The Ontario Building Code | General

7.5.7.1. General

(1) The size of every vent pipe shall conform to Table 7.5.7.1.

Table 7.5.7.1.
Minimum Permitted Size of vent pipe Based on Size of Trap

Forming Part of Sentence 7.5.7.1.(1)

Item	Column 1 Size of Trap Served, in.	Column 2 Minimum Size of vent pipe, in.
1.	1 ¼	1 ¼
2.	1 ½	1 ¼
3.	2	1 ½
4.	3	1 ½
5.	4	1 ½
6.	5	2
7.	6	2