CRC · California Residential Code
Requirements for floor trusses
Floor trusses in California must be engineered and documented: a registered design professional must prepare truss drawings showing spans, loads, reactions, connectors and required bracing; those drawings must be approved and present with the trusses before installation, and truss members cannot be cut or altered in the field without RDP approval (see § R502.12).
Last reviewed: July 6, 2026
What the code requires — 2-4 sentences
The California Residential Code requires that wood floor trusses be designed by a registered design professional and manufactured to accepted standards (including ANSI/TPI 1) and that their truss design drawings be submitted to and approved by the building official prior to installation. These obligations are set out in § R502.12.1 and § R502.12.4. Trusses must be braced for lateral stability and must not be cut, notched, spliced or otherwise altered without RDP approval per § R502.12.2 and § R502.12.3.
The single most important requirement: truss systems require engineered design and approved shop drawings on site before installation (see § R502.12.1 and § R502.12.4).
Requirements in detail
Design responsibility and standard compliance
- Design prepared by a registered design professional — every truss design drawing must be prepared by an RDP (engineer or architect) as required in § R502.12.1.
- Manufacturing standard — metal‑plate‑connected wood trusses must comply with ANSI/TPI 1 as required in § R502.12.1.
Bracing and stability
- Bracing to prevent rotation and provide lateral stability must be provided in accordance with the construction documents and the individual truss drawings; if no specific bracing is shown, accepted industry practices (for example, the SBCA BCSI guidance) must be used as called out in § R502.12.2.
Alterations and site modification limits
- No cutting, notching, splicing or other alteration of truss members or components without the approval of a registered design professional. Any alteration that would add loads beyond the design load is not permitted unless verified safe by an RDP (§ R502.12.3).
Truss design drawing submittal and minimum contents
- Truss design drawings must be submitted and approved prior to installation, and they must accompany trusses shipped to the job site (§ R502.12.4).
The code lists minimum information that must appear on the truss drawings; the items below are the decision‑relevant elements you must see on the drawings:
| Decision / question | Required information or value | Code reference |
|---|---|---|
| Who designed the trusses? | Prepared by a registered design professional | § R502.12.1 |
| Has the manufacturer complied with the national standard? | ANSI/TPI 1 for metal‑plate trusses | § R502.12.1 |
| Is the shop drawing on site? | Truss design drawings submitted & on job site with shipment | § R502.12.4 |
| Basic geometry needed | Slope or depth, span and spacing | § R502.12.4 (Item 1) |
| Joint and bearing info | Location of all joints; required bearing widths | § R502.12.4 (Items 2–3) |
| Loads to check | Top/bottom chord live & dead loads; concentrated loads; controlling wind & earthquake loads | § R502.12.4 (Items 4–4.6) |
| Connector & material specs | Joint connector type/description; lumber size/species/grade; connector locations | § R502.12.4 (Items 7–8, 9) |
| Structural verification details | Reaction forces/directions; max axial compression forces; calculated deflection ratios; permanent bracing locations | § R502.12.4 (Items 6, 11–12, 10) |
| Connections that require detail | Truss‑to‑girder, ply‑to‑ply, field splices | § R502.12.4 (Item 9) |
(That table is a checklist of the minimum drawing content required by § R502.12.4; it is not a substitute for full review by the building official or the project engineer.)
Cold‑formed steel floor trusses (related provision)
- Cold‑formed steel trusses must be designed, braced and installed in accordance with AISI S230 and, like wood trusses, must not have members notched or altered without approved design. See § R505.1.3 for applicability to steel trusses.
Exceptions & special cases
- If the construction documents or the truss drawings specify specific bracing, follow those drawings; where they are silent the code requires accepted industry practice such as SBCA BCSI for wood trusses (§ R502.12.2).
- Site modifications that change member geometry or increase loads (for example adding an equipment point load after installation) are not permitted unless an RDP verifies the truss can carry the new load (§ R502.12.3).
- For cold‑formed steel trusses, AISI S230 is the controlling design standard and the related bracing guidance (see § R505.1.3).
Common mistakes
- Installing trusses before the building official has approved the truss design drawings or without the drawings on site — the code explicitly requires drawings be submitted and present with the shipment (§ R502.12.4).
