Chimney Sealant

Chimney Sealant is an excellent product to use on the exterior of your masonry chimney that extends above your roof. Over time, water can cause damage to masonry. Using a sealant to prevent moisture problems will prolong the life of your chimney.

How Does Water Cause Damage?

Most masonry chimney structures are porous and can absorb water. Brick in particular acts like a sponge, soaking in outside moisture. This water absorption can lead to the decay of mortar and damage your chimney.

The biggest problem results from the freezing and thawing of the water. As we all know, water expands when it freezes. This causes masonry to shift and break. Translation: water in your masonry chimney is bad and will eventually cost you lots of money in repairs.

So how do you combat this problem? A waterproofing sealant of course!

ChimneySaver Water Repellant

ChimneySaver water repellant is one of the most popular brands of sealants and is specifically designed for chimneys. It works by providing a water repellant surface and is vapor permeable. This is important because it won't trap water vapors inside the chimney when burning fires. In essence, ChimneySaver lets moisture out but doesn't let outside moisture enter. The best of both worlds!

If you decide to purchase a different brand, make sure that it is vapor permeable and designed for chimneys. Using paint or any other non-vapor permeable sealant will trap water inside the chimney and worsen the problem.


Although the cost of buying a chimney sealant may seem expensive at first, it's not too bad when you consider the cost of fixing the chimney several years down the road.

Just make sure you purchase the correct product for the job. You don't want to put in the work and end up doing more harm than good.

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