The Ontario Building Code | Where Required
9.29.2.1. Where Required
(1) waterproof finish shall be provided to a height of not less than,
(a) 1 800 mm above the floor in shower stalls,
(b) 1 200 mm above the rims of bathtubs equipped with showers, and
(c) 400 mm above the rims of bathtubs not equipped with showers.