RUBEROID EnergyCap HW Plus Granule FR Membrane is a membrane with a factory-applied premium, heavy duty, fire-retarding modified bitumen membrane and a factory-applied layer of TOPCOAT EnergyCote Elastomeric Coating. RUBEROID EnergyCap HW Plus Granule FR Membrane is manufactured to stringent GAF specifications. Its core is a strong, heavyweight, resilient non-woven polyester mat that is coated with fire-resistant SBS polymer modified asphalt and surfaced with extra-fine mineral granules and TOPCOAT EnergyCote Elastomeric Coating.