The Ontario Building Code | Materials
9.27.7.1. Materials
(1) Shingles and shakes shall conform to,
(a) CSA O118.1, "Western Red Cedar Shakes and Shingles", or
(b) CSA O118.2-M, "Eastern White Cedar Shingles".
(2) Western cedar shakes shall be not less than No. 1 grade or Handsplit grade, and western cedar shingles not less than No. 2 grade, except that No. 3 grade may be used for undercoursing.
(3) Eastern white cedar shakes shall be at least B (clear) grade, except that C grade may be used for undercoursing.
In Plain Language
Materials for this cladding type 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.