7.5.6.

(1) Every vent pipe shall be installed without depression in which moisture can collect.

(2) Every waste pipe shall be installed and back vented at the same time.

(1) Every vent pipe in a plumbing system shall be installed so as to be direct as possible to a vent stack or open air, as the case may be, and so that any horizontal run below the flood level of the fixture to which the vent pipe is installed is eliminated where structurally possible.

(2) Except for wet vents, where a vent pipe is connected to a nominally horizontal soil or waste pipe, the connection shall be above the horizontal centre line of the soil or waste pipe.

(3) Unused vent pipes installed for future connections shall be permanently capped with an end cleanout or an adapter and plug.

(1) Except as provided in Sentences (2) and (3), a vent pipe that protects a fixture trap shall be located so that,

(a) the developed length of the trap arm is not less than twice the size of the fixture drain,

(b) the total fall of the trap arm is not greater than its inside diameter, and

(c) the trap arm does not have a cumulative change in direction of more than 135°.

(2) The trap arm of water closets, S-trap standards or any other fixture that also discharges vertically and depends on siphonic action for its proper functioning shall not have a cumulative change in direction of more than 225°.

(3) A vent pipe that protects a water closet or any other fixture that also depends on siphonic action for its proper functioning shall be located so that the distance between the connections of the fixture drain to the fixture and the vent pipe shall not exceed,

(a) 1 000 mm in the vertical plane, and

(b) 3 m in the horizontal plane.

(4) The maximum length and minimum slope of every trap arm shall conform to Table 7.5.6.3.

(5) The vent pipe from a water closet or any other fixture that has an integral siphonic flushing action may be connected to the vertical leg of its drainage pipe.

(1) Except for a wet vent, every vent pipe shall extend above the flood level rim of every fixture that it serves before being connected to another vent pipe.

(2) No vent pipe shall be connected in such a manner that a blockage in a soil or waste pipe would cause waste to drain through the vent pipe to the drainage system.

(1) Except as provided in Sentence (3), the upper end of every vent pipe that is not terminated in open air shall be connected to a venting system that terminates through a roof to open air.

(2) The upper end of every vent pipe that is terminated in open air, other than a vent pipe that serves an oil interceptor or a fresh air inlet, shall be extended above the roof.

(3) Where a vent pipe is installed as a result of additions or alterations to a plumbing system in an existing building, the vent pipe may be erected outside the building, provided that,

(a) no single change of direction of the vent pipe exceeds 45°,

(b) all parts of the vent pipe are nominally vertical,

(c) the vent pipe is increased to not less than 3 in. in size before penetrating a wall or roof, and

(d) where the building is 4 storeys or less in height, the vent pipe terminates above the roof of the building.

(4) Except for a fresh air inlet, where a vent pipe is terminated in open air, the terminal shall be located,

(a) not less than 1 000 mm above or not less than 3.5 m in any other direction from every air inlet, openable window or door,

(b) not less than 2 000 mm above or not less than 3.5 m in any other direction from a roof that supports an occupancy, and

(c) not less than 2 000 mm above ground.

(5) Where a vent pipe passes through a roof, it shall,

(a) be terminated high enough to prevent the entry of roof drainage but not less than 150 mm above the roof or above the surface of storm water, which could pond on the roof, and

(b) be equipped with flashing to prevent the entry of water between the vent pipe and the roof or the wall.

(6) Where a vent pipe passes through a roof or an outside wall of a building, it shall be protected from frost closure by increasing its diameter at least one size, but not less than 3 in. in size, immediately before it penetrates the roof or the wall.

(7) Where a vent pipe is located 2 000 mm or more above a roof, it shall be so constructed as to be stable and secure.

(8) Flashing shall be of material specified in Article 7.2.10.14. and on a shingled roof shall have a minimum dimension of 500 mm by 500 mm.

(9) Where a sleeve flashing is installed on a flat roof it shall extend at least 150 mm above the flood level and on a sloped roof shall be at least 150 mm high on the short side.

(10) No bore of a vent stack or stack vent shall be reduced or obstructed by the installation of a flashing.