Though brick construction is considered quite resistant, extreme weather can have a negative effect over time. Brick waterproofing can help the material last as long as possible by keeping out moisture. Waterproofing brick and stone walls can help eliminate the possibility of mold growing behind the brick which is great concern for anyone. Brick-and-mortar are actually quite easily penetrated by water and rain. In general, the water should run down and go out to weep holes. But the water is still there, it soaks into the sheathing, and the moisture stays back there for a while. A benefit of brick sealant is that, while it does not allow liquid moisture to seep through to the material, it does allow vapor to escape from the bricks. In areas where they don’t put a vapor barrier behind the brick, it can be a real problem. Coupled with the fact that the drip pans below the window sill are rarely installed properly, a lot of water can get behind there and cause further problems. Sealing the brick is a relatively inexpensive way to extend the service lives of buildings. Most of the sealants these days are water-based, and quite harmless to the environment.