inch by 1 inch) Finish light floor plate construction (on area of 1 inch by 1 inch) — 200 — 2025 CALIFORNIA BUILDING CODE 16A-11
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
CRC § 1607.1 Medium relevance — show source text
STRUCTURAL DESIGN
SECTION 1607—LIVE LOADS
1607.1 General. Buildings, structures, and parts thereof shall be designed to resist the effects of live loads.
TABLE 1607.1—MINIMUM UNIFORMLY DISTRIBUTED LIVE LOADS, L, AND MINIMUM CONCENTRATED LIVE LOADS
0Col2 Col3 Col4 Col5 Col6 OCCUPANCY OR USE OCCUPANCY OR USE OCCUPANCY OR USE UNIFORM
(psf)CONCENTRATE
D (pounds)ALSO SEE
SECTION1. Apartments (see residential) Apartments (see residential) — — — 2. Access floor systems Office use 50 2,000 — 2. Access floor systems Computer use 100 2,000 — 3. Armories and drill rooms Armories and drill rooms 150a — — 4. Assembly areas Fixed seats (fastened to floor) 60a — — 4. Assembly areas Lobbies 100a 4. Assembly areas Movable seats 100a 4. Assembly areas Stage floors 150a 4. Assembly areas Platforms (assembly) 100a 4. Assembly areas Bleachers, folding and telescopic seat-
ing and grandstands100a (See Section 1607.18) 4. Assembly areas Stadiums and arenas with fixed seats
(fastened to the floor)60a (See Section 1607.18) 4. Assembly areas Other assembly areas 100a 5. Balconies and decks Balconies and decks 1.5 times the live load for the area
served, not required to exceed 100— — 6. Catwalks for maintenance and service access Catwalks for maintenance and service access 40 300 — 7. Cornices Cornices 60 — — 8. Corridors First floor 100 — — 8. Corridors Other floors Same as occupancy
served except as indicatedSame as occupancy
served except as indicatedSame as occupancy
served except as indicated9. Dining rooms and restaurants Dining rooms and restaurants 100a — — 10. Dwellings (see residential) Dwellings (see residential) — — — 11. Elevator machine room and control room grating
(on area of 2 inches by 2 inches)Elevator machine room and control room grating
(on area of 2 inches by 2 inches)— 300 — 12. Finish light floor plate construction (on area of 1 inch by 1 inch) Finish light floor plate construction (on area of 1 inch by 1 inch) — 200 — 13. Fire escapes Fire escapes 100 — — 13. On single-family dwellings only 40 40 40 14. Fixed ladders Fixed ladders See Section 1607.10 See Section 1607.10 — 15. CRC § 1.1.1 Medium relevance — show source text
Exterior stairs R325.7
Habitable rooms R325
Interior stairs R325.6 Limited-Density Owner-Built Rural Dwellings Alternative provisions R301.1.1.1 Definition R202 Lining Flue R1003.11, R1003.12 Lintel R606.10, R608.8, R703.8.3, R1001.7 Liquid Fuel R202 Live Loads (see Loads)
Live/work Unit R101.2 Accessibility R322.2 Loads Chimneys R1003.8 Components and Cladding (see Wind Loads) Figure R301.2.1, Table 301.2.1(1), Table 301.2.1(2) Dead load R301.4 Flood (see Flood-Resistant Construction) R301.2.4 Live load R301.5, R301.7 Roof R301.6 Seismic risk map (see Seismic Loads) Figure R301.2.2.1(1), Figure R301.2.2.1(2), Figure R301.2.2.1(3), Figure R301.2.2.1(4), Figure R301.2.2.1(5), Figure R301.2.2.1(6), Figure R301.2.2.1(7) Snow load map (see Snow Loads) Figure 301.2(3) Wind speed map (see Wind Loads) Figure R301.2(2) Lodging House R101.2, R322.1 Lumber
Grade R502.1.1, R602.1.1, R802.1.1
Maintenance R102.6, R303.5.3, R303.5.4 Energy R330.11 Masonry Anchorage R606.11 Cavity wall R606.13 Chases R606.8
General R606
Hollow unit R606.13.1.2, R606.3.2.2 Inspection R109.1.4 Seismic requirements R606.12 Veneer R703.8
Veneer attachment R703.3
Materials
Alternative 1.8.7, R104.2.2 Combustible R1001.11, R1001.12, R1003.18, R1003.19 For flue liners R1003.11
For hearth extension R1001.9 For siding R703.5 Means of Appeal R112 Board of appeals Appendix AA Means of Egress R318 Attachment of landings, decks, balconies and stairs R318.5
