These specified strengths and modulus of elasticity are based on lumber that is graded in accordance with NLGA Standard Grading Rules for Canadian Lumber. Lumber should be identified by a grade stamp in accordance with the provisions or the CSA Standard CAN/CSA-O141. These values are referenced in the NBCC or the provincial equivalent.
These values are intended to be used by qualified designers and can be used in conjunction with the appropriate adjustment factors found in the CSA O86 Standard . Design tables, examples and background information can be found in the CWC's Wood Design Manual which includes a copy of CSA O86 supplemented with commentary material.