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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AfterFast, Reliable Duct Sealing Across North Lynnwood
Most duct sealing jobs in North Lynnwood run $450 – $1,200 for a typical single-family home, and we write the exact price down before touching anything. We’re Hollis Air Duct Cleaning, and our Duct Sealing crew serves North Lynnwood from our Seattle office, dispatching uniformed technicians who know the local housing stock. We’ve spent two decades working in Snohomish County’s wet climate, and we understand what decades of Pacific Northwest moisture does to the flex duct and metal trunks running through your crawlspace or attic. Call (361) 326-5060 for a free estimate, or keep reading to learn what we find in North Lynnwood homes and what it costs to fix.
Why Hollis Air Duct Cleaning Is North Lynnwood’s Preferred Duct Sealing Company
Hollis has been part of the Garrison Partners family since 2004, and our North Lynnwood customers come back because we show up inside the window, price in writing, and leave the site clean. That’s The Garrison Standard, and it’s how every job runs.
Our technicians are background-checked and uniformed. You know who’s walking into your home before they arrive. Phones are answered by a live person 24 hours a day, 7 days a week. No voicemail loops. No callback queues.
Every repair carries our 365-Day Done Right Promise in writing. If the work fails within a year, we return and make it right at no charge, including a free second visit. Competitors in this trade rarely match that in writing.
We know North Lynnwood’s neighborhoods. From the 1970s split-levels near 164th Street SW to the newer construction in Meadowdale and Lake Stickney, we’ve sealed ducts in homes with every common configuration this city offers.
Duct Insulation in North Lynnwood
Duct Insulation in North Lynnwood addresses a problem our wet climate makes worse: cold, unconditioned crawlspaces and attics that steal heat from your ducts before it ever reaches your vents. We wrap existing ductwork with formaldehyde-free fiberglass or foil-faced insulation, sealing the vapor barrier to prevent condensation. In North Lynnwood, this matters most in 1970s – 1990s homes where original flex duct runs through vented crawlspaces that stay damp eight months a year. A typical duct insulation job here runs $600 – $1,400 depending on linear footage and accessibility.
When Insulation Beats Replacement
Not every cold duct needs tearing out. If your flex duct is intact but uninsulated, adding a proper insulation jacket with sealed seams often solves the problem for half the cost of replacement. We check with a camera first.
Vapor Barrier Integrity
North Lynnwood’s humidity averages 80% through fall and winter. A compromised vapor barrier on duct insulation lets moisture condense inside, breeding mold. We tape every seam with foil tape rated for damp environments, not the cheap stuff that peels in six months.
HVAC Duct Sealing in North Lynnwood
HVAC Duct Sealing in North Lynnwood stops conditioned air from leaking into crawlspaces, attics, and wall cavities where it does you no good. We use mastic sealant, fiberglass mesh reinforcement, and mechanical fasteners to close gaps at joints, connections, and penetrations. For rigid metal trunks, we apply mastic in two coats. For flex duct, we replace damaged sections and seal transitions with code-approved methods. Most North Lynnwood homeowners pay $450 – $1,200 for residential HVAC duct sealing, with larger homes or extensive damage running toward the higher end.
Leak Detection Before Sealing
We pressurize your system and use a calibrated leak detector to find exactly where air escapes. In North Lynnwood’s older homes off 164th Street SW, we routinely locate disconnected runs that have been blowing into crawlspaces for years. You can’t seal what you can’t find.
Mastic vs. Duct Tape
Hardware-store duct tape fails in damp crawlspaces. We use water-based duct mastic that remains flexible and bonds to metal, flex, and fiberglass board. In North Lynnwood’s humidity, this is the only sealant we trust for a lasting repair.
Trusted Brands We Service in North Lynnwood
Our equipment roster includes Nikro negative-air machines for controlled containment during sealing work, plus filtration products from Honeywell and Aprilaire that we specify when duct sealing reveals a need for upgraded air cleaning. We stock common flex duct diameters, mastic, and rodent-resistant jacketing at our Seattle office, so most North Lynnwood jobs don’t wait on parts. If your system uses Abatement Technologies HEPA filtration, we can integrate sealing work with filter housing upgrades in the same visit.