Door R318.2 Floors and landings at exterior doors R318.3 Hallways R318.6 Mezzanines R314.4
Ramps R318.8 Sleeping lofts R315.5 Stairways R318.7 Vertical egress R318.4 Mechanical
Inspection R109.1.2 Membrane Polyethylene R504.2.2, R506.3.3 Waterproofing R406.2 Water-resistive R703.2
Metal Roof panels R905.10
2025 CALIFORNIA RESIDENTIAL CODE INDEX-3
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
INDEX
CRC § 5537.1 Medium relevance — show source text
SECTION R608—EXTERIOR CONCRETE WALL CONSTRUCTION
R608.1 General. Exterior concrete walls shall be designed and constructed in accordance with the provisions of this section or in accordance with the provisions of PCA 100, ACI 318 or ACI 332. Where PCA 100, ACI 318, ACI 332 or the provisions of this section are used to design concrete walls, project drawings, typical details and specifications shall not exempt construction documents from the requirement to be stamped by a California licensed architect or engineer. Notwithstanding other sections of law, the law establishing these provisions is found in Business and Professions Code Sections 5537.1 and 6737.1.
R608.1.1 Interior construction. These provisions are based on the assumption that interior walls and partitions, both load-bearing and nonload-bearing, floors and roof/ceiling assemblies are constructed of light-frame construction complying with the limitations of this code and the additional limitations of Section R608.2. Design and construction of light-frame assemblies shall be in accordance with the applicable provisions of this code. Where second-story exterior walls are of light-frame construction, they shall be designed and constructed as required by this code.
Aspects of concrete construction not specifically addressed by this code, including interior concrete walls, shall comply with ACI 318.
2025 CALIFORNIA RESIDENTIAL CODE 6-107
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
WALL CONSTRUCTION
R608.1.2 Other concrete walls. Exterior concrete walls constructed in accordance with this code shall comply with the shapes and minimum concrete cross-sectional dimensions of Table R608.3. Other types of forming systems resulting in concrete walls not in compliance with this section shall be designed in accordance with ACI 318.
R608.2 Applicability limits. The provisions of this section shall apply to the construction of exterior concrete walls for buildings not greater than 60 feet (18 288 mm) in plan dimensions, floors with clear spans not greater than 32 feet (9754 mm) and roofs with clear spans not greater than 40 feet (12 192 mm). Buildings shall not exceed 35 feet (10 668 mm) in mean roof height or two stories in height above grade. Floor/ceiling dead loads shall not exceed 10 pounds per square foot (479 Pa), roof/ceiling dead loads shall not exceed 15 pounds per square foot (718 Pa) and attic live loads shall not exceed 20 pounds per square foot (958 Pa). Roof overhangs shall not exceed 2 feet (610 mm) of horizontal projection beyond the exterior wall and the dead load of the overhangs shall not exceed 8 pounds per square foot (383 Pa).
Walls constructed in accordance with the provisions of this section shall be limited to buildings subjected to a maximum design wind speed of 160 mph (72 m/s) Exposure B, 136 mph (61 m/s) Exposure C and 125 mph (56 m/s) Exposure D. Walls constructed in accordance with the provisions of this section shall be limited to detached one- and two-family dwellings and townhouses assigned to Seismic Design Category A or B, and detached one- and two-family dwellings assigned to Seismic Design Category C.
Buildings that are not within the scope of this section shall be designed in accordance with PCA 100 or ACI 318.
R608.3 Concrete wall systems. Concrete walls constructed in accordance with these provisions shall comply with the shapes and minimum concrete cross-sectional dimensions of Table R608.3.
