The Ontario Building Code | Vent Stacks vent Stacks

(1) Except as provided in Sentence (2), every soilor waste stack draining fixturesfrom more than 4 storeys shall have a vent stack.

(2) A soil or waste stack that serves as a wet vent does not require a vent stack.

(3) The vent stack required by Sentence (1) shall be connected to a vertical section of the soilor waste stack at or immediately below the lowest soil or waste pipe connected to the soil or waste stack.

(4) Fixtures may be connected to a vent stack provided,

(a) the total hydraulic load of the connected fixtures does not exceed eight fixture units,

(b) at least one fixtureis connected to a vertical portion of the vent stack and upstream of any other fixtures,

(c) no other fixtureis connected downstream of a water closet,

(d) all fixturesare located in the lowest storey served by the vent stack, and

(e) the section of the vent pipe that acts as a wet vent conforms to the requirements regarding wet vents.