Whole-system duct and dryer vent check with before-and-after photos - you see exactly what came out of your vents
That "$99 whole-house special" is a bait ad - the real number appears once they are in your hallway, or the "clean" is a shop-vac at the register. We photograph the inside of your ducts before and after instead.
Before
After
Before
After
Before
AfterFast, Reliable Duct Sealing Across Vashon
We serve Vashon Island homeowners with duct sealing that accounts for what we actually find in local houses: retrofitted runs in wood-heat cabins, crushed flexible duct behind floor joists, and original galvanized pipe from early-1900s farmhouses that leaks more air than it delivers. Dispatch and scheduling are coordinated from our Seattle office, but our crews make the ferry trip with everything on the van to complete the job in one full-day visit. Call us at (361) 326-5060 for a free estimate.
Why Hollis Air Duct Cleaning Is Vashon’s Preferred Duct Sealing Company
We’ve been doing this since 2004 as part of the Garrison Partners family, and our Duct Sealing team knows Vashon’s housing stock. The island’s mix of historic farmhouses, 1970s cabins off Cove Road, and custom-built homes on rural lots means no two duct systems look alike. Our technicians are background-checked, uniformed, and trained to The Garrison Standard: arrive inside the quoted window, price the job in writing before touching anything, and leave the site clean.
Every repair we make is backed by our 365-Day Done Right Promise. If the seal fails within a year, we come back and make it right at no charge, including a free second visit. That promise is written on every job, not implied. Phones are answered by a live person 24 hours a day, 7 days a week, so you’re not waiting through a callback queue when you’ve got a duct leak blowing heated air into your crawlspace.
HVAC Duct Sealing in Vashon
HVAC Duct Sealing in Vashon typically addresses retrofitted duct runs that were never designed for the air handler currently in place, since many island homes were built around wood stoves or older oil furnaces rather than forced-air systems. The job involves identifying leaks at joints, collars, and crushed sections, then sealing them with mastic and mesh or foil tape rated for the application. In Vashon, a typical HVAC duct sealing job runs $450 – $850 for a partial system and $1,200 – $2,100 for a whole-house seal, depending on accessibility and whether we need to remove contamination first.
Sealing Retrofitted Runs
Wood-heat homes that later got forced-air retrofits often have supply runs cobbled together with flexible duct that’s too long, too sharp at turns, or crushed behind structural members. We map the system with a camera, cut out damaged sections, and seal the new connections properly.
Pressure Verification After Sealing
We don’t guess. After sealing, we run a pressure check to confirm the ducts hold static pressure. In Vashon’s damp crawlspaces, this step catches sealant that hasn’t cured fully or bonds compromised by residual moisture.
Duct Repair in Vashon
Duct Repair in Vashon usually means fixing what we find during inspection: disconnected collars, rodent-damaged flexible duct, or galvanized runs corroded through from decades of island humidity. Repair costs typically run $280 – $550 for a single run replacement or reconnection and $650 – $1,400 for multiple runs or extensive damage. We price the work in writing before starting, and that price does not move at the door.
Crushed and Disconnected Sections
On a 1970s cabin off Cove Road, our tech pulled a supply register and found the run had been crudely retrofitted with a flexible duct crushed behind a floor joist, dripping condensate onto the crawlspace insulation. After a camera inspection and source removal with agitation tools, we sealed the crushed run and the disconnected collar at the air handler with mastic and mesh, then verified with a blower-door-style pressure check. The homeowner, who had been smelling that damp, musty odor every winter for years, noticed the difference immediately.
Rodent and Moisture Damage
Rural Vashon properties often have crawlspace duct runs that rodents have chewed through or nested in. We remove the damaged material, treat the surrounding area, and install new duct with proper sealing and support to prevent recurrence.
