Fast, Reliable Duct Repair & Sealing Across Denver
Duct repair and sealing in Denver typically runs $180-$650 depending on whether we’re patching a flex-duct tear or resealing an entire galvanized trunk line, and most jobs are completed in a single visit. If you’re noticing uneven heating between rooms, dust pouring from vents, or utility bills climbing without explanation, the problem is often leaky or damaged ductwork pulling unconditioned air into your system. Call (844) 685-6342 for a free estimate - we’ll show you exactly what we find with a camera inspection before any work begins.
We’ve been driving to Denver jobs from our operation base for over 42 years, and we know the difference between a quick patch on a 1990s ranch in Stapleton and a full reseal on a retrofitted octopus system in a Curtis Park Denver Square. Denver’s 5,280-foot elevation, wild temperature swings, and aging housing stock create duct problems you simply don’t see in flatland cities. Our technicians carry heavy-duty elastomeric mastic, fiberglass mesh, and replacement flex and metal sections so we’re not making a second trip.
Why Bellows Air Duct & Vent Co. Is Denver’s Preferred Duct Repair & Sealing Company
Our reputation in Denver was built one house at a time, starting back in 1984. Homeowners in Capitol Hill, Five Points, and the Highlands call us because we’ve handled the weird stuff - the mismatched plenums, the crumbling asbestos wrap, the flex-duct patches that last crew left behind. We’re not a franchise crew racing through four jobs a day.
Calls to our office are answered by a live person, 24 hours a day. Not a voicemail tree. Not an app. A real person who can dispatch a background-checked, uniformed technician to Denver today if needed. Most repairs are finished in one visit because our trucks are stocked with Rotobrush inspection gear, Abatement Technologies equipment, and the mastic and sealants that actually hold up here.
Our pricing is disclosed upfront before we lift a single tool. The number you hear on the phone is the number on the invoice. We also honor our standing offers: $50 off any repair over $250, a free second opinion on any written estimate, and a permanent 5% discount for seniors and veterans.
Every job carries our 90-Day Done Right Promise - in writing, no paperwork required if something needs attention. We stand behind it because we’ve been standing behind it for four decades.
Our Duct Repair & Sealing Services in Denver
Duct Sealing & Air Leak Repair
Denver’s 40°F+ daily temperature swings cause sheet-metal ductwork to expand and contract aggressively, cracking standard mastic and opening seam gaps that pull unfiltered basement, crawl-space, or attic air directly into your supply stream. We locate these leaks with camera inspection and seal them with heavy-duty elastomeric mastic rated for thermal cycling - not the brittle stuff that fails in six months. In older homes near 80205 and 80206, we regularly find original galvanized trunks with failed seams that have been leaking for years, quietly driving up heating bills and circulating dust.
Metal Duct Repair
Post-war ranch homes on Denver’s eastern edges often contain original galvanized sheet-metal ductwork from the 1950s and 1960s with open seams, corrosion at joints, or sections crushed by subsequent remodeling. We repair or replace these metal runs with proper gauge material, reseal with fiberglass mesh and elastomeric mastic, and verify with before-and-after camera documentation. Metal duct repair in Denver typically runs $280-$550 depending on linear footage and accessibility.
Flex Duct Repair
Flex duct is common in retrofit work and additions throughout Denver’s older neighborhoods, but it’s easily crushed, torn by rodents, or disconnected at collars. We replace damaged flex sections with insulated, properly sized runs and secure them with mechanical fasteners - not just tape that dries and fails. A standard flex duct repair in Denver runs $180-$340.
Mastic Sealant Application
We emphasize mastic sealant on this page because it’s what separates a lasting repair from a callback. Denver’s climate destroys tape-based repairs. Our technicians apply heavy-body elastomeric mastic with fiberglass mesh reinforcement at all joints, collars, and plenum connections. For a full system reseal on a typical Denver home, expect $450-$650. We complete most of these in a single visit.
Duct Insulation
Uninsulated or deteriorated ductwork in unconditioned spaces - common in Denver’s basements and crawl spaces - wastes energy and creates condensation points. We install proper insulation wraps, particularly important given Denver’s dry climate where temperature differentials are extreme. Duct insulation work in Denver typically ranges $320-$580.
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 Denver
We repair and seal ductwork connected to equipment from Aprilaire, Abatement Technologies, and Rotobrush - brands that serious HVAC contractors specify and that we trust for our own equipment. Our trucks carry replacement collars, dampers, and sealant materials sized for the systems we encounter in Denver’s varied housing stock, from the compact mechanical rooms in Capitol Hill bungalows to the full basements in Park Hill foursquares. That inventory means we’re not ordering parts and making you wait.
