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.
Fast, Reliable Duct Sealing Across Maltby
We dispatch our Duct Sealing crews to Maltby from our Seattle office, and we know the drive well: up Highway 9 past the nursery fields, then onto the rural roads where mailboxes sit at the end of long gravel drives. Most Maltby properties aren’t suburban tract homes. They’re large-lot rural places, manufactured homes on acreage, older farmhouses with additions built piecemeal over decades. That matters for duct sealing because the ductwork in these homes is often idiosyncratic, poorly documented, and running through crawlspaces or outbuildings that a standard suburban crew doesn’t expect. When you call (361) 326-5060, you’ll reach a live person who understands Maltby’s layout and can schedule a technician who knows what rural Snohomish County duct systems look like.
Why Hollis Air Duct Cleaning Is Maltby’s Preferred Duct Sealing Company
We’ve been working in unincorporated Snohomish County long enough to know the difference between a Bothell split-level and a Maltby property on well water with a pellet stove in the shop. 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 in Maltby carries our 365-Day Done Right Promise – if the seal fails or the problem returns within a year, we come back and make it right at no charge, including a free second visit.
Phones are answered by a live person 24 hours a day, 7 days a week. No voicemail loops, no callback queues. When you’re dealing with a musty smell from damp ductwork during Maltby’s long wet shoulder season, that matters.
Air Duct Sealing in Maltby
Air Duct Sealing in Maltby means closing the gaps, joints, and seams in your ductwork so the air you’ve already paid to heat or cool actually reaches the rooms it was meant for. In this market, we see a lot of systems losing 20 – 30% of their conditioned air through leaks in crawlspaces, attics, and outbuilding runs. For a Maltby home heated with propane or oil, that’s money burning off into a damp crawlspace. For a home with a wood stove or pellet stove sharing the central system’s return ducts, leaks pull creosote-tinged ash and fine particulate back into the airflow.
Typical Air Duct Sealing in Maltby runs $450 – $1,200 for a whole-home system, depending on accessibility, duct material, and whether we’re sealing the main trunk, branch lines, or outbuilding runs. We price by the system, not by the vent, and we write the number down before any work starts.
Sealing for Wood-Heat and Mixed-Fuel Systems
Maltby homes often run central heat alongside a wood or pellet stove, and that combination leaves a distinctive film in return ducts. Standard negative-pressure cleaning won’t remove it before sealing, so we adapt our approach: source removal first, then mastic and mesh sealing. Skip the removal step and you’re trapping odor and fine ash against the duct wall under a fresh seal. That smell comes back.
Outbuilding and Shop Duct Runs
Detached shops, barn offices, and mother-in-law additions are common here. Their duct runs are frequently patched with foil tape that fails in Maltby’s damp shoulder season, pulling in nursery-field dust and pollen. We seal these with mastic and mechanical fasteners, then test static pressure at the air handler to confirm the fix.
Duct Sealing Services in Maltby
Duct Sealing Services in Maltby cover the full range of what rural Snohomish County properties need: inspection with camera and pressure testing, leak location and documentation, manual sealing with mastic and reinforced mesh, and post-seal verification. We don’t just tape over the problem. We find where the air is escaping, seal it properly, and prove the result with before-and-after pressure readings.
Our Duct Sealing Services in Maltby typically fall between $450 for a focused repair on a single leaky trunk and $1,200 for a comprehensive whole-system seal on a large rural property with multiple zones or outbuilding runs. Every price is written down and agreed to before work begins.
Camera Inspection and Pressure Testing
We start with a camera run and a static pressure test. In Maltby’s older farmhouses and piecemeal additions, duct layouts are rarely documented. Camera inspection lets us see what we’re working with before we quote, so the price we give is the price you pay.

Post-Seal Verification
After sealing, we test again. The pressure differential tells us whether the seal held and whether the blower motor is working against less resistance. Homeowners usually notice less dust and a quieter system within days.

