Abstract: A ventilated insulated roofing system comprises a rigid roof deck, a roof comprising a rigid roof support member or sheathing which is above and spaced from the roof deck, and an exterior covering layer supported on the sheathing, and an insulation course between the roof deck and the sheathing. The insulation course is preferably a rigid lightweight foamed insulation material comprising an imperforate first portion which rests on the roof deck and a second portion comprising a plurality of spaced projections forming a network of interconnected air channels which are in communication with the under side of the sheathing. The roofing system further includes a course composed of one or more panels along a peripheral edge or portion of the perimeter of the roofing system.

Abstract: A composite insulated roof board structure comprising a light-weight insulated roof board member having good thermal insulation properties and a protective top layer which overlies the insulated roof board member. The insulated roof board member comprises a main portion of rigid coherent solid insulating material, such as polyisocyanurate or expanded polystyrene, and a top portion comprising a plurality of spaced blocks above the main portion and integral therewith. The blocks form therebetween a network of interconnected channels which are at the same level for horizontal venting of water vapor to all peripheral edges of the roof board member. The blocks are typically square and the channels are typically in the form of two sets of mutually perpendicular channels. The roof board composite is typically formed as a panel of rectangular shape.

Abstract: Insulated roof board comprising a foamed plastic base layer, a coherent solid intermediate layer having void space therein to permit venting of water vapor, and a relatively hard, dense top layer. The intermediate layer is preferably foarmed by a plurality of shaped bodies, such as polystyrene beads, which are adhesively secured together.