DERBIGUM BC5 PRIMER is a quick-dry penetrating high bonding primer agent used between acceptable prepared substrates and DERBIGUM Liquid Applied Systems. It is used to prime a wide range of substrates including bitumen roofing, concrete, plywood, brick, steel, and glass. DERBIGUM BC5 PRIMER provides alkalinity protection for membrane surfaces prior to concrete or cementitious mortar/adhesive application.