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 § 6.895 Medium relevance — show source text
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.|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.CRC § 0.0254 Medium relevance — show source text
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.|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.CRC § 3-3 Medium relevance — show source text
2025 CALIFORNIA RESIDENTIAL CODE 3-3
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
3-4 2025 CALIFORNIA RESIDENTIAL CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
Part III— Building Planning and Construction
3 BUILDING PLANNING
User notes:
About this chapter: Chapter 3 contains a wide array of building planning requirements that are critical to designing a safe and usable building. This includes, but is not limited to, requirements related to general structural design, fire-resistant construction, light, ventilation, sanitation, plumbing fixture clearances, minimum room area and ceiling height, safety glazing, means of egress, automatic fire sprinkler systems, smoke and carbon monoxide alarm systems, accessibility and solar energy systems.
SECTION R300—SITE DRAINAGE
R300.1 Storm water drainage and retention during construction. Projects which disturb less than one acre of soil and are not part of a larger common plan of development which in total disturbs one acre or more, shall manage storm water drainage during construction in accordance with the California Green Building Standards Code, Chapter 4, Division 4.1.
R300.2 Grading and paving. Construction plans shall indicate how the site grading or drainage system will manage all surface water flows to keep water from entering buildings in accordance with the California Green Building Standards Code, Chapter 4, Division 4.1.
SECTION R301—DESIGN CRITERIA
R301.1 Application. Buildings and structures, and parts thereof, shall be constructed to safely support all loads, including dead loads, live loads, roof loads, flood loads, snow loads, wind loads and seismic loads as prescribed by this code. The construction of buildings and structures in accordance with the provisions of this code shall result in a system that provides a complete load path that meets the requirements for the transfer of loads from their point of origin through the load-resisting elements to the foundation. Buildings and structures constructed as prescribed by this code are deemed to comply with the requirements of this section.
Existing buildings housing existing protective social care homes or facilities established prior to 1972 (see Chapter 11 of the California Fire Code and the California Existing Building Code).
R301.1.1 Alternative provisions. As an alternative to the requirements in Section R301.1, the following standards are permitted subject to the limitations of this code and the limitations therein. Where engineered design is used in conjunction with these standards, the design shall comply with the California Building Code .
- AWC Wood Frame Construction Manual (WFCM).
- AISI Standard for Cold-Formed Steel Framing—Prescriptive Method for One- and Two-Family Dwellings (AISI S230).
- ICC Standard on the Design and Construction of Log Structures (ICC 400).
R301.1.1.1 Alternative provisions for limited-density owner-built rural dwellings. The purpose of this subsection is to permit alternatives that provide minimum protection of life, limb, health, property, safety and welfare of the general public and the owners and occupants of limited-density owner-built rural dwellings as defined in Chapter 2 of this code. For additional informa- tion see Chapter 1, Subchapter 1, Article 8, of Title 25, California Code of Regulations, commencing with Section 74.
CRC § 4.5 Medium relevance — show source text
5|DR|DR|4.5|DR|DR|DR|DR|DR|DR|DR|DR|DR|DR|DR| |130|110|50|4.5|DR|DR|DR|DR|DR|DR|DR|DR|DR|DR|DR|DR|DR|DR| |130|110|70|DR|DR|DR|DR|DR|DR|DR|DR|DR|DR|DR|DR|DR|DR|DR| |For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 mile per hour = 0.447 m/s.
DR = Design Required.
a. Design assumptions:
Maximum deflection criteria: L/240.
Maximum roof dead load: 10 psf.
Maximum roof live load: 70 psf.
Maximum ceiling dead load: 5 psf.
Maximum ceiling live load: 20 psf.
Maximum second-floor dead load: 10 psf.
Maximum second-floor live load: 30 psf.
Maximum second-floor dead load from walls: 10 psf.
Maximum first-floor dead load: 10 psf.
Maximum first-floor live load: 40 psf.
Wind loads based on Table R301.2.1(1).
Strength axis of facing material applied vertically.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 mile per hour = 0.447 m/s.
DR = Design Required.
a. Design assumptions:
Maximum deflection criteria: L/240.
