5 Places Chimney Leaks Start (and How to Spot Them!)

Chimney leaks are a headache for homeowners, but luckily we know the first places to look for common places chimney leaks start. If you’ve noticed water near your fireplace or damp spots on the ceiling around your chimney, you’re not alone. Chimney leaks are one of the most common problems homeowners in York & Cumberland County, Maine, and the Manchester, NH area face, especially with our harsh winters, coastal moisture, and heavy rains. At Frechette Chimney Sweeping, we’ve seen firsthand how a small leak can turn into bigger issues if left unchecked. The good news? Most chimney leaks can be traced back to just a few problem areas. By knowing where to look, you can often spot the warning signs before they become major chimney repairs. Here are the five most common places chimney leaks start and what you should watch for.

How Cracks in the Chimney Crown Let Water In

The crown is the slab of concrete or mortar that covers the very top of your chimney. Its job is to protect the brickwork and keep water out. Unfortunately, in Maine’s freeze-thaw cycles, small cracks can quickly expand. Once water finds its way in, it can travel down into the chimney structure. 
What to look for: water stains near the chimney indoors, crumbling or flaking concrete on top, or visible cracks when you glance up at the crown.

Why Damaged Flashing Is One of the Biggest Leak Culprits

Flashing is the metal seal between your chimney and the roof. When it’s properly installed, it keeps water from sneaking into the gap where the two meet. But if flashing starts to rust, separate, or shift, it becomes one of the most common and damaging sources of leaks. 
What to look for: water marks in the attic near the chimney, damp rafters, or rust and gaps visible where the chimney meets the roof.

The Simple Role of a Chimney Cap in Stopping Rain Leaks

A chimney cap may seem like a small piece of hardware, but it does big work. It keeps out rain, snow, debris, and even curious animals. Without a cap, or with one that’s damaged, water can pour straight into your flue every time it rains.
What to look for: moisture in the firebox, musty smells after a storm, or rusted metal parts inside the fireplace, like the damper.

How Brick and Mortar Absorb Water (and What That Means for You)

Brick and mortar are naturally porous. In our coastal and damp climate, that means chimneys act like sponges, soaking up moisture. Over time, this weakens the structure and leads to cracks, crumbling, and leaks. Freeze-thaw cycles only speed up the damage.
What to look for: dark, wet-looking areas on your chimney exterior, moss or vegetation growth, and bricks that look like they’re flaking or crumbling.

When “Leaks” Aren’t Rain at All: Condensation Inside the Chimney

Sometimes what looks like a chimney leak is actually condensation forming inside the flue. This often happens when the chimney isn’t properly lined or when gas appliances vent into the chimney. The result is water buildup that can cause just as much damage as a rainfall leak. 
What to look for: dripping or moisture inside the chimney even during dry weather, a persistent musty odor, or rust forming inside the flue.

Why Fixing Chimney Leaks Early Saves You Stress and Money

Water is relentless and stopping a chimney leak can be difficult. Once it finds a way into your chimney, it doesn’t stop there, it can damage walls, ceilings, and even structural supports. What begins as a small drip can quickly snowball into expensive repairs. At Frechette Chimney Sweeping, we take pride in being the local chimney service you can trust to keep your chimney functioning correctly. We know the unique challenges our Maine weather brings, and we go above and beyond to find lasting solutions, not just quick fixes. If you think your chimney might be leaking, don’t wait for the next storm to make things worse. Reach out today, and let’s make sure your chimney is ready to stand up to Maine’s moisture and New Hampshire’s changing seasons.

Frechette Chimney Sweeping
1550 Main St, Sanford, ME 04073
(207) 608-0564