CRC · California Residential Code

How must siding and cladding resist wind (tests, design methods)?

The CRC requires siding and cladding (and their backing and fasteners) to resist the wind loads shown in the R301 wind tables. Compliance is shown either by wind‑pressure testing (commonly ASTM E330) or by a design analysis using approved standards and engineering practice; the analysis or test must consider all likely failure modes (panel rupture, fastener withdrawal, head pull‑through) and the code allows using the assembly capacity when appropriate (see **§ R703.1** and **§ R703.1.2**) .

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Last reviewed: July 6, 2026

What the code requires — 2-4 sentences

Exterior wall coverings, backing materials and their attachments must be capable of resisting the wind loads required by the code — specifically per § R703.1 and § R703.1.2. The code requires wind‑pressure resistance be demonstrated by testing (for example ASTM E330) or by design analysis using approved design standards and generally accepted engineering practice; all applicable failure modes (bending rupture, fastener withdrawal, head pull‑through, etc.) must be considered. The wind loads themselves are taken from Tables R301.2.1(1) and R301.2.1(2) and applied to the cladding as component-and-cladding loads or as an assembly capacity as permitted by the code (see § R703.1.2) .

The single most important rule: siding, backing and fastenings must be shown to resist the code wind loads either by a recognized test (ASTM E330) or by an approved design analysis that accounts for all likely failure modes (per § R703.1.2) .

Requirements in detail

Scope and basic obligation

  • The exterior wall envelope must be weather‑resistant (water control + flashing) per § R703.1; where wind‑driven rain resistance is claimed through testing, ASTM E331 conditions and sizes apply for the water‑penetration test procedures .
  • The wind resistance requirement for wall coverings, backing materials and their attachments is stated in § R703.1.2: resist the wind loads from Tables R301.2.1(1) and R301.2.1(2), and demonstrate wind‑pressure resistance by test or by approved design analysis .

How you show compliance — two alternate routes

  • Test route: determine wind‑pressure resistance by a standard test method such as ASTM E330 (wind‑pressure test) for the siding, soffit and backing material and fasteners (per § R703.1.2) .
  • Design analysis route: use data from approved design standards and analyses that conform to generally accepted engineering practice (design per ASCE7, AWC, ICC 600, etc., as permitted elsewhere in the code) and ensure all applicable failure modes are included in the analysis (per § R703.1.2) .

What to consider in the test or analysis

  • Consider bending rupture of the siding, fastener withdrawal, fastener head pull‑through, and any other relevant failure modes; testing or analysis must address these (per § R703.1.2) .
  • The code allows use of the design capacity of the assembly when the wall covering, soffit and backing resist wind as an assembly (per § R703.1.2) .

Decision‑relevant dimensions, thresholds and test conditions

Decision item Required value / action Code reference
Mandatory reference for wind loads Use the wind loads from Tables R301.2.1(1) and R301.2.1(2) when sizing/qualifying cladding § R703.1.2
Accepted wind pressure test ASTM E330 (or other applicable standard test method) for wind‑pressure resistance of siding/backing/attachments § R703.1.2
Wind‑driven rain demonstration (water penetration) ASTM E331 test at minimum differential pressure of 6.24 psf (299 Pa), assembly size 4 ft × 8 ft, exposure minimum 2 hours § R703.1 (R703.1.1 exception)
Design analysis Use data from approved design standards and analyses conforming to generally accepted engineering practice; include all failure modes § R703.1.2
Assembly vs component approach Allowed to use design capacity of the assembly when the assembly resists wind load as an assembly § R703.1.2

(Notes: Tables with numerical component/cladding pressures and exposure modifiers are in Chapter R301; consult Tables R301.2.1(1) and R301.2.1(2) for the numeric design values applicable to your climate/exposure/height.)

