Chimney services, Portland metro
Chimney leak repair, flashing, counter flashing and the crown, traced to the source
We find where the water gets in before we touch anything, because a Portland chimney leak can start at the cap, the crown, the flashing, the brick itself or as condensation inside the flue. Then we fix it with new metal, not caulk.
Updated
What you are seeing
A chimney leak announces itself indoors long before anyone looks at the roof, and these are the versions Portland homeowners describe.
- A brown stain on the ceiling or wall beside the chimney that grows after each storm.
- Drips or a damp patch in the attic where the chimney passes through the roof deck.
- Water on the smoke shelf or the firebox floor with the cap in place.
- A line of caulk along the flashing that someone has already tried, cracked and lifting.
- Rust running from the flashing onto the shingles below the chimney.
What we do on a flashing visit
Leak work is detective work first and sheet metal second, and this order is what keeps us from re-flashing a chimney whose leak was the crown.
Start inside, where the water shows
We begin at the stain, the attic or the firebox, because where water appears says a lot about where it entered. Water at the roof deck points to flashing, water on the smoke shelf under a capped flue points to the crown or the brick, and a damp chimney breast with no roof stain points to condensation.
Check the top of the chimney before the flashing
On the roof we look at the cap, the crown and the mortar joints before the metal, since a leak at any of those three can pass for a flashing leak. A missing cap, an open crown crack or joints that have washed out get flagged, and if the flashing is sound we hand the job to the crown or masonry repair it needs.
Run a hose test, one piece at a time
When the source is not obvious, we wet the chimney from the bottom up with a hose while someone watches inside: flashing first, then the brick, then the crown, a few minutes each. The order matters, because wetting everything at once tells you nothing. The leak can show up within minutes at the piece that is failing.
Strip the old metal and the failed sealant
Old counter flashing that has pulled out of the joint, step flashing rusted through and every bead of roofing cement someone has smeared along the brick come off. Shingles around the chimney are lifted carefully so they can go back, and the roof deck is checked for rot where water has been sitting.
Fit new step flashing, counter flashing and a cricket where the roof needs one
New step flashing goes in one piece per shingle course, woven into the roofing so water runs over each piece onto the next. Counter flashing is cut into a mortar joint, bent down over the step flashing and sealed in the reglet, so no screw or caulk line is holding water back. A wide chimney gets a cricket on the uphill side to split the water.
Repoint the reglet and photograph it
The mortar joint that was cut for the counter flashing is repointed, the shingles are laid back, and the chimney gets a final hose test with someone inside watching. You get photos of the old flashing, the new metal and the inside surface dry after the test, delivered to your phone that evening.
Five places a chimney leak starts, and how we tell them apart
Water gets into a chimney through a missing cap, a cracked crown, failed flashing, porous brick and joints, or condensation in the flue, and each one leaves its own mark indoors.
| Source | What you see indoors | The fix |
|---|---|---|
| Missing or damaged cap | Water on the smoke shelf or firebox floor, worst in a downpour | A new stainless cap |
| Cracked or broken crown | Wet smoke shelf, white stains on the top courses outside | Crown coat or a new crown |
| Failed step or counter flashing | Stain on the ceiling or attic deck beside the chimney | New metal, cut into the joint |
| Brick and joints soaking up water | Damp chimney breast that dries slowly, efflorescence on the stack | Repointing, then a breathable repellent |
| Condensation inside the flue | Damp chimney wall in the basement with no roof stain | A correctly sized liner |
Step flashing, counter flashing and the cut in the mortar
Chimney flashing is two layers: step flashing woven into the shingles that turns water out onto the roof, and counter flashing set into the brick that covers the top of the step flashing so water cannot get behind it.
The counter flashing is the part most repairs get wrong. It belongs in a groove cut into a mortar joint, bent and sealed in that reglet, not face-nailed to the brick with caulk along the top edge. Surface-mounted flashing depends on the caulk, and caulk on a chimney gives out long before the metal does.
