(1)  Except as provided for in Sentence (2), every trap shall,

    (a)   have a trap seal depth of at least 38 mm,


    (b)   be so designed that failure of the seal walls will cause exterior leakage, and

    (c)   have a water seal that does not depend on the action of moving parts.

    (2)  The trap seal depth on fixtures draining to an acid waste system shall be a minimum of 50 mm.

    (3)  Except for a floor-mounted service sink, every trap that serves a lavatory, a sink or a laundry tray shall,

    (a)   be provided with a cleanout plug of a minimum ¾ in. size located at the lowest point of the trap and of the same material as the trap, except that a cast iron trap shall be provided with a brass cleanout plug,

    (b)   be designed so that the trap dip can be completely removed for cleaning purposes, or

    (c)   be provided with a cleanout installed above the floor as close as practical downstream of the trap when the trap is,

             (i)   installed below the floor, and

            (ii)   not readily accessible for cleaning as required by Clause (a).

    (4)  A bell trap or an S-trap shall not be installed in a drainage system.

    (5)  A drum trap shall not be installed in a drainage system.

    (6)  Except as permitted in Sentence (7), no bottle trap shall be used in a plumbing system.

    (7)  A bottle trap may be used on a laboratory sink or other fixture equipped with corrosion resistant fittings.

    (8)  No running trap shall be installed in a plumbing system unless an accessible handhole is provided for cleaning of the trap, and where the trap is too small to accommodate a handhole, a cleanout shall be provided.

Article Ontario Regulation 332/12 Building Code,   Information published by for educational purposes only.

Note : A sink trap or often referred to as a “P-trap” is a curved length of pipe located below the drain. This plumbing term refers to a section that prevents sewage gases from entering your kitchen when the sink is draining. Water sits at the bottom of the curved shape whenever the sink is not in use.