Whole-home duct cleaning
Dryer vent cleaning
Camera inspection
Sanitizing & deodorizingWhole-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.
Styles & brands we work with
- Whole-home duct cleaning
- Dryer vent cleaning
- Camera inspection
- Sanitizing & deodorizing
See the difference
Before
After
Before
After
Before
AfterHow Much Does Duct Repair & Sealing Cost in Thornton?
Duct repair and sealing in Thornton typically costs $185 to $450 for a single accessible repair, while full-home duct sealing runs $550 to $1,400 depending on how many leaks are found and how reachable the runs are. A duct replacement section, where flex duct has collapsed or been crushed, usually lands between $320 and $900 per run. Those are the ranges homeowners here see most often, and the written estimate sets the final price.
We arrive with Rotobrush and Nikro equipment, not a shop-vac and a promise, and we also repair what we find. That matters in a market where a lot of homes were built fast and hooked up to undersized flex. Call (888) 495-2236 for a free estimate. We answer 24/7. Fast dispatch from 7am to 7pm, Sunday through Friday.
Key Takeaways
- Most single-repair jobs in Thornton fall between $185 and $450.
- Whole-home duct sealing averages $550 to $1,400, priced per leak and per run.
- Crushed or disconnected flex duct replacement runs $320 to $900 per section.
- Leaks found during a cleaning get fixed in the same visit, so you don’t pay for a second contractor.
- The estimate is free, and it’s written. Our technicians have up to 12 years of experience.
Duct Repair & Sealing Cost Breakdown (2026)
Here’s what the line items look like in this market. These are typical ranges, not exact quotes. Every home has a different layout, and the written estimate is the number that counts.
| Line item | Typical range | What it covers |
|---|---|---|
| Single joint or seam seal (accessible) | $185 to $340 | Mastic or foil-tape seal on one reachable leak, usually at a trunk takeoff or plenum connection |
| Multiple leak sealing, half the system | $340 to $650 | Sealing across several runs when a cleaning turns up widespread separation |
| Whole-home duct sealing | $550 to $1,400 | System-wide sealing including trunk lines, takeoffs, and boots, priced per leak and per run |
| Flex duct section replacement (per run) | $320 to $900 | Removing crushed, torn or collapsed flex and replacing it with properly sized, supported duct |
| Rigid duct repair or reconnection | $280 to $750 | Reconnecting separated metal sections, repairing damaged trunk, re-supporting sagging runs |
| Register boot or collar repair | $150 to $325 per boot | Resealing the connection where duct meets the floor or wall register |
| Return-side leak repair | $225 to $600 | Sealing return plenum and return runs, often the biggest source of attic or crawlspace air |
What pushes a job toward the top of those ranges? Access is the big one. A leak in an open basement ceiling takes minutes to reach. The same leak on a run buried under blown-in insulation in a 100-degree attic takes real time, and time is what you’re paying for. The number of separate leaks matters too, since sealing is priced per connection. So does the condition of the duct itself: old, brittle flex that tears when you touch it needs section replacement, not just mastic. If the leak sits behind finished drywall or a hard ceiling, a drywall access point may be needed, and that adds to the estimate.
Homes with a Honeywell or Aprilaire whole-home air-quality system often have more duct connections to check, because those systems tie into the return and supply trunk. We service and are familiar with both brands, so we plan repair work around existing premium HVAC accessories rather than fighting them. Homeowners comparing this against a full cleaning often ask us to price both together; our duct cleaning Thornton page covers what that visit involves.
What Affects Duct Repair & Sealing Pricing in Thornton
- Attic and crawlspace access. Much of Thornton’s housing stock runs ductwork through unconditioned attic space, which gets brutally hot in summer and cold in winter. Reaching a leak up there means working in extreme temperatures with limited footing, and that labor time shows up in the estimate.
- Newer builds with tight-tolerance framing. Homes in the newer subdivisions off the northern and eastern edges of the city tend to have flex-heavy systems installed during construction. Flex is quick to install and quick to crush, and long runs with many bends are where leaks cluster. Homes in the older neighborhoods near the original downtown grid often have rigid metal trunk and branch systems, which fail differently: separated joints rather than crushed pipe.
- Number of separate leaks. Sealing is priced per connection. Three leaks on one trunk line cost less than fifteen scattered across the house, even though the per-leak cost drops a little on volume.
- Whether you’re already getting a cleaning. If a technician is already in the system with Rotobrush equipment and can see the leak, the repair is a smaller add-on than a stand-alone repair visit. That’s the practical reason we offer cleaning and repair together: cleaning, repair, and dryer vent service in a single visit.
- Duct material. Flex, rigid metal, and ductboard all fail in different ways and take different repair methods. Ductboard that’s been water-damaged or crushed may need section replacement rather than a seal.
