MasonrySaver All-Purpose Heavy-Duty Water Repellent is a one component, VOC compliant water repellent and chloride screen, which contains an optimized blend of silane/siloxane. This water-based blend penetrates concrete and masonry up to 1/4 inch or more depending on surface porosity and moisture content at the time of application. MasonrySaver Heavy-Duty Water Repellent reacts with the minerals in concrete and masonry in the presence of ultraviolet light and atmospheric moisture. This reaction forms strong permanent bonds beneath the surface and creates a hydro- phobic zone that prevents water molecules from penetrating, while allowing free migration of water vapors.