Section R703 — EXTERIOR WALL COVERING — 2025 California Residential Code (Title 24, Part 2.5)

R703.1 General. ¶

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…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

Ask AI about § R703.1

R703.2 Water-resistive barrier. ¶

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…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

Ask AI about § R703.2

R703.3 Wall covering nominal thickness and attachments. ¶

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. Nominal material thicknesses in Table R703.3(1) are based on a maximum stud spacing of 16 inches (406 mm) on center. Where specified by the siding manufacturer’s instructions…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

Ask AI about § R703.3

R703.4 Flashing. ¶

R703.4 Flashing. Approved corrosion-resistant flashing shall be applied in a manner to prevent entry of water into the wall cavity or penetration of water to the building structural framing components. Overlapped flashing shall be applied in shingle fashion. Selfadhered membranes used as flashing shall comply with AAMA 711. Fluid-applied membranes used as flashing in exterior walls shall comply with AAMA 714. The flashing shall extend to the surface of the exterior wall finish. Flashing shall be installed above deck ledgers in accordance with Section R507.9.1.5. Approved corrosion-resistant…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

Ask AI about § R703.4

R703.5 Wood, hardboard and wood structural panel siding. ¶

R703.5 Wood, hardboard and wood structural panel siding. Wood, hardboard and wood structural panel siding shall be installed in accordance with this section and Table R703.3(1). Hardboard siding shall comply with ANSI A135.5. R703.5.1 Vertical wood siding. Wood siding applied vertically shall be nailed to horizontal nailing strips or blocking set not more than 24 inches (610 mm) on center. R703.5.2 Panel siding. Three-eighths-inch (9.5 mm) wood structural panel siding shall not be applied directly to studs spaced more than 16 inches (406 mm) on center where long dimension is parallel to…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

Ask AI about § R703.5

R703.6 Wood shakes and shingles. Wood shakes and shingles shall conform to CSSB. ¶

R703.6 Wood shakes and shingles. Wood shakes and shingles shall conform to CSSB. R703.6.1 Application. Wood shakes or shingles shall be applied either single course or double course over nominal [1] / 2 -inch (12.7 mm) wood-based sheathing or to furring strips over [1] / 2 -inch (12.7 mm) nominal nonwood sheathing. A water-resistive barrier shall be provided in accordance with Section R703.2. Where horizontal furring strips are used, they shall be 1 inch by 3 inches or 1 inch by 4 inches (25 mm by 76 mm or 25 mm by 102 mm) and shall be fastened to the studs with minimum 7d or 8d box nails and…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

Ask AI about § R703.6

R703.7 Exterior plaster (stucco). ¶

R703.7 Exterior plaster (stucco). Installation of exterior plaster shall be in compliance with ASTM C926, ASTM C1063 and the provisions of this code. R703.7.1 Lath. Lath and lath attachments shall be of corrosion-resistant materials in accordance with ASTM C1063. Expanded metal, welded wire, or woven wire lath shall be attached to wood framing members or furring. Where the exterior plaster is serving as wall bracing in accordance with Table R602.10.4, the lath shall be attached directly to framing. The lath shall be attached with 1 [1] / 2 -inch-long (38 mm), 0.120-inch-diameter (3 mm),…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

Ask AI about § R703.7

R703.8 Anchored stone and masonry veneer, general. ¶

R703.8 Anchored stone and masonry veneer, general. Anchored stone and masonry veneer shall be installed in accordance with this chapter, Table R703.3(1) and Figures R703.8(1) and R703.8(2). These veneers installed over a backing of wood or cold-formed steel shall be limited to the first story above grade plane and shall not exceed 5 inches (127 mm) in thickness. See Section R602.10 for wall bracing requirements for masonry veneer for wood-framed construction and Section R603.9.5 for wall bracing requirements for masonry veneer for cold-formed steel construction. Exceptions: 1. For buildings…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

Ask AI about § R703.8

R703.9 Exterior insulation and finish system (EIFS)/EIFS with drainage. ¶

R703.9 Exterior insulation and finish system (EIFS)/EIFS with drainage. Exterior insulation and finish systems (EIFS) shall comply with this chapter and Section R703.9.1. EIFS with drainage shall comply with this chapter and Section R703.9.2. R703.9.1 Exterior insulation and finish systems (EIFS). EIFS shall comply with the following: 1. ASTM E2568. 2. EIFS shall be limited to applications over substrates of concrete or masonry wall assemblies. 3. Flashing of EIFS shall be provided in accordance with the requirements of Section R703.4. 4. EIFS shall be installed in accordance with the…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

Ask AI about § R703.9

R703.10 Fiber cement siding. ¶

R703.10 Fiber cement siding. R703.10.1 Panel siding. Fiber-cement panels shall comply with the requirements of ASTM C1186, Type A, minimum Grade II or ISO 8336, Category A, minimum Class 2. Panels shall be installed with the long dimension either parallel or perpendicular to framing. Vertical and horizontal joints shall occur over framing members and shall be protected with caulking, or with battens or flashing, or be vertical or horizontal shiplap, or otherwise designed to comply with Section R703.1. Panel siding shall be installed with fasteners in accordance with Table R703.3(1) or the…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

