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.
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Before
AfterTrusted Duct Repair & Sealing for Littleton Homeowners
Duct Repair & Sealing in Littleton typically costs $280-$1,200 depending on whether you’re addressing minor register leaks or replacing collapsed flex duct runs in a crawl space. Most jobs we complete in Littleton homes take 2-5 hours, and every one starts with a written price delivered before any work begins. Call (720) 315-7291 to schedule a free estimate with a documented photo inspection of your duct system.
Since 2013, CleanRun has repaired and sealed ductwork in more than 52,000 homes, and we’ve documented every run with before-and-after photos as standard practice. In Littleton specifically, we regularly find issues that trace back to the freeze-thaw cycles of the South Platte Valley and the older flex duct installations common in homes built during the 1990s and early 2000s housing boom. The camera doesn’t lie: we’ve pulled back insulation in Ken Caryl ranch basements to find completely detached collars, and we’ve traced airflow drops in Columbine Valley homes to mastic that cracked after a decade of seasonal expansion. Our technicians are background-checked, uniformed, and identified by name before arrival under Haven Standard Clause 3: Verified Crews. The 365-Day Done Right Promise backs every repair in writing, not as a policy that requires manager approval.
What Our Duct Repair & Sealing Service Includes
Duct Sealing
Duct sealing closes the gaps, cracks, and separations in your supply and return ductwork that leak conditioned air into attics, crawl spaces, and wall cavities. In Littleton, we see this problem most often in homes with original ductwork from the 1980s and 1990s, where tape adhesives have degraded and joints have worked loose from vibration. We seal with mastic compound or metal-backed tape rated for HVAC temperatures, and we pressure-test after completion to verify the seal holds under operating conditions. Every sealed joint is photographed before and after, and those images are delivered with your job record.
Flex Duct Repair
Flex duct, the insulated flexible tubing that connects your main trunk lines to individual room registers, is prone to crushing, kinking, and tearing - especially in Littleton homes where attic temperatures swing from below freezing to above 130°F in summer. We replace damaged flex duct with new, properly sized runs that maintain the manufacturer’s rated bend radius, and we support them with straps at intervals that prevent sagging. In a 2024 job near Chatfield Reservoir, we found a 12-foot flex duct run that had been compressed to 4 inches of diameter by a storage box shoved into an attic; the camera showed a 67% airflow restriction before we replaced it. The new run was photographed, measured, and documented in the customer’s job record.
Metal Duct Repair
Metal ductwork, typically galvanized steel in older Littleton homes and aluminum in newer construction, can corrode at seams, separate at joints, or develop holes from contact with roofing nails or electrical work. We repair metal duct with slip joints and drives, seal with high-temperature mastic, and reinforce where structural integrity is compromised. When repair isn’t practical - for instance, when corrosion has perforated the plenum (the main distribution box where your furnace connects to the duct system) - we replace the section and document the new installation with photos of the weld or mechanical connection. Our crews carry sheet metal tools and stock common fittings so we’re not making return trips.
Duct Insulation
Duct insulation prevents thermal loss as heated or cooled air travels through unconditioned spaces like attics, crawl spaces, and garage chases. In Littleton’s climate, where winter design temperatures hit -10°F and summer attic temperatures exceed 140°F, uninsulated or degraded duct insulation can raise your energy bills and create condensation that breeds microbial growth. We install foil-faced fiberglass insulation at R-6 or R-8 values depending on location, sealed with vapor-barrier tape at all seams. Every insulated run is photographed to verify complete coverage, and we note the R-value in your written job record.
Mastic Sealant
Mastic is a thick, water-based sealant applied with a brush or gloved hand to duct joints, seams, and connections; it remains flexible after curing and outlasts cloth-backed tape in temperature extremes. We apply mastic to all new connections and to existing joints where tape has failed, working it into gaps with a putty knife for full penetration. In Littleton’s dry climate, mastic cures properly in 24-48 hours, and we schedule return airflow testing when the system has been fully sealed. The application is photographed at key joints so you can verify coverage without climbing into your own attic.
Air Leak Repair
Air leak repair addresses the unintended pathways that draw unconditioned air into your duct system or blow conditioned air into spaces where it’s wasted. We locate leaks using smoke pencils, pressure differential testing, and visual inspection of accessible ductwork; in Littleton homes with finished basements, we often find leaks at the rim joist (where the foundation meets the floor framing) that pull musty air into return ducts. Each identified leak is marked, repaired, and verified with a follow-up pressure test. The locations, repair methods, and test results are documented in your job record with supporting photos.
