Under this project, a set of guidelines for using fingerjoined lumber for metal plate connected trusses has been prepared. This project is a result of several projects undertaken over the last 10 years on trusses, trusses and fingerjoined lumber, and the development of new structural wood adhesive standards.
The draft guidelines are based on findings from previous Value-to-Wood studies, and on information gathered from truss fabricator interviews and surveys carried out by FPInnovations Industry Advisors of the past year. The guidelines also assume that the fingerjoined lumber is produced to the recently updated National Lumber Grades Authority Special Products Standard (SPS) 4, which was revised to reference the latest edition of the Canadian wood adhesive standard CSA O112.10. While use of this standard permits the fingerjoined lumber industry to use a wider range of structural wood adhesives, it does require that the lumber be marked as “Dry Use Only”.
Given that NLGA SPS 4 is the first standard on commodity structural fingerjoined lumber to have a “Dry Use Only” label, the development of these guidelines is timely. The guidelines will not only help the truss industry and builders to better understand and properly use the product, but it will also help in code acceptance of the NLGA SPS 4 standard.