Brushbond Crystal Plus is crystalline capillary waterproofing system. it is a blend of proprietary Portland cements, aggregates and specialised chemicals. In the presence of moisture, the active chemical additives in Brushbond Crystal Plus penetrate concrete and react chemically with free lime to produce insoluble crystals. This crystalline growth reduces concrete porosity by blocking capillaries and filling hairline cracks caused by shrinkage or expansion. Unlike membrane types of waterproofing which only provide a surface barrier, Brushbond Crystal Plus continues to produce crystals in the presence of water therefore providing long lasting impermeability.