The Ontario Building Code | Required Eave Protection
9.26.5.1. Required Eave Protection
(1) Except as provided in Sentence (2), eave protection shall be provided on shingle, shake or tile roofs, extending from the edge of the roof a minimum of 900 mm up the roof slope to a line not less than 300 mm inside the inner face of the exterior wall.
(2) Eave protection is not required,
(a) over unheated garages, carports and porches,
(b) where the roof overhang exceeds 900 mm measured along the roof slope from the edge of the roof to the inner face of the exterior wall,
(c) on roofs of asphalt shingles installed in accordance with Subsection 9.26.8.,
(d) on roofs with slopes of 1 in 1.5 or greater, or
(e) in regions with 3 500 or fewer degree-days.
In Plain Language
Eave protection, an extra waterproof membrane at the roof edge, is required as set out in this article, guarding against water backing up under shingles from ice dams.
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.