- Field cutting, notching, splicing or otherwise altering truss members without RDP approval — prohibited by § R502.12.3.
- Assuming the truss manufacturer’s standard practice replaces the RDP’s design or the approved drawings — the truss drawings must be RDP‑prepared and show required design loads and reactions (§ R502.12.1, § R502.12.4). cite
- Failing to provide or follow permanent bracing locations and details shown on the truss drawings — bracing is required by § R502.12.2 and § R502.12.4 (Item 12).
- Using trusses as open‑edge framing for guards without explicitly accounting for guard loads in the edge member design — see floor edge framing requirements that call out the need to consider guard loads (§ R502.11).
Worked example — applying the rule with numbers
Scenario: A second‑floor wood floor truss spans 24 feet, truss spacing is 16 inches o.c., and the design includes a concentrated HVAC support load at a designated point.
Step 1 — Design and standard: The truss manufacturer supplies metal‑plate‑connected trusses designed to ANSI/TPI 1 and the truss design drawing is prepared by a registered design professional — this satisfies § R502.12.1.
Step 2 — Submittal: The RDP’s truss design drawing lists span = 24 ft, spacing = 16 in. o.c., top-chord live load, top-chord dead load, bottom‑chord loads, the point load magnitude and location for the HVAC equipment, bearing widths, each reaction force and direction, connector types, lumber species and grades, calculated deflection, and permanent bracing locations — this satisfies the minimum checklist in § R502.12.4. The drawings are submitted to and approved by the building official prior to installation as required.
Step 3 — Bracing: The truss drawings specify permanent diagonal continuous bracing and panel bracing locations. If the approved drawings had not specified bracing, the installer would have to apply accepted industry bracing practices (for example SBCA BCSI) as required by § R502.12.2.
Step 4 — Field work: During installation no chord members are cut or notched. If the HVAC contractor requested to field‑notch a bottom chord to run ducting through, that would be prohibited unless an RDP reviewed and approved the alteration per § R502.12.3.
Outcome: The project is code‑compliant for floor trusses when the RDP design, approved drawings with the required listed items, proper bracing, and no unauthorized alterations are all in place per § R502.12.1–.4.
Related provisions
- § R502.12.1 – R502.12.4 (Wood trusses: design, bracing, alteration limits, drawing requirements) — primary controlling text.
- § R502.11 (Floor framing supporting guards — consider guard loads when trusses/I‑joists are used as edge framing).
- § R502.8.2 (Engineered wood products: cuts/notches/holes in trusses and engineered members prohibited except as allowed by manufacturer or RDP) — reinforces § R502.12.3.
- § R503 (Floor sheathing requirements), often relevant for diaphragm action and bracing and for sheathing continuity called out in related bracing details.
- § R505.1.3 (Cold‑formed steel floor trusses — design, bracing and no notching without approved design) — use where cold‑formed steel trusses are specified.
- ANSI/TPI 1 (referenced standard for metal‑plate‑connected wood trusses) — referenced in § R502.12.1.
Code references
Grounded in the retrieved California Residential Code — click a citation to read the verbatim passage:
CRC § 11.2 High relevance — show source text
R502.11.2 Timber edge framing. Where a roll brace is not aligned with each guard post, the framing at the edge of the floor shall consist of a minimum 6-inch by 10-inch sawn timber or a minimum 5 [1] / 8 -inch by 9 [1] / 4 -inch (130 mm × 235 mm) structural gluedlaminated timber and shall be braced to resist rotation by roll bracing as described in Section R502.11.3 at intervals of 48 inches (1219 mm) or less.
R502.11.3 Roll bracing. Each roll brace shall be a joist or blocking matching the depth of the edge member and extending perpendicular to the edge member not less than 16 inches (406 mm) from the edge. Blocking shall have end connections with not fewer than six 16d common nails. Floor sheathing shall be continuous for not less than 24 inches (610 mm) from the edge and shall be fastened to each roll brace with not fewer than 12 (twelve) 10d common nails and shall be fastened to the edge member with a minimum of 12 (twelve) 10d common nails within 12 inches (305 mm) of the roll brace.
R502.12 Wood trusses.
R502.12.1 Design. Wood trusses shall be designed in accordance with approved engineering practice. The design and manufacture of metal-plate-connected wood trusses shall comply with ANSI/TPI 1. The truss design drawings shall be prepared by a registered design professional.