Trusted Brands We Service in Vashon
We carry equipment and materials from Rotobrush, Aprilaire, Abatement Technologies, and Guardsman on every van that makes the ferry to Vashon. That means we’re not ordering parts from Seattle and making you wait for a second trip. Our rotary brush systems handle creosote and wood-smoke residue that mainland crews rarely see, and our sealing products are rated for the damp conditions found in island crawlspaces. When we quote a job, we confirm we have what we need on the van before we board the ferry.
Common Duct Sealing Problems We See in Vashon Homes
- Undersized original ductwork. Early-1900s farmhouses on Vashon were never built for forced air. The original galvanized runs are too narrow for modern air handlers, so sealing leaks without addressing capacity still leaves rooms starved for air and feeling drafty no matter how tight the joints are.
- Damp crawlspace conditions. Rural homes on well water and septic often lack central humidification or dehumidification. Duct sealant applied over surfaces that stay damp year-round, especially in rodent-damaged crawlspace runs, can fail prematurely if we don’t prep and dry the surface first.
- Creosote-coated sealing surfaces. Wood-stove backdraft deposits residue inside ductwork. If we don’t remove it first with agitation tools and degreasing, mastic or tape won’t bond, and the seal fails within a season. We see this regularly in cabins near Lisabeula and Dockton.
- Crushed flexible duct from retrofits. 1970s and 1980s cabins often have flexible duct jammed through spaces too tight for the bend radius, flattening the airway and creating leaks at stress points. These need section replacement, not just sealing.
Pricing for Duct Sealing in Vashon, WA
A typical duct sealing job in Vashon runs $450 – $850 for partial-system work on a few problem runs and $1,200 – $2,100 for a whole-house seal with pressure verification. Duct repair, when we need to replace crushed or rodent-damaged sections, adds $280 – $550 per run. What moves the price: how many runs need attention, whether we need to remove creosote or rodent contamination before sealing, and crawlspace accessibility. Homes on Maury Island or the far north end may incur a modest trip charge to account for ferry scheduling. We give you a written price before any work starts, and that price is flat per system, not per vent. Call (361) 326-5060 for an exact quote. Estimates are free.
We Also Serve Cities Near Vashon
Our crews also handle duct sealing in Wauna, Port Orchard, Federal Way, and Gig Harbor. Each job gets the same written price, the same 365-Day Done Right Promise, and the same live-answer scheduling, whether we’re crossing the Narrows Bridge or the Vashon ferry.
Serving Vashon, WA - Our Local Coverage Area
We’re based in the Vashon area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About Duct Sealing in Vashon
We seal it. Our crews carry mastic, mesh, foil tape, and replacement duct sections on every van. We clean the surface first, apply sealant, and verify with a pressure check. If you want a DIY kit, a hardware store will sell you one. We do the job, guarantee it for 365 days, and write the price down before we start. Call (361) 326-5060 to schedule.
It matters if you have any forced-air component, even a small one. Many Vashon homes have retrofitted duct runs for a backup heat pump or oil furnace that leaks conditioned air into crawlspaces and draws musty air back inside. Sealing those runs stops the draft and the odor. Even primarily wood-stove homes often have ductwork that should be sealed. Call (361) 326-5060 and we’ll inspect it.
We use a borescope camera on a flexible rod, plus remote inspection tools that fit where a person can’t. For the tightest Vashon crawlspaces, we may access from inside the home through registers or cut a small inspection port that we seal afterward. We determine the approach during your free estimate visit.
We use water-based duct mastic with embedded mesh for joints and collars, and foil tape rated for temperature cycling on accessible seams. In Vashon’s damp crawlspaces, we prep the surface with degreaser and a drying pass, and we select sealant formulations rated for high-humidity applications. The 365-Day Done Right Promise covers seal failure regardless of cause.
It affects how we schedule, not how long the work itself takes. Because Vashon has no bridge, we bundle materials and equipment for a single full-day visit, including sealant cure time. We don’t split a job across two ferry trips. Most residential duct sealing in Vashon is completed in one day, start to finish.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Vashon since 2004.