Exceptions & special cases

  • Where an exterior wall envelope has been shown to resist wind‑driven rain by testing in accordance with ASTM E331 under the specified conditions (4′×8′ assembly, 6.24 psf, 2‑hour exposure), the normal water‑resistive barrier/drainage requirements may be waived; see the exception in § R703.1 (R703.1.1) .
  • The code permits using the design capacity of a cladding assembly rather than treating every part separately when the assembly has been demonstrated to resist the wind loads (see § R703.1.2) .
  • Specific cladding types have additional limits or tables (for example, vinyl siding over foam plastic sheathing has minimum wind‑load ratings in § R703.11.2 and attendant tables) — consult those specific sections for numeric requirements and exceptions .
  1. Read the row for 110 mph and the column for Case 1, Exposure C: the adjusted minimum design wind pressure (ASD) shown in the table is −44.5 psf (negative indicates suction) .
  2. To comply with § R703.1.2, you must either:
    • Provide a test report showing the installed siding/backing/attachment resists the required pressure (for example via ASTM E330 testing to at least the required ASD), or
    • Provide a design analysis based on approved design standards showing the siding and its fastenings (and backing or supporting attachment system) resist the ASD −44.5 psf, accounting for fastener withdrawal, head pull‑through, and panel rupture as applicable (per § R703.1.2) .
  3. If the vinyl manufacturer provides a validated wind‑load rating specifically for installation over foam sheathing that matches or exceeds −44.5 psf, that rating may be used under the exceptions in § R703.11.2 (install per manufacturer instructions) .

Key authority used: § R703.1.2 (methods: ASTM E330 or approved design analysis) and Table R703.11.2 for the numeric ASD for this cladding/condition .

Related provisions

  • § R703.1 — Exterior wall envelope / wind‑driven rain testing (ASTM E331 conditions)
  • § R703.1.2 — Wind resistance requirements; ASTM E330 or design analysis; list of failure modes; assemblies permitted
  • § R301.2.1(1) and § R301.2.1(2) — The component and cladding wind loads and exposure adjustments referenced by § R703.1.2 (see Chapter R301 for the tables)
  • § R703.11.2 — Specific required minimum wind‑load design pressures for vinyl siding installed over foam plastic sheathing (numeric table)
  • § R703.3.2 — Wind limitations and when attachment must be designed to resist component and cladding loads (limits and the 10 ft2 effective wind area rule)

Code references

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

  • CRC § 2.4. High relevance — show source text

    2.4. Exterior wall envelope assemblies shall be subjected to the minimum test exposure for a minimum of 2 hours. The exterior wall envelope design shall be considered to resist wind-driven rain where the results of testing indicate that water did not penetrate control joints in the exterior wall envelope, joints at the perimeter of openings penetration or intersections of terminations with dissimilar materials.

    R703.1.2 Wind resistance. Wall coverings, backing materials and their attachments shall be capable of resisting wind loads in accordance with Tables R301.2.1(1) and R301.2.1(2). Wind-pressure resistance of the siding, exterior soffit and backing materials shall be determined by ASTM E330 or other applicable standard test methods. Where wind-pressure resistance is determined by design analysis, data from approved design standards and analysis conforming to generally accepted engineering practice shall be used to evaluate the siding, exterior soffit and backing material and its fastening. All applicable failure modes including bending rupture of siding, fastener withdrawal and fastener head pull-through shall be considered in the testing or design analysis. Where the wall covering, exterior soffit and backing material resist wind load as an assembly, use of the design capacity of the assembly shall be permitted. R703.2 Water-resistive barrier. Not fewer than one layer of water-resistive barrier shall be applied over studs or sheathing of all exterior walls with flashing as indicated in Section R703.4, in such a manner as to provide a continuous water-resistive barrier behind the exterior wall veneer and behind deck ledgers. The water-resistive barrier material shall be continuous to the top of walls and terminated at penetrations and building appendages in a manner to meet the requirements of the exterior wall envelope as described in Section R703.1. Where the water-resistive barrier also functions as a component of a continuous air barrier, the waterresistive barrier shall be installed as an air barrier in accordance with Section N1102.5.1.1. Water-resistive barrier materials shall comply with one of the following:

    1. No. 15 felt complying with ASTM D226, Type 1.

    2. ASTM E2556, Type 1 or 2.

    3. Foam plastic insulating sheathing water-resistive barrier systems complying with Section R703.1.1 and installed in accordance with the manufacturer’s installation instructions.

    4. ASTM E331 in accordance with Section R703.1.1.

    5. Other approved materials in accordance with the manufacturer’s installation instructions. No.15 asphalt felt and water-resistive barriers complying with ASTM E2556 shall be applied horizontally, with the upper layer lapped over the lower layer not less than 2 inches (51 mm), and where joints occur, shall be lapped not less than 6 inches (152 mm). Exception: A water-resistive barrier shall not be required in unconditioned detached tool sheds, storage sheds, playhouses, and other similar accessory structures provided all of the following requirements are met:

    6. Exterior wall covering is limited to siding that is attached direct to studs.

    7. Exterior walls are uninsulated.

    8. Interior side of exterior walls has no wall covering or wall finishes. R703.3 Wall covering nominal thickness and attachments. The nominal thickness and attachment of exterior wall coverings shall be in accordance with Table R703.3(1), the wall covering material requirements of this section, and the wall covering manufacturer’s installation instructions. Cladding attachment over foam sheathing shall comply with the additional requirements and limitations of Sections R703.15 through R703.17.

