fully cured thermoset ethylene - propylene rubber sheets having integral thermoplastic adhesive strips molded along the lateral edges are produced using a manufacturing method where the strips are applied prior to vulcanization of the rubber sheeting . the factory applied adhesive strip is non - tacky and dry but is activated by heat to securely bond the ethylene - propylene rubber sheets together in an overlap splicing procedure . a method of using the integral adhesive rubber sheeting for single - ply rubber roofing membrane or pond liners is also disclosed . instantaneous attainment of maximum seam strength , water tightness and consistency of the seams are advantages over conventional solvent - based adhesive methods .