Stops leaks through brick and mortar with crack Magic. This is a brushable sealant seals cracks up to 1/2 inch wide on brick faces and at mortar or brick joints inter face. It dries to a clear , translucent milky film in several hours, cleans up easy with soap and water. A 1 gallon container will teat mortar joints surrounding approx 550 standard size bricks or 100 square feet of a wall surface. it so easy its like Magic!