R502.12.2 Bracing. Trusses shall be braced to prevent rotation and provide lateral stability in accordance with the requirements specified in the construction documents for the building and on the individual truss design drawings. In the absence of specific bracing requirements, trusses shall be braced in accordance with accepted industry practices, such as the SBCA Building Compo- nent Safety Information (BCSI) Guide to Good Practice for Handling, Installing & Bracing of Metal Plate Connected Wood Trusses .
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.
2025 CALIFORNIA RESIDENTIAL CODE 5-11
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
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.
CRC § 12.3 High 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.
2025 CALIFORNIA RESIDENTIAL CODE 5-11
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
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 § 25.4 Medium relevance — show source text
@ 16″|—|32″
(287)|25″
(356)|36″
(263)|29″
(345)|21″
(428)|29″
(367)|20″
(484)|—|23″
(471)|—|—| |2 × 12 @ 12″|—|42″
(209)|31″
(263)|—|37″
(253)|27″
(317)|36″
(271)|27″
(358)|17″
(447)|31″
(348)|19″
(462)|—| |2 × 12 @ 8″|—|48″
(136)|45″
(169)|—|48″
(164)|38″
(206)|—|40″
(233)|26″
(294)|36″
(230)|29″
(304)|18″
(379)| |For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. Tabulated values are for clear-span roof supported solely by exterior bearing walls.
b. Spans are based on No. 2 Grade lumber of Douglas fir-larch, Southern pine, hem-fir and spruce-pine-fir for repetitive (three or more) members.
c. Ratio of backspan to cantilever span shall be not less than 3:1.
d. Connections capable of resisting the indicated uplift force shall be provided at the backspan support.
e. Uplift force is for a backspan to cantilever span ratio of 3:1. Tabulated uplift values are permitted to be reduced by multiplying by a factor equal to 3 divided by the actual
backspan ratio provided (3/backspan ratio).
f. See Section R301.2.2.6, Item 1, for additional limitations on cantilevered floor joists for detached one- and two-family dwellings in Seismic Design Category D0, D1 or D2 and
townhouses in Seismic Design Category C, D0, D1 or D2.
g. Linear interpolation shall be permitted for building widths and ground snow loads other than shown.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. Tabulated values are for clear-span roof supported solely by exterior bearing walls.
b. Spans are based on No. 2 Grade lumber of Douglas fir-larch, Southern pine, hem-fir and spruce-pine-fir for repetitive (three or more) members.
c. Ratio of backspan to cantilever span shall be not less than 3:1.
d. Connections capable of resisting the indicated uplift force shall be provided at the backspan support.
e. Uplift force is for a backspan to cantilever span ratio of 3:1. Tabulated uplift values are permitted to be reduced by multiplying by a factor equal to 3 divided by the actual
backspan ratio provided (3/backspan ratio).
f.CRC § 1.1 Medium relevance — show source text
SECTION R505—COLD-FORMED STEEL FLOOR FRAMING
R505.1 Cold-formed steel floor framing. Elements shall be straight and free of any defects that would significantly affect structural performance. Cold-formed steel floor framing members shall be in accordance with the requirements of this section.
R505.1.1 Applicability limits. The provisions of this section shall control the construction of cold-formed steel floor framing for buildings not greater than 60 feet (18 288 mm) in length perpendicular to the joist span, not greater than 40 feet (12 192 mm) in width parallel to the joist span and less than or equal to three stories above grade plane. Cold-formed steel floor framing constructed in accordance with the provisions of this section shall be limited to sites where the ultimate design wind speed is less than 140 miles per hour (63 m/s), Exposure Category B or C, and the ground snow load is less than or equal to 70 pounds per square foot (3.35 kPa).
R505.1.1.1 Alternate applications. Cold-formed steel floor framing for buildings exceeding the applicability limits of Section R505.1.1 is permitted to be designed and constructed in accordance with AISI S230, subject to the limits therein.
R505.1.2 In-line framing. Where supported by cold-formed steel-framed walls in accordance with Section R603, cold-formed steel floor framing shall be constructed with floor joists located in-line with load-bearing studs located below the joists in accordance with the tolerances specified in AISI S240, Section B1.2.3.