  • CRC § 1.1 High relevance — show source text

    R703.1 General. Exterior walls shall provide the building with a weather-resistant exterior wall envelope. The exterior wall envelope shall include flashing as described in Section R703.4. Exception: Log walls designed and constructed in accordance with the provisions of ICC 400. R703.1.1 Water resistance. The exterior wall envelope shall be designed and constructed in a manner that prevents the accumulation of water within the wall assembly by providing a water-resistive barrier behind the exterior cladding as required by Section R703.2 and a means of draining to the exterior water that penetrates the exterior cladding. Exceptions:

    1. A weather-resistant exterior wall envelope shall not be required over concrete or masonry walls designed in accordance with Chapter 6 and flashed in accordance with Section R703.4 or R703.8.
    2. Compliance with the requirements for a means of drainage, and the requirements of Sections R703.2 and R703.4, shall not be required for an exterior wall envelope that has been demonstrated to resist wind-driven rain through testing of the exterior wall envelope, including joints, penetrations and intersections with dissimilar materials, in accordance with ASTM E331 under the following conditions: 2.1. Exterior wall envelope test assemblies shall include at least one opening, one control joint, one wall/eave interface and one wall sill. All tested openings and penetrations shall be representative of the intended enduse configuration. 2.2. Exterior wall envelope test assemblies shall be at least 4 feet by 8 feet (1219 mm by 2438 mm) in size. 2.3. Exterior wall assemblies shall be tested at a minimum differential pressure of 6.24 pounds per square foot (299 Pa). 2.4. Exterior wall envelope assemblies shall be subjected to the minimum test exposure for a minimum of 2 hours. The exterior wall envelope design shall be considered to resist wind-driven rain where the results of testing indicate that water did not penetrate control joints in the exterior wall envelope, joints at the perimeter of openings penetration or intersections of terminations with dissimilar materials.

    R703.1.2 Wind resistance. Wall coverings, backing materials and their attachments shall be capable of resisting wind loads in accordance with Tables R301.2.1(1) and R301.2.1(2). Wind-pressure resistance of the siding, exterior soffit and backing materials shall be determined by ASTM E330 or other applicable standard test methods. Where wind-pressure resistance is determined by design analysis, data from approved design standards and analysis conforming to generally accepted engineering practice shall be used to evaluate the siding, exterior soffit and backing material and its fastening. All applicable failure modes including bending rupture of siding, fastener withdrawal and fastener head pull-through shall be considered in the testing or design analysis. Where the wall covering, exterior soffit and backing material resist wind load as an assembly, use of the design capacity of the assembly shall be permitted. R703.2 Water-resistive barrier. Not fewer than one layer of water-resistive barrier shall be applied over studs or sheathing of all exterior walls with flashing as indicated in Section R703.4, in such a manner as to provide a continuous water-resistive barrier behind the exterior wall veneer and behind deck ledgers. The water-resistive barrier material shall be continuous to the top of walls and terminated at penetrations and building appendages in a manner to meet the requirements of the exterior wall envelope as described in Section R703.1.

