SOPRAVAP'R is composed of a proprietary formulation of elastomeric styrene-butadiene-styrene (SBS) polymer modified bitumen in combination with a high tack self-adhesive specifically designed for use with steel decks. SOPRAVAP'R is a SBS-modified bitumen vapor barrier for use in approved multi-ply membrane and flashing assemblies. The topside is surfaced with high strength tri-laminate polyethylene film and the underside is surfaced with protective polyolefin release film that is removed during application.