Load-bearing uncoupling: Flexbone UI 740 bonds to the subfloor and uncouples tile to help prevent cracked tile and grout in heavy-traffic floors, for lasting value and dependable results. Waterproof-capable: With proper seam treatment it adds a waterproof layer for wet areas such as bathrooms, showers and kitchens, for new construction and renovation work alike. Griplock studs: Bone-shaped studs fill with thin-set in one pass and lock in mechanically for an extremely strong mortar-to-membrane bond, for a clean, professional and long-lasting finish. Vapor equalization: A felt backing with ventilation channels equalizes vapor pressure over concrete and wood subfloors, including basements, for new construction and renovation work alike. Extra-heavy rated: For ceramic tile, porcelain tile, marble tile, granite tile and natural stone in shops, restaurants, gyms, hotels and commercial spaces. ARDEX Flexbone UI 740 is a high load-bearing uncoupling and crack-isolation membrane for tile flooring, 1/8 in (3 mm) thick and made in Germany. Bonded to the prepared subfloor with polymer-modified thin-set mortar, it protects ceramic, porcelain, quarry and natural stone tile from lateral movement, substrate shifts and existing cracks that lead to tile or grout failure. Its bone-shaped stud pattern with GripLock technology accepts thin-set in one pass; as the mortar cures, the undercut studs lock in mechanically for an extremely strong mortar-to-membrane bond. The stud structure distributes heavy loads, supports the tile and absorbs lateral shear movement, extending tile and grout-joint life. A felt backing with integrated ventilation channels equalizes vapor pressure, a critical factor over wood and concrete subfloors and in basement renovations, helping support long-term floor performance. With proper seam treatment, UI 740 also provides waterproofing for wet areas. Rated Extra Heavy for load bearing, it suits high-stress residential and commercial spaces such as shops, restaurants, kitchens, hallways, gyms, offices, hotels, hospitals and food courts. It works with ceramic tile, porcelain tile, cement tile, marble tile, granite tile and natural stone in bathrooms, kitchens, basements, retail and hospitality floors, indoors. It is well suited to both professional contractors and confident do-it-yourself homeowners. It represents a practical, cost-effective choice for a wide range of interior and, where applicable, exterior projects. Careful handling and correct installation help maximize its performance and service life. Consistent quality and reliable performance are built into every unit for lasting value. It is engineered to deliver dependable, professional results on every project. Trusted by tradespeople and homeowners alike, it is made to perform job after job.