TT-205 T&G Cedar Siding - Nominal 1x6 and wider over 1/2 gypsum board

Defiance Forest Products' listing 8160-2294:0501 identifies nominal 1-by-6 and wider TT-205 profiles in the horizontal-projection-underside category. The gypsum backing is part of that description. The handbook prints its backing value as “1/2” without giving a unit, so confirm the precise backing specification in the manufacturer's documents rather than inferring a dimension from the abbreviated wording.

OSFM names SFM 12-7A-3 as the test protocol. Keep that eaves application and the backing condition with the TT-205 product identification. A matching cedar profile alone does not establish the whole underside construction.

Use the manufacturer's installation instructions and product data sheets to check both the visible tongue-and-groove boards and the concealed gypsum layer. Confirm the exact GOVmotus listing before specifying the assembly. The useful distinction for an eaves proposal is whether the named profile, its nominal size range and the required backing are all accounted for.