B-1.1, r. 2 - Construction Code

Full text
8.97. The vent referred to in section 8.95 must be located outside a building and positioned in such a manner that flammable vapours cannot be drawn into the building.
The end must be
(1)  higher than the end of the fill pipe;
(2)  at a distance of not less than 3.5 m, in the case of a tank containing a Class 1 petroleum product, or 2 m in the case of a tank containing other petroleum products;
(3)  at a distance of not less than 1.5 m from any building opening in the case of a tank containing a Class 1 petroleum product, or not less than 600 mm in the case of a tank containing other petroleum products; and
(4)  at a distance of not less than 7.5 m from any dispenser, in the case of an underground tank containing gasoline.
O.C. 220-2007, s. 1.