The Ontario Building Code | Drilled and Tapped Joints
7.3.3.1. Drilled and Tapped Joints
(1) Except as provided in Sentences (2) to (4), no water distributing pipe, drainage pipe or fittings shall be drilled, tapped or swaged.
(2) A water distributing pipe may be drilled or tapped to provide for a mechanically extracted T in copper tubing of Type L or K provided that all branch connections shall be notched and dimpled to limit depth of insertion and conform to the inner contour of the main.
(3) A copper water distributing pipe of 1 in. size or larger may be mechanically swaged to permit the joining of other copper pipe of equal size.
(4) A drainage pipe or fitting may be drilled or tapped,
(a) to provide for the connection of atrap seal primer line,
(b) to connect a device designed to dispense germicidal or odour control chemicals or trapseal water to a floor drain downstream of a vacuum breakeror flush valve in a flush tube connected to a sanitary unit,
(c) to provide a hole for a branch connection to a drainage pipe, where the branch connection is made with a saddle hub as permitted by Article 7.2.10.5. and where the hole is drilled to provide a smooth clean hole of the required size and orientation, or
(d) to provide for the connection of pipe or fittings to metal or rigid plastic pipe and fittings where the pipe or fittings are thick enough to be threaded or are bossed for tapping.
(5) No pipe adaption shall be made by the use of a bushing that leaves a square edge or shoulder on the inside of the pipe or fitting.