Ask AI about § R703.10

R703.11 Vinyl siding. ¶

R703.11 Vinyl siding. Vinyl siding shall be certified and labeled as conforming to the requirements of ASTM D3679 by an approved agency. R703.11.1 Installation. Vinyl siding, insulated vinyl siding and compatible accessories shall be installed in accordance with the manufacturer’s installation instructions. R703.11.1.1 Starter strip. The first course of horizontal siding shall be secured using a starter strip as specified in the manufacturer’s installation instructions. See Figure R703.11.1.1(1). Where the first course of siding has to be cut or trimmed, the bottom edge shall be secured with…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

Ask AI about § R703.11

R703.12 Adhered masonry veneer installation. ¶

R703.12 Adhered masonry veneer installation. Adhered masonry veneer shall comply with the requirements of Section R703.7.3 and the requirements in Sections 13.1 and 13.3 of TMS 402. Adhered masonry veneer shall be installed in accordance with Section R703.7.1, Article 3.3D of TMS 602 or the manufacturer’s instructions. R703.12.1 Clearances. On exterior stud walls, adhered masonry veneer shall be installed in accordance with one of the following: 1. Not less than 4 inches (102 mm) above the earth. 2. Not less than 2 inches (51 mm) above paved areas. 3. Not less than [1] / 2 inch (12.7 mm)…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

Ask AI about § R703.12

R703.13 Insulated vinyl siding. ¶

R703.13 Insulated vinyl siding. Insulated vinyl siding shall be certified and labeled as conforming to the requirements of ASTM D7793 by an approved agency. R703.13.1 Insulated vinyl siding and accessories. Insulated vinyl siding and compatible accessories shall be installed in accordance with Sections R703.11.1 and R703.11.2 and the manufacturer’s installation instructions.

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height

Ask AI about § R703.13

R703.14 Polypropylene siding. ¶

R703.14 Polypropylene siding. Polypropylene siding shall be certified and labeled as conforming to the requirements of ASTM D7254, and those of Section R703.14.2 or Section R703.14.3, by an approved agency. R703.14.1 Polypropylene siding and accessories. Polypropylene siding and accessories shall be installed in accordance with manufacturer’s installation instructions. R703.14.1.1 Installation. Unless otherwise specified in the manufacturer’s installation instructions, polypropylene siding shall be installed over and attached to wood structural panel sheathing with minimum thickness of [7] /…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

Ask AI about § R703.14

R703.15 Cladding attachment over foam sheathing to wood framing. ¶

R703.15 Cladding attachment over foam sheathing to wood framing. Cladding shall be specified and installed in accordance with Section R703, the cladding manufacturer’s approved instructions, including any limitations for use over foam plastic sheathing, or an approved design. In addition, the cladding or furring attachments through foam sheathing to framing shall meet or exceed the minimum fastening requirements of Section R703.15.1, Section R703.15.2, or an approved design for support of cladding weight. Exceptions: 1. Where the cladding manufacturer has provided approved installation…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

Ask AI about § R703.15

R703.16 Cladding attachment over foam sheathing to cold-formed steel framing. ¶

R703.16 Cladding attachment over foam sheathing to cold-formed steel framing. Cladding shall be specified and installed in accordance with Section R703, the cladding manufacturer’s approved instructions, including any limitations for use over foam plastic sheathing, or an approved design. In addition, the cladding or furring attachments through foam sheathing to framing shall meet or exceed the minimum fastening requirements of Section R703.16.1, Section R703.16.2 or an approved design for support of cladding weight. Exceptions: 1. Where the cladding manufacturer has provided approved…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

Ask AI about § R703.16

R703.17 Cladding attachment over foam sheathing to masonry or concrete wall construction. ¶

R703.17 Cladding attachment over foam sheathing to masonry or concrete wall construction. Cladding shall be specified and installed in accordance with Section R703.3 and the cladding manufacturer’s instructions or an approved design. Foam sheathing shall be attached to masonry or concrete construction in accordance with the insulation manufacturer’s installation instructions or an approved design. Furring and furring attachments through foam sheathing into concrete or masonry substrate shall be designed to resist design loads determined in accordance with Section R301, including support of…

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use

Ask AI about § R703.17

R703.18 Fiber-mat reinforced cementitious backer units. ¶

R703.18 Fiber-mat reinforced cementitious backer units. Fiber-mat reinforced cementitious backer units used on exterior walls as a substrate for the application of exterior finish materials shall comply with ASTM C1325. Installation shall be in accordance with the manufacturer’s installation instructions. Backer units shall be installed using corrosion-resistant fasteners. Finish materials shall be installed in accordance with the manufacturer’s instructions.

provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development standard accessory yard section structure compliance use provision permitted lot commission district approval parking minimum height dwelling application requirement review coverage subject setback occupancy development

Ask AI about § R703.18