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 Littleton
Duct repair and sealing in Littleton typically runs $280-$890 for most residential jobs, with flex duct repairs on the lower end and full metal duct restoration in older homes toward the upper range. We’re CleanRun Air Duct Cleaning Littleton, and our crews work Littleton addresses daily, dispatching from our Denver office to reach homes from historic downtown to the Highlands Ranch subdivisions that carry Littleton mailing addresses. Call (720) 315-7291 for a written estimate before any work starts.
Littleton’s housing stock splits into two distinct eras, and each one fails differently. The 1950s-1970s ranch homes in historic Littleton proper still carry original fiberglass-lined sheet-metal ductwork that has gone brittle after decades of use. Meanwhile, the massive Highlands Ranch development, built rapidly in the 1990s and early 2000s with Littleton addresses in zip codes 80126, 80129, and 80130, installed identical builder-grade flex-duct systems that are now hitting the 25-35 year mark simultaneously. That’s an unusually concentrated wave of aging residential ductwork that no neighboring suburb replicates at this scale. Our Duct Repair & Sealing team has documented both failure types across thousands of Littleton-area jobs since 2013.
Why CleanRun Air Duct Cleaning Littleton Is Littleton’s Preferred Duct Repair & Sealing Company
We’ve served over 52,000 homes since founding in 2013, every one with a written price before work began and a documented photo record when we left. In Littleton specifically, our reputation rests on what we can show homeowners, not what we claim. The photo record from every duct run, delivered as a standard job document, lets customers verify that their system was actually opened, inspected, and sealed rather than merely vacuumed at the register.
Our response time to Littleton addresses averages same-week scheduling, with dispatch coordinated from our Denver office. Technicians are background-checked, uniformed, and identified by name before arrival under Haven Standard Clause 3: Verified Crews. Tomas Reyes, who leads CleanRun, established the H.A.V.E.N. Standard in 2013 to replace the industry’s coupon-driven chaos with documented accountability. Every Littleton job carries the 365-Day Done Right Promise in writing, not as a policy subject to manager approval.
Littleton customers specifically value our Free Second Opinion on any written estimate. Bring a competitor’s quote; we put our number next to it in writing. No call-for-pricing games. Haven Standard Clause 1 requires a written price before any panel comes off.
Our Duct Repair & Sealing Services in Littleton

Duct Sealing with Mastic Sealant
Mastic sealant is the proper repair for leaking plenum joints, boot connections, and seams in both metal and flex-duct systems. In Littleton’s historic ranch homes, we routinely find the original fiberglass-lined sheet-metal supply trunks have separated at the longitudinal seam, blowing conditioned air into crawl spaces or wall cavities. A typical mastic sealing job in Littleton runs $280-$450 for a single system. We apply Abatement Technologies professional-grade mastic, then pressure-test to confirm seal integrity. The homeowner receives before-and-after photos of every joint.

Flex Duct Repair
Flex duct repair addresses the sagging, punctured, and disconnected runs we find in Highlands Ranch homes built 1990-2005. The outer mylar jacket degrades in Colorado’s intense UV exposure through attic vents, and the inner wire helix kinks at tight turns installed by builders working fast. In an 80126 Highlands Ranch cul-de-sac off Quebec Street, our tech ran a camera inspection on a 1999 tract home’s flex duct and found the supply run to the master bedroom punctured by a roofing nail, sagging between joists, and disconnected at the boot. We reconnected the run, sealed the boot and plenum joints with mastic sealant, then confirmed with a blower motor amp-draw reading that the air handler was no longer fighting a leaking duct. The homeowner noticed the bedroom finally heated evenly within a day. Flex duct repair in Littleton typically runs $180-$340 per run, with full system replacement when multiple runs have failed.

Metal Duct Repair
Metal duct repair in Littleton means working with galvanized steel or fiberglass-lined sheet metal from the 1950s-1970s. The lining sheds into the airstream once the adhesive fails, and the metal itself can corrode at low points where condensation collects. We patch or replace sections using professional-grade materials, then seal with mastic. Metal duct restoration runs $450-$890 depending on linear feet and access difficulty. These jobs take longer than flex duct work because the original materials are heavier and often buried in finished spaces.

Duct Insulation
Duct insulation in Littleton addresses a specific Front Range problem: attic ducts that lose conditioned air to spaces that see temperature swings from below freezing to 120°F between January and July. We install foil-faced fiberglass insulation on repaired runs, sealed at all seams, to maintain the temperature the air handler worked to create. Insulation add-on to a repair job typically runs $120-$280.

Air Leak Repair
Air leak repair targets the return side of the system, where negative pressure pulls unconditioned attic air, dust, and wildfire smoke into the ductwork. Littleton sits at roughly 5,360 feet on the semi-arid Front Range, where low humidity and frequent Chinook wind events off the nearby Rocky Mountain foothills push fine particulate dust through home envelopes continuously. The metro’s increasingly severe wildfire smoke seasons also infiltrate HVAC systems. Once smoke odor is pulled into ductwork, it recirculates until the system is cleaned and the leaks are sealed. Return leak repair in Littleton runs $220-$380.