R505.1.3 Floor trusses. Cold-formed steel trusses shall be designed, braced and installed in accordance with AISI S230, Section D8. In the absence of specific bracing requirements, trusses shall be braced in accordance with accepted industry practices, such as the SBCA Cold-Formed Steel Building Component Safety Information (CFSBCSI), Guide to Good Practice for Handling, Installing & Bracing of Cold-Formed Steel Trusses . Truss members shall not be notched, cut or altered in any manner without an approved design.
5-14 2025 CALIFORNIA RESIDENTIAL CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
FLOORS
R505.2 Structural framing. Load-bearing cold-formed steel floor framing members shall be in accordance with this section.
R505.2.1 Material. Load-bearing cold-formed steel framing members shall be cold formed to shape from structural quality sheet steel complying with the requirements of AISI S240, Section A3.
R505.2.2 Corrosion protection. Load-bearing cold-formed steel framing shall have a metallic coating complying with AISI S240, Section A4.
R505.2.3 Dimension, thickness and material grade. Load-bearing cold-formed steel floor framing members shall comply with AISI S230, Section A4.3 and material grade requirements as specified in AISI S230, Section A4.4.
R505.2.4 Identification. Load-bearing cold-formed steel framing members shall meet the product identification requirements of AISI S240, Section A5.5.
R505.2.5 Fastening. Screws for steel-to-steel connections shall be installed with a minimum edge distance and center-to-center spacing of [1] / 2 inch (12.7 mm), shall be self-drilling tapping, and shall conform to ASTM C1513.
CRC § 10.6.5 Medium relevance — show source text
Linear interpolation shall be permitted.
b. The total length of bracing required for a given wall line is the product of all applicable adjustment factors.
c. The length-to-width ratio for the floor/roof diaphragm shall not exceed 3:1.
d. Applies to stone or masonry veneer exceeding the first story height.
e. The adjustment factor for stone or masonry veneer shall be applied to all exterior braced wall lines and all braced wall lines on the interior of the building, backing or perpen-
dicular to and laterally supporting veneered walls.
f. See Section R602.10.6.5 for requirements where stone or masonry veneer does not exceed the first-story height.
g. One- and two-family dwellings in Seismic Design Category D2 exceeding two stories shall be designed in accordance with accepted engineering practice.|For SI: 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. Linear interpolation shall be permitted.
b. The total length of bracing required for a given wall line is the product of all applicable adjustment factors.
c. The length-to-width ratio for the floor/roof diaphragm shall not exceed 3:1.
d. Applies to stone or masonry veneer exceeding the first story height.
e. The adjustment factor for stone or masonry veneer shall be applied to all exterior braced wall lines and all braced wall lines on the interior of the building, backing or perpen-
dicular to and laterally supporting veneered walls.
f. See Section R602.10.6.5 for requirements where stone or masonry veneer does not exceed the first-story height.
g. One- and two-family dwellings in Seismic Design Category D2 exceeding two stories shall be designed in accordance with accepted engineering practice.|2025 CALIFORNIA RESIDENTIAL CODE 6-33
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
WALL CONSTRUCTION
R602.10.3.1 Wall height for wood framing. For determination of braced wall and panel adjustment factors in accordance with Section R602.10, wall height shall be the vertical distance from the lower edge of the bottom plate to the upper edge of the upper top plate determined in accordance with Figure R602.10.3.1.
FIGURE R602.10.3.1—WALL HEIGHT FOR WOOD FRAMING
WALL TOP PLATE
WALL TOP PLATE
WALL BOTTOM PLATE
TOP OF GROUND FLOOR SUPPORT
CONCRETE MASONRY FOUNDATION
CRAWL SPACE FRAMING
Col1 Col2 Col3 WALL ST
ROOF FRAMING
•
RAFTERS
•
CEILING JOIST
•
TRUSSES
•
OTHERWALL ST
ROOF FRAMING
•
RAFTERS
•
CEILING JOIST
•
TRUSSES
•
OTHERWALL ST
ROOF FRAMING
•
RAFTERS
•
CEILING JOIST
•
TRUSSES
•
OTHERFLOOR SHEATHING FLOOR SHEATHING TOP STORY BELOW THE ROOF
WALL BOTTOM PLATE
CRC § 19-1.1 Medium relevance — show source text
Floor and beam
construction consisting of
3"-deep cellular steel floor
unit mounted on steel
members with 1:4 (propor-
tion of Portland cement to
perlite aggregate) perlite-
concrete floor slab on top.|19-1.1|Suspended envelope ceiling of perlite
gypsum plaster on metal lath attached
to3/4" cold-rolled channels, secured to
11/2" cold-rolled channels spaced 42"
on center supported by 0.203 inch (No.
