COLPHENE Flam 180 is a SBS-modified bitumen base ply for use in approved multiply waterproofing assemblies. This is composed of a proprietary formulation of elastomeric styrene-butadiene-styrene (SBS) polymer modified bitumen and is reinforced with a tough, dimensionally stable non-woven polyester mat. The topside & underside are surfaced with polyolefin burn-off film to optimize heat welding.