MasterSeal 555 - Flexible, polymer cement waterproofing slurry ​How does MasterSeal 555 work? MasterSeal 555 is recommended as a waterproofing membrane below concrete, mortar, tiles etc. It is also suitable as a waterproofing coating to concrete structures. Typical applications include: Flat and Pitched Roofs Wet areas, Bathrooms and kitchens Terraces and balconies It is also suitable as a waterproofing coating to concrete structures such as: Bridge parapets, beams and pillars Reservoirs, sumps and tanks foundations below and above ground What makes MasterSeal 555 a unique solution? MasterSeal 555 meets the needs of customers who want a cementitious waterproofing product with high crack bridging ability. How can you benefit from MasterSeal 555? Flexible - Bridges cracks up to 2 mm when subject to normal movements Permeable to water vapours - Allows surface to breath, preventing build-up of vapour pressure