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 Redmond
We dispatch to Redmond from our Seattle office, and most calls get a crew on the road the same day or next. If you’re in Education Hill, Overlake, or the newer townhomes off Redmond-Woodinville Road, we’ve already worked on ductwork in your neighborhood. Roy Castellanos and our team know the local housing stock: the 1980s subdivisions with sagging flex duct, the 1990s ranches with garage-mounted air handlers, and the 2010s+ townhomes built on slab with sealed chases that hide construction debris for months. Duct sealing in Redmond isn’t a generic job. The damp climate, the glacial till that forces slab-on-grade construction, and the builder-grade materials used during the tech boom all create problems that need local eyes to spot. Call us at (361) 326-5060 for a free estimate.
Why Hollis Air Duct Cleaning Is Redmond’s Preferred Duct Sealing Company
We’ve been in business since 2004 as part of the Garrison Partners family, and our Duct Sealing team has built a reputation in Redmond by showing up inside the quoted window and pricing in writing before we touch anything. Homeowners here are busy. They don’t have time for no-shows or technicians who renegotiate at the door. Our background-checked, uniformed technicians arrive with professional-grade equipment from Rotobrush and Abatement Technologies, and every job carries our 365-Day Done Right Promise in writing. If the seal fails 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.
HVAC Duct Sealing in Redmond
HVAC Duct Sealing in Redmond addresses the leaks, gaps, and disconnected joints that let conditioned air escape into your attic, crawl space, or wall cavities before it reaches your rooms. In Redmond’s housing stock, we see this problem constantly: original 1980s – 90s flex duct in older subdivisions like those near Redmond Town Center has sagged and pulled apart at the collars, while newer townhomes have builder-grade seals that fail inside sealed chases where no one can see them. A typical HVAC duct sealing job in Redmond runs $450 – $1,200 depending on system size and accessibility. We use mastic and mesh for permanent seals, not tape that dries and cracks. The price is written down before we start, and it does not move.
Sealing Blind Chases in Slab-On-Grade Homes
Redmond’s rocky glacial till forces most 2010s+ townhomes onto slab-on-grade or post-tension foundations with no full basement. Ductwork gets routed through sealed floor and wall chases. We regularly pull construction drywall dust and joint-compound grit out of those chases months after handover. Our socket-and-camera protocol lets us inspect and seal what other crews miss entirely.
Negative-Air Containment During Sealing
We seal under negative pressure when contamination is present. A Nikro negative-air machine pulls a vacuum on the duct system while we work, so any disturbed debris is captured at a HEPA filtration unit rather than pushed into your living space. This matters in Redmond’s damp climate, where microbial growth is common and sealing over it traps problems behind the new seal.
Duct Repair in Redmond
Duct Repair in Redmond fixes the physical damage that sealing alone cannot address: crushed flex duct, corroded metal fittings, and sections chewed by rodents in the crawl spaces beneath 1990s ranches. We also replace disconnected collars and repair sagging runs that have pulled away from the plenum. In Redmond’s older neighborhoods, we find original ductwork that has simply reached end of life. A typical duct repair in Redmond runs $200 – $600 for localized fixes, or $1,500 – $3,500 for full system replacement when the original flex duct is too degraded to save. We inspect with cameras, show you what we found, and write the price down before any work begins.
Garage-Mounted Air Handler Repairs
Many Redmond homes, especially the 1990s stock in neighborhoods like Education Hill, have air handlers mounted in the garage. These units suffer temperature swings and vibration that crack the plenum connections. We reinforce with metal-backed mastic and support straps that stop the flex from working loose again.
When Replacement Makes More Sense Than Repair
Original 1980s flex duct with multiple sags, tears, and rodent damage often costs more to patch than replace. We’ll tell you straight if that’s the case. No point sealing a system that’s structurally failed. Our written estimate breaks out repair versus replacement so you can decide with real numbers.
Trusted Brands We Service in Redmond
We stock parts and filtration products from Aprilaire, Abatement Technologies, and Guardsman for fast turnaround on Redmond jobs. These aren’t hardware-store brands. Aprilaire media filters and whole-home purifiers integrate with the systems we seal, and Guardsman antimicrobial treatments address the biological growth Redmond’s damp climate promotes. When we seal a duct system, we make sure the filtration upgrade matches what that home actually faces: pollen from the conifers on Education Hill, construction dust in new Overlake builds, or the musty microbial load that builds up during our mild, wet winters. Our technicians carry common fittings and mastic compounds on every truck, so most repairs don’t wait for a parts run.
Common Duct Sealing Problems We See in Redmond Homes
- Builder-grade flex duct sagging in sealed chases. The 2010s+ townhomes off Redmond-Woodinville Road and near the Microsoft campus use flex duct routed through floor and wall chases that can’t be inspected without a camera. The duct sags, disconnects at joints, and leaks conditioned air into the structure for years before anyone notices the energy bills climbing.