Common Duct Repair & Sealing Problems We See in Denver Homes
- Cracked mastic from thermal cycling. Denver’s daily temperature swings harden and crack standard duct mastic within a year or two. We find this constantly on sheet-metal systems in homes across 80203 and 80204. Heavy-duty elastomeric formulation is the only fix that lasts.
- Asbestos-containing insulation on octopus-furnace plenums. In Capitol Hill, Curtis Park, and Five Points, pulling a register in a pre-1960 home often reveals the original octopus-furnace plenum wrapped in deteriorating asbestos insulation. This is a legal stop-work condition requiring abatement referral before any repair proceeds. Flat-rate national crews routinely miss this on the estimate call.
- Oversized, debris-trapping plenums from 1950s retrofits. The forced-air conversions done on Denver Squares and bungalows often left irregular plenums that don’t match standard equipment. Debris accumulates in these dead zones and recontaminates the system within weeks if the technician doesn’t account for the geometry.
- Flex-duct disconnections in crawl spaces and attics. Denver’s dry climate and rodent pressure mean flex runs in unconditioned spaces get chewed or work loose at collars. We secure these with mechanical fasteners and proper support, not tape.
Pricing for Duct Repair & Sealing in Denver, CO
Here’s what duct repair and sealing costs in Denver’s current market:
| Service | Typical Range |
|---|---|
| Flex duct repair (single run) | $180 - $340 |
| Metal duct repair (section) | $280 - $550 |
| Mastic sealant reseal (partial system) | $320 - $480 |
| Full system mastic reseal | $450 - $650 |
| Duct insulation (partial) | $320 - $580 |
Accessibility matters in Denver’s older homes - tight crawl spaces in Curtis Park or finished basements in Cherry Creek add time. The condition of existing ductwork matters too; a simple patch on accessible flex duct runs far less than resealing a full octopus-retrofit system with multiple mismatched plenums. We inspect with cameras before quoting, so you see what we see. Estimates are free, and our $50 off any repair over $250 applies to most jobs on this list. Call (844) 685-6342 for your exact number.
We Also Serve Cities Near Denver
Our Duct Repair & Sealing in Denver coverage extends to Lakewood, Wheat Ridge, Commerce City, and Englewood. Same trucks, same technicians, same upfront pricing and 90-Day Done Right Promise. Whether you’re in a mid-century ranch near Sloan’s Lake or a bungalow off Colfax, we’ll be there when we say.
Serving Denver, CO - Our Local Coverage Area
We’re based in the Denver 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 - Duct Repair & Sealing in Denver
Yes, we specialize in these systems, but we approach them differently than standard ductwork. The 1950s forced-air retrofits common in Denver Squares and bungalows often left oversized, irregular plenums with deteriorating asbestos-containing insulation wrap. We camera-inspect first, halt work if abatement is required by law, and then reseal or replace with properly sized components that don’t trap debris. Call (844) 685-6342 - we’ll walk through what to expect before we arrive.
Heavy-body elastomeric mastic with fiberglass mesh reinforcement - not tape, not standard mastic, not spray foam. Standard sealants crack within a year under Denver’s 40°F+ daily thermal expansion. We apply elastomeric mastic rated for continuous flexing, then verify with camera inspection. The material costs more upfront. It costs far less than a callback.
Every three to five years for most Denver properties, but annually if you’ve had wildfire smoke exposure or visible dust increase. Denver’s semi-arid climate means fine particles stay airborne longer and settle deeper into ductwork, accelerating accumulation. Acreage properties with longer duct runs and more exposure to outdoor particulate matter often show leaks and debris buildup faster than city homes. Our $89 Seasonal Tune-Up includes a basic leak check.
Sealing alone won’t remove smoke particles already in your ducts, but it prevents your system from pulling contaminated outdoor or crawl-space air into the supply stream. After a smoke event, we typically recommend camera inspection to assess contamination, then duct cleaning followed by sealing of any new leaks opened by thermal cycling. Denver’s bowl geography traps Front Range particulate matter and wildfire smoke longer than flatland cities - sealing is part of a complete response, not a standalone fix. Call for a free post-smoke inspection.
Very common, especially in additions, basement finishes, and retrofitted attic runs in neighborhoods like Five Points and the Highlands. Original flex from the 1980s and 1990s is often brittle, undersized, or improperly supported. We replace damaged sections with properly insulated, code-compliant flex and secure with mechanical fasteners. Most flex repairs in Denver run $180-$340 and finish in one visit. Call (844) 685-6342 for an exact quote - estimates are free.
Written by Ray Castillo, Owner at Bellows Air Duct & Vent Co., serving Denver since 1984.