Chimney Leak Repair in Denver

Denver is dry, with about 15 inches of precipitation a year at the Denver-Stapleton station in NOAA's normals, so a leaking chimney surprises people. But the water arrives in bursts: heavy spring storms, hail, and wet snow that sits on the chimney and melts in the sun for days. A small opening that stays dry most of the year can soak a ceiling in one week of thaw.

There are five usual ways in: flashing that has let go, a crown with cracks, brick and joints that soak water up, a flue left uncapped, and on prefab chimneys a chase cover dented or rusted into a dish that holds water. Simple fixes at the cap, crown or with a sealant typically run $300 to $1,000; flashing or masonry repairs $800 to $2,500.

Signs you need this

• Water or rust in the firebox after rain or snowmelt
• A stain on the ceiling or wall beside the chimney
• Musty or damp smell from the fireplace
• Rust streaks running down the chase siding
• Peeling paint or bubbling plaster near the chimney

How we do it

1. Free leak checkWe inspect from inside, the attic and the roof, and photograph every place water could be getting in.
2. Prove the sourceWhen it is not obvious, we run water over one section at a time, starting low, until the leak shows.
3. Fix that spotCap, crown, flashing, chase cover or masonry, priced in writing before we start.
4. Seal if it helpsAfter repairs, a breathable water repellent on the brick can cut down how much water it soaks up.

Can you find a leak that only shows after big storms?

Yes, usually. Leaks that appear only with wind-driven rain or heavy snowmelt are harder to catch, so we test section by section with a hose: flashing first, then the brick, then the crown and cap. When the leak shows, we know which part to fix and which parts to leave alone.

That matters because leak repairs are often done in the wrong order. Resealing the brick does nothing if the water is coming under the flashing, and new flashing does nothing if the crown is cracked.

Why is rust running down my chimney chase?

On a prefab chimney, the top of the chase is a sheet-metal cover. Many original covers are galvanized steel that rusts once the coating is worn or chipped by hail. Dents turn the cover into a shallow bowl, water sits in it, rust streaks down the siding, and eventually water drips into the chase and down the metal flue.

The fix is a new chase cover, typically $300 to $700, made of stainless steel with a slope or cross-break so water runs off, and a drip edge that keeps it away from the siding.

Will waterproofing stop my leak?

Only if the brick itself is the problem, and only after the cap, crown and flashing are sound. A breathable water repellent typically costs $300 to $800 for a chimney. It helps porous brick in a freeze-thaw climate, but it is not a cure for a cracked crown or bad flashing.