Duvall, King County
Expect $285 to $790 to waterproof a chimney in Duvall. Stack size and roof access explain the range. What goes on is a vapor-open repellent, laid by brush or sprayer over brick that has been cleaned and found sound; it sheds rain while letting vapor escape from inside the masonry. We do not coat over cracks, so joints are checked first.
Typical investment
$285–$790
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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 Duvall home — we'll point you to the right fix.
What we do
The same crew, the same written quote — for Duvall homes.
A Level 1 check, or a Level 2 with a camera run through the flue when the visible parts are not enough
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Brushing of the whole flue, top to firebox, with brush heads sized to the liner
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A photographed assessment that separates cosmetic wear from structural damage
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A camera run and full measurements before any liner is ordered
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Measurement of each flue, or of the full crown for a multi-flue cap
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Cleaning and testing of the burner, the pilot assembly and the ignition
Learn moreRanges shown for orientation — the exact figure is written up on-site, after the inspection.
Timing rules this job in Duvall. WeatherSpark's figures for the town put December, the grayest month, at 76 percent overcast or mostly cloudy skies, and a clearer stretch of roughly 3.6 months running from around June 20 to early October. Repellent needs dry brick and a dry day or two afterward, so that summer window is when most of the year's treatments have to happen.
The sample behind the number is small, 125 households plus or minus 113, yet Census data still shows a larger proportion of wood-heated homes in Duvall than anywhere else on our route: about 4.5 percent, measured as primary heating fuel.
A masonry flue in daily service is warm inside and soaked outside for much of the winter. Water held in the brick turns to vapor when the flue heats and has to leave through the wall, which is why the repellent we use breathes. The Department of Ecology's parallel advice is about the fuel: keep firewood covered while it seasons.
Every chimney waterproofing we do in Duvall includes:
Smoke coming back into the room, or a smell that won't go? Book the inspection first.
Book nowSummer humidity is not the enemy here: the same source rates muggy conditions at about zero percent all year. The moisture that matters arrives cold. The Monroe cooperative station, north of town along the valley, averaged 47.80 inches of precipitation a year over a record running from 1929 to 2016. Untreated brick absorbs part of every shower, and a wall that stays damp for months grows moss on its shaded side.
Puget Sound Clean Air Agency's 2024 summary reports that wood smoke from home heating pushed fine-particle levels past the agency's health goal on as many as four winter days that year. King County as a whole logged 257 good air days and 105 moderate ones.
Burn bans exist for episodes like those. A chimney left unlit under a Stage 2 ban, which covers every wood-burning fireplace, stove and insert plus pellet stoves, cools right through. Brick that was sealed in summer meets that cold spell holding far less water.
The appointment is set for dry weather and moved when rain is forecast, since wet brick will not take the product.
Open joints and crown cracks are fixed or quoted separately; repellent is not a filler.
Growth and grime are removed by hand and low pressure so the pores are open.
The repellent goes on from the bottom up until the brick stops drinking it; surroundings stay covered throughout.
What this work is quoted at for Duvall homes — the exact figure comes from the $99 on-site inspection, credited toward the work.
| Service | Price in Duvall | What that covers |
|---|---|---|
| Chimney Waterproofing | $285–$790 | Breathable sealer — reapplied every 3–5 years in this climate |
| 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 $1,900 | 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 Duvall. 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.
Duvall is a hillside town above the Snoqualmie River, incorporated in 1913, with homes with a median build year of 2000, almost all of them built since 1980. We work every part of it — Old Town, the upper plateau included.
DuvallKing County, WA · 47.742, -121.986
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.
Between late June and early October, when clear days are most likely. Outside that period we wait for a confirmed dry stretch.
Surface and access. A short stack reached from a low roof is quick; a tall one on a steep hillside roof needs more setup and more product.
No coating does. WSU Extension ties moss to our cool, moist climate and to surfaces that stay wet for long periods, and lists cutting back shading branches among the controls. Drier brick simply gives it less to live on.
A $99 on-site inspection, a written quote before any work, and photos of every item we touch.
