Protects Chimneys From Rain And Water Damage. Chimneys are damaged by extreme temperatures, snow, sunrays, wind, and rain. Damage from rainwater is particularly common because bricks are so porous that they soak up water like a sponge. The American Brick institute says that you don't want to put a sealer on exterior brick. Water can still get in, but can't get out. The result is a damaged chimney, and it's is a serious problem; it can create dangerous living conditions and cost thousands of dollars to repair. The best way to stay safe and save money is to prevent problems from occurring. To stop deterioration due to water damage, your chimney sweep may recommend a Crown Seal to prevent water penetration through the top of your chimney, or a Crown replacement for chimneys with more severe deterioration.
Never use popular commercial waterproofing sealants that actually accelerate damage by sealing moisture into the bricks. Look for Chimney Saver products which are available only through chimney professionals. This long-lasting treatment actually changes the polarity of the bricks so that they repel water like a magnet.