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 regularly repair and seal ductwork connected to Honeywell air cleaners and zoning systems, including their Enviracaire and F100 series units common in Littleton homes built between 2005 and 2018. Our crews understand how Honeywell zone dampers integrate with duct geometry, and we verify that repairs don’t compromise the pressure balances these systems require. We’ve also serviced hundreds of Aprilaire whole-home humidifiers and dehumidifiers, which attach directly to supply plenums; when we seal or replace ductwork near these units, we check that the drain lines remain properly pitched and the bypass dampers operate freely.
Nikro equipment is part of our standard inventory for negative-pressure extraction and duct access, and we use Abatement Technologies HEPA filtration on jobs where disturbed insulation or construction debris requires containment. Whether your system includes these brands or any other make - Carrier, Trane, Lennox, Rheem, or a combination installed by previous owners - we can assess, repair, and document the work. Our free second opinion applies to any written estimate you’ve received; we put our number next to it, with line-item detail, before you decide.
BeforeAfterSigns You Need Duct Repair & Sealing Right Now
- Uneven temperatures room to room. If your master bedroom in Columbine runs five degrees warmer than your kitchen in January, the likely cause is a disconnected or leaking supply duct, not a failing furnace. We see this pattern frequently in Littleton’s 1990s-era homes where flex duct has pulled loose from boots (the angled fittings that connect duct to floor or ceiling registers).
- Dust accumulation immediately after cleaning. A home that coats surfaces with dust within days of vacuuming often has return duct leaks pulling air from attics, crawl spaces, or wall cavities. In Littleton’s windy conditions, these leaks act like vacuum hoses for insulation particles and construction debris.
- Energy bills that spike without explanation. When conditioned air leaks into unconditioned spaces, your HVAC system runs longer to hit thermostat setpoints. We’ve documented cases in Ken Caryl where duct sealing alone reduced winter gas usage by 18-23%, with before-and-after utility bills provided as part of the job record.
- Whistling or rushing air sounds from registers. These noises indicate high velocity at the register, usually caused by duct restrictions or leaks upstream that reduce available airflow. The sound is a symptom; the underlying problem is often a crushed flex run or a gap between duct sections that’s blowing air into your wall cavity.
- Musty or chemical odors when the system runs. Leaky return ducts draw air from wherever they can - moldy crawl spaces, garage areas with stored solvents, or wall cavities with rodent activity. In Littleton’s older homes near downtown, we’ve traced odors to return leaks at deteriorated basement windows that pulled in soil gas.
Our Duct Repair & Sealing Process - Step by Step
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Written estimate delivered before work begins. We inspect accessible ductwork, identify visible damage, and test system pressure if indicated. You receive a line-item written price with no obligation. Haven Standard Clause 1 requires this; we do not start work until you’ve approved the scope and price in writing.
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Documented photo record of existing conditions. Before any repair, we photograph the interior of every duct run we will access, the exterior of damaged sections, and any surrounding conditions that affect the work. These images establish baseline conditions and protect both parties.
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Repair or replacement with trade-verified methods. We use mastic rated for HVAC temperature cycling, metal-backed tape with acrylic adhesive, and mechanical fasteners appropriate to the duct material. Flex duct is supported per manufacturer specifications; metal duct is sealed at all joints. Our equipment includes Rotobrush and Nikro tools for access and extraction where needed.
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Pressure testing and airflow verification. After repairs, we verify seal integrity with a pressure test where accessible, and we confirm that register airflow matches or exceeds pre-repair measurements. In zoned systems, we verify damper operation and balance.
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Final photo documentation and written job record delivered. You receive before-and-after photos of every repaired or sealed run, a written description of work performed, the 365-Day Done Right Promise in writing, and any maintenance recommendations. This documentation is your record for warranty claims, home sale disclosures, or future service planning.
How Much Does Duct Repair & Sealing Cost in Littleton?
A typical register boot reattachment or single joint seal in Littleton runs $280-$450, so you can see how much Duct Repair & Sealing costs for smaller jobs. Replacing a crushed flex duct run of 15-25 feet, including proper support and mastic-sealed connections, typically falls between $480 and $780. Full plenum replacement or extensive metal duct repair in an attic or crawl space can range from $890 to $1,200, depending on accessibility and the extent of corrosion or damage. These are whole-system prices, not per-vent teaser rates that balloon once the truck is in your driveway.
