Elastobase is an SBS modified bitumen roofing membrane base sheet, reinforced with a fiberglass mat saturated and coated with a rubberized asphaltic compound with exceptional waterproofing and weatherability properties. Elastobase is specially designed for use as a base ply or interply layer in hot asphalt, cold-applied, mechanically attached and heat-welded applications. Elastobase can also be used as a base sheet for Self-Adhered systems when poly film on top. Top and bottom surfaces of Elastobase are provided with either sand/poly, poly/sand, or poly/poly.