Signs of a Leaky Chimney

Chimney leaks are a common problem in areas with seasonal freeze/thaw cycles and inclement weather. This post looks at how to identify a leaking chimney, what causes it, and what you can do about it.

Signs of a Leaky Chimney

The sooner you notice that your chimney is leaking, the sooner you can schedule repairs and reduce the damage to your chimney, fireplace, and home. Here’s how to spot a leaking chimney.

Wall Stains
Water stains on the walls or ceiling could mean that you have a leaking roof or the chimney flashing is damaged and allowing water to get in. Furthermore, be on the lookout for warped or moldy drywall.

Condensation
If you see condensation forming in your fireplace, it could mean there’s a leak in your chimney. Condensation and signs of moisture in the fireplace can be difficult to spot. It’s wise to grab a flashlight and inspect it periodically, and especially after heavy rain or snow.

Musty Odors
Mold thrives in damp environments, so if your chimney is leaking and causing moisture buildup in the firebox, or in the flue, it won’t be long until you begin noticing musty or moldy odors. Mold isn’t just a problem because it causes foul smells; it can be dangerous to people with allergies or upper respiratory conditions.

White Residue
Water leaks often leave a white, chalky residue behind on the chimney’s outer walls. This phenomenon is called efflorescence and occurs when moisture moves through the concrete or masonry materials, forming crystals on the surface after evaporation. The residue isn’t harmful, but it indicates that you may have a leak.

Spalling Masonry
Spalling is the term used to describe bricks and mortar joints that are loose or flaking, and it’s fairly easy to notice. Water is a chimney’s primary enemy; once it gets into the masonry materials and freezes, it creates tiny cracks that worsen over time. If you don’t fix these minor cracks, they lead to spalling, which can require a complete chimney rebuild in severe cases.

What Causes Chimney Leaks?

If you know what can cause a chimney to leak, you can take steps to prevent it. Here are the most common reasons why water gets into the chimney.

Cracked Chimney Crown
The chimney crown is a cement structure that sits on top of the chimney, designed to stop water from getting into the flue.

However, because the crown is typically made from cement, it’s susceptible to cracks like mortar and brick. If the crown falls into disrepair, it allows water to get in, which can damage the flue liner.

No Chimney Cap
If there’s no cap on your chimney, it’s exposed to elements like rain, snow, and sleet falling directly into the home through the chimney.

Moreover, not having a chimney cap can lead to blockages caused by falling branches, leaves, debris, and critters that get in and build their nests.

Mortar & Brick Deterioration
As mentioned, water is the number one enemy of your chimney because the masonry materials absorb water like a sponge. When water gets in and undergoes the seasonal freeze/thaw cycle, it causes the mortar joints and bricks to crack, allowing water to get in. The more water that gets in, the worse the problem gets every year.

Damaged Flashing
When your chimney was built, the contractor probably installed flashing around the areas where the chimney connects to the roof. The flashing is designed to create a waterproof seal to keep moisture from seeping in. Most flashing material is made from aluminum, which deteriorates over time, which is why it’s wise to inspect it every year and replace it when necessary.

What Can You Do About a Leaking Chimney?

The best thing you can do to avoid a leaky chimney is to prevent it in the first place by scheduling annual chimney cleaning, inspection, and maintenance. Reputable and certified chimney professionals like the ones at Advanced Chimney Sweep can detect minor issues and repair them before they turn into expensive disasters. Once your chimney is buttoned up and in good shape, you can opt for waterproofing, which will prevent water from getting into the bricks and mortar and extend the lifespan of your chimney. Whether you need chimney waterproofing, cleaning, inspection, maintenance, or dryer vent service, you can count on our fireplace specialists for all that and more.

We’re a family owned, local company with over 15 years of experience, and our technicians are certified in all areas of chimney/fireplace services. We proudly serve residents throughout South Carolina and Georgia. Call us today to book an appointment. In Georgia, call (706) 833-4630. In South Carolina, call (803) 508-3990.