Maximum roof dead load: 10 psf.
Maximum roof live load: 70 psf.
Maximum ceiling dead load: 5 psf.
Maximum ceiling live load: 20 psf.
Maximum second-floor dead load: 10 psf.
Maximum second-floor live load: 30 psf.
Maximum second-floor dead load from walls: 10 psf.
Maximum first-floor dead load: 10 psf.
Maximum first-floor live load: 40 psf.
Wind loads based on Table R301.2.1(1).
Strength axis of facing material applied vertically.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 mile per hour = 0.447 m/s.
DR = Design Required.
a.CRC § 2.1 Medium relevance — show source text
a. Design assumptions:
Maximum deflection criterion: L/240.
Maximum roof dead load: 10 psf.
Maximum ceiling load: 5 psf.
Maximum ceiling live load: 20 psf.
Maximum second-floor live load: 30 psf.
Maximum second-floor dead load: 10 psf.
Maximum second-floor dead load from walls: 10 psf.
Maximum first floor dead load: 10 psf.
Wind loads based on Table R301.2.1(1).
Strength axis of facing material applied horizontally.
b. Building width is in the direction of horizontal framing members supported by the header.
c. The table provides for roof slopes between 3:12 and 12:12.
d. The maximum roof overhang is 24 inches (610 mm).|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
DR = Design Required.
a. Design assumptions:
Maximum deflection criterion: L/240.
Maximum roof dead load: 10 psf.
Maximum ceiling load: 5 psf.
Maximum ceiling live load: 20 psf.
Maximum second-floor live load: 30 psf.
Maximum second-floor dead load: 10 psf.
Maximum second-floor dead load from walls: 10 psf.
Maximum first floor dead load: 10 psf.
Wind loads based on Table R301.2.1(1).
Strength axis of facing material applied horizontally.
b. Building width is in the direction of horizontal framing members supported by the header.
c. The table provides for roof slopes between 3:12 and 12:12.
d. The maximum roof overhang is 24 inches (610 mm).|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
DR = Design Required.
a. Design assumptions:
Maximum deflection criterion: L/240.
Maximum roof dead load: 10 psf.
Maximum ceiling load: 5 psf.
Maximum ceiling live load: 20 psf.
Maximum second-floor live load: 30 psf.
Maximum second-floor dead load: 10 psf.
Maximum second-floor dead load from walls: 10 psf.
Maximum first floor dead load: 10 psf.
Wind loads based on Table R301.2.1(1).
Strength axis of facing material applied horizontally.
b. Building width is in the direction of horizontal framing members supported by the header.
c. The table provides for roof slopes between 3:12 and 12:12.
d. The maximum roof overhang is 24 inches (610 mm).|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
DR = Design Required.
a.CRC § 2.1 Medium relevance — show source text
Design assumptions:
Maximum deflection criteria: L/240.
Maximum roof dead load: 10 psf.
Maximum roof live load: 70 psf.
Maximum ceiling dead load: 5 psf.
Maximum ceiling live load: 20 psf.
Maximum second-floor dead load: 10 psf.
Maximum second-floor live load: 30 psf.
Maximum second-floor dead load from walls: 10 psf.
Maximum first-floor dead load: 10 psf.
Maximum first-floor live load: 40 psf.
Wind loads based on Table R301.2.1(1).
Strength axis of facing material applied vertically.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 mile per hour = 0.447 m/s.
DR = Design Required.
a. Design assumptions:
Maximum deflection criteria: L/240.
Maximum roof dead load: 10 psf.
Maximum roof live load: 70 psf.
Maximum ceiling dead load: 5 psf.
Maximum ceiling live load: 20 psf.
Maximum second-floor dead load: 10 psf.
Maximum second-floor live load: 30 psf.
Maximum second-floor dead load from walls: 10 psf.
Maximum first-floor dead load: 10 psf.
Maximum first-floor live load: 40 psf.
Wind loads based on Table R301.2.1(1).
Strength axis of facing material applied vertically.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 mile per hour = 0.447 m/s.
DR = Design Required.
a. Design assumptions:
Maximum deflection criteria: L/240.