A cricket for the uphill side of a wide chimney
A chimney that sits broadside to the slope dams the water and debris coming down the roof, and a cricket, a small peaked saddle on the uphill side, splits that flow around the brick.
The model building code calls for one when the chimney is more than about 30 inches wide, and some older Portland roofs never got one, so fir needles and moss pile up behind the stack and hold water against the back flashing all winter.
Why Portland chimney leaks show up in November and vanish in July
A flashing that weeps only under sustained rain can stay dry and unnoticed for half the year, because roughly 65 percent of the 37 inches the Portland airport records in a normal year falls from November through March.
The January 2024 ice storm added a different cause: limbs and whole trees onto roofs across Multnomah and Clackamas counties, and a branch that lands on a chimney can shear the counter flashing out of its joint. If a tree touched your roof that week, the flashing is worth a look before the next wet season.
When the roofer should go first
The roofer goes first when the roof is near the end of its life, so the flashing is done once, as part of the re-roof. We coordinate timing with your roofer and handle the crown, cap and masonry while they handle the shingles.
What moves the price of flashing and leak repair
The board price covers finding the source and resealing or repairing the flashing on a walkable roof, with the additions below quoted separately.
- All new metal, step and counter flashing on every side, rather than repairing one failed face.
- A cricket built and flashed on the uphill side of a wide chimney.
- A steep roof, a tall chimney or a slate or tile roof that slows every step of the work.
- Rotted roof deck under the flashing, cut out and replaced before new metal goes on.
When a repair stops making sense
Flashing stops being a repair and becomes part of a re-roof when the shingles around the chimney are brittle, curled or on their last few years, because new metal woven into a dying roof is pulled apart when the roof is replaced.
In the other direction, a leak that is really brick soaking up water on a stack with washed-out joints is not a flashing job at all; it goes to repointing and a breathable repellent.
Flashing: common questions
How do you tell a chimney flashing leak from a crown leak?
By where the water shows up and by a hose test. Flashing water lands on the roof deck and stains the ceiling or attic beside the chimney; crown water runs down inside the chimney and lands on the smoke shelf or firebox. When it is unclear we wet one piece at a time from the bottom up and watch indoors.
Is roofing sealant enough to fix chimney flashing?
No, sealant is a stopgap, so we use it only to get a chimney through a storm. Sealant shrinks, cracks and lets go of wet brick, and each new layer traps more water behind the metal. Flashing that has pulled out of the joint or rusted through gets new metal.
What is counter flashing on a chimney and why is it cut into the mortar?
Counter flashing is the upper layer of metal, set into the brick, that covers the top edge of the step flashing. It is let into a groove cut in a mortar joint so the brick itself sheds water over it, rather than relying on a caulk line along the top. Face-nailed counter flashing with caulk is the version that fails.
Does my chimney need a cricket to stop the leak?
If the chimney is wide and sits across the slope, probably. A cricket is the small peaked saddle on the uphill side that splits water and debris around the brick instead of letting them pile up behind it. The model code asks for one once a chimney passes about 30 inches wide, and some older roofs never got one.
Why does my chimney only leak in heavy Portland rain?
Because the gap is small and needs sustained water to overwhelm it. A lifted counter flashing or a hairline in the crown can shed a shower, then weep steadily after a day of November rain once the brick is saturated. Those leaks are the hardest to find in dry weather, which is what the hose test is for.
Should the roofer or the chimney company fix the flashing?
Either can, and the right answer depends on the roof. If the roof is being replaced, the roofer should flash the chimney as part of that job while we handle the crown, cap and masonry. If the roof has years left and the chimney is the problem, we re-flash it.
Related pages
Where we do this
We trace and repair chimney leaks in the Portland neighborhoods and suburbs that follow, from the steep roofs of the Southwest Hills to Milwaukie and Troutdale.
Ready to book a sweep?
Call with what the fireplace is doing, or text a photo of the opening and one of the chimney top, and we will name the service and its posted price before we come out.