CRC · California Residential Code
What roof sheathing materials, grades and minimum thicknesses does the CRC allow?
For homeowners: the CRC requires either solid lumber at the minimum net thickness in **Table R803.1** or marked wood structural panels (plywood/OSB) that meet DOC PS/CSA standards and the span tables in **Table R503.2.1.1(1)** (or APA E30). Verify the product grade mark, exposure rating, and the table row that matches your rafter spacing and span before purchasing or installing sheathing.
Last reviewed: July 6, 2026
What the code requires — plain English
The California Residential Code requires that roof sheathing be either lumber sized/graded to the minimum net thicknesses in Table R803.1 or wood structural panels that meet identification, grade and exposure requirements and meet the allowable spans in Table R503.2.1.1(1) (installation per the table or APA E30). See § R803.1 and § R803.2 / § R803.2.1 for the controlling text.
The single most important rule: select sheathing material by the code section that matches the product (lumber vs. wood structural panel), use the minimum thickness/grade for your rafter/truss spacing, and install per the applicable fastening and exposure rules in § R803.1 and § R803.2.
Requirements in detail
Governing sections (first mentions are bold)
- § R803.1 — Lumber roof sheathing minimum net thickness requirements (by rafter/beam spacing).
- § R803.2 — Wood structural panel roof sheathing requirements, allowable spans and installation references.
- § R803.2.1 — Identification, grade and exposure durability for wood structural panels.
Minimum thickness / grade summary (decision table)
| Application / decision input | Minimum material, grade or thickness (code citation) | Code Reference |
|---|---|---|
| Solid lumber sheathing — rafters / beams 24 in. o.c. | 5/8 in. net minimum (solid lumber) — see § R803.1. | § R803.1 (Table R803.1) |
| Solid lumber sheathing — rafters / beams 48 in. o.c. | 1-1/2 in. T&G (tongue & groove) (grade/Fb/E requirements noted in table footnotes) — § R803.1. | § R803.1 (Table R803.1) |
| Wood structural panel (Plywood / OSB) — typical allowed nominal panel thicknesses used for roofs | Common nominal panel thicknesses referenced for allowable span tables include 15/32 in., 7/16 in., 1/2 in., 19/32 in., 5/8 in., 23/32 in., 3/4 in., etc.; allowable spans are taken from Table R503.2.1.1(1) or APA E30 and are limited by panel grade/span rating. See § R803.2 and § R803.2.1. | § R803.2, § R803.2.1 (Table R503.2.1.1(1) / APA E30) |
| Panel identification/grade required | Panels must conform to DOC PS 1, DOC PS 2, CSA O325 or CSA O437 and be identified by grade mark or certificate (grade, bond class, performance). See § R803.2.1. | § R803.2.1 |
| Exposure durability | Panels intended to be permanently exposed outdoors must be of exterior exposure durability. Panels exposed to the underside may be Exposure 1 interior type bonded with exterior glue. See § R803.2.1.1. | § R803.2.1.1 |
| Installation / cantilever limit | Install panels per Table R602.3(1) / APA E30; wood structural panel roof sheathing shall not cantilever more than 9 in. beyond the gable endwall unless supported by overhang framing. See § R803.2.3. | § R803.2.3 |
Notes on the panel table: the CRC directs you to use the tabulated allowable spans in Table R503.2.1.1(1) (or APA E30) to select panel thickness vs. rafter/truss spacing and direction of strength axis; those tables list specific span ratings (e.g., 24/0, 24/16, 32/16, 48/24, etc.) and corresponding panel thicknesses and maximum spans. Use the table for a definitive selection. § R803.2 and § R803.2.2 require adherence to those span tables.
Grades and identification (what “grade” means here)
- Plywood / OSB used as roof sheathing must carry a grade mark showing the applicable product standard and the grade/bond (for example, DOC PS 1 or DOC PS 2 markings such as “Structural I — Sheathing (Exposure 1)”). See § R803.2.1.
- Fire‑retardant‑treated plywood must be graded and have allowable unit stresses and fastener values developed by an approved investigation (see § R803.2.1.2).
Exceptions & special cases
- Spaced lumber sheathing for wood shingle/shake roofing must meet Sections R905.7 and R905.8; spaced sheathing is not allowed in Seismic Design Category D2. See § R803.1.