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.
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You approve before work beginsNothing starts until you say go.
Before
AfterTrusted Brands We Service in Littleton
CleanRun stocks parts and uses equipment from Nikro, Honeywell, and Aprilaire on Littleton jobs. Nikro negative-pressure extraction equipment handles the debris removal before sealing begins. Honeywell and Aprilaire air quality components integrate with sealed duct systems to maintain what the repair achieved. We don’t claim performance beyond manufacturer specifications. What we do promise is that the equipment on your job is professional-grade, name-brand, and documented in your job record. Parts availability from our Denver office means most Littleton repairs complete in one visit without waiting on shipped materials.
Common Duct Repair & Sealing Problems We See in Littleton Homes

- Original fiberglass-lined metal ducts shedding lining. In historic Littleton ranches near Downtown Littleton and along South Broadway, the 1950s-1970s sheet-metal supply and return ducts have gone brittle. The fiberglass lining separates from the metal shell and enters the airstream as visible particulate. Homeowners describe “dust that never stops” even after cleaning. The fix is metal duct repair or replacement, followed by mastic sealing of all new joints.
- Builder-grade flex duct sagging and puncturing in Highlands Ranch. Highlands Ranch cul-de-sacs in zip codes 80126 and 80130 were built so fast that identical builder-grade flex-duct layouts were installed by the same crews in the same year. When we open one attic and find a sagging, punctured run packed with debris, we can predict the exact same failure at the same age in nearly every neighboring home. The fix is flex duct repair or replacement, with proper support straps to prevent future sagging.
- Wildfire smoke odor trapped in unsealed returns. Front Range wildfire smoke seasons push fine particulate past home envelopes. Without sealed ducts, that smoke is drawn into the return, recirculated, and trapped in the lint pathway. The fix is air leak repair on the return side, followed by system cleaning to remove residual odor.
- Disconnected boots and plenum joints from thermal cycling. Colorado’s extreme temperature swings, from well below freezing to triple-digit summer days, cause duct materials to expand and contract. Mastic sealant cracks, screws back out, and flex duct pulls off boots. The fix is reconnection and fresh mastic sealing, with photos to confirm the repair.
Pricing for Duct Repair & Sealing in Littleton, CO
| Service | Typical Range in Littleton |
|---|---|
| Mastic sealant sealing (single system) | $280-$450 |
| Flex duct repair (per run) | $180-$340 |
| Metal duct repair / restoration | $450-$890 |
| Air leak repair (return side) | $220-$380 |
| Duct insulation add-on | $120-$280 |
| Full system assessment with written scope | Free |
What moves a job within these ranges? Access difficulty is the main variable. A flex duct run in an open Highlands Ranch attic takes less time than the same repair in a historic Littleton ranch with a low crawl space. The extent of contamination matters too. A run packed with debris requires more extraction time before sealing can begin. Multiple disconnected joints add labor. Every job gets a written price before work starts, under Haven Standard Clause 1. No per-vent pricing, no teaser coupons, no invoice inflation once the van is on your drive. Call (720) 315-7291 for an exact quote. Estimates are free.
We Also Serve Cities Near Littleton

Our crews work Littleton addresses daily and also serve Englewood, Parker, Denver, and Aurora. Scheduling is coordinated from our Denver office, with routing optimized to reach all metro locations efficiently. The same H.A.V.E.N. Standard, written pricing, and documented photo record apply regardless of address.
Serving Littleton, CO - Our Local Coverage Area
We’re based in the Littleton 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 Littleton

You likely need both, but sealing is the fix that lasts. A 1998 Highlands Ranch home has flex duct that is now 27 years old, past the typical 20-25 year service life for builder-grade materials. Cleaning removes accumulated debris but does nothing for the sagging, punctured, or disconnected runs that are pulling attic air into your system. Our camera inspection shows exactly which runs have failed structurally. Call (720) 315-7291 for a free assessment with written scope.
They can often be repaired if the metal shell is intact. We see this exact scenario in historic Littleton ranches near Downtown Littleton. The fiberglass lining has usually degraded, but the galvanized steel itself often remains sound. We remove the failed lining, repair or replace sections as needed, and seal with mastic. Replacement becomes necessary only when corrosion has perforated the metal or access makes repair impractical. The written scope we provide before work starts specifies which approach applies to your system.
Check for rooms that never reach the thermostat setting, dust accumulation at registers that returns quickly after cleaning, or higher-than-expected energy bills with no equipment change. In Littleton specifically, wildfire smoke odor that persists indoors after outdoor air clears is a strong indicator of return-side leaks pulling contaminated air into the system. These are clues, not confirmations. Our camera inspection and pressure testing provide the documentation. Call (720) 315-7291 to schedule.
Yes. Littleton’s elevation and Front Range location expose homes to increasingly severe wildfire smoke events. Unsealed return ducts operate under negative pressure, actively pulling outdoor air through every gap in the building envelope. Once smoke particulate enters the ductwork, it recirculates until physically removed and the leak points are sealed. Sealed ducts don’t make your home smoke-proof, but they eliminate the active suction path that makes unsealed systems far worse. The 365-Day Done Right Promise covers our sealing work if smoke infiltration persists from the same leak points.
We start with a camera inspection of every accessible run, documented with photos you receive. The written scope specifies what we found, what we’ll do, and the exact price. After your approval, we extract debris with Nikro negative-pressure equipment, repair or replace failed materials, seal all joints with mastic, and test to confirm the system operates within manufacturer specifications. You receive before-and-after photos of every duct run as a standard job document. The entire process is governed by the H.A.V.E.N. Standard and backed by the 365-Day Done Right Promise in writing.
Ready to see what’s actually inside your ductwork? Call (720) 315-7291 for a free estimate with written scope. CleanRun Air Duct Cleaning Littleton serves all Littleton addresses, from historic downtown to Highlands Ranch, with background-checked technicians, professional-grade equipment, and the documentation to prove the work was done right.
Written by Tomas Reyes, Owner at CleanRun Air Duct Cleaning Littleton, serving Littleton since 2013.




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