Guttrz / Blog / Chimney leak: flashing or chimney
Chimney leaks: is it the flashing or the chimney?
The owner inspects every chimney leak himself, sends a photo report the same day, and gives you one written price good for a year.
A chimney leak comes from one of two places: the flashing, which is the metal where the chimney meets the roof, or the chimney itself, meaning the crown, the cap, the mortar joints or the brick. Flashing leaks show up low, near the ceiling where the chimney passes through, and get worse with wind-driven rain. Masonry leaks soak the brick from above and often show as damp brick, white mineral deposits or water in the firebox. Guttrz in North Canton repairs chimney flashing across Stark, Summit and Medina counties; the owner inspects himself, sends a photo report the same day, and gives one written price good for a year, but crowns, caps and mortar are a mason's job.
Every chimney leak comes down to one question: flashing or chimney? The flashing is the metal that seals the joint between the roof and the brick. The chimney is everything above that line, the brick, the mortar, the concrete crown on top and the cap over the flue. Both leak, both stain the same ceiling, and they are fixed by different trades. Guttrz fixes flashing. A mason fixes the chimney. This post shows how to tell which one you have before you pay anyone. The owner inspects every chimney himself, sends a photo report the same day, and gives one written price good for a year.
Chimney leak: flashing or chimney, which parts can let water in?
Water can get into a chimney at six places. Three are roofing and three are masonry.
| Part | What it does | Who fixes it |
|---|---|---|
| Step and counter flashing | Seals the sides of the chimney to the shingles | Roofer |
| Back pan or cricket | Turns water around the uphill side | Roofer |
| Apron | Seals the downhill face over the shingles | Roofer |
| Crown | The concrete or mortar slab on top that sheds water off the brick | Mason |
| Cap | The metal hood over the flue that keeps rain and animals out | Mason or chimney sweep |
| Mortar and brick | The body of the chimney, which soaks up water once joints open | Mason |
Brick is porous. A tall chimney above the roof line takes rain on four faces, and once the mortar joints open or the crown cracks, it drinks water like a sponge. That water travels down inside the masonry and comes out wherever it can, often right at the roof line, which is why a masonry leak gets blamed on the flashing so often.
What does a flashing leak look like?
- The stain is low. It shows up on the ceiling where the chimney passes through, or on the attic rafters and roof boards right beside the chimney.
- It follows wind. Rain blowing against the uphill side or the face of a step joint finds gaps that steady rain does not.
- The attic shows a clear path. Wet wood begins at the roof deck beside the brick, not on the brick itself above the deck.
- You can see the patch. Thick roof cement, a strip of metal face-nailed into the brick, or counter flashing pulled away from the joint all point to the flashing.
What does a leak in the chimney itself look like?
- The brick is wet in the attic above the roof deck line, or the chimney breast inside is damp well above the ceiling.
- White, powdery deposits on the brick, called efflorescence, show where water has been moving through the masonry and drying out.
- Water in the firebox or a damper that rusts is a sign that rain is coming down the flue, which means a missing or damaged cap.
- From the yard with binoculars, you can often see a cracked crown, mortar washed out of the joints, or brick faces flaking off. Spalled brick is a sign the masonry has been soaking up water and freezing for years.
- It keeps leaking after a flashing repair. This is the most common sign of all, and an expensive way to find out.
Northeast Ohio is hard on masonry. Water soaked into a brick freezes and thaws many times between November and March, and each cycle pushes the crack a little wider. A crown that had a hairline crack in fall can be in pieces by spring.
Can you test it yourself with a garden hose?
A hose test can separate the two, but it takes two people and a safe way onto the roof, so it is not for everyone. One person runs water on one area at a time, starting low at the apron and the sides, for ten to fifteen minutes each, while the other watches inside with a flashlight. Then the hose moves to the brick faces, and last to the crown. The first area that makes water appear inside is the source. Never soak the whole chimney at once, because then you learn nothing. If your roof is steep or two stories up, skip the test and have it inspected instead.
What if it is both?
On an old chimney, it often is. Mortar holds the counter flashing, so when the joints crumble, the counter flashing falls out with them. The right order is the mason first, then the roofer. New flashing set into mortar that is about to be ground out and repointed is money spent twice. Guttrz will not sell you flashing on a chimney that needs masonry work first, and the photo report says so plainly.
What does Guttrz do, and what does it not do?
We are honest about this up front. Guttrz is a roofing and gutter company. We replace the step flashing, counter flashing, apron, back pan and cricket, and the shingles and decking around them. We do not rebuild crowns, install chimney caps, repoint mortar or replace brick. Those are a mason's work, and a cracked crown or bad mortar is a mason's job no matter who you call first. What the owner does do is photograph the whole chimney while he is up there, crown and cap included, so the report tells you which trade you need. The chimney flashing repair page covers the flashing side in detail, including when a cricket is required. Chimney work is one of the roof repair services Guttrz offers in Stark County.
Is it worth fixing if the roof is old?
If the shingles around the chimney are worn out, a new roof reflashes the chimney as part of the tear-off. Fixing the flashing alone on a roof that is due means paying twice. The free inspection rates the roof Good, Watch or Replace Soon, so you know which case you are in before you spend anything. If the roof is sound and the masonry is sound, a chimney flashing repair from Guttrz is the fix. A job minimum applies, and the written price is fixed before any work starts and good for a year.
The owner looks at the flashing and the masonry himself, sends the photo report that day, and puts one written price on the flashing work, good for a year. Get a written price for your chimney leak repair, or text your address and a photo of the stain to (330) 818-5584 and we text or call you within the hour.
Common questions
Will a chimney cap stop my chimney from leaking?
Only if the water is coming down the flue. A cap keeps rain out of the flue opening, so it stops water showing up in the firebox or the damper. It does nothing for water soaking through the brick sides or getting past the flashing at the roof line. Caps are installed by masons and chimney sweeps.
Can a cracked chimney crown be sealed instead of rebuilt?
Small hairline cracks are often sealed with a crown sealant made for the purpose, which is a reasonable first step. A crown that is crumbling, broken through or missing pieces usually has to be rebuilt. A mason is the right person to judge which one you have; Guttrz does not do crown work.
Should I put a waterproofing sealer on my brick chimney?
A breathable masonry water repellent can help brick that soaks up rain, but it has to be the vapor-permeable kind made for chimneys. Paint or a film-forming sealer traps moisture inside the brick and makes freeze damage worse. Have a mason fix open joints and the crown first, because a sealer cannot bridge cracks.
Why did my chimney start leaking after a new roof?
Either the flashing was reused or caulked instead of replaced during the roof job, or the masonry was already failing and the new roof made the timing look related. Check whether new step and counter flashing went in, then look at the crown and mortar. Photos from the roof job help sort it out.
Who should I call first, a roofer or a mason?
If you can see crumbling mortar, flaking brick or a broken crown from the ground, call a mason first. If the masonry looks sound and the stain is low near the ceiling, start with the flashing. If you cannot tell, an inspection that photographs the whole chimney answers the question, and the Guttrz report names the trade you need.
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Written by Christian Schaffner, owner of Guttrz. Updated November 8, 2026.
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