The Ontario Building Code | Installation
9.26.6.2. installation
(1) When used with shingles, underlay shall be installed parallel to the eaves with head and end lap of not less than 50 mm.
(2) The top edge of each strip referred to in Sentence (1) shall be fastened with sufficient roofing nails to hold it in place until the shingles are applied.
(3) The underlay referred to in Sentence (1) shall overlap the eave protection by not less than 100 mm.
9.26.7. asphalt Shingles on Slopes of 1 in 3 or Greater
In Plain Language
This roofing component must be installed as set out in this article, ensuring proper function within the overall roofing assembly.
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.