What Happens if Water Gets Into Your Chimney?

Category: Chimney

What Happens if Water Gets Into Your Chimney?

Anyone who has been around home improvement projects knows that when there’s water exposure, there’s a problem.  Homes are outfitted from top to bottom with water-proofing measures.  Basements are waterproofed, gutter systems channel rainfall and water runoff away from the foundation, windows are protected with awnings, and walls and floors are sealed inside and out to prevent water damage. But what about your chimney?  It’s nothing more than one long brick opening that exposes your home from the roof to your living space.  It can’t be a good thing when water leaks into the masonry. In general, a chimney leak can cause:
  • Mold and mildew growth
  • A negative impact on your home’s structural integrity like foundational issues, warped windows, doorframes, and walls
  • A dank and damp living space/environment
  • The need for expensive repairs
  • Issues during resale


One prevailing issue of water exposure within your chimney is the damage it can cause to your chimney’s masonry.  This is probably the worst damage that can be inflicted on your chimney, not to mention one of the most expensive problems to fix. Masonry, when exposed to water for long periods of time, can begin to crack and crumble.  Masonry issues often go unnoticed by homeowners because it’s happening on the inside of the chimney. Depending on where and how deeply the water has affected the masonry, you’ll likely need to think about rebuilding at least part of the chimney.  Chimney masonry repairs are expensive as you’ll need to hire a certified, professional mason.  Labor and materials will also run up your bill. This is one reason why the CSIA suggests annual chimney inspections conducted by a trained professional at least once a year.  A chimney sweep investigates the interior of the chimney by using a specialized camera and will catch issues early on before water damage sets in as well as directing you to a solution if repairs are needed.

Flue Lining

The flue lining is an essential part of the chimney, responsible for the draft that pulls the dangerous and toxic combustion byproducts produced by the fire to the outside.  Flue linings are made of clay or metal, both will deteriorate if left exposed to water damage. Like the chimney’s interior masonry, damage to the flue liner can go undetected without a yearly chimney inspection.  Without a properly working flue duct, you’ll find yourself having a hard time getting your fire going and notice that smoke isn’t be drafted out of the house.

Warped Siding

If your home has wooden siding and you have a leaking chimney with a water problem, you’ll notice that siding will become warped over time if you don’t address it.  Prolonged neglect and water exposure down the chimney can slowly erode the integrity of your siding, deforming it in the process. Replacing wooden siding is extremely expensive, so be sure to have your chimney inspected every year so you can stop water from damaging it. Water in Chimney


When chimneys get water inside of them, the firebox becomes prone to condensation.  This sweating can have a major impact on the brickwork which again, negatively affects your masonry and can lead to costly repairs.  The mortar can also begin to erode, and that leads to loose bricks that can crack and crumble. Sometimes firebox condensation or discoloration doesn’t mean your chimney is leaking, but it could be a sign of a structural leak.  That alone is worth examining.


A leaky chimney may not be your only water problem.  Water and gravity work together, so if water is running down your chimney, it may also find another path elsewhere in your house.  That might explain some rather inexplicable leaks.

What Causes a Leaky Chimney and How Do You Fix It?

A big reason why chimneys leak is due to the absence of a proper chimney cap.  A cap protects the top of your chimney from water, critters and their nests, and debris from getting inside.  A simple cap makes for a simple solution and seeing as to how many issues come about when your chimney is exposed to water, it’s a no-brainer to have one installed if you don’t have one already. As mentioned earlier, yearly inspections make for an ounce of prevention.  It doesn’t cost an arm and a leg to have a professional chimney sweep company come out once a year to give your chimney the good once-over. They’ll clean your chimney for you—which should be done to ensure the safety of your household and loved ones—as well as inspect the interior of the chimney.  Any issues are written up into a report and solutions are then discussed to prevent further damage. Whether you're in the market for chimney repairs or masonry, Vertical Chimney Care has been Chicagoland's go to choice since 1985. We prioritize great service to all our clients by keeping your home cleaner and safer.

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