- Wood structural panels used where the underside is exposed (e.g., open rafter tails) may be an Exposure 1 interior-bonded panel, but panels designed to remain exposed outdoors must be exterior exposure rated. See § R803.2.1.1.
- Fire‑retardant treatments alter allowable design stresses and fastener values; treated plywood must be graded and have design values documented by an approved method. See § R803.2.1.2.
- Cantilever limits: wood structural panel roof sheathing shall not cantilever more than 9 in. past the gable endwall unless supported by gable overhang framing. See § R803.2.3.
If your project requires spans or conditions not covered by the tables (very long spans, unusual loads, or non-standard materials), the CRC allows design by accepted engineering practice — but the code tables are the default. See § R803.2.2 and the referenced tables (APA E30).
Common mistakes
- Assuming “any OSB” is code‑compliant — the panel must be marked to an accepted standard (DOC PS 1/2 or CSA) and the correct panel span rating must be used. See § R803.2.1.
- Picking panel thickness without checking the correct span rating (e.g., 24/0 vs 48/24) — the allowable span depends on panel rating and orientation. Use Table R503.2.1.1(1) / APA E30 as required by § R803.2.2.
- Using spaced sheathing for shingle installations in Seismic Design Category D2 — CRC prohibits spaced lumber sheathing in SD D2 (see § R803.1).
- Forgetting exposure classification — installing an interior‑bond panel where the underside is subject to prolonged outdoor exposure when the panel is not rated for exterior exposure violates § R803.2.1.1.
Worked example — pick the right panel for a 24"‑oc rafter roof
Scenario: residential roof, rafters at 24 in. o.c., typical live/total roof loads. You want to use wood structural panels (OSB or plywood).
- The CRC requires you to use the allowable spans in Table R503.2.1.1(1) or APA E30 per § R803.2.2.
- From the span table (examples in the referenced table): a 7/16 in. Structural I panel is shown for some 24" spans (many span ratings allow 7/16 in. at a 24" maximum span depending on rating), and 15/32 in. or 1/2 in. panels are commonly used where required by the rating. Use the table row that matches the panel’s span rating (e.g., 24/0, 24/16, 32/16).
- Confirm the product has the required grade mark (DOC PS 1 / DOC PS 2 or CSA) per § R803.2.1 and the proper exposure classification per § R803.2.1.1.
- Install panels per § R803.2.3 and the fastening schedule in Table R602.3(1) / APA E30 (edge and field nailing patterns) — the CRC references those for installation.
Practical outcome: for 24" o.c. rafters many builders commonly use 7/16 in. to 15/32 in. Structural I sheathing if the panel span rating and table allow it for the specific roof geometry — but you must verify the specific panel marking, span rating and the table row that applies. See § R803.2.2 and Table R503.2.1.1(1).
Related provisions (CRC sections)
- § R905 — Roof coverings (requirements that affect sheathing type and spacing for specific roof coverings).
- § R804 — Cold‑formed steel roof framing (tables for panel installation on steel framing; R803 references R804 tables for steel framing).
- § R802 / § R802.11.2 — Rafter uplift and attachment requirements (connection design that can affect sheathing diaphragm loads).
- Table references: Table R803.1 (lumber sheathing minima) and Table R503.2.1.1(1) (wood structural panel allowable spans / thicknesses) — consult these tables directly when selecting material and thickness.
If you want, I can extract the exact rows from Table R503.2.1.1(1) and Table R803.1 for your specific rafter spacing, roof span and panel product (give me rafter spacing, roof span direction, desired panel type — OSB or plywood — and whether the underside will be exposed). The code text cited above is the source for each of these requirements.
Code references
Grounded in the retrieved California Residential Code — click a citation to read the verbatim passage:
CRC § 1.1. High relevance — show source text
Plywood shall be of the following minimum grades in accordance with DOC PS 1 or DOC PS 2:
1. DOC PS 1 Plywood grades marked:
1.1. Structural I C-D (Exposure 1).
1.2. C-D (Exposure 1).
2. DOC PS 2 Plywood grades marked:
2.1. Structural I Sheathing (Exposure 1).
2.2. Sheathing (Exposure 1).
3. Where a major portion of the wall is exposed above ground and a better appearance is desired, the following plywood grades marked exterior are suitable:
3.1. Structural I A-C, Structural I B-C or Structural I C-C (Plugged) in accordance with DOC PS 1.
3.2. A-C Group 1, B-C Group 1, C-C (Plugged) Group 1 or MDO Group 1 in accordance with DOC PS 1.
3.3. Single Floor in accordance with DOC PS 1 or DOC PS 2.
b. Minimum thickness15/32 inch, except crawl space sheathing shall have not less than3/8 inch for face grain across studs 16 inches on center and maximum 2-foot depth of
unequal fill.
