2021 IRC (International Residential Code) | Chapter 27 Section P2709 Shower Receptors
Where a shower receptor has a finished curb threshold, it shall be not less than 1 inch (25.4 mm) below the sides and back of the receptor. The curb shall be not less than 2 inches (51 mm) and not more than 9 inches (229 mm) deep when measured from the top of the curb to the top of the drain. The finished floor shall slope uniformly toward the drain not les: than ¼ unit vertical in 12 units horizontal (2-percent slope) nor more than unit vertical per 12 units horizontal (4-percent slope) and floor drains shall be flanged to provide a watertight joint in the floor.
P2709.2 Lining required.
The adjoining walls and floor framing enclosing on-site built-up shower receptors shall be lined with one of the following materials:
- Sheet lead.
- Sheet copper.
- Plastic liner material that complies WithASTM D4068 or ASTM D4551.
- Hot mopping in accordance with Section P2709.2.3.
- Sheet-applied load-bearing, bonded waterproof membranes that comply with ANSI A118.10.
The lining material shall extend not less than 2 inches (51 mm) beyond or around the rough jambs and not less than 2 inches (51 mm) above finished thresholds. Sheet-applied load bearing, bonded waterproof membranes shall be applied in accordance with the manufacturer's instructions.
P2709.2.1 PVC sheets.
Plasticized polyvinyl chloride (PVC) sheet shall meet the requirements of ASTM D4551. Sheets shall be joined by solvent welding in accordance with the manufacturer's instructions.
P2709.2.2 Chlorinated polyethylene (CPE) sheets.
Nonplasticized chlorinated polyethylene sheet shall meet the requirements of ASTM D4068. The liner shall be joined in accordance with the manufacturer's instructions.
P2709.2.3 Hot-mopping.
Shower receptors lined by hot mopping shall be built-up with not less than three layers of standard grade Type 15 asphalt-impregnated roofing felt. The bottom layer shall be fitted to the formed subbase and each succeeding layer thoroughly hot-mopped to that below. Corners shall be carefully fitted and shall be made strong and watertight by folding or lapping, and each corner shall be reinforced with suitable webbing hot-mopped in place. Folds, laps and reinforcing webbing shall extend not less than 4 inches (102 mm) in all directions from the corner and webbing shall be of approved type and mesh, producing a tensile strength of not less than 50 pounds per inch (893 kg/m) in either direction.
P2709.2.4 Liquid-type, trowel-applied, load-bearing, bonded waterproof materials.
Liquid-type, trowel-applied, load-bearing, bonded waterproof materials shall meet the requirements of ANSI A118.10 and shall be applied in accordance with the manufacturer's instructions.
P2709.3 Installation.
Lining materials shall be sloped / unit vertical in 12 units horizontal (2-percent slope) to weep holes in the subdrain by means of a smooth, solidly formed subbase, shall be properly recessed and fastened to approved backing so as not to occupy the space required for the wall covering, and shall not be nailed or perforated at any point less than 1 inch (25.4 mm) above the finished threshold.
P2709.3.1 Materials.
Lead and copper linings shall be insulated from conducting substances other than the connecting drain by 15-pound (6.80 kg) asphalt felt or its equivalent. Sheet lead liners shall weigh not less than 4 pounds per square foot (19.5 kg/m2).
Sheet copper liners shall weigh not less than 12 ounces per square foot (3.7 kg/m?), Joints in lead and copper pans or liners shall be burned or silver brazed, respectively, Joints in plastic liner materials shall be joined in accordance with the manufacturer's instructions.
P2709.4 Receptor drains.
An approved flanged drain shall be installed with shower subpans or linings. The flange shall be placed flush with the subbase and be equipped with a clamping ring or other device to make a watertight connection between the lining and the drain. The flange shall have weep holes into the drain.