6 B.W. gage) wire 36" on center. Beams
in envelope with 3" minimum airspace
between beam soffit and lath have a 4-
hour rating.|2p|—|—|—|1 l|—|—|—| |20. Perlite concrete propor-
tioned 1:6 (Portland cement
to perlite aggregate) poured
to1/8" thickness above top of
corrugations of 15/16"-deep
galvanized steel deck maxi-
mum span 8′-0" for 0.024"
(No. 24 galvanized sheet
gage) or 6′-0" for 0.019" (No.
26 galvanized sheet gage)
with deck supported by indi-
vidually protected steel
framing. Approved polysty-
rene foam plastic insulation
board having a flame spread
not exceeding 75 (1" to 4"
thickness) with vent holes
that approximate 3 percent of
the board surface area placed
on top of perlite slurry. A 2′ by
4′ insulation board contains
six 23/4" diameter holes.
Board covered with 21/4"
minimum perlite concrete
slab. Slab reinforced with
mesh consisting of 0.042"
(No.19 B.W. gage) galvanized
steel wire twisted together to
form 2" hexagons with
straight 0.065" (No. 16 B.W.
gage) galvanized steel wire
woven into mesh and spaced
3". Alternate slab reinforce-
ment shall be permitted to
consist of 4" × 8",
0.109/0.238" (No. 12/4 B.W.
gage), or 2" × 2", 0.083/0.083"
(No. 14/14 B.W. gage) welded
wire fabric. Class A or B roof
covering on top.|20-1.1|None|—|—|Varies|—|—|—|—|—| |21. Wood joists, wood I-
joists, floor trusses and flat
or pitched roof trusses
spaced a maximum 24" o.c.
with1/2" wood structural
panels with exterior glue
applied at right angles to
top of joist or top chord of
trusses with 8 d nails.CRC § 11.1 Medium relevance — show source text
R502.10 Framing of openings. Openings in floor framing shall be framed with header and trimmer joists. Where the header joist span does not exceed 4 feet (1219 mm), the header joist shall be a single member the same size as the floor joist. Single trimmer joists shall be used to carry a single header joist that is located within 3 feet (914 mm) of the trimmer joist bearing. Where the header joist span exceeds 4 feet (1219 mm), the trimmer joists and the header joist shall be doubled and of sufficient cross section to support the floor joists framing into the header.
R502.11 Floor framing supporting guards. The framing at the open edge of a floor supporting a required guard assembly shall be constructed in accordance with Section R502.11.1 or R502.11.2 for guard assemblies not exceeding 44 inches (1118 mm) in height, or shall be designed in accordance with accepted engineering practice to support the guard assembly. Where trusses and I-joists are used as edge framing members supporting guards, the effects of the guard loads shall be specifically considered in the design of the edge member.
R502.11.1 Conventional edge framing. Where a roll brace is aligned with each guard post, the framing at the edge of the floor shall consist of a solid or built-up member of lumber, structural glued-laminated timber or structural composite lumber having a net width of not less than 3 inches (76 mm) and a net depth of not less than 9 [1] / 4 inches (235 mm), and shall be braced to resist rotation by roll bracing as described in Section R502.11.3.
R502.11.2 Timber edge framing. Where a roll brace is not aligned with each guard post, the framing at the edge of the floor shall consist of a minimum 6-inch by 10-inch sawn timber or a minimum 5 [1] / 8 -inch by 9 [1] / 4 -inch (130 mm × 235 mm) structural gluedlaminated timber and shall be braced to resist rotation by roll bracing as described in Section R502.11.3 at intervals of 48 inches (1219 mm) or less.
