Section R406 — FOUNDATION WATERPROOFING AND DAMPPROOFING — 2025 California Residential Code (Title 24, Part 2.5)

R406.1 Concrete and masonry foundation dampproofing. ¶

R406.1 Concrete and masonry foundation dampproofing. Except where required by Section R406.2 to be waterproofed, foundation walls that retain earth and enclose interior spaces and floors below grade shall be dampproofed from the finished grade to the higher of the top of the footing or 6 inches (152 mm) below the top of the basement floor. Masonry walls shall have not less than [3] / 8 inch (9.5 mm) Portland cement parging applied to the exterior of the wall. The parging shall be dampproofed in accordance with one of the following: 1. Bituminous coating. 2. Three pounds per square yard (1

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 § R406.1

R406.2 Concrete and masonry foundation waterproofing. ¶

R406.2 Concrete and masonry foundation waterproofing. In areas where a high water table or other severe soil-water conditions are known to exist, exterior foundation walls that retain earth and enclose interior spaces and floors below grade shall be waterproofed from the finished grade to the higher of the top of the footing or 6 inches (152 mm) below the top of the basement floor. Walls shall be waterproofed in accordance with one of the following: 1. Two-ply hot-mopped felts. 2. Fifty-five-pound (25 kg) roll roofing. 3. Forty-mil (1 mm) polymer-modified asphalt. 4. Sixty-mil (1.5 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 § R406.2

R406.3 Dampproofing for wood foundations. ¶

R406.3 Dampproofing for wood foundations. Wood foundations enclosing habitable or usable spaces located below grade shall be dampproofed in accordance with Sections R406.3.1 through R406.3.4. R406.3.1 Panel joint sealed. Plywood panel joints in the foundation walls shall be sealed full length with a caulking compound capable of producing a moistureproof seal under the conditions of temperature and moisture content at which it will be applied and used. R406.3.2 Below-grade moisture barrier. A 6-mil-thick (0.15 mm) polyethylene film shall be applied over the below-grade portion of exterior…

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 § R406.3

R406.4 Precast concrete foundation system dampproofing. ¶

R406.4 Precast concrete foundation system dampproofing. Except where required by Section R406.2 to be waterproofed, precast concrete foundation walls enclosing habitable or useable spaces located below grade shall be dampproofed in accordance with Section R406.1. R406.4.1 Panel joints sealed. Precast concrete foundation panel joints shall be sealed full height with a sealant meeting ASTM C920, Type S or M, Grade NS, Class 25, Use NT, M or A. Joint sealant shall be installed in accordance with the manufacturer’s instructions. on Jul 18, 2025 11:14 AM (CDT) THEREUNDER. FOUNDATIONS

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

Ask AI about § R406.4