What happens when you call
- 1
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 Maltby
We seal and service ductwork connected to equipment from Honeywell, Aprilaire, and Abatement Technologies, and we carry filtration products from Guardsman for Maltby customers who need upgraded protection against the pollen and agricultural dust that rural properties here collect. Our rotary brush systems from Rotobrush and negative-air machines from Nikro are the same tools commercial crews use, not hardware-store gear. For Maltby’s well-water households running humidifiers, we stock the right filtration to handle the mineral dust that standard suburban schedules don’t account for. Parts are on the van, so most jobs don’t wait on a Seattle supply run.
Common Duct Sealing Problems We See in Maltby Homes
- Leaky outbuilding runs patched with failing tape. On a large-lot property off a rural Maltby road with a detached shop, we found the shop’s supply duct run patched with foil tape and leaking at every joint, pulling in nursery-field dust and fine ash from a pellet stove. We performed camera inspection, agitation tools, and HEPA filtration on the main return, then sealed the shop trunk with mastic and mesh before testing static pressure at the air handler. The homeowner reported less dust on the shop benches and a quieter blower motor within a week.
- Creosote-tinged ash trapped under new seals. Return ducts and cold-air intakes coated in residue from wood or pellet stoves can’t be sealed effectively until they’re properly cleaned. Seal over the film and you’ve locked in odor and fine particulate that will circulate for years.
- Mineral dust from well-water humidifiers clogging the system. Maltby’s many well-water households often run humidifiers that deposit mineral scale in registers and on duct walls. That dust combines with agricultural particulate to overload filters and obscure leaks that a standard inspection would miss.
- Moisture intrusion in damp crawlspaces and attics. Maltby’s wet winters and long damp shoulder season let moisture into duct systems through gaps that should have been sealed. The result is musty airflow and, in some cases, mold-friendly conditions inside the trunk lines.
Pricing for Duct Sealing in Maltby, WA
A typical duct sealing job in Maltby runs $450 – $1,200. Here’s how that breaks down:
| Service Level | Price Range | What It Covers |
|---|---|---|
| Focused trunk or branch repair | $450 – $650 | Single accessible leak, camera verification, mastic seal, pressure test |
| Whole-home standard seal | $700 – $950 | Main trunk and branch lines, up to 15 registers, before/after pressure test |
| Large property / outbuilding runs | $950 – $1,200 | Multiple zones, shop or addition ductwork, comprehensive documentation |
What moves the price: accessibility (crawlspace height, attic hatch location), duct material (sheet metal, flex duct, or fiberboard), and whether we need to coordinate with other trades for access. We do not quote per-vent or bait with a low teaser that jumps once we’re on site. The price is written down before any work starts, and it does not move at the door. Call (361) 326-5060 for a free estimate – we’ll ask about your property type, heating setup, and any outbuilding runs so we can give you an honest range before scheduling.
We Also Serve Cities Near Maltby
Our crews regularly travel from Maltby to Seattle, Spokane, Tacoma, and Vancouver for scheduled work. Dispatch and scheduling are coordinated from our Seattle office, but the technicians who serve Maltby live in the area and know the rural roads, the nursery traffic patterns, and the specific conditions that Snohomish County properties face.
Serving Maltby, WA - Our Local Coverage Area
We’re based in the Maltby 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 Maltby
Rural Maltby properties typically need inspection and cleaning every 2 – 3 years, not the 4 – 5 year suburban standard, because of higher particulate loads from unpaved roads, agricultural operations, and wood or pellet heat. Duct sealing should be checked whenever you notice uneven heating, rising fuel bills, or musty airflow – often sooner than a city schedule would suggest. Call (361) 326-5060 and we’ll help you set an interval that matches your property’s conditions.
Yes, and it’s often where we find the worst leaks. Outbuilding duct runs in Maltby are frequently owner-installed, poorly insulated, and patched with tape that fails in the damp season. Sealing these properly with mastic and mesh stops the dust infiltration and reduces the load on your main blower. We price outbuilding runs as part of a whole-system job or as a standalone repair.
The cleaning removed surface debris but didn’t address moisture entering through unsealed gaps, or it sealed over organic film without source-removing it first. In Maltby’s damp climate, leaky ductwork in crawlspaces pulls in humid air that carries mold-friendly conditions. Proper sealing after thorough cleaning solves this. If you’re smelling mustiness post-cleaning, call us for a camera inspection – the 365-Day Done Right Promise covers our work for a full year.
They do. Well-water humidifiers deposit mineral scale on duct walls and registers, which can obscure leaks and overload filtration. We account for this during inspection and recommend the right filter upgrades from our Guardsman and Aprilaire stock to handle the extra load. Sealing without addressing the mineral buildup is a temporary fix at best.
It stops you from paying to heat your crawlspace. Propane and oil are expensive fuels, and in Maltby’s large rural homes with long duct runs, even a 20% leak means real money lost. Sealing also reduces the drafts, dust, and pollen that leaks pull in from outside. For a home running $3,000 – $5,000 in annual heating costs, a proper seal often pays for itself in the first season.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Maltby and the greater Snohomish County area since 2004.




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