718.3 Protection from Damage. No building sewer or

other drainage piping or part thereof, which is constructed of materials other than those approved for use under or within a building, shall be installed under or within 2 feet (610 mm) of a building or structure, or part thereof, nor less than 1 foot (305 mm) below the surface of the ground. The provisions of this subsection include structures such as porches and steps, whether covered or uncovered; breezeways; roofed porte cochere; roofed patios; carports; covered walks; covered driveways; and similar structures or appurtenances.

TABLE 717.1

MAXIMUM/MINIMUM FIXTURE UNIT LOADING

For SI units: 1 inch = 25 mm, 1 inch per foot = 83.3 mm/m

• See also Appendix H, Private Sewage Disposal Systems. For alternate methods of sizing drainage piping, see Appendix C.

176 2025 CALIFORNIA PLUMBING CODE

SANITARY DRAINAGE