Trusted Duct Repair & Sealing for Seattle Homeowners
Affordable Duct Repair & Sealing in Seattle, WA typically costs between $250 and $850 depending on the scope, with most single-room fixes completed in under three hours and whole-system sealing done in a single day. Bellows Air Duct & Vent Co. has been repairing and sealing ductwork for Seattle homeowners since 2012, and we still answer our own phones around the clock. If your upstairs rooms never warm up, your energy bills keep climbing, or you’ve noticed musty air coming from specific vents, the problem is likely in your ducts, not your furnace. We use camera inspection to show you exactly where the leaks or damage are before we quote a price, and we back every repair with our 90-Day Done Right Promise in writing. Call (833) 700-5198 for a free estimate with no obligation.
What Our Duct Repair & Sealing Service Includes
Duct Sealing
Duct sealing closes the gaps, cracks, and loose connections that let heated and cooled air escape into your attic, crawl space, or walls before it ever reaches your rooms. For the Best Duct Repair & Sealing in Seattle, WA, look to experienced technicians who know that in older homes-especially in neighborhoods like Wallingford and Phinney Ridge where original ductwork from the 1960s and 70s still runs through unconditioned spaces-we regularly find systems leaking 20 to 30 percent of their airflow. Our technicians seal accessible joints with mastic compound and mechanical fasteners, then pressure-test the system to verify the improvement. We show you the before-and-after camera footage so you can see the difference yourself.
Flex Duct Repair
Flex duct, the ribbed plastic tubing common in Seattle home additions and basement conversions, crushes, kinks, and deteriorates faster than metal. We see this constantly in Ravenna and Greenwood basements where flex runs were installed too long ago with too many tight bends, and we also handle our Duct Repair & Sealing in White Center. When flex duct collapses or tears, rooms go dead and your HVAC system works harder for no gain. We replace damaged sections with properly sized new flex, support it every four feet to prevent sagging, and seal all connections with code-approved mastic, not duct tape, which fails within months in our damp Pacific Northwest climate.
Metal Duct Repair
Galvanized steel ductwork lasts decades but rusts at seams, separates at joints, and can crack from vibration or house settling. In Seattle’s Magnolia and Queen Anne hills, we find metal ducts corroded from decades of moisture in crawl spaces that never fully dry out, and we provide Duct Repair & Sealing - Bellevue as well. We cut out rusted sections, fabricate replacement pieces on site, and seal with professional-grade mastic sealant. For separated seams, we install drive cleats and sealant rather than relying on screws alone, which pull loose over time. Every metal repair gets pressure-tested before we leave.
Duct Insulation
Uninsulated or degraded duct insulation in attics and crawl spaces wastes energy and creates condensation problems that lead to mold. Seattle’s temperature swings, even mild ones, mean cold ducts in summer collect moisture that soaks fiberglass wrap and collapses it. We remove water-damaged insulation, treat any surface mold with EPA-registered sanitizer, and install new foil-faced fiberglass or closed-cell foam insulation rated for your application. In homes near Puget Sound in neighborhoods like Alki and West Seattle, where salt air accelerates corrosion, proper insulation also protects the metal underneath from premature failure.
Mastic Sealant Application
Mastic is a thick, water-based sealant that remains flexible for years and bonds to metal, flex duct, and fiberglass insulation better than any tape. We apply it with brushes and caulking guns at every joint, seam, and penetration, then let it cure before pressurizing the system. In Seattle’s climate, where temperature differentials between attic and living space are constant for nine months of the year, mastic outlasts foil tape by a factor of ten. We use mastic rated for HVAC applications, not hardware-store caulk, and we apply it thick enough that light won’t show through, which is the standard our technicians are trained to meet.
Air Leak Repair
Air leaks in ductwork show up as rooms that never reach temperature, dust streaks near vent covers, or whistling sounds in walls. We pressurize the system and use smoke pencils to pinpoint leaks that camera inspection alone might miss. In multi-level Seattle homes, particularly in Capitol Hill and Madrona where ductwork runs through finished walls, we access leaks through existing registers or small strategic openings rather than tearing out drywall. Once located, we seal from the inside with aerosol sealant or access and repair directly, depending on location and severity. The goal is stopping the leak with the least disruption to your home.
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.