  • CRC § 2.67. High relevance — show source text

    The
    vinyl siding shall comply with an adjusted design wind pressure requirement in accordance with Note b, using an adjustment factor of 2.67.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 square foot = 0.0929 m2, 1 mile per hour = 0.447 m/s, 1 pound per square foot = 0.0479 kPa.
    a. Linear interpolation is permitted.
    b. The table values are based on a maximum 30-foot mean roof height, and effective wind area of 10 square feet Wall Zone 5 (corner), and the ASD design component and cladding
    wind pressure from Table R301.2.1(1), adjusted for exposure in accordance with Table R301.2.1(2), multiplied by the following adjustment factors: 1.87 (Case 1) and 2.67 (Case 2).
    c. Gypsum wallboard, gypsum panel product or equivalent.
    d. For the indicated wind speed condition and where foam sheathing is the only sheathing on the exterior of a frame wall with vinyl siding, the wall assembly shall be capable of
    resisting an impact without puncture at least equivalent to that of a wood frame wall with minimum7/16-inch OSB sheathing as tested in accordance with ASTM E1886. The
    vinyl siding shall comply with an adjusted design wind pressure requirement in accordance with Note b, using an adjustment factor of 2.67.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 square foot = 0.0929 m2, 1 mile per hour = 0.447 m/s, 1 pound per square foot = 0.0479 kPa.
    a. Linear interpolation is permitted.
    b. The table values are based on a maximum 30-foot mean roof height, and effective wind area of 10 square feet Wall Zone 5 (corner), and the ASD design component and cladding
    wind pressure from Table R301.2.1(1), adjusted for exposure in accordance with Table R301.2.1(2), multiplied by the following adjustment factors: 1.87 (Case 1) and 2.67 (Case 2).
    c. Gypsum wallboard, gypsum panel product or equivalent.
    d. For the indicated wind speed condition and where foam sheathing is the only sheathing on the exterior of a frame wall with vinyl siding, the wall assembly shall be capable of
    resisting an impact without puncture at least equivalent to that of a wood frame wall with minimum7/16-inch OSB sheathing as tested in accordance with ASTM E1886. The
    vinyl siding shall comply with an adjusted design wind pressure requirement in accordance with Note b, using an adjustment factor of 2.67.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 square foot = 0.0929 m2, 1 mile per hour = 0.447 m/s, 1 pound per square foot = 0.0479 kPa.
    a. Linear interpolation is permitted.
    b.

  • CRC § 2.67. High relevance — show source text

    Gypsum wallboard, gypsum panel product or equivalent.
    d. For the indicated wind speed condition and where foam sheathing is the only sheathing on the exterior of a frame wall with vinyl siding, the wall assembly shall be capable of
    resisting an impact without puncture at least equivalent to that of a wood frame wall with minimum7/16-inch OSB sheathing as tested in accordance with ASTM E1886. The
    vinyl siding shall comply with an adjusted design wind pressure requirement in accordance with Note b, using an adjustment factor of 2.67.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 square foot = 0.0929 m2, 1 mile per hour = 0.447 m/s, 1 pound per square foot = 0.0479 kPa.
    a. Linear interpolation is permitted.
    b. The table values are based on a maximum 30-foot mean roof height, and effective wind area of 10 square feet Wall Zone 5 (corner), and the ASD design component and cladding
    wind pressure from Table R301.2.1(1), adjusted for exposure in accordance with Table R301.2.1(2), multiplied by the following adjustment factors: 1.87 (Case 1) and 2.67 (Case 2).
    c. Gypsum wallboard, gypsum panel product or equivalent.
    d. For the indicated wind speed condition and where foam sheathing is the only sheathing on the exterior of a frame wall with vinyl siding, the wall assembly shall be capable of
    resisting an impact without puncture at least equivalent to that of a wood frame wall with minimum7/16-inch OSB sheathing as tested in accordance with ASTM E1886. The
    vinyl siding shall comply with an adjusted design wind pressure requirement in accordance with Note b, using an adjustment factor of 2.67.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 square foot = 0.0929 m2, 1 mile per hour = 0.447 m/s, 1 pound per square foot = 0.0479 kPa.
    a. Linear interpolation is permitted.
    b. The table values are based on a maximum 30-foot mean roof height, and effective wind area of 10 square feet Wall Zone 5 (corner), and the ASD design component and cladding
    wind pressure from Table R301.2.1(1), adjusted for exposure in accordance with Table R301.2.1(2), multiplied by the following adjustment factors: 1.87 (Case 1) and 2.67 (Case 2).
    c. Gypsum wallboard, gypsum panel product or equivalent.
    d. For the indicated wind speed condition and where foam sheathing is the only sheathing on the exterior of a frame wall with vinyl siding, the wall assembly shall be capable of
    resisting an impact without puncture at least equivalent to that of a wood frame wall with minimum7/16-inch OSB sheathing as tested in accordance with ASTM E1886. The
    vinyl siding shall comply with an adjusted design wind pressure requirement in accordance with Note b, using an adjustment factor of 2.67.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 square foot = 0.0929 m2, 1 mile per hour = 0.447 m/s, 1 pound per square foot = 0.0479 kPa.
    a. Linear interpolation is permitted.
    b.

