Where a concrete floor on grade is used, it shall have a thickness of not less than three-and-one-half (3 1/2) inches. The surface of a concrete floor shall not be less than two and one-half (2 1/2) inches above the adjacent grade. Wood sills shall not be less than six (6) inches from adjacent earth. A wood floor may be laid directly on a waterproofed concrete slab.
Cal. Code Regs. Tit. 25, § 1452
Note: Authority cited: Section 18300, Health and Safety Code. Reference: Section 18552, Health and Safety Code.