The Ontario Building Code | Fixtures Draining into Vent Pipes
184.108.40.206. Fixtures Draining into vent pipes
(1) The trap arm of a fixturethat has a hydraulic load of not more than 1 ½ fixture units may be connected to the vertical section of a circuit vent, additional circuit vent, offset relief vent or yoke vent, provided that,
(a) not more than two fixtures are connected to the vent pipe,
(b) where two fixturesare connected to the vent pipe, the connection is by means of a double fitting, in accordance with Table 220.127.116.11., and
(c) the section of the vent pipe that acts as a wet vent conforms to the requirements regarding wet vents.
7.5.5. Miscellaneous vent Pipes