BOSTIK POWERMASTIK is a permanently plastic, solvent-free, waterproof compound,which remains unaffected by extreme temperature changes. It has good adhesion to all dust-free, non-bituminous surfaces. It will remain plastic under normal structural and thermal movement of the joint to which it is applied. Can be painted with any non-bituminous paint after skin has formed. BOSTIK POWERMASTIK is excellent for providing a durable, protective seal against entry of water, dust, fumes, etc.