The Ontario Building Code | Lumber Grades
9.3.2.2. Lumber Grades
(1) Except for joists, rafters, trusses and beams, visually graded lumber shall conform to the grades in Table 9.3.2.1.
In Plain Language
Different lumber grades are described in this article, corresponding to different allowable strength values used in structural design calculations.
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.