rFOIL® Reflective Insulation is an effective energy barrier that can greatly reduce the transfer of radiant heat through siding and roofing. While most insulating materials rely on retarding the flow of heat through walls and ceilings, rFOIL® Reflective Insulation works by reflecting as much as 96% of the radiant energy back away from its surface. This can dramatically cut energy costs in air-conditioned housing, as well as create an effective “shade” in non-cooled out-buildings, garages, porches, and utility buildings.rFOIL® Reflective Insulation is a single or double layer of polyethylene bubbles bonded to and sandwiched between a radiant barrier metalized film surface and a white polyethylene sheet. It can be taped to purlins, stapled to rafters or studs, or rolled out onto roof decking or existing shingles prior to installation of metal roofing or siding panels.