TOPCOAT MB Plus Membrane can be used on modified bitumen, BUR, Hypalon, metal as a primer, wood, and concrete. For use with water-based sealants and top coats only. This product is a water-based, low VOC, acrylic, sprayable polymeric liquid, which cures to form a seamless rubber membrane. Covers and protects most roof surfaces including modified bitumen (smooth and granulated), smooth BUR, and metal. MB Plus Membrane is an ENERGY STAR-qualified reflective product that will help to reduce building temperatures.