R502.11.3 Roll bracing. Each roll brace shall be a joist or blocking matching the depth of the edge member and extending perpendicular to the edge member not less than 16 inches (406 mm) from the edge. Blocking shall have end connections with not fewer than six 16d common nails. Floor sheathing shall be continuous for not less than 24 inches (610 mm) from the edge and shall be fastened to each roll brace with not fewer than 12 (twelve) 10d common nails and shall be fastened to the edge member with a minimum of 12 (twelve) 10d common nails within 12 inches (305 mm) of the roll brace.
R502.12 Wood trusses.
R502.12.1 Design. Wood trusses shall be designed in accordance with approved engineering practice. The design and manufacture of metal-plate-connected wood trusses shall comply with ANSI/TPI 1. The truss design drawings shall be prepared by a registered design professional.
CRC § 0.42. Medium relevance — show source text
Portions of connections of wood-framed floor systems not noted in the figures shall be in accordance with Section R502, or AWC WFCM, if applicable. Wood framing members shall be of a species having a specific gravity equal to or greater than 0.42. 2. For floor systems of cold-formed steel construction, the provisions of Section R608.9.1 and the prescriptive details of Figures R608.9(5) through R608.9(8), where permitted by the tables accompanying those figures. Portions of connections of coldformed steel-framed floor systems not noted in the figures shall be in accordance with Section R505, or AISI S230, if applicable. 3. Proprietary connectors selected to resist loads and load combinations in accordance with Appendix A (ASD) or Appendix B (LRFD) of PCA 100. 4. An engineered design using loads and load combinations in accordance with Appendix A (ASD) or Appendix B (LRFD) of PCA 100.
- An engineered design using loads and material design provisions in accordance with this code, or in accordance with ASCE 7, ACI 318, and AWC NDS for wood-framed construction or AISI S100 for cold-formed steel frame construction.
R608.9.3 Connections between concrete walls and light-frame ceiling and roof systems. Connections between concrete walls and light-frame ceiling and roof systems shall be in accordance with one of the following:
- For ceiling and roof systems of wood-framed construction, the provisions of Section R608.9.1 and the prescriptive details of Figures R608.9(9) and R608.9(10), where permitted by the tables accompanying those figures. Portions of connections of wood-framed ceiling and roof systems not noted in the figures shall be in accordance with Section R802, or AWC WFCM, if applicable. Wood framing members shall be of a species having a specific gravity equal to or greater than 0.42.
- For ceiling and roof systems of cold-formed steel construction, the provisions of Section R608.9.1 and the prescriptive details of Figures R608.9(11) and R608.9(12), where permitted by the tables accompanying those figures. Portions of
2025 CALIFORNIA RESIDENTIAL CODE 6-171
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
WALL CONSTRUCTION
connections of cold-formed steel-framed ceiling and roof systems not noted in the figures shall be in accordance with Section R804, or AISI S230, if applicable. 3. Proprietary connectors selected to resist loads and load combinations in accordance with Appendix A (ASD) or Appendix B (LRFD) of PCA 100. 4. An engineered design using loads and load combinations in accordance with Appendix A (ASD) or Appendix B (LRFD) of PCA 100.
- An engineered design using loads and material design provisions in accordance with this code, or in accordance with ASCE 7, ACI 318, and AWC NDS for wood-framed construction or AISI S100 for cold-formed steel-framed construction.