Common Duct Sealing Problems We See in North Lynnwood Homes
- Rodent-damaged flex duct in 1970s – 80s subdivisions. Off 164th Street SW, original flex duct in vented crawlspaces attracts rodents seeking shelter from rain. They chew through the jacketing, collapse the wire helix, and leave runs leaking conditioned air directly into the dirt below your floor.
- Condensation-driven mold compromising seals. North Lynnwood’s persistent high humidity, especially October through April, condenses on cold duct surfaces in unconditioned spaces. Mold grows, degrades mastic bonds, and re-contaminates the system after cleaning.
- Disconnected runs in split-level homes. The 1980s – 90s split-levels common near Meadowdale have long flex branches that sag in damp crawlspaces, pulling apart at takeoffs. Homeowners notice weak airflow to second-floor vents first.
- Poorly sealed rigid trunk joints in newer construction. Homes built 2000 – 2020 in Lake Stickney and surrounding planned communities often have rigid metal trunks with flex branches in vented attics. Builder-grade sealing at joints leaks conditioned air into cold attic space, wasting energy and risking condensation on the trunk exterior.
Pricing for Duct Sealing in North Lynnwood, WA
A typical residential duct sealing job in North Lynnwood runs $450 – $1,200. Single-story homes with accessible crawlspaces and minor joint sealing fall at the lower end. Two-story homes with rodent damage, multiple disconnected runs, or rigid trunk work in attics trend toward $800 – $1,200. Duct insulation added to sealing runs $600 – $1,400 additional, depending on linear footage.
What moves the price: accessibility (tight crawlspaces take longer), extent of damage (partial replacement vs. pure sealing), and whether we find rodent entry points that need exclusion work before sealing holds. We inspect with a camera, write the price down, and get your approval before starting. No per-vent pricing. No teaser coupons that balloon once we’re inside. One flat price per system, agreed before work starts. Call (361) 326-5060 for a free estimate.
We Also Serve Cities Near North Lynnwood
Our Duct Sealing in North Lynnwood crew also travels to Seattle, Spokane, Tacoma, and Vancouver for scheduled jobs. Dispatch and scheduling are coordinated from our Seattle office, with local technicians serving each metro area.
Serving North Lynnwood, WA - Our Local Coverage Area
We’re based in the North Lynnwood 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 North Lynnwood
It depends on what our camera inspection finds. If the wire helix is intact and damage is limited to jacketing tears or disconnected takeoffs, sealing and partial section replacement usually suffices. If rodents have collapsed multiple runs or mold has degraded the flex core, replacement becomes the more durable fix. We give you the camera footage and a written price for both options before you decide. Call (361) 326-5060 to schedule an inspection.
Our marine climate keeps crawlspaces humid eight months a year, which condenses on cold duct surfaces and degrades sealants that aren’t rated for damp environments. We use water-based mastic with mold inhibitors and verify vapor barrier integrity on any insulation we install. Without this attention, a sealing job that looks fine in June can fail by November. The persistent moisture here makes proper material selection non-negotiable.
Sealing alone won’t stop rodents, but it’s a critical part of the solution. In the 1970s – 80s subdivisions off 164th Street SW, we routinely find rodent entry through damaged flex duct. We seal the ductwork with rodent-resistant jacketing, then identify and block the exterior entry points. A homeowner in that area called us after noticing musty odors and high energy bills. During our camera inspection, we found that rodents had torn through the original flex duct in the crawlspace, and condensation had led to mold growth along several runs. We removed the damaged sections, sealed the remaining ducts with mastic and mesh, and installed new flex branches with rodent-resistant jacketing. The homeowner immediately noticed better airflow and lower bills.
Rooms that never reach temperature, musty odors when the system runs, dust streaking near vents, and unexpectedly high heating bills are the most common indicators. In North Lynnwood’s older homes, we also see ice damming in attics from warm, moist air leaking through poorly sealed duct joints. If your crawlspace feels noticeably warmer than outside in winter, you’re likely heating it instead of your living space.
Yes, and we often recommend it for North Lynnwood homes with uninsulated flex duct in crawlspaces or attics. Sealing stops air leakage; insulation stops thermal loss. Together they reduce energy waste and prevent the condensation that leads to mold in our humid climate. We price both services together as one flat system price, written before work starts. Call (361) 326-5060 for a free estimate.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving North Lynnwood since 2004.