SEC. 91.1807. FOUNDATION WALLS, RETAINING WALLS, AND

(Amended by Ord. No. 182,850, Eff. 1/3/14.)

Section 1807 of the CBC is adopted by reference, except Sections 1807.1.4 and 1807.1.6 the CBC are not adopted; and, in lieu, LAMC Subdivisions 91.1807.1.4 and 91.1807.1.6 are added. (Amended by Ord. No. 185,587, Eff. 7/16/18.)

91.1807.1.4. Permanent Wood Foundation Systems. (Amended by Ord. No. 186,488, Eff. 12/27/19.) Permanent wood foundation systems shall be designed and installed in accordance with AF & PA PWF and as otherwise approved by the Department. Lumber and plywood shall be treated in accordance with AWPA U1 (Commodity Specification A, Use Category 4B and Section 5.2) and shall be identified in accordance with CBC Section 2303.1.9.1. Permanent wood foundation systems shall not be used for structures assigned to Seismic Design Category D, E or F.

EXCEPTION: Accessory buildings not used for human occupancy and less than 120 square feet (11.1 m² ) in area may be supported on treated wood mud sills.

91.1807.1.6. Prescriptive Design of Concrete and Masonry Foundation Walls. Concrete and masonry foundation walls that are laterally supported at the top and bottom shall be permitted to be designed and constructed in accordance with this Section. Prescriptive design of foundation walls shall not be used for structures assigned to Seismic Design Category D, E or F.