CRC § 2.5 Medium relevance — show source text
Parapet construction R302.2.5 Scope R101.2 Separation R302.2 Structural independence R302.2.6 Trusses
Steel R505.1.3, R804.3.6 Wood R502.12, R802.10 Tubular Daylighting Device (TDD) (see Skylights) Two-Family Dwellings R302.3
Under Floor
Space R408
Vapor Retarders R702.7 Capillary break R506.2.3.1 Under floor R408.8 Vehicular Gates Appendix BH Veneer
Masonry R703.7 Ventilation Adjoining rooms R325.1.3 Bathroom and kitchen R325.2
Habitable rooms R325.1
Roof R806
Under floor R408.1 Venting (Mechanical) Chimney and vent connectors R1006 Fireplace R1006 General R325.3
Violations R113 Visible Transmittance (VT)
Wall Furnace (see Appliance) Wallboard (see Gypsum) Walls
Bathtub compartments R327.2 Bracing, steel R603.9 Bracing, wood R602.10 Construction Chapter 6 Covering Chapter 7 Crawl space R202 Cripple R602.9
INDEX-4 2025 CALIFORNIA RESIDENTIAL CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
INDEX
Deflection R301.7
Exterior, defined R202 Exterior covering R703 Finishes R327.2, R702 Fireplace R1001.5 Foundation R404 Insulating concrete form R608.3, R608.4, R608.5.3 Steel framing R603 Structural insulated panels (SIP) R610 Thickness, masonry chimneys R1003.10 Wood framing R602 Waste
Construction waste R334
Water Closet R326.1, R327 Clearances for R327.1 Waterproofing And dampproofing R406 Wells (see Individual Water Supply) Whirlpool Bathtubs R324.3.1, P2720 Wind
Design criteria R301.2, R301.2.1 Speed maps Figure R301.2(2) Window R609 Emergency Escape and Rescue Openings R319, R321.2.2 Fall protection R321.2 Glazing R324 Light and ventilation R325 Opening limiting devices R321.2.2 Wood
Floor construction R502
Foundation walls R404.2 Protection against decay R304 Roof-ceiling construction R802 Shakes R905.8 Shingles R905.7 Trusses R502.12, R802.10 Walls R602
Yard R318.1, R319.1, R319.2.4, R325.1.1
2025 CALIFORNIA RESIDENTIAL CODE INDEX-5
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
INDEX-6 2025 CALIFORNIA RESIDENTIAL CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
HISTORY NOTE APPENDIX
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:
Floor and roof dead and live loads.
Ground snow load, p g, and allowable stress design ground snow load, p g(asd) .
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.
Seismic design category and site class.
Flood design data, if located in flood hazard areas established in Section 1612 A .3.
Design load-bearing values of soils.
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:
- Flat-roof snow load, p f .
- Snow exposure factor, C e .
- Risk category.
- Thermal factor, C t .
- Slope factor(s), C s .
- Drift surcharge load(s), p d , where the sum of p d and p f exceeds 30 psf (1.44 kN/m [2] ) .
- Width of snow drift(s), w .
- 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:
- 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 § 3.3. Medium relevance — show source text
= On Center.
a. Steel framing shall be minimum 33-ksi steel for 33-mil and 43-mil steel, and 50-ksi steel for 54-mil steel or thicker.
b. Where cladding is attached to wood structural panel sheathing only, fastening requirements shall be in accordance with Table R703.3.3. For brick veneer tie connections to
wood structural panels, refer to Table R703.8.4(2).
c. Screws shall comply with the requirements of ASTM C1513.
d. Foam sheathing shall have a minimum compressive strength of 15 psi in accordance with ASTM C578 or ASTM C1289.|For SI: 1 inch = 25.4 mm, 1 mil = 0.0254 mm, 1 pound per square foot = 0.0479 kPa, 1 pound per square inch = 6.895 kPa.
DR = Design Required.
o.c. = On Center.
a. Steel framing shall be minimum 33-ksi steel for 33-mil and 43-mil steel, and 50-ksi steel for 54-mil steel or thicker.
b. Where cladding is attached to wood structural panel sheathing only, fastening requirements shall be in accordance with Table R703.3.3. For brick veneer tie connections to
wood structural panels, refer to Table R703.8.4(2).
c. Screws shall comply with the requirements of ASTM C1513.
d. Foam sheathing shall have a minimum compressive strength of 15 psi in accordance with ASTM C578 or ASTM C1289.|For SI: 1 inch = 25.4 mm, 1 mil = 0.0254 mm, 1 pound per square foot = 0.0479 kPa, 1 pound per square inch = 6.895 kPa.
DR = Design Required.
o.c. = On Center.
a. Steel framing shall be minimum 33-ksi steel for 33-mil and 43-mil steel, and 50-ksi steel for 54-mil steel or thicker.
b. Where cladding is attached to wood structural panel sheathing only, fastening requirements shall be in accordance with Table R703.3.3. For brick veneer tie connections to
wood structural panels, refer to Table R703.8.4(2).
c. Screws shall comply with the requirements of ASTM C1513.
d. Foam sheathing shall have a minimum compressive strength of 15 psi in accordance with ASTM C578 or ASTM C1289.|R703.16.2 Furred cladding attachment. Where steel or wood furring is used to attach cladding over foam sheathing, furring minimum fastening requirements to support the cladding weight shall be as specified in Table R703.16.2. Where placed horizontally, wood furring shall be preservative-treated wood in accordance with Section R304.1 or naturally durable wood and fasteners shall be corrosion resistant in accordance with Section R304.3. Steel furring shall have a minimum G60 galvanized coating.
