March 5, 2014
The 2014 Edition of the “Standard Grading Rules for Canadian Lumber” now Available for Free Download
- The January 2014 edition of the NLGA Standard Grading Rules for Canadian Lumber is now available in pdf formatted sections. Please check “Publications for Download” on the menu displayed above.
January 20, 2014
Update on the NLGA Species Groups Lumber Properties Monitoring Program
- NLGA periodically tests samples of Canadian dimension lumber from all producing regions as part of its ongoing lumber properties monitoring program to determine whether design values published in the “NLGA Standard Grading Rules for Canadian Lumber” and in other design standards, continue to be applicable.
- The NLGA program, which has evolved since 1999, covers the major species groups S-P-F, DFir-L (N) and Hem-Fir (N). These monitoring studies used NO. 2 grade, 2 by 4, 8 ft. lumber, an item that is readily available for sampling from all producing regions, as a bellwether size and grade. The previous monitoring studies all provided evidence to support the assignment of design values in the NLGA Grade Rules and design standards.
- NLGA contributes to the development and maintenance of the lumber quality system in North America as a rules writing member of American Lumber Standard Committee, Incorporated (ALSC) and as a member of the American Society for Testing and Materials (ASTM). More recent NLGA monitoring studies completed in 2007 and 2008 were used to better understand and refine lumber properties monitoring and have been used to contribute to these organizations’ discussions.
- Although the ASTM D1990 standard, “Standard Practice for Establishing Allowable Properties for Visually-Graded Lumber from In-Grade Tests of Full-Size Specimens”, has not yet been revised to provide guidance on monitoring and interpretation of results, a monitoring protocol is currently being balloted following the ASTM standards development process. Ongoing monitoring programs following the proposed protocol have been implemented by all North American rules-writing agencies to be in compliance with ALSC requirements.
S-P-F and DFir-L (N) Species Groups Monitoring Studies
- NLGA found that the 2011 S-P-F and 2012 DFir-L (N) monitoring studies both supported the statement that “there is no reason to believe that there has been a significant shift in the MOE and MOR properties of the monitored size / grade / species group”, and the ongoing monitoring of these species groups will continue.
Hem-Fir (N) Species Group Monitoring Study
- NLGA found that test results from the 2013 Hem-Fir (N) monitoring study were low which triggers further action under the proposed revisions to ASTM D1990. NLGA has informed ALSC and will follow the proposed monitoring protocol.
- The actions proposed in the ASTM D1990 monitoring protocol include verifying whether a change has actually occurred. To do this, NLGA will re-sample Hem-Fir (N) NO. 2 grade, 2 x 4 and simultaneously sample Hem-Fir (N) NO. 2 grade, 2 x 10. NLGA will also review the current Hem-Fir (N) monitoring study methodology and results more thoroughly to identify potential factors that may influence the test results.