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.
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After
Before
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Before
AfterFast, Reliable Duct Sealing Across Shoreline
We dispatch our Duct Sealing crews to Shoreline from our Seattle office, and most appointments are scheduled within a few business days. If you live near Richmond Highlands, Ridgecrest, or the Aurora corridor, you’re in our regular rotation. Call (361) 326-5060 to book a free estimate. We’ll show up in the window we promised, price the job in writing before we touch anything, and stand behind it for a full year.
Shoreline’s wet climate and older housing stock create duct problems that don’t show up the same way in drier markets. We’ve learned that the hard way, crawling through enough damp crawlspaces here to know what separates a real fix from a temporary patch.
Why Hollis Air Duct Cleaning Is Shoreline’s Preferred Duct Sealing Company
We’ve been in business since 2004 as part of the Garrison Partners family, and our Shoreline customers come back because we write the price down before we start and we don’t move it at the door. The 365-Day Done Right Promise covers every job in writing: if the seal fails or the problem returns within a year, we come back at no charge, including a free second visit.
Our technicians are background-checked and uniformed. You’ll know who’s walking into your home before they arrive. Phones are answered by a live person 24 hours a day, seven days a week. No voicemail loops, no callback queues.
We know Shoreline’s neighborhoods. Richmond Highlands has its 1950s ranches with original metal ductwork. Ridgecrest has the mid-century split-levels. The newer townhomes near Aurora have flex duct that sags in humid crawlspaces. That local knowledge changes what we look for and how we fix it.
Air Duct Sealing in Shoreline
Air Duct Sealing in Shoreline is often a moisture-control job disguised as an energy-efficiency job. Because many Shoreline homes sit on unsealed crawlspaces in post-war neighborhoods like Richmond Highlands, original metal duct runs there are often found with disconnected joints that pull in damp soil air. So duct sealing here is less about comfort and more about stopping crawlspace moisture, mold spores, and pests from entering the supply and return ducts.
We were called to a 1952 ranch in Richmond Highlands where the homeowner kept finding grit on the registers and a musty smell near the air handler. A camera inspection showed a separated joint in the crawlspace duct run that was drawing in soil air and debris, so we used source removal under negative pressure with HEPA filtration, then sealed the joint and the nearby flex duct connections. Follow-up testing showed the supply and return ducts holding pressure, and the MERV rating upgrade on the filter helped keep the crawlspace debris out of the blower motor.
When Sealing Becomes Necessary
You’ll know it’s time when rooms stay cold despite the furnace running, when dust reappears on registers within days of cleaning, or when your energy bills climb without explanation. In Shoreline, the musty smell is often the first clue, since damp crawlspace air carries mold spores straight into your living space through disconnected duct joints.
What the Process Looks Like
We pressurize the system to find leaks, then seal accessible joints with mastic or metal-backed tape rated for ductwork. We don’t use standard cloth tape, it fails in Shoreline’s humidity. For flex duct, we support sagging runs before sealing, otherwise the seal cracks as the duct shifts. Every job gets a written price before we start.
Duct Sealing Services in Shoreline
Duct Sealing Services in Shoreline cover everything from spot repairs on disconnected crawlspace joints to full-system sealing for townhomes with compromised flex duct runs. A typical sealing job in Shoreline runs $450 – $950 for partial sealing of accessible joints, and $1,200 – $2,400 for full-system sealing that includes crawlspace work, register boot sealing, and pressure testing to verify results.
Partial vs. Full-System Sealing
Partial sealing targets the worst leaks, usually disconnected joints in crawlspaces and gaps at the plenum connection. Full-system sealing addresses every accessible joint, boot, and transition, plus we upgrade supports for sagging flex duct. In Shoreline’s humidity, unsupported flex duct will sag again and break the seal within a season.
Pressure Testing After the Work
We test before and after with a duct blaster or similar pressure diagnostic. You see the numbers. If the system doesn’t hold pressure, we find the leak and fix it. No guesswork, no “trust us, it’s better.” The Garrison Standard requires we prove the work.
