The design values for visually graded and mechanically graded Hem-Fir (N) dimension lumber have been updated in response to the routine assessment of strength and stiffness to ensure reliable performance in structural applications.
These updates take effect on April 1, 2025, and are published in the NLGA Standard Grading Rules for Canadian Lumber, CSA O86 – Engineering Design in Wood, and the National Design Specification® (NDS®) Supplement for Wood Construction, developed by the American Wood Council (AWC). Within the NDS® Supplement, these updates specifically apply to Tables 4A and 4C, with additional impacts on Table 4G.
The following Frequently Asked Questions provide detailed information about the updated design values, their implementation, and practical implications. This content is provided as general information only and is not intended to be relied upon for design decisions. For actual use and design implications, users of Hem-Fir (N) should consult the applicable design guides or specifications (e.g., CSA O86 – Engineering design in wood or the National Design Specifications® (NDS).

