c. For this fill height, thickness and grade combination, panels that are continuous over less than three spans (across less than three stud spacings) require blocking 16 inches
above the bottom plate. Offset adjacent blocks and fasten through studs with two 16d corrosion-resistant nails at each end.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
a. Plywood shall be of the following minimum grades in accordance with DOC PS 1 or DOC PS 2:
1. DOC PS 1 Plywood grades marked:
1.1. Structural I C-D (Exposure 1).
1.2. C-D (Exposure 1).
2. DOC PS 2 Plywood grades marked:
2.1. Structural I Sheathing (Exposure 1).
2.2. Sheathing (Exposure 1).
3. Where a major portion of the wall is exposed above ground and a better appearance is desired, the following plywood grades marked exterior are suitable:
3.1. Structural I A-C, Structural I B-C or Structural I C-C (Plugged) in accordance with DOC PS 1.
3.2. A-C Group 1, B-C Group 1, C-C (Plugged) Group 1 or MDO Group 1 in accordance with DOC PS 1.
3.3. Single Floor in accordance with DOC PS 1 or DOC PS 2.
b. Minimum thickness15/32 inch, except crawl space sheathing shall have not less than3/8 inch for face grain across studs 16 inches on center and maximum 2-foot depth of
unequal fill.
c. For this fill height, thickness and grade combination, panels that are continuous over less than three spans (across less than three stud spacings) require blocking 16 inches
above the bottom plate. Offset adjacent blocks and fasten through studs with two 16d corrosion-resistant nails at each end.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
a.CRC § 25.4 High relevance — show source text
Applicable to all grades of sanded exterior-type plywood. See DOC PS 1 for plywood species groups.
c. Applicable to underlayment grade, C-C (plugged) plywood, and single floor grade wood structural panels.|For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kN/m2.
a. Spans limited to value shown because of possible effects of concentrated loads. Allowable uniform loads based on deflection of1/360 of span is 100 pounds per square foot
except allowable total uniform load for 11/8-inch wood structural panels over joists spaced 48 inches on center is 65 pounds per square foot. Panel edges shall have approved
tongue-and-groove joints or shall be supported with blocking, unless1/4-inch minimum thickness underlayment or 11/2 inches of approved cellular or lightweight concrete is
placed over the subfloor, or finish floor is3/4-inch wood strip.
b. Applicable to all grades of sanded exterior-type plywood. See DOC PS 1 for plywood species groups.
c. Applicable to underlayment grade, C-C (plugged) plywood, and single floor grade wood structural panels.|23-14 2025 CALIFORNIA BUILDING CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
WOOD
TABLE 2304.8(5)—ALLOWABLE LOAD (PSF) FOR WOOD STRUCTURAL PANEL ROOF
SHEATHING CONTINUOUS OVER TWO OR MORE SPANS AND STRENGTH AXIS PARALLEL TO SUPPORTS
(Plywood structural panels are five-ply, five-layer unless otherwise noted)aCol2 Col3 Col4 Col5 PANEL GRADE THICKNESS
(inch)MAXIMUM SPAN
(inches)LOAD AT MAXIMUM SPAN
(psf)LOAD AT MAXIMUM SPAN
(psf)PANEL GRADE THICKNESS
(inch)MAXIMUM SPAN
(inches)Live Totalc Structural I sheathing 7/16 24 20 30 Structural I sheathing 15/32 24 35b 45b Structural I sheathing 1/2 24 40b 50b Structural I sheathing 19/32, 5/8 24 70 80 Structural I sheathing 23/32, 3/4 24 90 100 Sheathing, other grades covered in DOC PS 1 or DOC PS 2 7/16 16 40 50 Sheathing, other grades covered in DOC PS 1 or DOC PS 2 15/32 24 20 25 Sheathing, other grades covered in DOC PS 1 or DOC PS 2 1/2 24 25 30 Sheathing, other grades covered in DOC PS 1 or DOC PS 2 19/32 24 40b 50b Sheathing, other grades covered in DOC PS 1 or DOC PS 2 5/8 24 45b 55b Sheathing, other grades covered in DOC PS 1 or DOC PS 2 23/32, CRC § 0.0254 High relevance — show source text
Deflection criteria:L/360 for live loads,L/240 for total loads.
b. Design load assumptions:
Second-floor dead load is 10 psf.
