Cementone Fast Drying Water Seal - 5LCementone Fast Drying Water Seal is a durable and water repellent solution designed for porous external walls and fascias. This waterseal forms a rainproof resin that reacts with residual moisture to reduce rain penetration, while still allowing the substrate to breathe. It is backed by a 1 year guarantee. Key Information Efficient water repellent for porous brickwork and cement renderings Protects against rain, damp, and frost Improves insulation,