“Single-wall” construction typically utilizes ¾-inch to 1-inch thick tongue and groove cedar or redwood boards placed vertically to form a load-bearing exterior wall without studs. A flat, wood top plate is attached against the vertical siding board to serve as a ledger for attachment of the ceiling and nailing of the roof truss rafter. Roof construction in single-wall residences is typically light non-engineered framing with composition shingles on tongue and groove (T & G) wood decking, or corrugated metal deck roofng directly attached to shallow wood rafters. Full plywood sheathing of the roof is not provided, and rafters are sometimes spaced up to four feet apart in the T&G roofed systems.