The rsltwsu5l thompsons one coat water seal ultra protects against water damage in one coat the silicone micro emulsion effectively penetrates below the surface of porous materials carrying waterproofing resins deep into the pores of the substrate the breathable waterproofing membrane allows moisture vapour inside the substrate to evaporate whilst protecting against water penetration and damage the invisible membrane is protected from ultraviolet light and is long lasting even under heavy moistu