The Ontario Building Code | Showers
(1) shower receptors shall be constructed and arranged so that water cannot leak through the walls or floor.
(2) Not more than six shower heads shall be served by a single shower drain.
(3) Where two or more shower heads are served by a shower drain, the floor shall be sloped and the drain located so that water from one head cannot flow over the area that serves another head.
(4) Except for column showers, when a battery of shower heads is installed, the horizontal distance between two adjacent shower heads shall be at least 750 mm.