  • CRC § 3.1 High relevance — show source text

    Screws shall comply with ASTM C1513 and shall penetrate a minimum of three threads through minimum 33 mil (20 gage) cold-formed steel frame construction.
    b. Screw head diameter shall be not less than the nail head diameter required by Table R703.3(1).
    c. Number and spacing of screw fasteners shall comply with Table R703.3(1).
    d. Pan head, hex washer head, modified truss head or other screw head types with a flat attachment surface under the head shall be used for vinyl siding attachment.
    e. Aluminum siding shall not be fastened directly to cold-formed steel light frame construction.|

    R703.3.1 Siding clearance at wall and adjacent surfaces. Unless otherwise specified by the cladding manufacturer or this code, polypropylene, insulated vinyl and vinyl claddings shall have clearance of not less than 6 inches (152 mm) from the ground and not less than [1] / 2 inch (13 mm) from other adjacent surfaces (decks, roofs, slabs).

    R703.3.2 Wind limitations. Where the design wind pressure exceeds 30 psf or where the limits of Table R703.3.2 are exceeded, the attachment of wall coverings shall be designed to resist the component and cladding loads specified in Table R301.2.1(1) for walls, adjusted for height and exposure in accordance with Table R301.2.1(2). For the determination of wall covering, component and cladding loads shall be determined using an effective wind area of 10 square feet (0.93 m [2] ).

    TABLE R703.3.2—LIMITS FOR ATTACHMENT PER TABLE R703.3(1) Col2 Col3 Col4
    ** MAXIMUM MEAN ROOF HEIGHT** ** MAXIMUM MEAN ROOF HEIGHT** ** MAXIMUM MEAN ROOF HEIGHT** ** MAXIMUM MEAN ROOF HEIGHT**
    ** Ultimate Wind Speed**
    (mph 3-second gust)    		 ** Exposure** ** Exposure** ** Exposure**
    ** Ultimate Wind Speed**
    (mph 3-second gust)    		 ** B** ** C** ** D**
    95 NL NL NL
    100 NL NL NL
    105 NL NL NL
    110 NL NL 40′
    115 NL 50′ 20′
    120 NL 30′ DR
    130 60′ 15′ DR
    140 35′ DR DR
    For SI: 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s.
    NL = Not Limited by Table R703.3.2, DR = Design Required.    		 For SI: 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s.
    NL = Not Limited by Table R703.3.2, DR = Design Required.    		 For SI: 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s.
    NL = Not Limited by Table R703.3.2, DR = Design Required.    		 For SI: 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s.
    NL = Not Limited by Table R703.3.2, DR = Design Required.

    7-12 2025 CALIFORNIA RESIDENTIAL CODE

  • CRC § 44.5 High relevance — show source text

    8|-44.5|-52.8|-45.4|-63.5|-75.3| |115|-35.5|-49.7|-59.0|-50.7|-71.0|-84.2| |120|-37.4|-52.4|-62.1|-53.4|-74.8|-88.6| |130|-44.9|-62.8|-74.5|-64.1|-89.7|-106| |> 130|See Note d|See Note d|See Note d|See Note d|See Note d|See Note d| |For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 square foot = 0.0929 m2, 1 mile per hour = 0.447 m/s, 1 pound per square foot = 0.0479 kPa.
    a. Linear interpolation is permitted.
    b. The table values are based on a maximum 30-foot mean roof height, and effective wind area of 10 square feet Wall Zone 5 (corner), and the ASD design component and cladding
    wind pressure from Table R301.2.1(1), adjusted for exposure in accordance with Table R301.2.1(2), multiplied by the following adjustment factors: 1.87 (Case 1) and 2.67 (Case 2).
    c. Gypsum wallboard, gypsum panel product or equivalent.
    d. For the indicated wind speed condition and where foam sheathing is the only sheathing on the exterior of a frame wall with vinyl siding, the wall assembly shall be capable of
    resisting an impact without puncture at least equivalent to that of a wood frame wall with minimum7/16-inch OSB sheathing as tested in accordance with ASTM E1886. The
    vinyl siding shall comply with an adjusted design wind pressure requirement in accordance with Note b, using an adjustment factor of 2.67.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 square foot = 0.0929 m2, 1 mile per hour = 0.447 m/s, 1 pound per square foot = 0.0479 kPa.
    a. Linear interpolation is permitted.
    b. The table values are based on a maximum 30-foot mean roof height, and effective wind area of 10 square feet Wall Zone 5 (corner), and the ASD design component and cladding
    wind pressure from Table R301.2.1(1), adjusted for exposure in accordance with Table R301.2.1(2), multiplied by the following adjustment factors: 1.87 (Case 1) and 2.67 (Case 2).
    c. Gypsum wallboard, gypsum panel product or equivalent.
    d. For the indicated wind speed condition and where foam sheathing is the only sheathing on the exterior of a frame wall with vinyl siding, the wall assembly shall be capable of
    resisting an impact without puncture at least equivalent to that of a wood frame wall with minimum7/16-inch OSB sheathing as tested in accordance with ASTM E1886. The
    vinyl siding shall comply with an adjusted design wind pressure requirement in accordance with Note b, using an adjustment factor of 2.67.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 square foot = 0.0929 m2, 1 mile per hour = 0.447 m/s, 1 pound per square foot = 0.0479 kPa.
    a.

