SOPRAJOINT® is an SBS-modified bitumen expansion joint membrane for use in approved multi-ply membrane and flashing assemblies. SOPRAJOINT 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 surfaced with polyolefin burn-off film to optimize heat welding while the underside is surfaced with a foil bond breaker and a protective polyolefin release film that is removed during application.

Product Properties

  • Type Membrane Accessories


Prior to installation, unroll SOPRAJOINT onto the roof surface and allow to relax. Place SOPRAJOINT in desired position over expansion joint and back roll the product. SOPRAJOINT is heat welded on both sides of the foil bond breaker. Subsequent approved inter-ply or cap ply membranes are applied to SOPRAJOINT via heat welding.

Testing & Approvals

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