This Standard covers the load test procedure for evaluating the strength and deformation performance of wood roof trusses intended for use in housing and small buildings as defined in Part 9 of the National Building Code of Canada.
Note: Part 9 of the National Building Code of Canada provides detailed requirements for the construction of houses and small buildings up to 600 m² in building area and 3 storeys in building height and applies to all occupancies except assembly, institutional, and high-hazard industrial.
This Standard does not stipulate mandatory performance criteria (see Appendix A for acceptable performance criteria).
Intent of Test
This load test procedure is intended to evaluate the adequacy of wood roof truss designs and is not intended as a quality control test. The procedure may, however, be used for retesting production run samples in cases where the quality of the truss is in dispute.
Note: It is recognized that measures to ensure the quality of production of trusses must be maintained for on-going production of designs acceptable under this Standard.
Assemblies to be tested by this procedure are limited to:
(a) Triangulated trusses having a maximum span of 12 m; or
(b) Bowstring or lenticular trusses having a maximum span of 4.3 m;
whose members are connected using mechanical connectors or nailed gusset plates and which are intended to be installed at a maximum spacing of 600 mm on centres and in such a manner that the top chords are suitably sheathed or braced to prevent lateral buckling.
Note: Clause 2 has been renumbered A2 and has been relocated in Appendix A, page 18.