Los Angeles Municipal Code § 91.2305 General Design Requirements for Lateral Force-Resisting System

(Amended by Ord. No. 185,587, Eff. 7/16/18.)

Section 2305 of the CBC is adopted by reference, except that LAMC Subsections 91.2305.4 and 91.2305.5 are added.

In Seismic Design Category D, E or F, mechanically driven nails used in wood structural panel shear walls shall meet the same dimensions as that required for hand-driven nails, including diameter, minimum length and minimum head diameter. Clipped head or box nails are not permitted in new construction. The allowable design value for clipped head nails in existing construction may be taken at no more than the nail-head-area ratio of that of the same size hand-driven nails. (Readopted by Ord. No. 188,797, Eff. 12/31/25.)

In Seismic Design Category D, E or F, hold-down connectors shall be designed to resist shear wall overturning moments using approved cyclic load values or 75 percent of the allowable seismic load values that do not consider cyclic loading of the product. Connector bolts into wood framing shall require steel plate washers on the post on the opposite side of the anchorage device. Plate size shall be a minimum of 0.229 inch by 3 inches by 3 inches (5.82 mm by 76 mm by 76 mm) in size. Hold-down connectors shall be finger tight and 1/2 turn just prior to covering the wall framing. (Readopted by Ord. No. 188,797, Eff. 12/31/25.)