Mercer Island, King County
Chimney flashing repair on Mercer Island runs $329 to $1,495. If the existing flashing is sound and only needs resealing, you pay near the bottom; a full replacement of step flashing, counter flashing and a cricket on a wide chimney lands near the top. We confirm the leak is really at the flashing before we quote.
Typical investment
$329–$1,495
Book an inspection
Book your $99 inspection
$99 plus tax, deducted when you approve the repair
Not sure where to start
Pick what you're seeing at your Mercer Island home — we'll point you to the right fix.
What we do
The same crew, the same written quote — for Mercer Island homes.
Level 1 or Level 2 inspection, with a camera scan where warranted
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Complete sweep of the flue and firebox, protected by drop cloths and HEPA filtration
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Restoration of brick, mortar joints and firebox
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A stainless-steel or ceramic liner run the full height of the flue
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A stainless cap fitted to your flue's exact dimensions
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Cleaning of the burner, pilot and valve assembly
Learn moreRanges shown for orientation — the exact figure is written up on-site, after the inspection.
Where a chimney passes through the roof, two materials that move differently meet at a joint that has to stay watertight for decades. On an island where rain falls most days through the depths of winter, a small gap in that joint lets in a lot of water before anyone sees a stain inside.
Lake Washington, which King County identifies as Washington's second largest natural lake, closes in on Mercer Island from every direction. About half of the city's mapped area is lake rather than land.
Across western Washington, the WRCC reports that the strongest gusts typically arrive out of the south and southwest once fall gives way to winter. A roof joint that faces that weather takes rain sideways, which is where weak counter flashing gives up first.
Moss on a roof holds water, and WSU Extension says unchecked growth shortens a roof's lifespan. OSU Extension links it to shade and damp, and recommends cutting back trees as the lasting fix while warning that pressure washing harms shingles.
Moss that collects above the stack, where the roof drains into it, slows runoff and keeps the flashing joint wet for days after each storm. We clear it by hand around the stack as part of any flashing repair.
Every chimney flashing repair we do in Mercer Island includes:
Smoke coming back into the room, or a smell that won't go? Book the inspection first.
Book nowThe leaks we trace here usually come from one of three places: sealant that has dried and cracked along the counter flashing, step flashing that was never woven into the shingles properly, or a wide chimney with no cricket behind it, so water piles up against the upslope side. Each looks similar from the attic and needs a different fix.
Parallel strands of the Seattle fault cut across Mercer Island, at least two of them by the city's count. FLASH and FEMA both describe masonry chimneys in wood-frame homes as among the parts of a house most vulnerable to an earthquake.
Even when a chimney survives shaking, it can shift slightly against the roof framing, opening the flashing joint. If you felt a tremor and a leak appeared by the chimney later, that sequence is worth mentioning when you call.
We look from the attic and the roof to find where water actually enters. A crown crack or porous brick can mimic a flashing leak, and we would rather tell you that than replace good metal.
Resealing, partial replacement or full replacement each have a different price. The quote says which one and shows the photos behind that choice.
We lace new step flashing in with each course of shingles, then cut counter flashing into a mortar joint and seal it so water runs over the joint, not behind it.
Where conditions allow, we run water over the repair and check the attic, then clear debris from the roof and gutters.
IRC R1003.20, as Washington's residential code applies it, requires a flashed and counterflashed cricket whenever a chimney spans more than 30 inches along the ridge. CSIA counts sound flashing among its four inexpensive protections against water, which it ranks as a worse enemy of masonry chimneys than fire.
Both matter because of how much rain the joint sees. Per the regional climate center, the western half of the state turns wet in October and stays wettest through winter, with measurable precipitation on most midwinter days.
What this work is quoted at for Mercer Island homes — the exact figure comes from the $99 on-site inspection, credited toward the work.
| Service | Price in Mercer Island | What that covers |
|---|---|---|
| Chimney Flashing Repair | $329–$1,495 | Reseal at the low end, full flashing replacement at the high |
| Chimney Sweep | $189–$449 | Full flue swept, Level 1 inspection included |
| Chimney Inspection | $99 plus tax | Level 1 visual; Level 2 adds a full camera scan |
| Chimney Relining | From $1,895 | Full-length stainless liner, sized to the appliance |
| Chimney Repair | From $425 | Masonry repair — brick and mortar, scoped after diagnosis |
Ranges are what these jobs are quoted at in Mercer Island. The exact figure is set on site after a $99 inspection (credited toward the job if you go ahead), and you approve it before any work starts.
Mercer Island is an island city in the middle of Lake Washington, on Lake Washington, with mid-century and high-value waterfront homes.
Mercer IslandKing County, WA · 47.571, -122.222
Before and after
Illustrations of what each repair changes on a typical chimney — not photos of a specific job.
Before
After
Before
After
Before
After
Four steps, each one on paper — so you always know what happens next.
Choose a genuine opening on the crew's calendar. Confirmation is immediate.
Liner, crown, cap, flashing and masonry examined in order — each finding photographed.
One document, plain numbers, covering only the work your chimney genuinely needs.
The repair is completed, then handed over with before-and-after photos of every item.
$329 to $1,495. The low end covers resealing flashing that is otherwise sound; the high end covers full replacement, including a cricket on a wide chimney.
A small peaked diverter behind the chimney, on the upslope side. Code calls for one once a chimney's width along the ridge passes 30 inches, and it gets flashed and counterflashed like the rest.
Caulk over a failed joint lasts a season, sometimes less. It also hides where the water is getting in, which makes the proper repair harder later.
A $99 on-site inspection, a written quote before any work, and photos of every item we touch.