Roof/ceiling dead load is 12 psf.
Second-floor live load is 40 psf.
Third floor live load is 30 psf.
Attic live load is 10 psf.
c. Building width is in the direction of horizontal framing members supported by the header.
d. Minimum Grade 33 ksi steel shall be used for 33 mil and 43 mil thicknesses. Minimum Grade 50 ksi steel shall be used for 54 and 68 mil thicknesses.|For SI: 1 mil = 0.0254 mm, 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 pound per square inch = 6.895 kPa, 1 ksi = 1,000 psi = 6.895 MPa.
a. Deflection criteria:L/360 for live loads,L/240 for total loads.
b. Design load assumptions:
Second-floor dead load is 10 psf.
Roof/ceiling dead load is 12 psf.
Second-floor live load is 40 psf.
Third floor live load is 30 psf.
Attic live load is 10 psf.
c. Building width is in the direction of horizontal framing members supported by the header.
d. Minimum Grade 33 ksi steel shall be used for 33 mil and 43 mil thicknesses. Minimum Grade 50 ksi steel shall be used for 54 and 68 mil thicknesses.|For SI: 1 mil = 0.0254 mm, 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 pound per square inch = 6.895 kPa, 1 ksi = 1,000 psi = 6.895 MPa.
a. Deflection criteria:L/360 for live loads,L/240 for total loads.
b. Design load assumptions:
Second-floor dead load is 10 psf.
Roof/ceiling dead load is 12 psf.
Second-floor live load is 40 psf.
Third floor live load is 30 psf.
Attic live load is 10 psf.
c. Building width is in the direction of horizontal framing members supported by the header.
d. Minimum Grade 33 ksi steel shall be used for 33 mil and 43 mil thicknesses. Minimum Grade 50 ksi steel shall be used for 54 and 68 mil thicknesses.|2025 CALIFORNIA RESIDENTIAL CODE 6-83
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
WALL CONSTRUCTION
TRACK
TRACK
TRACK
TRACK OR C-SHAPE ATTACH WITH NO. 8 SCREWS (MINIMUM DEPTH = HEADER DEPTH MINUS ½ INCH)
KING STUD(S)
JACK STUD(S)
NO. 8 SCREWS THROUGH SHEATHING TO EACH JACK AND KING STUD
AT 12 ON CENTER ˝
STRUCTURAL SHEATHING
FIGURE R603.6(1)—BOX BEAM HEADER
For SI: 1 inch = 25.4 mm.
CRC § 25.4 High relevance — show source text
Deflection criterion_L_/240.
b. Design load assumptions:
Ground snow load is 70 psf.
Roof/ceiling dead load is 12 psf.
Floor dead load is 10 psf.
Floor live load is 40 psf.
Attic dead load is 10 psf.
c. Building width is in the direction of horizontal framing members supported by the wall studs.
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 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mil = 0.0254 mm, 1 mile per hour = 0.447 m/s, 1 pound per square foot = 0.0479 kPa, 1 ksi = 1,000 psi = 6.895 MPa.
a. Deflection criterion_L_/240.
b. Design load assumptions:
Ground snow load is 70 psf.
Roof/ceiling dead load is 12 psf.
Floor dead load is 10 psf.
Floor live load is 40 psf.
Attic dead load is 10 psf.
c. Building width is in the direction of horizontal framing members supported by the wall studs.
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.|R603.3.3 Stud bracing. The flanges of cold-formed steel studs shall be laterally braced in accordance with one of the following:
- Gypsum board on both sides, structural sheathing on both sides, or gypsum board on one side and structural sheathing on the other side of load-bearing walls with gypsum board installed with minimum No. 6 screws in accordance with Section R702 and structural sheathing installed in accordance with Section R603.9 and Table R603.3.2(1).
