Each of a plurality of vertically disposed trusses having angled rafters and a joint is coupled to a ridge board. Upper TboxTrusses function as the rafters. Each upper TboxTruss has a planar plate. The planar plate has a hollow box depending downwardly there from. An interior sheet of fire resistant fabric sheet material is above the upper TboxTrusses. An exterior sheet of the fire resistant fabric sheet material is below the upper TboxTrusses. Insulation material is located between the interior and exterior sheets and bounded by adjacent hollow boxes.