What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Shoreline
We carry sealing materials and filtration upgrades from Aprilaire, Abatement Technologies, and Guardsman, plus we use Rotobrush rotary systems for source removal before we seal. For Shoreline customers, that means we don’t wait on parts shipments. If your system needs a specific collar, boot, or mastic rated for wet-climate application, we likely have it on the van. Fast turnaround matters when you’re running a furnace that’s pulling crawlspace air through a separated joint in January.
Common Duct Sealing Problems We See in Shoreline Homes
- Disconnected joints in 1950s ranch crawlspaces. Original metal ductwork in Richmond Highlands and similar neighborhoods often separates at the seams where soil moisture has corroded the connections. The crawlspace air, complete with mold spores and rodent debris, gets pulled straight into your supply ducts.
- Sagging flex duct in humid crawlspaces. Shoreline’s newer townhomes have flex duct that wasn’t properly supported. The sag creates low spots where condensation pools, and when we seal without correcting the support, the duct shifts and the seal fails within months.
- Mold and mildew trapped behind fresh seals. Some crews seal over contaminated ductwork without source removal and microbial treatment first. You’re left with a tight duct system full of active mold, pumping spores into every room more efficiently than before.
- Pinholes in townhome flex duct from rodent activity. Even newer Shoreline homes can have compromised flex duct if crawlspace ventilation is poor or rodents have accessed the space. The holes draw in unfiltered outside air, and sealing only the plenum leaves the real problem untouched.
Pricing for Duct Sealing in Shoreline, WA
A typical partial duct sealing job in Shoreline runs $450 – $950. Full-system sealing with crawlspace access, pressure testing, and flex duct support correction runs $1,200 – $2,400. What moves you up or down: how much of the system is accessible, whether we need to remove contamination before sealing, and if the crawlspace requires additional prep for safe entry.
We don’t quote per-vent or offer teaser coupons that balloon once we’re inside. One flat price per system, agreed in writing before work starts. That’s The Garrison Standard. Estimates are free. Call (361) 326-5060.
We Also Serve Cities Near Shoreline
Our crews regularly handle Duct Sealing in Shoreline and surrounding areas including Seattle, Spokane, Tacoma, and Vancouver. Scheduling is coordinated from our Seattle office, with local crews serving each market under independently owned Garrison Partners locations.
Serving Shoreline, WA - Our Local Coverage Area
We’re based in the Shoreline 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 Shoreline
Every 3 – 5 years for cleaning, with sealing inspected every 2 – 3 years due to Shoreline’s moisture load. The damp crawlspace accelerates corrosion at metal joints and sag in flex supports. Call (361) 326-5060 to schedule an inspection, estimates are free.
Original metal duct in Shoreline’s post-war neighborhoods was installed with minimal sealing at joints, and decades of soil moisture have corroded connections. Newer flex duct has different failure modes, sagging and pinholes, but the metal systems in Richmond Highlands are prone to complete separation at the seams. Call (361) 326-5060 for a camera inspection.
Yes, when the smell is coming from crawlspace air entering through disconnected duct joints. Sealing stops the infiltration, but only after source removal and microbial treatment eliminate what’s already growing inside. Sealing over active mold makes the problem worse. Call (361) 326-5060 to diagnose the source.
We inspect for sagging runs and rodent damage, support the duct properly, then seal joints with mastic rated for wet-climate application. Flex duct in Shoreline’s humidity shifts seasonally, so support is as important as the seal itself. Call (361) 326-5060 for a written quote.
Yes, if the dust is coming from leaks in the return duct pulling in unfiltered air. Wood heat creates pressure imbalances that exacerbate infiltration through disconnected joints. Sealing the duct system, combined with proper filtration, keeps combustion particles and crawlspace debris out of your supply air. Call (361) 326-5060 for an assessment.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Shoreline since 2004.