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 Repair & Sealing Across Denver
Duct repair and sealing in Denver typically runs $340-$890 for a whole-system repair, with most jobs completed in one scheduled day. CleanRun Air Duct Cleaning Denver dispatches crews from our metro office to handle everything from cracked flex duct in eastern plains ranches to failed mastic seals in 1960s Harvey Park ranches. Call (720) 799-2292 for a written price before any work starts.
We know the Denver market because we work it daily. Our technicians have photographed the inside of duct runs in Capitol Hill bungalows, Barnum ranches, and rural properties out toward Kiowa. That local familiarity matters when your home sits on unpaved land with easterly winds pushing prairie soil into returns, or when your 1950s sheet metal was sealed with original mastic that has dried to dust in Denver’s 40% humidity.
Why CleanRun Air Duct Cleaning Denver Is Denver’s Preferred Duct Repair & Sealing Company
CleanRun has served Denver-area homeowners since 2013 with a documented photo record on every visit. Our Duct Repair & Sealing team has completed over 52,000 jobs, every one with a written price agreed before a single panel came off.
Denver customers choose us because we show what we find. The camera reveals the 3-inch debris build-up at the first elbow, the cracked flex duct in the crawlspace, the failed mastic joint pulling soil past the filter. You see it before we discuss what needs to happen. Haven Standard Clause 1 requires that written price; Haven Standard Clause 3: Verified Crews means your technician arrives background-checked, uniformed, and identified by name.
Our 365-Day Done Right Promise is backed in writing on every job, not stated in marketing copy and forgotten. If the work is not right, we make it right. No manager approval required.
We coordinate dispatch and scheduling from our Denver office, with crews serving the metro and eastern plains. All calls are answered by a live person, 24/7.
Our Duct Repair & Sealing Services in Denver

Mastic Sealant Application
Denver’s semi-arid climate destroys old mastic. In Harvey Park, Barnum, and Westwood ranches built 1955-1975, we regularly find original asbestos-containing mastic or duct tape crumbled to powder at sheet-metal joints. Our crew assesses these connections before disturbing them, then applies new professional-grade mastic sealant to restore airtight joints. A typical mastic reseal for a Denver ranch runs $280-$520.

Flex Duct Repair
Flex duct liner dries and cracks faster in Denver’s 40% annual humidity than in any humid metro. We’ve replaced failed flex runs in crawlspaces from Congress Park to rural properties near Kiowa, where unpaved driveways let soil infiltrate through cracks the homeowner never saw. Our crew uses Rotobrush and Nikro equipment for source removal, then installs new flex duct rated for the dry climate. Flex duct repair in Denver typically costs $180-$440 per run.

Metal Duct Repair
Original sheet-metal trunk lines in Denver’s 1950s-1970s housing stock suffer seam separation and corrosion where old mastic has failed. We repair metal duct with proper mechanical fastening and resealing, then re-insulate where Denver’s temperature swings cause condensation. Metal duct repair runs $320-$680 depending on accessibility and extent.

Duct Insulation
Denver’s 5,280-foot elevation means longer blower cycles and greater temperature differential across duct surfaces. Uninsulated or degraded duct insulation in attics and crawlspaces wastes conditioned air and creates condensation points. We install new insulation on repaired metal trunks and replace degraded flex duct with properly insulated runs. Duct insulation work in Denver ranges $260-$580.

What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Before
AfterTrusted Brands We Service in Denver
CleanRun crews work with professional-grade equipment from Honeywell, Aprilaire, and Rotobrush, plus Nikro and Abatement Technologies for negative-pressure extraction systems. We stock common repair parts at our Denver office for faster turnaround on standard jobs. Customers can verify every brand independently; we name them so you know what sits in the van before you agree to a price.
Common Duct Repair & Sealing Problems We See in Denver Homes

