The Ontario Building Code | Sanitary T Fittings

7.2.4.2. sanitary T Fittings

(1) A double sanitary T fitting shall not be used to connect the fixture drains of two urinals where no cleanout fitting is provided above the connection.

(2) No pipe fitting, joint or connection that would tend to intercept solids or reduce the flow through a pipe by more than 10 per cent shall be used in a plumbing system.