The purpose of this Technical Bulletin is to describe fire-resistive separation requirements when a residential occupancy cantilevers over a parking space.

When any enclosed portion of a Group R, Division 1, 2 or 3 Occupancy cantilevers greater than 5 feet over a space where motor vehicles can be parked, the enclosed space shall be separated by not less than 5/8” type X gypsum board or an equivalent. All structural elements, supporting the space covered by the 5/8” type X gypsum board or equivalent, shall be protected by 5/8” type X gypsum wallboard or an equivalent on the underside (CBC Section 406.3.3.1 and CRC Section R302.6.) See Figures 1 and 2.