- Failed original mastic in mid-century ranches. Harvey Park and Barnum homes built 1955-1975 used asbestos-containing mastic or duct tape at sheet-metal joints. Denver’s low humidity dries these materials to dust, opening leaks that pull fine prairie soil into returns before the filter catches anything.
- Gravity-furnace “octopus” dead-ends. Capitol Hill and Congress Park bungalows converted to forced air in the 1960s-70s kept original gravity-furnace trunk lines. Horizontal dead-end runs collect compacted debris and occasional mouse nesting material undisturbed for 50+ years, defeating standard negative-pressure cleaning until the dead-end is sealed or removed.
- Cracked flex duct from dry air. Denver’s 40% annual humidity dries flex duct liner faster than humid regions. Interior surfaces crack and shed insulation into the airstream, coating the air handler coil with material that restricts airflow and drives up static pressure.
- Wildfire smoke infiltration. The Front Range’s intensifying fire seasons, including the December 2021 Marshall Fire 20 miles from downtown, drive homeowners to seal windows and run HVAC continuously. Fine ash and smoke particulates embed in duct systems, accelerating debris loading and degrading seals.
Pricing for Duct Repair & Sealing in Denver, CO
Most Denver duct repair and sealing jobs fall between $340 and $890 for a whole system. Single repairs, like one flex duct run or a partial mastic reseal, start around $180. Full system resealing with insulation replacement on a large ranch can reach $1,200.
| Service | Typical Range in Denver |
|---|---|
| Mastic sealant (whole system) | $280-$520 |
| Flex duct repair (per run) | $180-$440 |
| Metal duct repair | $320-$680 |
| Duct insulation | $260-$580 |
| Full system repair + sealing | $340-$890 |
What moves the price: accessibility (crawlspace vs. basement), extent of failed material, whether original gravity-furnace dead-ends need modification, and whether wildfire smoke residue requires additional source removal. We deliver one flat price per system, agreed in writing before work starts. No per-vent pricing. No coupon that triples once the van arrives. Call (720) 799-2292 for a free estimate.
We Also Serve Cities Near Denver

CleanRun crews based in Denver also serve Aurora, Englewood, Thornton, and Littleton. Rural properties on the eastern plains draw from our Denver dispatch.
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

Every 2 to 5 years for rural Denver properties on unpaved roads, not the 3-to-7-year city schedule. Fine prairie soil blown in by easterly winds stays suspended in Denver’s 40% humidity, infiltrating returns continuously. Sealing infiltration points first, then cleaning, extends the interval. Call (720) 799-2292 and we’ll photograph the current loading to give you a specific interval.
Yes, with assessment first. Original gravity-furnace “octopus” trunk lines kept during forced-air conversions can be sealed if structurally sound, but dead-end horizontal runs must be addressed. Our camera inspection finds where debris has compacted for decades and whether the original mastic contains asbestos. We document what we find, quote a written price, and proceed only with your approval.
Yes, especially for outbuilding systems pulling from unpaved areas. Unsealed ducts in shops, barns, and detached garages pull soil and pollen directly into the main house system when interconnected. Mastic sealing the outbuilding runs prevents cross-contamination and reduces the load on your main air handler. A typical outbuilding seal in the Denver area runs $180-$340.
Yes. Front Range wildfire seasons, including the 2021 Marshall Fire, drive homeowners to seal buildings and run HVAC continuously, embedding fine particulates deep in duct systems. Smoke residue degrades mastic seals and loads filters faster. We inspect for smoke-related seal degradation and include source removal in our scope when needed. The repair approach changes after heavy smoke events.
Rotobrush and Nikro agitation tools, Abatement Technologies negative-pressure extraction systems, and Honeywell and Aprilaire air quality components. We name these brands so customers can verify specifications independently. Every job concludes with a Documented Photo Record delivered as a standard deliverable, not an extra.
Our crew worked a 1960s ranch near Kiowa where the original gravity furnace trunk lines had been kept during a forced-air conversion - the main trunk had a dead-end horizontal run packed with 50 years of compacted prairie dust and a mouse nest. Using a camera inspection we found flex duct in the crawlspace cracked from Denver’s dry air, letting soil from the unpaved driveway pull into the return. After source removal with agitation tools under negative pressure and HEPA filtration, we mastic-sealed the seams, re-insulated the metal trunk, and replaced the failed flex run; the blower motor’s static pressure dropped back to normal.
Ready for a written price? Call (720) 799-2292. We’ll answer live, schedule at your convenience, and deliver a flat price per system before any work starts. Every job includes a Documented Photo Record and the 365-Day Done Right Promise, backed in writing.
Written by Tomas Reyes, Owner at CleanRun Duct Repair & Cleaning, serving Denver since 2013.




Before
After
Before
After