Elevate™ ISOGARD GL flat and tapered roof insulation consists of a closed cell polyiso foam core laminated to a glass reinforced mat facer on both major surfaces. Flat and tapered ISOGARD insulation provides outstanding thermal performance on commercial roofing applications, while providing positive rooftop drainage to help eliminate ponding water when tapered ISOGARD GL insulation is used. All Elevate polyisocyanurate foam insulations use EPA accepted blowing agents. Elevate ISOGARD GL incorporates a HCFC-free blowing agent that does not contribute to the depletion of the ozone layer (ODP-free).