Several factors move the price within these ranges. Attic access matters: a walk-up attic with decking costs less to work in than a crawl space requiring plywood placement. The age of existing ductwork affects whether repairs are practical or replacement is the better value; 1980s flex duct with degraded insulation is rarely worth patching. Zoning systems and integrated air cleaners add complexity to disconnection and reconnection. We factor all of this into the written price we deliver before work starts, and we explain each line item so you can compare it to any other estimate you’ve received.
To avoid overpaying, get the scope in writing. A legitimate duct repair estimate specifies which runs will be accessed, what materials will be used, and what verification testing is included. Be cautious of quotes that list only a single price with no breakdown, or that quote a low “per vent” rate without defining what constitutes a vent. Our free second opinion service exists for exactly this situation: bring us any written estimate, and we’ll put our line-item price next to it at no charge. Every estimate from CleanRun Air Duct Cleaning Littleton includes the documented photo record as standard; it’s not an upsell.
Duct Repair & Sealing Near Littleton - Our Service Area
We repair and seal ductwork throughout the Littleton metro, including Duct Repair & Sealing in Englewood, Duct Repair & Sealing in Highlands Ranch, and homes in Cherry Hills Village, Greenwood Village, Centennial, Lakewood, Wheat Ridge, Denver, Parker, Golden, and Arvada. Response scheduling is typically 2-4 business days for non-urgent repairs; we do not claim same-day dispatch because duct repair requires proper diagnosis and material preparation, and rushing either costs you money. For homes in the foothills west of Littleton or in older neighborhoods with limited attic access, we schedule a preliminary inspection to confirm we can bring the right equipment and crew for the job.
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.
Frequently Asked Questions - Duct Repair & Sealing in Littleton
Duct repair and sealing fixes the physical damage and air leaks in your home’s forced-air distribution system, including disconnected joints, crushed flex duct, corroded metal sections, and failed insulation. The goal is to restore the system’s designed airflow and prevent conditioned air from leaking into spaces where it’s wasted. CleanRun delivers a written scope and price before starting, then documents every repair with before-and-after photos included in your job record.
Most residential duct repairs in Littleton take 2-5 hours from arrival to final testing, depending on the number of runs affected and attic or crawl space accessibility. A single register boot repair might take 90 minutes; replacing multiple flex duct runs in a finished basement could extend to a full day. We provide a time estimate with our written price so you can plan accordingly.
Minor sealing work runs $280-$450, flex duct replacement typically $480-$780, and extensive metal duct or plenum repair $890-$1,200. The final price depends on accessibility, materials needed, and whether integrated components like zone dampers or humidifiers require disconnection. Call (720) 315-7291 for a free, written estimate with line-item detail - no obligation, no “call for pricing.”
Yes. We regularly repair ductwork connected to Honeywell air cleaners and zoning systems, Aprilaire humidifiers and dehumidifiers, and all major HVAC equipment brands. Our crews carry the tools and fittings to disconnect and reconnect these components without damaging warranty coverage, and we verify proper operation before leaving. If your system includes a brand we haven’t named, we research the specifications before arriving.
We do not advertise emergency dispatch because duct repair is rarely a same-day safety issue; the exception is a complete duct collapse that has disabled heating or cooling in extreme weather. For urgent situations, our live answering service reaches the on-call technician who can assess whether temporary measures are possible or if the situation requires an HVAC contractor for immediate equipment service. We schedule proper repairs as soon as materials and crew availability allow.
Every repair is backed by the 365-Day Done Right Promise: if the work is not right, we make it right, documented in writing on every job record. This covers materials and workmanship, including seal failure, support strap failure, or airflow problems traceable to our repair. Haven Standard Clause 5 requires this warranty in writing, not as a verbal assurance subject to manager discretion.
Clear a path to your furnace and to any attic or crawl space access points; remove stored items within 3 feet of the work area. If you have pets, secure them in a separate room during the visit. We do not need you to clean or prepare the ductwork itself - that’s our job, and we photograph conditions exactly as found. Have any previous service records or estimates available if you’d like us to address specific concerns or provide a second opinion.
Schedule Your Duct Repair & Sealing Service in Littleton Today
Call (720) 315-7291 to speak with a live person and schedule your free estimate. You’ll receive a written price before any work begins, a documented photo record of every duct run we access, and the 365-Day Done Right Promise in writing. No per-vent gimmicks, no bait-and-switch, no urgency theatre. Just documented evidence of what your ductwork needs and what it will cost to fix it right.
Written by Tomas Reyes, Owner at CleanRun Air Duct Cleaning Littleton, serving Littleton, Englewood Duct Repair & Sealing, Highlands Ranch, and surrounding communities since 2013.