  • CRC § 2.1 High relevance — show source text

    Linear interpolation is permitted.
    b. The table values are based on a maximum 30-foot mean roof height, and effective wind area of 10 square feet Wall Zone 5 (corner), and the ASD design component and cladding
    wind pressure from Table R301.2.1(1), adjusted for exposure in accordance with Table R301.2.1(2), multiplied by the following adjustment factors: 1.87 (Case 1) and 2.67 (Case 2).
    c. Gypsum wallboard, gypsum panel product or equivalent.
    d. For the indicated wind speed condition and where foam sheathing is the only sheathing on the exterior of a frame wall with vinyl siding, the wall assembly shall be capable of
    resisting an impact without puncture at least equivalent to that of a wood frame wall with minimum7/16-inch OSB sheathing as tested in accordance with ASTM E1886. The
    vinyl siding shall comply with an adjusted design wind pressure requirement in accordance with Note b, using an adjustment factor of 2.67.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 square foot = 0.0929 m2, 1 mile per hour = 0.447 m/s, 1 pound per square foot = 0.0479 kPa.
    a. Linear interpolation is permitted.
    b. The table values are based on a maximum 30-foot mean roof height, and effective wind area of 10 square feet Wall Zone 5 (corner), and the ASD design component and cladding
    wind pressure from Table R301.2.1(1), adjusted for exposure in accordance with Table R301.2.1(2), multiplied by the following adjustment factors: 1.87 (Case 1) and 2.67 (Case 2).
    c. Gypsum wallboard, gypsum panel product or equivalent.
    d. For the indicated wind speed condition and where foam sheathing is the only sheathing on the exterior of a frame wall with vinyl siding, the wall assembly shall be capable of
    resisting an impact without puncture at least equivalent to that of a wood frame wall with minimum7/16-inch OSB sheathing as tested in accordance with ASTM E1886. The
    vinyl siding shall comply with an adjusted design wind pressure requirement in accordance with Note b, using an adjustment factor of 2.67.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 square foot = 0.0929 m2, 1 mile per hour = 0.447 m/s, 1 pound per square foot = 0.0479 kPa.
    a. Linear interpolation is permitted.
    b. The table values are based on a maximum 30-foot mean roof height, and effective wind area of 10 square feet Wall Zone 5 (corner), and the ASD design component and cladding
    wind pressure from Table R301.2.1(1), adjusted for exposure in accordance with Table R301.2.1(2), multiplied by the following adjustment factors: 1.87 (Case 1) and 2.67 (Case 2).
    c. Gypsum wallboard, gypsum panel product or equivalent.
    d. For the indicated wind speed condition and where foam sheathing is the only sheathing on the exterior of a frame wall with vinyl siding, the wall assembly shall be capable of
    resisting an impact without puncture at least equivalent to that of a wood frame wall with minimum7/16-inch OSB sheathing as tested in accordance with ASTM E1886.

  • CRC § 11.2 Medium relevance — show source text

    R703.11.2 Installation over foam plastic sheathing. Where vinyl siding or insulated vinyl siding is installed over foam plastic sheathing, the vinyl siding shall comply with Section R703.11 and shall have a wind load design pressure rating in accordance with Table R703.11.2.

    Exceptions:

    1. Where the foam plastic sheathing is applied directly over wood structural panels, fiberboard, gypsum sheathing or other approved backing capable of independently resisting the design wind pressure, the vinyl siding shall be installed in accordance with Sections R703.3.3 and R703.11.1.

    2. Where the vinyl siding manufacturer’s product specifications provide an approved wind load design pressure rating for installation over foam plastic sheathing, use of this wind load design pressure rating shall be permitted and the siding shall be installed in accordance with the manufacturer’s installation instructions.

    3. Where the foam plastic sheathing and its attachment have a design wind pressure resistance complying with Sections R303.8 and R301.2.1, the vinyl siding shall be installed in accordance with Sections R703.3.3 and R703.11.1.

