Thompson's Emergency Leak Fix is a high-performance clear sealant, which seals and repairs virtually any exterior surface, providing a long-lasting, highly durable waterproof repair. The unique formulation adheres to most surfaces, even in damp conditions, to form a waterproof seal that remains flexible over time protecting against cracking and splitting. Ideal for sealing doors and windows, the unique formula has been developed to be over-painted with solvent-based or water-based paints and stains. Usage Areas wood, painted surfaces, glass, PVCu, plastics, brickwork, stone, roof felt, slate, tile and zinc.