IKO Enerfoil Sheathing Wall Insulation is a rigid, polyisocyanurate foam insulation board with high thermal properties. It is constructed from closed cell polyisocyanurate foam core bonded on each side to aluminum foil facers during the manufacturing process. Enerfoil is designed to be a non-structural, non-permeable sheathing in cavity wall, stud wall or interior basement construction. When used with IKO AquaBarrierTM Tapes, IKO Enerfoil can act as insulation, air barrier and weather resistant barrier all in one! Enerfoil is lightweight, easy to handle and can be sized with ease and has a high thermal R-value (R6.2 per inch) that provides outstanding insulation protection, which helps reduce energy costs.