The MasterSeal 501 waterproofing system ensures a total and permanent solution to water leakage, ingress, or seepage in concrete structures or any cementitious substrate. The formation and development of insoluble crystals into water bearing capillaries and interstices effectively blocks the further passage of water. Supplied as a powder and mixed to a slurry consistency with potable water. MasterSeal 501 is applied directly to concrete, blockwork or cement renders in areas where general waterproofing is required.