- Horizontal steel straps fastened in accordance with Figure R603.3.3(1) on both sides at mid-height for 8-foot (2438 mm) walls, and at one-third points for 9-foot and 10-foot (2743 mm and 3048 mm) walls. Horizontal steel straps shall be not less than 1 [1] / 2 inches in width and 33 mils in thickness (38 mm by 0.84 mm). Straps shall be attached to the flanges of studs with one No. 8 screw. In-line blocking shall be installed between studs at the termination of straps and at 12-foot (3658 mm) intervals along the strap. Straps shall be fastened to the blocking with two No. 8 screws.
- Sheathing on one side and strapping on the other side fastened in accordance with Figure R603.3.3(2). Sheathing shall be installed in accordance with Item 1. Steel straps shall be installed in accordance with Item 2.
2025 CALIFORNIA RESIDENTIAL CODE 6-75
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
WALL CONSTRUCTION
FIGURE R603.3.3(1)—STUD BRACING WITH STRAPPING ONLY
TO FORM VERTICAL
1½ ″ x 33 MIL FLAT STRIP (MINIMUM)
WALL FRAMING
California Residential Code High relevance — show source text
|100 psf|1 hr
23 min|||7|1, 2|11/3| |F/C-4-RC-9|4″|4″ deep (4370 psi);1/4″ reinforcement bars
at 6″ pitch with3/4″ cover;1/4″ main rein-
forcement bars at 4″ pitch perpendicular
with1/2″ cover; 13′1″ span restrained.|150 psf|2 hrs|||7|1, 3|2| |F/C-4-RC-10|4″|4″ thick (5140 psi) deck;1/4″ reinforce-
ment bars at 71/2″ pitch with7/8″ cover;3/8″
main reinforcement bars at 33/4″ pitch
perpendicular with1/2″ cover; 13′1″ span
restrained.|140 psf|1 hr
16 min|||7|1, 5|11/4| |F/C-4-RC-11|4″|4″ thick (4000 psi) concrete deck;
3″ × 11/2″ × 4 lbs R.S.J.; 2′6″ C.R.S.; flush
with top surface; 4″ × 6″ x 13 SWG mesh
reinforcement 1″ from bottom of slab; 6′6″
span restrained.|150 psf|2 hrs|||7|1, 3|2| |F/C-4-RC-12|4″|4″ deep (2380 psi) concrete deck;
3″ × 11/2″ × 4 lbs R.S.J.; 2′6″ C.R.S.; flush
with top surface; 4″ × 6″ x 13 SWG mesh
reinforcement 1″ from bottom surface;
6′6″ span restrained.|150 psf|1 hr
3 min|||7|1, 2|1| |F/C-4-RC-13|41/2″|41/2″ thick (5200 psi) deck;1/4″ reinforce-
ment bars at 71/4″ pitch with7/8″ cover;3/8″
main reinforcement bars at 33/4″ pitch
perpendicular with1/2″ cover; 13′1″ span
restrained.|140 psf|2 hrs|||7|1, 3|2| |F/C-4-RC-14|41/2″|41/2″ deep (2525 psi) concrete deck;1/4″
reinforcement bars at 71/2″ pitch with7/8″
cover;3/8″ main reinforcement bars at
33/8″ pitch perpendicular with1/2″ cover;
13′1″ span restrained.|150 psf|42 min|||7|1, 5|2/3| |F/C-4-RC-15|41/2″|41/2″ deep (4830 psi) concrete deck;
11/2″ × No.CRC § 0.0254 High relevance — show source text
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:
Roof/ceiling dead load is 12 psf.
Attic dead 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:
Roof/ceiling dead load is 12 psf.
Attic dead 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:
Roof/ceiling dead load is 12 psf.
Attic dead load is 10 psf.
c. Building width is in the direction of horizontal framing members supported by the header.
d. Minimum Grade 33 ksi steel shall be used for 33 mil and 43 mil thicknesses. Minimum Grade 50 ksi steel shall be used for 54 and 68 mil thicknesses.|6-78 2025 CALIFORNIA RESIDENTIAL CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
WALL CONSTRUCTION
TABLE R603.6(2)—BOX-BEAM AND BACK-TO-BACK HEADER SPANS
(HEADERS SUPPORTING ROOF AND CEILING ONLY)a, b, dCol2 Col3 Col4 Col5 Col6 Col7 Col8 Col9 Col10 Col11 MEMBER
DESIGNATIONGROUND SNOW LOAD
(50 psf)GROUND SNOW LOAD
**(50CRC § 1.75. High relevance — show source text
Deflection limit:L/240.
b. Head and sill track spans are based on components and cladding wind pressures and 48-inch tributary span.
c. For openings less than 4 feet in height that have both a head track and sill track, the spans are permitted to be multiplied by 1.75. For openings less than or equal to 6 feet in
height that have both a head track and a sill track, the spans are permitted to be multiplied by a factor of 1.5.
