Mapeproof Swell has been specially developed to form flexible, waterproof seals in cracked reinforced concrete or in prefabricated elements with infiltration of water. A single component hydrophilic paste used in repair and waterproofing operations. It may be applied on damp or uneven surfaces and may be used at any temperature and with any kind of water which infiltrates or seeps through. On contact with water its volume increases and if well confined is resistant to considerable hydrostatic pressure. Mapeproof Swell bonds perfectly to slightly damp surfaces as long as they are clean and solid.