The Chimney Pro Blog

Have a leaky chimney? Here’s how you can fix it.

Chimneys are usually all but forgotten until its winter and you can not wait to build that first fire, but sometimes a problem arises that demands your immediate attention. Water! Chimneys have the most exposed brick/rock on your home, so the severe weather with freeze/thaw cycles and rain takes it’s toll. Brick and mortar joints are porous, so when it rains the water is absorbed. The fact that brick are porous is what makes them stick together when laid called a hydraulic bond. So with all this being said your masonry chimney is essentially a big sponge or wick on the exterior of your home or above your roof line. Trying to diagnose exactly where the water is penetrating can be tricky. Many times it’s assumed water is coming through the flashing at the base of a chimney or down the flue, but in most cases it is caused by years of exposure to the elements. This exposure can wreak havoc on a masonry chimney’s structure.

If your chimney has an active water leak there are a few indicators you should look for to help diagnose the problem. Wet brick on your chimney exterior days after it has rained, dark mortar joints or moss typically near on the top half of your chimney, or the face of your brick have popped off (also known as spalling) these are all indications of an active leak. If so, immediate action should be taken to preserve your chimney.

Now what steps to take to solve this issue, if you are planning a DIY project. First, gather all the needed equipment for job safety (rope, harness, etc.). Gain access to the roof to see how much material will need to apply. The chimney will need to be pressure washed to ensure proper application of the water repellent. Water repellent is very slippery when the overspray gets on the bottom your shoes, so use extreme caution. You can purchase a water repellent at one of the big box stores that has a 1 year guarantee but they usually only last about 6 months before you must reapply.

We recommend calling a Chimney Professional because as in other expertise they have the experience and specialty products not available to an individual. Sealants are not recommended due to the fact that when your chimney heats up then cools down it creates moisture that can not escape through sealant. This could potentially create more damage and leave you with a lingering mildew odor inside the home. Professionals use water repellent specifically designed for chimneys that allow the moisture to escape but prevents water from entering. You can visit to find a local professional, and of course if you are in Northwest Georgia contact us here at Chimney Pro.

Please remember a fireplace can add up to ten percent to the value of your home. Don’t get frustrated or take advice suggesting you tear it down before having a Chimney Professional complete an inspection. There is a extremely high chance your leak can be stopped!

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