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 mile per hour = 0.447 m/s, 1 ksi = 1,000 psi = 6.895 MPa.
a. Deflection limit:L/240.
b. Head and sill track spans are based on components and cladding wind pressures and 48-inch tributary span.
c. For openings less than 4 feet in height that have both a head track and sill track, the spans are permitted to be multiplied by 1.75. For openings less than or equal to 6 feet in
height that have both a head track and a sill track, the spans are permitted to be multiplied by a factor of 1.5.
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 mile per hour = 0.447 m/s, 1 ksi = 1,000 psi = 6.895 MPa.
a. Deflection limit:L/240.
b. Head and sill track spans are based on components and cladding wind pressures and 48-inch tributary span.
c. For openings less than 4 feet in height that have both a head track and sill track, the spans are permitted to be multiplied by 1.75. For openings less than or equal to 6 feet in
height that have both a head track and a sill track, the spans are permitted to be multiplied by a factor of 1.5.
d. Minimum Grade 33 ksi steel shall be used for 33 mil and 43 mil thicknesses. Minimum Grade 50 ksi steel shall be used for 54 and 68 mil thicknesses.|6-86 2025 CALIFORNIA RESIDENTIAL CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
WALL CONSTRUCTION
R603.9 Structural sheathing. Structural sheathing shall be installed in accordance with Figure R603.9 and this section on all sheathable exterior wall surfaces, including areas above and below openings.
FIGURE R603.9—STRUCTURAL SHEATHING FASTENING PATTERN
STRUCTURAL SHEATHING
R603.9.1 Sheathing materials. Structural sheathing panels shall consist of minimum [7] / 16 -inch-thick (11 mm) oriented strand board or [15] / 32 -inch-thick (12 mm) plywood.
CRC § 11.2 High relevance — show source text
R802.11.2 Rafter uplift resistance. Individual rafters shall be attached to supporting wall assemblies by connections capable of resisting uplift forces as determined by Table R802.11 or as determined by accepted engineering practice. Connections for beams used in a roof system shall be designed in accordance with accepted engineering practice.
SECTION R803—ROOF SHEATHING
R803.1 Lumber sheathing. Allowable spans for lumber used as roof sheathing shall conform to Table R803.1. Spaced lumber sheathing for wood shingle and shake roofing shall conform to the requirements of Sections R905.7 and R905.8. Spaced lumber sheathing is not allowed in Seismic Design Category D 2 .
TABLE R803.1—MINIMUM THICKNESS OF LUMBER ROOF SHEATHING Col2 ** RAFTER OR BEAM SPACING (inches)** ** MINIMUM NET THICKNESS (inches)** 24 5/8 48a 11/2 T & G 60b 60b 72c 72c For SI: 1 inch = 25.4 mm.
a. Minimum 270_F_ b, 340,000_E.
b. Minimum 420_F b, 660,000_E.
c. Minimum 600_F b, 1,150,000_E._For SI: 1 inch = 25.4 mm.
a. Minimum 270_F_ b, 340,000_E.
b. Minimum 420_F b, 660,000_E.
c. Minimum 600_F b, 1,150,000_E._R803.2 Wood structural panel sheathing.
R803.2.1 Identification and grade. Wood structural panels shall conform to DOC PS 1, DOC PS 2, CSA O325 or CSA O437, and shall be identified for grade, bond classification and performance category by a grade mark or certificate of inspection issued by an approved agency. Wood structural panels shall comply with the grades specified in Table R503.2.1.1(1).
8-30 2025 CALIFORNIA RESIDENTIAL CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
ROOF-CEILING CONSTRUCTION
R803.2.1.1 Exposure durability. Wood structural panels, when designed to be permanently exposed in outdoor applications, shall be of an exterior exposure durability. Wood structural panel roof sheathing exposed to the underside shall be permitted to be of interior type bonded with exterior glue, identified as Exposure 1.
