Abstract: A fireproof insulated roofing sandwich type assembly having incombustible rigid gypsum formboard beneath and toward the interior of a building from a layer of synthetic polymer foam placed above to the exterior of the building from the rigid formboard and a waterproof wearing surface to the exterior of the synthetic polymer foam. The roofing assemblies of this invention provide Class 1 and hourly fire ratings to precast wood fiber cement-bonded boards. The roofing assembly of this invention is also suitable for installation over steel roof decks.

Abstract: An insulated decking structure and method using a sheet metal structural shape as a purlin or sub-purlin which is symmetrical about a vertical bisecting plane and having a central vertical web, two legs projecting downwardly from the bottom of said web at an angle of about 45.degree. to 75.degree. to the horizontal, each leg having a substantially horizontal flange projecting outwardly at its lower extremity, and a stiffening member at the upper edge of the web.