Mechanically Fixed, Single Ply Waterproofing Systems Tapered Roof ALU is a high performance Polyisocyanurate Tapered Roof Insulation with vapour-tight aluminium foil facings suitable for use with single ply membranes. It is part of the comprehensive range of Unilin’s high performance tapered roof boards providing total solutions for tapered roof projects. An Environmental Product Declaration (EPD), certified by IGBC is available for this product. Please contact technical support for further details.