    TABLE R703.11.2—REQUIRED MINIMUM WIND LOAD DESIGN
    PRESSURE RATING FOR VINYL SIDING INSTALLED OVER FOAM PLASTIC SHEATHING ALONE    		 Col2 Col3 Col4 Col5 Col6 Col7
    ** ULTIMATE**
    DESIGN WIND SPEED
    (MPH)    		 ** ADJUSTED MINIMUM DESIGN WIND PRESSURE (ASD) (PSF)a, b** ** ADJUSTED MINIMUM DESIGN WIND PRESSURE (ASD) (PSF)a, b** ** ADJUSTED MINIMUM DESIGN WIND PRESSURE (ASD) (PSF)a, b** ** ADJUSTED MINIMUM DESIGN WIND PRESSURE (ASD) (PSF)a, b** ** ADJUSTED MINIMUM DESIGN WIND PRESSURE (ASD) (PSF)a, b** ** ADJUSTED MINIMUM DESIGN WIND PRESSURE (ASD) (PSF)a, b**
    ** ULTIMATE**
    DESIGN WIND SPEED
    (MPH)    		 ** Case 1: With interior gypsum wallboardc** ** Case 1: With interior gypsum wallboardc** ** Case 1: With interior gypsum wallboardc** ** Case 2: Without interior gypsum wallboardc** ** Case 2: Without interior gypsum wallboardc** ** Case 2: Without interior gypsum wallboardc**
    ** ULTIMATE**
    DESIGN WIND SPEED
    (MPH)    		 ** Exposure** ** Exposure** ** Exposure** ** Exposure** ** Exposure** ** Exposure**
    ** ULTIMATE**
    DESIGN WIND SPEED
    (MPH)    		 ** B** ** C** ** D** ** B** ** C** ** D**
    ≤ 95 -30.0 -33.2 -39.4 -33.9 -47.4 -56.2
    100 -30.0 -36.8 -43.6 -37.2 -52.5 -62.2
    105 -30.0 -40.5 -48.1 -41.4 -57.9 -68.6
    110 -31.8 -44.5 -52.8 -45.4 -63.5 -75.3
    115 -35.5 -49.
  • CRC § 0.099 Medium relevance — show source text
    TABLE R703.3(2)—SCREW FASTENER SUBSTITUTION FOR SIDING
    ATTACHMENT TO COLD-FORMED STEEL LIGHT FRAME CONSTRUCTIONa, b, c, d, e    		 Col2
    ** NAIL DIAMETER PER TABLE R703.3(1)** ** MINIMUM SCREW FASTENER SIZE**
    0.099″ No. 6
    0.113″ No. 7
    0.120″ No. 8
    For SI: 1 inch = 25.4 mm.
    a. Screws shall comply with ASTM C1513 and shall penetrate a minimum of three threads through minimum 33 mil (20 gage) cold-formed steel frame construction.
    b. Screw head diameter shall be not less than the nail head diameter required by Table R703.3(1).
    c. Number and spacing of screw fasteners shall comply with Table R703.3(1).
    d. Pan head, hex washer head, modified truss head or other screw head types with a flat attachment surface under the head shall be used for vinyl siding attachment.
    e. Aluminum siding shall not be fastened directly to cold-formed steel light frame construction.    		 For SI: 1 inch = 25.4 mm.
    a. Screws shall comply with ASTM C1513 and shall penetrate a minimum of three threads through minimum 33 mil (20 gage) cold-formed steel frame construction.
    b. Screw head diameter shall be not less than the nail head diameter required by Table R703.3(1).
    c. Number and spacing of screw fasteners shall comply with Table R703.3(1).
    d. Pan head, hex washer head, modified truss head or other screw head types with a flat attachment surface under the head shall be used for vinyl siding attachment.
    e. Aluminum siding shall not be fastened directly to cold-formed steel light frame construction.

    R703.3.1 Siding clearance at wall and adjacent surfaces. Unless otherwise specified by the cladding manufacturer or this code, polypropylene, insulated vinyl and vinyl claddings shall have clearance of not less than 6 inches (152 mm) from the ground and not less than [1] / 2 inch (13 mm) from other adjacent surfaces (decks, roofs, slabs).

    R703.3.2 Wind limitations. Where the design wind pressure exceeds 30 psf or where the limits of Table R703.3.2 are exceeded, the attachment of wall coverings shall be designed to resist the component and cladding loads specified in Table R301.2.1(1) for walls, adjusted for height and exposure in accordance with Table R301.2.1(2). For the determination of wall covering, component and cladding loads shall be determined using an effective wind area of 10 square feet (0.93 m [2] ).

    |TABLE R703.3.2—LIMITS FOR ATTACHMENT PER TABLE R703.

