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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

In Plain Language

This article sets the general requirements for the venting methods covered in this Subsection, establishing the baseline rules that the more specific vent-type articles build on.

This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.