Chimney Leak Repair in St. Louis, MO

Five usual suspects, in order of frequency: a cracked chimney crown, failed flashing where the chimney meets the roof, a missing or damaged cap, mortar joints letting water soak through the brick, and unsealed porous masonry. It is often more than one at once — and the stain on your ceiling does not tell you which. Only tracing the water at the chimney itself does.

That is the most common mistake we get called in to undo. The wet spot is where the water ends up, not where it gets in — sealing it traps moisture inside the masonry and the leak finds a new path. Worse, the trapped water freezes in winter and spalls the brick. A leak repair that lasts starts with finding the actual entry point.

We are available 24/7, and active leaks get priority. If water is coming in right now, call (314) 887-7250 rather than using the form.

Usually not. Most leaks trace to the crown, the flashing or the cap — repairs measured in hundreds, not thousands. A rebuild only enters the picture when water has been getting in for years and the masonry itself has deteriorated. The inspection tells you honestly which situation you are in.

Snow sitting on the crown melts from chimney heat and finds the same entry points rain does. And moisture already inside the masonry freezes, expands and opens new paths. Winter leaks are the same disease at a later stage — which is why they should not wait until spring.

Insurance generally covers sudden damage — storm, hail, a lightning strike — and generally does not cover slow deterioration. Our photo documentation of the source is exactly what you submit with a claim, and you get it whether or not you hire us for the repair.

It depends where the water gets in, which is exactly what is unknown when the stain first appears. Flashing, where the roof meets the chimney, sits between both trades. The crown, the cap, the chase cover and the brick and mortar are chimney work, and a roofer who re-flashes a chimney with a cracked crown has not fixed the leak. We inspect every one of those points, including the flashing, and repair whichever one the photographs show is letting water in.

We do not publish repair prices, because the number depends on what the inspection finds. What drives it: which entry point is failing (a cap or chase cover is a different job from flashing, a crown or masonry), how many of them are failing at once, how high and steep the roof is, and how long water has been getting in. It starts with the $69 inspection, you get one fixed price in writing before any work, and the $69 comes off it.

That is a factory-built chimney: a metal flue inside a framed, sided chase, common in homes built from the mid-1980s on in areas like Chesterfield and St. Charles County. The usual leak is the chase cover, the flat metal lid on top. Galvanized covers rust through, and covers built flat let water pool instead of shedding it, so the water runs down inside the chase. The fix is usually a properly sloped stainless chase cover, sometimes with repair of the wood inside the chase if the leak has been going on a while.

Stop using the fireplace, move anything valuable away from the wet area, catch the water, and take photographs of the stain and the chimney from the ground for the record. Do not go up on the roof, especially in rain or ice. Then call (314) 887-7250 rather than using the form, because active leaks get priority.

It can look like one. When a gas furnace, water heater or gas insert vents into an old masonry flue that is far too large for it, the exhaust cools on the way up, its water vapour condenses inside the flue and soaks into the brick. The result is brown staining, damp patches and white chalky deposits that appear in dry weather. That is not a roof problem and no amount of sealing fixes it; a correctly sized flue liner does.