Laminated bituminous roofing membrane

A self-adhesive, multi-layer, laminated, bituminous roofing membrane, comprising a flexible base sheet having superposed on the entirety of at least one surface thereof a first coating layer of uniform thickness applied in direct face-to-face, mutually adhering contact therewith, said first coating layer consisting essentially of a substantially solid, waterproofing roofing bitumen;

• a second coating layer of uniform thickness surperposed on a portion of said first coating layer and having its inner surface in direct, face-to-face, mutually cohering contact with the outer surface of said portion of said first coating layer, said second coating layer being of lesser thickness than said first coating layer and consisting essentially of a compound bitumen, said compound bitumen consisting essentially of roofing bitumen containing from about 5 to 95 percent by weight of substance selected from the group consisting of rubber, thermoplastic resin and mixtures thereof, said compound bitumen being of high tackiness at ambient temperature and being self-adhesive to the second coating layer of another like roofing membrane;
• a flexible release sheet having a release substance in direct face-to-face releasably adhering contact with the entire outer surface of said coating layer, said release sheet being an exposed outer layer of said roofing membrane, said second layer having been adhered in a molten state to said portion of said first coating layer;
• and the remainder of said first coating layer being covered by a layer of mineral granules, a synthetic polymer film or a metal foil directly adhered to the remainder of said first coating layer.