Are there any published studies or guidelines on the fire rating of floor trusses built with 2×3 lumber?
Jager Industries of Canada has tested some 45-minute and one-hour rated assemblies for trusses with 2×3 material using Jager/Truswal connector plates. Alpine Engineered Products’ assemblies also include the use of 2×3 members. Contact us if you would like a copy of these assemblies. The Canadian Wood Council is currently in the process of conducting fire endurance tests for assemblies constructed with various wood products. They are planning to test wood truss assemblies in the near future. WTCA has asked them to test at least one assembly built with 2×3 trusses. We will keep the industry informed as to the results of this testing. One option that will provide a one-hour assembly is to use a directly applied ceiling of two layers of 5/8-in. type X gypsum board (GA File No. FC 5406). This assembly is listed in the Gypsum Association’s Fire Resistance Manual. The assembly is drawn using 2×10 joists, however, the note at the bottom of the assembly description indicates that the two layer
