COLVENT Flam 180 FR GR is an SBS-modified bitumen vented membrane used as a recover on existing roofing membranes. COLVENT Flam 180 FR GR is reinforced with a tough, dimensionally stable non-woven polyester mat that is saturatedand coated on both sides with a proprietary formulation of elastomeric styrene-butadiene-styrene (SBS) polymer modified bitumen.