408.5 Finished Curb or Threshold.

Where a shower receptor has a finished dam, curb, or threshold, it shall be not less than 1 inch (25.4 mm) lower than the sides and back of such receptor. In no case, shall a dam or threshold be less than 2 inches (51 mm) or exceeding 9 inches (229 mm) in depth where measured from the top of the dam or threshold to the top of the drain. Each such receptor shall be provided with an integral nailing flange to be located where the receptor meets the vertical surface of the finished interior of the shower compartment. The flange shall be watertight and extend vertically not less than 1 inch (25.4 mm) above the top of the sides of the receptor. The finished floor of the receptor shall slope uni

formly from the sides towards the drain not less than ¹ ⁄ 8 inch per foot (10.4 mm/m), nor more than ¹ ⁄ 2 inch per foot (41.6 mm/m).

Thresholds shall be of sufficient width to accommodate a minimum 22 inch (559 mm) door. Shower doors shall open so as to maintain not less than a 22 inch (559 mm) unobstructed opening for egress. Where there is a shower without a threshold, the floor space within the same room shall be considered a wet location and shall comply with the requirements of the California Building Code, California Residential Code, and California Electrical Code . Exceptions: (1) Showers in accordance with Section 403.2. (2) A cast-iron shower receptor flange shall be not less than

0.3 of an inch (7.62 mm) in height. (3) For flanges not used as a means of securing, the sealing

flange shall be not less than 0.3 of an inch (7.62 mm) in height.