SOPRALENE® 250 SP 4.0 is an SBS-modified bitumen base ply for use in approved multi-ply membrane and flashing assemblies. SOPRALENE 250 SP 4.0 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 is surface with fine mineral aggregate and underside is surfaced with polyolefin burn-off film to optimize heat welding.
Prior to installation, unroll SOPRALENE 250 SP 4.0 onto the roof surface and allow to relax. Position SOPRALENE 250 SP 4.0 in desired position and back roll the product. SOPRALENE 250 SP 4.0 is then heat welded to approved substrates. Subsequent approved inter-ply or cap ply membranes are applied to SOPRALENE 250 SP 4.0 via cold adhesive or hot asphalt. Refer to the SOPREMA SBS Roofing Manual for additional application guidelines.