  • CRC § 1404.15.1. Medium relevance — show source text

    Exceptions:

    1. Where the foam plastic insulating sheathing is applied directly over wood structural panels, fiberboard, gypsum sheathing or other approved backing capable of independently resisting the design wind pressure, the vinyl siding or insulated vinyl siding shall be installed in accordance with Section 1404.15.1.

    2. Where the vinyl siding or insulated vinyl siding manufacturer’s product specifications provide an approved wind load design pressure rating for installation over foam plastic insulating sheathing, use of this wind load design pressure rating shall be permitted and the siding shall be installed in accordance with the manufacturer’s installation instructions.

    3. Where the foam plastic insulating sheathing and its attachment has a design wind pressure resistance complying with Sections 1609 and 2603.10, the vinyl siding or insulated vinyl siding shall be installed in accordance with Section 1404.15.1.

    [BS] TABLE 1404.15.2—REQUIRED MINIMUM WIND LOAD DESIGN PRESSURE
    RATING FOR VINYL SIDING INSTALLED OVER FOAM PLASTIC SHEATHING ALONE    		 Col2 Col3 Col4 Col5 Col6 Col7
    ULTIMATE
    DESIGN WIND
    SPEED (MPH)    		 ADJUSTED MINIMUM DESIGN WIND PRESSURE (ASD) (PSF)a, b ADJUSTED MINIMUM DESIGN WIND PRESSURE (ASD) (PSF)a, b ADJUSTED MINIMUM DESIGN WIND PRESSURE (ASD) (PSF)a, b ADJUSTED MINIMUM DESIGN WIND PRESSURE (ASD) (PSF)a, b ADJUSTED MINIMUM DESIGN WIND PRESSURE (ASD) (PSF)a, b ADJUSTED MINIMUM DESIGN WIND PRESSURE (ASD) (PSF)a, b
    ULTIMATE
    DESIGN WIND
    SPEED (MPH)    		 Case 1: With interior gypsum wallboardc Case 1: With interior gypsum wallboardc Case 1: With interior gypsum wallboardc Case 2: Without interior gypsum wallboardc Case 2: Without interior gypsum wallboardc Case 2: Without interior gypsum wallboardc
    ULTIMATE
    DESIGN WIND
    SPEED (MPH)    		 Exposure Exposure Exposure Exposure Exposure Exposure
    ULTIMATE
    DESIGN WIND
    SPEED (MPH)    		 B C D B C D
    ≤ 95 -30.0 -33.2 -39.4 -33.9 -47.4 -56.2
    100 -30.0 -36.8 -43.6 -37.2 -52.5 -62.2
    105 -30.0 -40.5 -48.1 -41.4 -57.9 -68.6
    110 -31.8 -44.5 -52.8 -45.4 -63.5 -75.3
    115 -35.5 -49.7 -59.0 -50.7 -71.0 -84.2
    120 -37.4 -52.4 -62.1 -53.4 -74.8 -88.

Frequently asked questions

What test standard does the CRC say to use for wind‑pressure resistance of siding?

The CRC explicitly calls out ASTM E330 (or other applicable standard test methods) for wind‑pressure resistance of siding, soffits and backing materials in § R703.1.2 .

Can I use a manufacturer’s wind rating instead of testing?

Yes, if the manufacturer’s product specifications provide an approved wind‑load design pressure rating for the exact installation condition (for example, vinyl over foam) and you install per the manufacturer’s instructions, that rating may be used — see the specific cladding section exceptions (for example § R703.11.2) .

If I do a design analysis what standards are acceptable?

The code requires data from approved design standards and analysis that conform to generally accepted engineering practice (per § R703.1.2). Methods listed elsewhere in the code (e.g., ASCE 7, AWC, ICC 600) are acceptable approaches for wind design; use the referenced wind tables in Chapter R301 for numeric loads .

Do I have to check fastener withdrawal and pull‑through?

Yes — § R703.1.2 specifically requires that all applicable failure modes including bending rupture of siding, fastener withdrawal and fastener head pull‑through be considered in the test or design analysis .

What if my siding resists wind as a tested assembly?

If the wall covering, soffit and backing material have been demonstrated to resist wind load as an assembly, you may use the assembly’s design capacity to show compliance (per § R703.1.2) .

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