Chimney Waterproofing – Can Water Damage Really Destroy Your Masonry Chimney?

crown1 016Here in Cincinnati, I’m sure I don’t speak for myself when I say I have a new respect for hurricanes. We recently experienced hurricane force winds that caused more damage to chimneys than this city has seen in a while. When someone thinks of a hurricane, lots of water comes to mind, and when it comes to chimneys, few things are more detrimental to its life and quality than water damage. Not to mention there are few things more aggravating than the drip, drip, drip of water entering the chimney, resonating through your home and eventually through your very soul… Well, it may not be that annoying but no one wants to have to write a check for a major chimney overhaul due to moisture damage when it is easily preventable.

crown with moss growingWater Damage: A $1 Billion Per Year Problem

This damage comes in the form of staining, loss of insulation value, freeze-thaw damage, deterioration, and ultimately, structural failure. In light of this, I’d like to discuss a few systems, products, and techniques to ensure your family is safe, warm, and dry this hurricane or winter season, whichever you are preparing for.

Masonry chimneys are more prone to water damage than the rest of your home because they extend far above the roofline, unprotected from the elements. Waterproofing is a good idea because it protects the mortar joints from moisture entry and helps a repair last longer.

Waterproofing and Sealers

As far as waterproofing goes, Chimneysaver© is a ” Professional Grade ” product we use out in the field. It’s important to know the difference between waterproofers and sealers. ChimneySaver is not a sealer. Sealers and silicone coatings form a water resistant surface film which traps water vapors. If these vapors cannot escape, they will add to the deterioration of your brick.

Your chimney needs to breathe, which is why we use Chimneysaver©. It’s 100% breathable, or vapor permeable, meaning water vapor trapped inside the brick can easily pass through it. This is a non film-forming water repellent that will penetrate and line masonry pores to prevent water from deteriorating the brick.

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Mortar Joint Repair

crackmagik-buynowBefore you waterproof, make sure all the mortar joints are in good condition. If there’s any cracks or missing pieces of mortar, you may need to do some tuckpointing. If the cracks aren’t severe, you may be able to apply a brushable product called Crack & Joint Sealant. Think of it like a brushable caulk that dries semi-clear. This waterproofs the gaps and cracks in the mortar up to 1/8″.

Waterproofing your masonry chimney can preserve your chimney and prevent water damage and deterioration. A good water repellent normally only needs to be applied once every 5-10 years and will save you the headache of having to replace or rebuild your chimney.

Clay Lamb

Clay Lamb is a Cincinnati Chimney Sweep contractor and the executive producer of the YouTube channel, podcast, and blog Ask the Chimney Sweep. He is also an award-winning educator and public speaker in the chimney and fireplace industry.….Educational Videos….American Chimney Cincinnati, OH We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.

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