Maximum roof dead load: 10 psf.
Maximum roof live load: 70 psf.
Maximum ceiling dead load: 5 psf.
Maximum ceiling live load: 20 psf.
Maximum second-floor dead load: 10 psf.
Maximum second-floor live load: 30 psf.
Maximum second-floor dead load from walls: 10 psf.
Maximum first-floor dead load: 10 psf.
Maximum first-floor live load: 40 psf.
Wind loads based on Table R301.2.1(1).
Strength axis of facing material applied vertically.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 mile per hour = 0.447 m/s.
DR = Design Required.
a.CRC § 25.4 Medium relevance — show source text
Building width is in the direction of horizontal framing members supported by the header.
c. The table provides for roof slopes between 3:12 and 12:12.
d. The maximum roof overhang is 24 inches (610 mm).|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
DR = Design Required.
a. Design assumptions:
Maximum deflection criterion: L/240.
Maximum roof dead load: 10 psf.
Maximum ceiling load: 5 psf.
Maximum ceiling live load: 20 psf.
Maximum second-floor live load: 30 psf.
Maximum second-floor dead load: 10 psf.
Maximum second-floor dead load from walls: 10 psf.
Maximum first floor dead load: 10 psf.
Wind loads based on Table R301.2.1(1).
Strength axis of facing material applied horizontally.
b. Building width is in the direction of horizontal framing members supported by the header.
c. The table provides for roof slopes between 3:12 and 12:12.
d. The maximum roof overhang is 24 inches (610 mm).|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
DR = Design Required.
a. Design assumptions:
Maximum deflection criterion: L/240.
Maximum roof dead load: 10 psf.
Maximum ceiling load: 5 psf.
Maximum ceiling live load: 20 psf.
Maximum second-floor live load: 30 psf.
Maximum second-floor dead load: 10 psf.
Maximum second-floor dead load from walls: 10 psf.
Maximum first floor dead load: 10 psf.
Wind loads based on Table R301.2.1(1).
Strength axis of facing material applied horizontally.
b. Building width is in the direction of horizontal framing members supported by the header.
c. The table provides for roof slopes between 3:12 and 12:12.
d. The maximum roof overhang is 24 inches (610 mm).|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
DR = Design Required.
a. Design assumptions:
Maximum deflection criterion: L/240.
Maximum roof dead load: 10 psf.
Maximum ceiling load: 5 psf.
Maximum ceiling live load: 20 psf.
Maximum second-floor live load: 30 psf.
Maximum second-floor dead load: 10 psf.
Maximum second-floor dead load from walls: 10 psf.
Maximum first floor dead load: 10 psf.
Wind loads based on Table R301.2.1(1).
Strength axis of facing material applied horizontally.
b. Building width is in the direction of horizontal framing members supported by the header.
c. The table provides for roof slopes between 3:12 and 12:12.
d. The maximum roof overhang is 24 inches (610 mm).|6-182 2025 CALIFORNIA RESIDENTIAL CODE
Frequently asked questions
What is the single controlling requirement for floor loads in the CRC?
Floors must be capable of accommodating all applicable loads in accordance with § R301 and must transmit those loads to supporting elements — this requirement is stated in § R501.2.
Where do the numeric live‑load values (like 40 psf) come from?
Those are the prescriptive design assumptions shown in CRC design tables under § R301 (typical values: 40 psf for first-floor living areas, 30 psf for upper floors, 10 psf for some attics). Use the table values unless an engineered design specifies otherwise.
Do floor diaphragms have to resist lateral loads too?
Yes — floors can act as diaphragms to transfer lateral loads to vertical resisting elements; the overall lateral‑load design and load path requirements are in § R301. For diaphragm details and collector design, refer to the applicable engineered provisions or referenced standards.
If I use prefabricated trusses, how do I know the floor loads were accounted for?
Truss design drawings are required to show top/bottom chord live and dead loads, concentrated loads and each reaction so you can verify the load path and bearing. See R502.12.4.
Are deck guard loads part of the floor load requirements?
Yes — deck guard loads must be transferred to the deck framing and joists via a continuous load path and proper connectors; see § R507.10.
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