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