MuleHide Poly ISO Tapered insulations consist of a closed-cell polyisocyanurate foam core laminated to heavy, (non-asphaltic) glass fiber reinforced felt facers. The product insulations are compatible with all MuleHide membranes and accessories and are available in 20 and 25 psi densities. MuleHide Poly ISO insulation boards may be used for ballasted, mechanically attached and fully adhered single-ply roofing systems. Poly ISO insulation board may be installed over approved decks and substrates on new construction, tearoffs and recover (retrofit) projects. Rated for use in UL Class A and FM Class 1 assemblies.