HydroStop FlexCoat Wall Coating is a flexible, elastomeric that fills cracks & provides a smooth, watertight barrier for masonry surfaces. As masonry and stucco surfaces are primary points of entry for water, FlexCoat Wall Coating is carefully formulated to remain flexible and allow for movement while providing a high-quality water seal. FlexCoat Wall Coating is a "crack bridging" elastomeric coating designed for waterproofing exterior walls. It is formulated with the highest quality resins and raw materials available to form a tough yet flexible mildew-resistant coating for masonry, stucco, and block substrates.