Tips on Waterproofing your Chimney
Have you ever wondered how to waterproof your chimney? It could be you didn’t know waterproofing was necessary, but it is very important. When it comes to your chimney, moisture is enemy number one. The damage caused by water in your chimney system can include very costly problems which can also lead to safety hazards that put your family at risk. You may have heard that there is a waterproofing sealant that can be applied to your chimney; while many recommend it, the effectiveness of that solution is debatable. There are other strategies that are reliable and have lasting results in keeping damaging moisture out of your chimney system.
Chimney Crown Repair
At the very top of your chimney is the chimney crown, which serves the purpose of keeping moisture from entering between the chimney masonry and the flue liner. When water does work its way in those tight spots, the resulting damage could be extensive and expensive. If a small crack develops in the chimney crown, it’s very possible a repair of the crack can solve the problem. If the crown is neglected, however, and large cracks grow, it is usually necessary to replace the crown altogether. Fixing the crown is just part of the solution. If the crown has that much damage, you may need to repair the chimney masonry and other potential damage caused by the breach.
Install a Chimney Cap
A very basic solution to water problems is to install a chimney cap. This appliance is enormously important, to prevent rain water from pouring directly into your chimney. If you get a chimney cap that also has mesh, it will keep out critters and debris, in addition to water.
The mortar that forms a seal between chimney masonry serves the important purpose of helping to keep moisture from getting trapped in the masonry and causing extensive damage. While masonry that is well-maintained easily lasts a century, mortar usually only lasts about 25 years at most. At some point, the mortar deteriorates. You may begin to notice that it is cracked and flaking off. Deteriorating mortar is a real problem because it can compromise the entire chimney. When damaged mortar has been ignored, homeowners have many times ended up with a chimney that leans or collapses altogether, creating the necessity of completely rebuilding the chimney.
Another problem that occurs when the mortar is no longer keeping out moisture is that water gets into the masonry. During winter months, that moisture begins to go through freezing and thawing cycles. The movement in the masonry often causes it to begin braking or flaking off, which is called “spalling.” If you ever see chimney debris around the chimney or on the ground below, it is probably a sign of spalling.
The best way to address damaged mortar is with a process called “tuckpointing.” The damaged mortar is removed and new mortar replaces it, adding new stability and a fresh new look to the entire chimney.
Repair Damaged Flashing
A common problem that causes a leaky chimney and costly damage involves the flashing. The metal part at the base of the chimney is supposed to be a watertight system where the chimney meets the roof. Flashing is rather difficult to install correctly; but even when it starts out nice and watertight, the metal can rust. Holes often develop in the flashing, which can wreak havoc on your roof structure because of water leaking in.
It’s a very good thing to know how to waterproof your chimney because a damaged chimney is not only expensive, but it can also be dangerous. Among the problems caused when the chimney is in a state of disrepair due to moisture issues are:
- The flue can become damaged and expose combustible parts of the home to heat that causes a house fire; and
- Obstruction in the flue could cause toxic gases such as deadly carbon monoxide to enter your home.
What steps do you need to take to waterproof your chimney?