Sika Top 501 deep penetrative,reactive,capillary Waterproofing system for concrete and mortar. Sika Top 501 seal crystalline capillary Waterproofing system.these products contain specialist additives that play the role of the catalyst inthe formation of water-interstices crystalline micro-structures deep within the capillaries and interstices of Cementitious matrix of concrete and mortar. Sika Top 501 seal can be used as a coating or dry shake. Sika Top 501seal for patch repair and as render on old concrete surface. Water tanks, reservoirs. Building basements and foundations. Swimming Pools and water parks. Sewage and water treatment plant.Retaining walls & sea defense walls.Concrete pipes.