|TABLE R703.16.2—FURRING MINIMUM FASTENING REQUIREMENTS FOR
APPLICATION OVER FOAM PLASTIC SHEATHING TO SUPPORT CLADDINGCRC § 25.4 Medium relevance — show source text
= on center.
a. Cold-formed steel framing shall be minimum 33 ksi steel for 33 mil and 43 mil steel and 50 ksi steel for 54 mil steel or thicker.
b. Screws shall comply with the requirements of AISI S240.
c. Foam sheathing shall have a minimum compressive strength of 15 pounds per square inch in accordance with ASTM C578 or ASTM C1289.|For SI: 1 inch = 25.4 mm, 1 pound per square foot (psf) = 0.0479 kPa, 1 pound per square inch = 0.00689 MPa.
DR = design required, o.c. = on center.
a. Cold-formed steel framing shall be minimum 33 ksi steel for 33 mil and 43 mil steel and 50 ksi steel for 54 mil steel or thicker.
b. Screws shall comply with the requirements of AISI S240.
c. Foam sheathing shall have a minimum compressive strength of 15 pounds per square inch in accordance with ASTM C578 or ASTM C1289.|For SI: 1 inch = 25.4 mm, 1 pound per square foot (psf) = 0.0479 kPa, 1 pound per square inch = 0.00689 MPa.
DR = design required, o.c. = on center.
a. Cold-formed steel framing shall be minimum 33 ksi steel for 33 mil and 43 mil steel and 50 ksi steel for 54 mil steel or thicker.
b. Screws shall comply with the requirements of AISI S240.
c. Foam sheathing shall have a minimum compressive strength of 15 pounds per square inch in accordance with ASTM C578 or ASTM C1289.|For SI: 1 inch = 25.4 mm, 1 pound per square foot (psf) = 0.0479 kPa, 1 pound per square inch = 0.00689 MPa.
DR = design required, o.c. = on center.
a. Cold-formed steel framing shall be minimum 33 ksi steel for 33 mil and 43 mil steel and 50 ksi steel for 54 mil steel or thicker.
b. Screws shall comply with the requirements of AISI S240.
c. Foam sheathing shall have a minimum compressive strength of 15 pounds per square inch in accordance with ASTM C578 or ASTM C1289.|[BS] 1404.5.2.2 Furred cladding attachment. Where steel or wood furring is used to attach cladding over foam sheathing, furring minimum fastening requirements to support the cladding weight shall be as specified in Table 1404.5.2.2. Where placed horizontally, wood furring shall be preservative-treated wood in accordance with Section 2303.1.9 or naturally durable wood and fasteners shall be corrosion resistant in accordance Section 2304.10.6. Steel furring shall have a minimum G60 galvanized coating.
2025 CALIFORNIA BUILDING CODE 14-9
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
EXTERIOR WALLS
|[BS] TABLE 1404.5.2.2—FURRING MINIMUM FASTENING REQUIREMENTS FOR
APPLICATION OVER FOAM PLASTIC SHEATHING TO SUPPORT CLADDING
Frequently asked questions
Who must prepare the truss design drawings?
A registered design professional must prepare the truss design drawings as required by § R502.12.1.
Must the truss drawings be on the jobsite?
Yes — the code requires truss design drawings be submitted and approved prior to installation and be provided with the shipment of trusses to the job site (§ R502.12.4).
Can a contractor field‑notch a truss to run mechanicals?
No — truss members shall not be cut, notched, spliced or otherwise altered without approval of a registered design professional (§ R502.12.3).
What do I do if the truss drawings don’t show bracing details?
If the approved drawings are silent on bracing, the installer must provide bracing in accordance with accepted industry practice (for example SBCA BCSI) as required by § R502.12.2.
Are steel trusses covered the same way?
Cold‑formed steel floor trusses are covered under § R505.1.3 and must be designed and braced per AISI S230; they are also not to be notched or altered without approved design.
More in California Residential Code
Ask about the CRC
Get cited, plain-English answers on the California Residential Code for your project — any code section, any scenario.
Start Free Trial