Flat-roof - roof sealing is vital to a building because it receives the greatest stress on it and directly affects the quality of life and health of its occupants. Moisture problems on a roof gradually cause the concrete to disintegrate and oxidize its reinforcement. The materials mainly used are asphalt membranes (bitumen sheets) and coatings (polyurethane, cementitious and acrylic). Asphalt membranes are more common in our country because of their long life. They are covered with quartz (gray or white) or aluminum sheets.