R803.2.1.2 Fire-retardant-treated plywood. The allowable unit stresses for fire-retardant-treated plywood, including fastener values, shall be developed from an approved method of investigation that considers the effects of anticipated temperature and humidity to which the fire-retardant-treated plywood will be subjected, the type of treatment and redrying process. The fire-retardant-treated plywood shall be graded by an approved agency.
R803.2.2 Allowable spans. The maximum allowable spans for wood structural panel roof sheathing shall not exceed the values set forth in Table R503.2.1.1(1) or APA E30.
California Residential Code High relevance — show source text
2, 3 and 4)b**|Fastener spacing (inches)
at other panel edges
(Cases 1, 2, 3 and 4)b| |PANEL
GRADE|STAPLE
LENGTH
AND
GAGEd|MINIMUM
FASTENER
PENETRATION
IN FRAMING
(inches)|MINIMUM
NOMINAL
PANEL
THICKNESS
(inch)|MINIMUM
NOMINAL WIDTH
OF FRAMING
MEMBERS AT
ADJOINING PANEL
EDGES AND
BOUNDARIESe
(inches)|6|6|4|3|3|3| |Structural I
grades|11/2 16
gage|1|3/8|2|175|235|350|400|155|115| |Structural I
grades|11/2 16
gage|1|3/8|3|200|265|395|450|175|130| |Structural I
grades|11/2 16
gage|1|15/32|2|175|235|350|400|155|120| |Structural I
grades|11/2 16
gage|1|15/32|3|200|265|395|450|175|130| |Sheathing,
single floor
and other
grades
covered in
DOC PS 1
and PS 2|11/2 16
gage|1|3/8|2|160|210|315|360|140|105| |Sheathing,
single floor
and other
grades
covered in
DOC PS 1
and PS 2|11/2 16
gage|1|3/8|3|180|235|355|400|160|120| |Sheathing,
single floor
and other
grades
covered in
DOC PS 1
and PS 2|11/2 16
gage|1|7/16|2|165|225|335|380|150|110| |Sheathing,
single floor
and other
grades
covered in
DOC PS 1
and PS 2|11/2 16
gage|1|7/16|3|190|250|375|425|165|125| |Sheathing,
single floor
and other
grades
covered in
DOC PS 1
and PS 2|11/2 16
gage|1|15/32|2|160|210|315|360|140|105| |Sheathing,
single floor
and other
grades
covered in
DOC PS 1
and PS 2|11/2 16
gage|1|15/32|3|180|235|355|405|160|120| |Sheathing,CRC § 25.4 High relevance — show source text
FRAMING**
(inches)|MINIMUM
NOMINAL
PANEL
THICKNESS
(inch)|MINIMUM NOMI-
NAL WIDTH OF
FRAMING
MEMBER AT
ADJOINING
PANEL EDGES
AND
BOUNDARIESe|LINES OF
FASTENERS|6|4|4|3|3|2| |Structural I
grades|14 gage
staples|2|15/32|3|2|600|600|860|960|1,060|1,200| |Structural I
grades|14 gage
staples|2|15/32|4|3|860|900|1,160|1,295|1,295|1,400| |Structural I
grades|14 gage
staples|2|19/32|3|2|600|600|875|960|1,075|1,200| |Structural I
grades|14 gage
staples|2|19/32|4|3|875|900|1,175|1,440|1,475|1,795| |Sheathing
single floor
and other
grades
covered in
DOC PS 1
and PS 2|14 gage
staples|2|15/32|3|2|540|540|735|865|915|1,080| |Sheathing
single floor
and other
grades
covered in
DOC PS 1
and PS 2|14 gage
staples|2|15/32|4|3|735|810|1,005|1,105|1,105|1,195| |Sheathing
single floor
and other
grades
covered in
DOC PS 1
and PS 2|14 gage
staples|2|19/32|3|2|600|600|865|960|1,065|1,200| |Sheathing
single floor
and other
grades
covered in
DOC PS 1
and PS 2|14 gage
staples|2|19/32|4|3|865|900|1,130|1,430|1,370|1,485| |Sheathing
single floor
and other
grades
covered in
DOC PS 1
and PS 2|14 gage
staples|2|23/32|4|3|865|900|1,130|1,490|1,430|1,545| |For SI: 1 inch = 25.4 mm, 1 pound per foot = 14.5939 N/m.
a.