- Construction debris left in new-build ducts. Drywall dust and joint-compound grit from the original construction sits in supply and return ducts, clogging the air handler and getting pushed back through registers. Sealing over this debris without source removal traps it in the system and defeats the purpose of the seal.
- Microbial growth behind failed seals. Redmond’s damp, mild winters keep duct interiors humid. When previous sealing was done over contaminated surfaces, or with tape that later failed, moisture gets trapped behind the seal and promotes mold that spreads odor through the registers.
- Disconnected collars at garage-mounted air handlers. Vibration and temperature cycling in unconditioned garage spaces loosen the flex duct connections. We find this constantly in 1990s Redmond ranches where the original installer used zip ties or inadequate support.
Pricing for Duct Sealing in Redmond, WA
A typical duct sealing job in Redmond runs $450 – $1,200 for residential systems up to about 3,500 square feet. Larger homes or systems with extensive accessibility issues in sealed chases can run $1,500 – $2,500. Duct repair, when we can save the existing runs, typically falls between $200 – $600 per location. Full replacement of degraded 1980s flex duct in an older Redmond subdivision usually runs $1,500 – $3,500 depending on linear footage and air handler configuration.
What moves the number: system size, duct accessibility (crawl space versus sealed chase), whether we need to clean before sealing to NADCA standards, and if the air handler connections need reinforcement. We do not quote per-vent pricing. We price per system, in writing, before any work starts. One flat price. No add-ons at the door. Call (361) 326-5060 for a free estimate. We’ll inspect with a camera, show you what we found, and give you a written number you can compare.
We Also Serve Cities Near Redmond
Our crews work throughout the Eastside. We regularly handle Duct Sealing in Redmond and the surrounding communities of Kirkland, Sammamish, Bellevue, and Medina. Each area has its own housing stock and climate exposure. Bellevue’s older basement-heavy homes present different access challenges than Redmond’s slab-on-grade townhomes. We adjust our approach accordingly.
Serving Redmond, WA - Our Local Coverage Area
We’re based in the Redmond 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 Redmond
Yes, and we see why constantly. Redmond’s 2010s+ townhomes on slab-on-grade foundations often have construction drywall dust and joint-compound grit left in sealed duct chases that the builder’s punch list never caught. That debris clogs your air handler and gets pushed through registers, and any disconnected joints in those blind chases leak conditioned air you’ll pay for every month. We recommend a camera inspection within six months of move-in. Call (361) 326-5060 to schedule – estimates are free.
Redmond’s mild, humid winters and rainy autumns keep duct interiors damp, which promotes microbial growth and musty odors rather than the dry dust accumulation common in Spokane or Yakima. Sealing here must account for moisture: we clean to NADCA standards before sealing when contamination is present, and we use mastic compounds rated for humid conditions. Tape alone fails faster in our climate. Call (361) 326-5060 for a free estimate.
It depends on condition, and we’ll show you with a camera. Original 1980s – 90s flex duct in Redmond subdivisions like those near Redmond Town Center is notorious for sagging and disconnecting at joints. If the material is intact with localized failures, we can seal and support it for $450 – $1,200. If it’s brittle, torn, or rodent-damaged, replacement at $1,500 – $3,500 is the honest recommendation. We write the price for both options when it’s a close call. Call (361) 326-5060 for an inspection.
We inspect the full system with a camera, seal disconnected joints with mastic and mesh, reinforce the plenum connections with metal-backed support straps, and pressure-test to verify no leaks remain. For garage-mounted units common in 1990s Redmond ranches, we also check for temperature-related expansion damage and vibration wear at the flex connections. The price is written before we start. Call (361) 326-5060 for a free estimate.
Schedule a camera inspection within three to six months of move-in. That’s when construction debris has had time to migrate through the system, and any builder-grade seal failures in blind chases will have shown up as dust at registers or uneven heating. We were called to a new-build in the Overlake area where the homeowners had been sneezing since move-in day; a camera inspection showed a thick layer of drywall dust coating the inside of the flex runs, and our tech used agitation tools under negative pressure to pull it back to a HEPA filtration unit. After we sealed the disconnected joints at the air handler with mastic and mesh, their blower motor amp draw dropped and the musty odor in the upstairs registers cleared within a week. Call (361) 326-5060 to book your inspection – estimates are free.
Ready to stop paying for conditioned air that leaks into your walls and attic? Call Hollis Air Duct Cleaning at (361) 326-5060 for a free estimate on duct sealing in Redmond. We’ll arrive inside the quoted window, inspect with a camera, and give you a written price before any work starts. Every job 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. Background-checked, uniformed technicians. Live person answering the phone, 24 hours a day, 7 days a week. That’s The Garrison Standard.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Redmond and the Eastside since 2004.