Brands We Service for Duct Repair & Sealing
We’ve worked on duct systems connected to Honeywell air cleaners and zoning panels for over two decades, and we understand how their bypass dampers and electronic air cleaners integrate with existing ductwork. When we seal or repair ducts serving Honeywell components, we verify that airflow rates stay within manufacturer specifications so your air cleaner and zoning system continue to function as designed. We’ve also serviced hundreds of Aprilaire humidifiers and ventilation systems in Seattle homes, particularly in dry winter months when proper duct sealing prevents over-humidification and the mold issues that follow. Our technicians carry common Aprilaire parts and know which duct configurations work best with their whole-house dehumidifiers and fresh air ventilators.
We regularly repair and seal ductwork for systems using Abatement Technologies HEPA filtration and containment equipment, especially in homes where occupants have allergies or respiratory concerns and need verified airtight duct performance. For homeowners with Guardsman UV air treatment systems installed in their ductwork, we take care to preserve UV lamp positioning and wiring during any repair or sealing work. Whether you have Honeywell, Aprilaire, Abatement Technologies, Guardsman, or any other make of HVAC component connected to your ducts, we can assess the system, repair what’s failing, and seal what leaks without compromising the equipment you already own.
Signs You Need Duct Repair & Sealing Right Now
- Uneven temperatures from room to room. If your bedroom is ten degrees colder than your hallway in winter, or your kitchen cooks while your living room freezes, conditioned air is escaping before it reaches the register. This is one of the most common complaints we hear from Seattle homeowners in Ballard and Fremont, and it’s almost always fixable in a single visit.
- Dust that returns within days of cleaning. Leaky return ducts in attics or crawl spaces pull in fiberglass particles, rodent droppings, and construction debris, then distribute it through your vents. If you’re dusting constantly and your filters are clean, your ducts are likely drawing air from the wrong places.
- Energy bills that climb without explanation. When 25 to 40 percent of your heated or cooled air leaks into unconditioned space, your HVAC system runs longer cycles to compensate. We’ve seen Seattle homeowners in older homes near Green Lake and Leschi cut their heating bills by 15 to 20 percent after proper duct sealing, with payback in under two winters.
- Whistling, rattling, or whooshing sounds from vents or walls. These noises indicate high-velocity air escaping through gaps, loose dampers, or disconnected sections. A whistle often means a small but significant leak under pressure; a rattle can signal a section of duct that has separated entirely and is vibrating against framing.
- Musty or stale odors when the system runs. Leaks in return ducts pull air from musty crawl spaces or attics where moisture has accumulated. In Seattle’s climate, this is a year-round issue, not just a winter one, and it won’t resolve with air fresheners or filter changes. Sealing the leak stops the odor at its source.
Our Duct Repair & Sealing Process - Step by Step
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Camera inspection and system assessment. We start by running a high-resolution camera through your accessible ductwork to document existing conditions, locate damage, and identify leak points. We show you the footage in real time so you see what we see. No guesswork, no scare tactics, just the actual state of your system.
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Pressure testing to quantify leakage. We temporarily seal your registers and pressurize the duct system to measure total leakage in CFM25, the industry standard. This gives us a baseline and helps us prioritize repairs for maximum impact. In Seattle, where many homes test at 25 to 40 percent leakage, this step separates cosmetic fixes from meaningful improvements.
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Upfront pricing with no surprises. Before any tool touches your ducts, we present a written quote with line-item pricing for each repair or sealing option. The number we give is the number on the invoice. Our current standing offer is $50 off any repair over $250, and we also provide free second opinions on any written estimate you’ve received from another company.
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Repair and seal with professional-grade materials. Our background-checked, uniformed technicians complete most repairs in a single visit using mastic sealant, mechanical fasteners, replacement duct sections, and insulation rated for your specific application. We work cleanly, protect your floors and furnishings, and keep you informed throughout the job.
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Post-repair verification and documentation. We camera-inspect again after work is complete, re-test system pressure to confirm leakage reduction, and provide you with before-and-after documentation for your records. Every job is backed by our 90-Day Done Right Promise: if anything isn’t right, we return at no charge with no paperwork required.
How Much Does Duct Repair & Sealing Cost in Seattle?
A typical single-register air leak repair in Seattle runs $250 to $400, while sealing an entire duct system in a 2,000-square-foot home generally falls between $600 and $1,200 depending on accessibility and the extent of existing damage. Flex duct replacement in a crawl space or attic typically costs $350 to $650 per section, including proper support and insulation. Metal duct repair, which requires cutting, fabricating, and sealing, usually ranges from $400 to $850 depending on location and whether we need to create access.
Several factors move these numbers. Crawl spaces with less than 18 inches of clearance take longer to work in and cost more. Homes with original ductwork from the 1950s through 1970s often need more extensive repair than newer construction. The number of stories matters too; multi-level homes in Queen Anne or Magnolia with long vertical duct runs require more material and labor than single-story ranches in Northgate or Wedgwood.