- Return-side problems. A leaking return pulls attic air, garage air, or crawlspace air straight into the system. Those repairs are often the most valuable and sometimes the trickiest, since the return plenum is frequently the hardest part of the system to reach.
One more local factor worth knowing: the dry air and wide seasonal temperature swings along the Front Range put duct connections under constant expansion and contraction. Mastic that was fine at installation can crack over several heating and cooling cycles. That’s why we check every visible joint during a cleaning rather than only the one you called about.
How to Save on Duct Repair & Sealing
The best way to save is to stop paying for a second visit. When our technicians run Rotobrush equipment through the system, they can see crushed flex, separated joints, and torn boots at the same time. Fixing them during that visit means one dispatch instead of two, and it’s why we treat air duct repair as a named service rather than a referral. If you suspect a leak, have the cleaning and the inspection done together.
Second: ask for the whole list before you approve anything. A written estimate that itemizes each leak and each run lets you decide what’s urgent now and what can wait. We don’t inflate a job to fill a visit, and the estimate is free, so there’s no cost to getting the full picture first.
Third: fix the return side, not just the supply. A leaking return is the one that moves the most air, and sealing it often delivers more comfort per dollar than chasing every small supply leak. Ask the technician to tell you which leaks matter most.
Fourth: know when replacement beats repair. If a run is crushed along most of its length or is old flex that tears instead of holding a seal, replacement is the cheaper path over time. If a joint is simply separated, sealing it is the right call. For a broader view of what a full visit includes across the city, see the service overview for Thornton.
Ready to know what your system actually needs? Call (888) 495-2236 for a free estimate. We answer 24/7. Fast dispatch from 7am to 7pm, Sunday through Friday.
Why Professional Sealing Beats a DIY Tube of Caulk
Homeowners often ask whether they can just seal a leak themselves. Sometimes a single reachable joint at a floor register is a reasonable DIY fix, but a real assessment of a duct system usually needs eyes on the attic and crawlspace runs, and that’s where the danger and the difficulty live.
Working in an attic in a Thornton summer is genuinely hazardous: temperatures can climb well past what’s safe for a sustained effort, footing is limited to joists under insulation, and the space in tight-tolerance newer construction can be barely wide enough to move. Combine that with the fact that a duct leak near the furnace plenum sits beside the heat exchanger and gas connections, and it becomes clear why a trained technician is the right person for anything beyond a single easy joint. We also use Abatement Technologies negative-air and HEPA-filtration equipment during the work, so displaced debris is captured rather than pushed back into the house. That’s the same containment discipline a remediation job uses.
FAQs – Duct Repair & Sealing Cost
What does duct sealing cost in Thornton?
Whole-home duct sealing in Thornton typically costs $550 to $1,400, and a single accessible repair runs $185 to $450. The spread depends on how many leaks there are and how hard they are to reach. Call (888) 495-2236 for a free estimate.
Is it cheaper to repair or replace ductwork?
Repair is almost always cheaper for a localized leak: sealing a separated joint runs $150 to $600, while replacing a single flex run runs $320 to $900. Full replacement only makes sense when most of the system is crushed or failing. The written estimate will tell you which situation you’re in. Call (888) 495-2236 to book one.
Can you fix a duct leak the same day you clean?
Yes, in most cases. When a technician is already in the system with Rotobrush equipment and finds a crushed run or a separated joint, the repair gets worked into the same visit. We answer 24/7. Fast dispatch from 7am to 7pm, Sunday through Friday.
Does duct sealing cost more if there are multiple leaks?
Yes, because sealing is priced per connection. A single seal runs $185 to $340, while work across several runs climbs into the $340 to $650 range. The per-leak cost tends to drop a little as the job grows. Get a free estimate by calling (888) 495-2236.
How much does it cost to repair a crushed flex duct in Thornton?
Replacing a crushed flex duct section typically costs $320 to $900 per run in Thornton. The range reflects the length of the run and how hard it is to reach in the attic or crawlspace. Call (888) 495-2236 for an exact quote on your system.
Why are my ducts leaking more in a newer Thornton home?
Newer builds often use long flex runs with many bends, and flex crushes and separates at the takeoffs, so leaks tend to cluster at those connections. Duct sealing in these homes runs $550 to $1,400 for a full-home job. A free estimate tells you exactly where yours are leaking.
Pricing reflects the Thornton market as of 2026. Duct Cleaning Thornton offers free estimates – call (888) 495-2236.
What Our Customers Say
"Fair price and thorough work. They ran about an hour and a half past the estimated finish time, so don't schedule anything tight after."
- Tracy Rhodes"Job was done well and the house smells better. There was some dust knocked loose around a couple of the registers that I had to wipe down afterward."
- Ryan Reed"Found a disconnected run in the crawlspace while they were in there and told me about it rather than cleaning around it."
- Carlos Torres