subject: Water Proof Your Chimney To Prevent Expensive Repairs [print this page] Each and every day you take multiple steps to protect yourself from various stimuli in our environment. You wear clothes and sunscreen to shield yourself from the sun's harmful rays or the wind's biting blow, you arm yourself with knowledge before going at a new situation, and you put a roof over your head at night before falling asleep. Your brick, especially the brick on the chimney, needs similar protection. The brick on the chimney has no buffers to protect it from the elements. When it is hailing, the chimney gets hit. When it rains, the chimney gets wet. There is no overhanging part of the roof or a windowsill to protect this part of your home naturally, so you absolutely must apply protection to the brick on your chimney.
First off, you must figure out what has happened to your chimney over the years, especially if you haven't lived in the home since it was built. Is it new? Has it been treated before? Does it have cracks or missing mortar joints that will need repaired before waterproofing? It is imperative to check these things to extend the life of your chimney because neglect will only turn a pesky repair into serious damage.
If there are cracks in your brick, you will need to fill them before sealing them. Using a crack filler or a high quality caulk, you will need to fill the cracks to prevent water from entering and causing freezing and thawing damage, which will make the cracks deepen. By taking care of repairs early you are ultimately saving yourself from even more costly repairs down the road, including but not limited to removing courses of brick and replacing them or tearing down the whole chimney and starting from scratch.
After you have filled any cracks on the chimney and ruled out the need of overhauling the chimney, the best and easiest way to protect the integrity of your chimney is to coat it with a waterproofing product that is going to allow the brick to "breathe" while still preventing water from entering. Water repellents that trap vapors inside the brick will actually cause the faces of the brick to pop off more readily than if you hadn't water proofed at all. A water repellent that permits the small percentage of moisture naturally found in brick to move freely while still preventing rain, snow, etc. from penetrating is the best protection available.