To avoid overpaying, get a written estimate that specifies exactly what’s included, and be wary of phone quotes that don’t account for your specific home. At Bellows, we inspect first and quote second. Our free estimates include camera footage, pressure test results, and itemized pricing. We also offer a free second opinion on any written estimate from another contractor, and our $89 Seasonal Tune-Up can identify duct problems before they become expensive repairs. Seniors and veterans receive a permanent 5% discount on all services.
Duct Repair & Sealing Near Seattle - Our Service Area
We dispatch from our Seattle location to homes throughout the metro area, including Duct Repair & Sealing in City of Sammamish, Bellevue, Kirkland, White Center, Boulevard Park, Inglewood-Finn Hill, Riverton, Bryn Mawr-Skyway, Newcastle, and Bainbridge Island. Most Seattle neighborhoods see same-day or next-day availability, with response times under two hours for urgent situations like disconnected ducts or significant air leaks affecting system operation. Whether you’re in a century-old Craftsman in Wallingford or a mid-century home in Duct Repair & Sealing in Mercer Island, we arrive with the equipment and parts to finish most jobs in one visit. We also serve Duct Repair & Sealing in Seattle and surrounding communities with the same 42-year commitment to showing up when we say we will.
Serving Seattle, WA - Our Local Coverage Area
We’re based in the Seattle area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
Frequently Asked Questions - Duct Repair & Sealing in Seattle
Duct repair and sealing fixes the leaks, gaps, disconnected sections, and damaged insulation in your home’s air distribution system so heated and cooled air reaches your rooms instead of escaping into walls, attics, and crawl spaces. The process includes camera inspection to locate problems, pressure testing to measure leakage, physical repair of damaged duct sections, and sealing of all joints and seams with mastic compound. At Bellows, we document everything with before-and-after camera footage and verify results with a final pressure test.
Most single repairs or small sealing jobs take two to four hours, while whole-system sealing in an average Seattle home requires a full day. We complete the vast majority of jobs in a single visit because our technicians arrive with stocked trucks and the parts to handle common flex duct, metal duct, and insulation repairs on the spot. Call (833) 700-5198 to schedule, and we’ll give you a time estimate based on your specific situation.
Single-register leak repairs typically run $250 to $400, section replacements $350 to $650, and whole-system sealing $600 to $1,200 depending on home size and accessibility. We provide free written estimates with line-item pricing before any work begins, and we honor our $50 off any repair over $250 standing offer. For an exact quote on your home, call (833) 700-5198 to schedule a free inspection.
Yes, we repair and seal ductwork connected to Honeywell, Aprilaire, Abatement Technologies, Guardsman, and all other major HVAC component brands. Our technicians understand how duct modifications affect airflow requirements for air cleaners, humidifiers, zoning systems, and UV treatments, and we verify that repairs maintain manufacturer specifications. We carry common parts and can source others quickly if needed.
Yes, we answer calls 24 hours a day, every day, and we prioritize urgent situations like completely disconnected ducts, major leaks causing system shutdown, or damage from rodents or construction accidents. Our live answering service connects you directly to our dispatch team, not a voicemail system or call center. For emergency duct repair in Seattle, call (833) 700-5198 any time.
Every duct repair and sealing job is covered by our 90-Day Done Right Promise in writing. If the repair fails, the seal breaks, or the problem recurs within 90 days, we return and make it right at no charge with no paperwork required. This guarantee is non-negotiable and has been our standard since 2012. We also honor manufacturer warranties on any parts we install.
Clear a path to your HVAC system, attic access, crawl space entry, and all registers so our technicians can work efficiently and safely. Remove fragile items from shelves near work areas, as vibration from tools can occasionally cause movement. You don’t need to cover furniture or vacate the home; we bring drop cloths and work carefully. If you have pets, securing them in a separate room helps us move freely with equipment and keeps them safe. Call (833) 700-5198 with any questions before your appointment.
Schedule Your Duct Repair & Sealing Service in Seattle Today
Call Bellows Air Duct & Vent Co. at (833) 700-5198 for a free, no-obligation estimate on duct repair and sealing in Seattle. We’ll send a background-checked, uniformed technician to inspect your system with a camera, pressure-test for leaks, and show you exactly what needs attention before any work begins. One honest price, no bait coupons, no surprises on the bill. We’ve been serving Seattle homeowners since 2012, and we stand behind every job for 90 days with no paperwork and no arguing.
Written by Colin Merritt, Owner at Bellows Air Duct & Vent Co., serving Seattle since 2012.