Notice: This site currently shows the 2012/2017 edition of the Ontario Building Code. The current legally effective code is the 2024 edition (O.Reg. 163/24), in effect since January 1, 2025. Confirm current requirements at ontario.ca.

The Ontario Building Code | Materials for Flashing

9.20.13.1. Materials for Flashing

(1) Materials used for flashing shall conform to Table 9.20.13.1.

(2) Aluminum flashing in contact with masonry or concrete shall be effectively coated or separated from the masonry or concrete by an impervious membrane.

Table 9.20.13.1.
Flashing Materials

Forming Part of Sentence 9.20.13.1.(1)

Item

Column 1

Column 2

Column 3

Material

Minimum Thickness, mm

Exposed Flashing

Concealed Flashing

1.

Aluminum

0.48

2.

copper

0.46

0.46

3.

copper or aluminum laminated to felt or kraft paper

0.05

4.

Hot dipped or galvanized steel

0. 33

0.33

5.

Lead sheet

1.73

1.73

6.

Polyethylene

0.50

7.

Roll roofing, Type S

standard

8.

Zinc

0.46

0.46

In Plain Language

Flashing materials, which direct water away from vulnerable points in a masonry wall, must conform to the standards referenced in this article.

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.