Prefabricated multi-layer roofing panel and system

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/ft3 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/ft3 and 25 lbs/ft3 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.