Plumbing Regulations: Backflow Prevention and Fixture Spacing Quiz

Shower Receptors and Installation Requirements

• Each shower receptor shall be an approved type and be constructed to have a finished dam, curb or threshold which is at least 25.4 mm lower than the outside floor at the sides and back of such receptor.
• The finished floor of the receptor shall slope uniformly from the sides towards the drain not less than 1% or 2% or more than 4% or 40 mm/m.
• Thresholds shall be of sufficient width to accommodate a minimum 559 mm wide door.
• In no case shall any dam or threshold be less than 51 mm nor more than 228 mm in depth when measured from the top of the dam or threshold to the top of the drain.

Sub-base and Hot-mopped Installation

• The sub-base shall be smooth and solidly formed, and hot-mopped in place.
• Each succeeding layer shall be thoroughly hot-mopped to the formed sub-base.
• All comers shall be carefully fitted, strengthened, and watertight by folding or lapping, and each corner shall be reinforced with suitable metal webbing.
• All folds, laps, and reinforcing webbing shall extend to at least 101 mm in all directions from the corner.

Reinforcement and Webbing

• All folds, laps, and reinforcing webbing shall produce a tensile strength of not less than 0.9 kg/mm in either direction.
• Non-metallic shower sub-pans or linings may also consist of multi-layers of other approved materials suitably reinforced.
• Linings 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 which may be less than 25.4 mm above the finished dam or threshold.

Sub-drains and Drainage

• An approved type sub-drain shall be installed with every shower sub-pan or lining.
• Each such sub-drain shall be of the type that sets flush with the sub-base and weep holes, and shall be equipped with a clamping ring or other device to make a tight connection between the lining and the drain.
• The sub-drain shall have a connection into the waste line.

Public Shower Rooms

• Floors of public shower rooms shall have a rounded corner, non-skid surface, and shall be drained in such a manner that wastewater will not pass over areas occupied by other bathers.
• No water closet or bidet shall be set closer than 0.75 meter from its center to any side wall or obstruction, or 0.75 meter center to center to any similar fixture.

Accessibility and Clearances

• No urinal shall be set closer than 0.3 meter from its center to any sidewall or partition, or 0.3 meter center to center.
• Each shower receptor shall have a minimum finished interior area of 0.6 square meter, and shall also be capable of encompassing a 762 mm diameter circle.
• The minimum distance between the door or entry to the drain opening shall be 1.2 meters.
• Shower receptors built directly on the ground shall be watertight, and shall be constructed from approved-type dense, non-absorbent, and non-corrosive materials.