For framing of other species: (1) Find specific gravity for species of framing lumber in ANSI/AWC NDS. (2) For staples, find shear value from table for Structural I panels (regard-
less of actual grade) and multiply value by 0.82 for species with specific gravity of 0.42 or greater, or 0.65 for all other species.
b.CRC § 2.1 High relevance — show source text
The adjustment coefficients in Table R301.2.1(2) shall not be
used to multiply the tabulated forces for Exposures C and D or for other mean roof heights.
b. The uplift connection forces include an allowance for roof and ceiling assembly dead load of 15 psf.
c. The tabulated uplift connection forces are limited to a maximum roof overhang of 24 inches.
d. The tabulated uplift connection forces shall be permitted to be multiplied by 0.75 for connections not located within 8 feet of building corners.
e. For buildings with hip roofs with 5:12 and greater pitch, the tabulated uplift connection forces shall be permitted to be multiplied by 0.70. This reduction shall not be
combined with any other reduction in tabulated forces.
f. For wall-to-wall and wall-to-foundation connections, the uplift connection force shall be permitted to be reduced by 60 pounds per linear foot for each full wall above.
g. Linear interpolation between tabulated roof spans and wind speeds shall be permitted.
h. The tabulated forces for a 12-inch on-center spacing shall be permitted to be used to determine the uplift load in pounds per linear foot.|R802.11.1 Truss uplift resistance. Trusses shall be attached to supporting wall assemblies by connections capable of resisting uplift forces as specified on the truss design drawings for the ultimate design wind speed as determined by Figure R301.2(2) and listed in Table R301.2 or as shown on the construction documents. Uplift forces shall be permitted to be determined as specified by Table R802.11, if applicable, or as determined by accepted engineering practice.
R802.11.2 Rafter uplift resistance. Individual rafters shall be attached to supporting wall assemblies by connections capable of resisting uplift forces as determined by Table R802.11 or as determined by accepted engineering practice. Connections for beams used in a roof system shall be designed in accordance with accepted engineering practice.
SECTION R803—ROOF SHEATHING
R803.1 Lumber sheathing. Allowable spans for lumber used as roof sheathing shall conform to Table R803.1. Spaced lumber sheathing for wood shingle and shake roofing shall conform to the requirements of Sections R905.7 and R905.8. Spaced lumber sheathing is not allowed in Seismic Design Category D 2 .
TABLE R803.1—MINIMUM THICKNESS OF LUMBER ROOF SHEATHING Col2 ** RAFTER OR BEAM SPACING (inches)** ** MINIMUM NET THICKNESS (inches)** 24 5/8 48a 11/2 T & G 60b 60b 72c 72c For SI: 1 inch = 25.4 mm.
a. Minimum 270_F_ b, 340,000_E.
b. Minimum 420_F b, 660,000_E.
c. Minimum 600_F b, 1,150,000_E._For SI: 1 inch = 25.4 mm.
a. Minimum 270_F_ b, 340,000_E.
b. Minimum 420_F b, 660,000_E.
c. Minimum 600_F b, 1,150,000_E._R803.2 Wood structural panel sheathing.
Frequently asked questions
What is the minimum plywood grade I must use for roof sheathing?
Plywood used as roof sheathing must comply with DOC PS 1 or DOC PS 2 and be identified by a grade mark (for example, product markings such as “Structural I — Sheathing (Exposure 1)”) as required by § R803.2.1.
Can I use spaced lumber sheathing beneath asphalt shingles?
Spaced lumber sheathing for wood shingles/shakes is allowed when it meets R905.7/R905.8 requirements, but spaced lumber sheathing is not permitted in Seismic Design Category D2 per § R803.1.
Do I have to use exterior‑grade panels if the underside of the sheathing is in the attic space?
If the panel is only exposed to the underside (interior exposure), the code allows Exposure 1 (interior type bonded with exterior glue). Permanently exposed outdoor applications require exterior exposure durability. See § R803.2.1.1.
Is there a maximum cantilever for roof sheathing panels?
Yes — wood structural panel roof sheathing shall not cantilever more than 9 inches beyond the gable endwall unless supported by gable overhang framing (see § R803.2.3).
How do I determine the correct panel thickness for my roof?
Use the allowable spans and panel thickness entries in Table R503.2.1.1(1) (or APA E30) as directed by § R803.2.2; match the panel’s marked span rating to the rafter/truss spacing and direction of span.
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