Patent ID: 7607271

Claim:
A roofing system for a low-slope roof, comprising: a low-slope roof deck substrate overlaid by a plurality of prefabricated multi-layer roofing panels; the prefabricated multi-layer roofing panels being secured to the substrate; and the prefabricated multi-layer roofing panels each comprising: an insulation layer; the insulation layer being a low-density predominantly polymer material foam layer having a density less than 6 lbs/ft 3 and a thickness between about 0.50 inches and about 6 inches; the insulation layer having a length, a width, and a thickness; the insulation layer having a top major surface and a bottom major surface that are each defined by the length and the width of the insulation layer; the insulation layer having a first pair of edges that are each defined by the length and the thickness of the insulation layer; the insulation layer having a second pair of edges that are each defined by the width and the thickness of the insulation layer; the bottom major surface of the insulation layer forming the bottom surface of the prefabricated multi-layer roofing panel and having self adhering adhesive thereon for adhering the prefabricated multi-layer roofing panel to the roofing substrate; a cover board; the cover board being a high density predominantly polymer material layer having a density between 6 lbs/ft 3 and 25 lbs/ft 3 and a thickness between about 0.08 inches and 0.75 inches; the cover board having a length, a width, and a thickness; the length and the width of the cover board being substantially equal to the length and the width of the insulation layer; the cover board having a top major surface and a bottom major surface that are each defined by the length and the width of the cover board; the cover board having a first pair of edges that are each defined by the length and the thickness of the cover board; the cover board having a second pair of edges that are each defined by the width and the thickness of the cover board; a waterproofing membrane; the waterproofing membrane having a length and a width; the waterproofing membrane having a top major surface and a bottom major surface that are each defined by the length and the width of the waterproofing membrane; the waterproofing membrane overlying the top major surface of the cover board and being bonded to the top major surface the cover board; and the prefabricated multi-layer roofing panels being bonded to the low-slope deck substrate by the self-adhering adhesive on the bottom major surface of the insulation layer of the prefabricated multi-layer roofing panel.