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.
Trusted Duct Repair & Sealing for Ashburn Homeowners
Our Duct Repair & Sealing in Ashburn typically addresses hidden leaks and disconnected runs that waste 20-30% of conditioned air before it reaches your rooms. Most Ashburn homes built between 2015 and 2025 in communities like One Loudoun, Brambleton, and Ashburn Village show measurable duct leakage within their first decade, especially where flex duct meets metal plenum connections. We’ve documented this pattern across 52,000+ homes since 2013, and every repair we perform in Ashburn starts with a written price delivered before any panel comes off. Call (240) 771-1508 for a free estimate with no obligation to proceed.
Ashburn’s clay-heavy soils and seasonal freeze-thaw cycles put unique stress on HVAC infrastructure. Homes near the home base of our operations in Loudoun County frequently develop duct separation in crawl spaces and attics where temperature swings exceed 40 degrees between seasons. Our crews photograph every duct run before and after repair, so you see exactly what was found and what was fixed. The 365-Day Done Right Promise applies to every job in writing, not as a verbal courtesy.
What Our Duct Repair & Sealing Service Includes
Duct Sealing
Duct sealing closes the gaps, cracks, and disconnected joints that allow conditioned air to escape into your attic, crawl space, or wall cavities. In Ashburn, we regularly find that new construction homes in neighborhoods like Loudoun Valley Estates were never properly sealed at the plenum connections during original build-out, leaving homeowners with high utility bills and rooms that never reach set temperature. Our crews use professional-grade mastic sealant and metal-backed tape rated for HVAC applications, not the hardware-store foil tape that peels within two seasons. Every sealed joint is photographed and included in your documented photo record.

Flex Duct Repair
Flex duct, the insulated flexible tubing common in residential construction, collapses, tears, or disconnects at its collar connections over time. Ashburn’s humid summers and occasional rodent pressure in wooded lots near Bles Park or the W&OD Trail contribute to flex duct degradation that restricts airflow to second-floor bedrooms. We replace damaged flex duct with new R-6 or R-8 insulated runs sized to your system’s CFM requirements, secured with mechanical fasteners and sealed with mastic. The old run is photographed in place before removal, and the new installation is documented after completion.

Metal Duct Repair
Metal ductwork, found in older Ashburn homes and commercial conversions, develops corrosion at seams, punctures from previous contractor work, or noise-inducing vibrations where supports have failed. We repair galvanized steel and aluminum duct with proper sheet metal patches, drive cleats, and sealed joints that restore structural integrity without the airflow restriction of tape-only repairs. Our crews carry sheet metal fabrication tools on every truck, so most metal repairs in Ashburn are completed in a single visit without waiting for fabricated parts. Haven Standard Clause 1 applies: the written price covers the full repair scope, not an hourly open-ended ticket.

Duct Insulation
Duct insulation prevents thermal loss as heated or cooled air travels through unconditioned spaces. In Ashburn, attics regularly exceed 140 degrees in July, and uninsulated or degraded duct wrap turns that metal trunk line into a radiator working against your compressor. We install new fiberglass duct wrap with vapor barrier or replace damaged insulation on existing runs, with particular attention to the plenum and first ten feet of trunk line where losses are greatest. The before-and-after thermal difference is visible in your photo record, and we note any insulation R-value upgrades that may qualify for utility rebates.

Mastic Sealant Application
Mastic sealant is a thick, fiber-reinforced compound brushed onto duct seams and joints that cures to a permanent, flexible seal superior to any tape product. We apply mastic to every accessible joint during a sealing job, including the longitudinal seams of metal duct that were never factory-sealed and the collar connections where flex duct meets plenums. In Ashburn’s climate, mastic outlasts foil tape by a factor of ten to one, and we verify seal integrity with a pressure test when the application is complete. Your written job record notes which joints received mastic and which required additional repair.

Air Leak Repair
Air leak repair targets the specific points where your duct system loses pressure to unintended spaces, identified through diagnostic testing rather than visual guesswork. We use calibrated pressure measurement to quantify leakage before work begins and verify reduction after repairs are complete, with results documented in your job record. Ashburn homeowners often discover they’ve been cooling their attic for years through a single disconnected return duct, and the repair typically pays for itself in reduced run times within two cooling seasons. The 365-Day Done Right Promise covers leak recurrence at repaired joints.

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.
Signs You Need Duct Repair & Sealing Right Now

- Uneven temperatures between rooms. If your master bedroom in Ashburn runs five degrees warmer than the hallway thermostat while the basement is frigid, restricted or leaking duct runs are the likely cause. This pattern worsens over time as leaks expand and debris accumulates at failure points.
- Dust accumulation immediately after professional cleaning. You had your ducts cleaned last season, but the registers are dirty again within weeks. That debris is entering through leaks in the return side, pulling attic insulation and particulate into the airflow stream.
- Utility bills that climb without rate increases. Dominion Energy rates in Northern Virginia have been stable, but your summer cooling costs keep rising. Duct leakage forces longer compressor run times to achieve the same indoor temperature, and the waste is measurable.
- Whistling or rushing air sounds from walls or ceilings. Air moving through a gap in ductwork creates turbulence noise that travels through framing cavities. In Ashburn’s townhome communities like The Villages at Ashburn, we’ve traced persistent noise to a single separated flex duct joint behind a bedroom wall.
- Musty odors when the system cycles on. Leaks in the return duct draw air from musty crawl spaces or attics, introducing odors that bypass your filter. Sealing the leak eliminates the source; masking it with air fresheners does not.
Before
AfterOur Duct Repair & Sealing Process - Step by Step
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System inspection and pressure diagnostics. We start with a visual assessment of accessible ductwork and a static pressure test to quantify how much air your system is losing to unintended spaces. The pressure reading is recorded and explained before any repair discussion begins.
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Written scope and price delivered. Haven Standard Clause 1 requires a written price before work starts, every time. Your scope lists each duct run to be sealed or repaired, the materials to be used, and the total cost. No per-vent add-ons, no surprise charges when the crew is already in your attic.
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Photo documentation of existing conditions. Before touching any duct, we photograph the inside of every accessible run with a borescope camera. These images show debris load, corrosion, disconnected joints, and insulation condition. You receive these as part of your documented photo record.
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Repair and sealing execution. Our crews perform the scoped work using professional-grade equipment from Abatement Technologies and Guardsman, with mastic application, mechanical fastening, and insulation replacement as specified. Technicians are background-checked, uniformed, and identified by name before arrival under Haven Standard Clause 3: Verified Crews.
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Post-repair verification and photo record delivery. We re-test system pressure to confirm leakage reduction, photograph completed work, and deliver your full job record: before images, after images, pressure readings, written scope, and the 365-Day Done Right Promise. All calls are answered by a live person, 24/7, if questions arise after we leave.
How Much Does Duct Repair & Sealing Cost in Ashburn?

See how much Duct Repair & Sealing costs: a typical single-system Ashburn home runs $850-$1,400 depending on accessible duct length, number of plenum connections, and whether the attic or crawl space requires safety preparation. Flex duct replacement for a single damaged run ranges $280-$450, while metal duct repair with patch fabrication typically falls between $320-$580. Full-system duct sealing in larger Ashburn homes with multiple zones or complex attic layouts can reach $1,800-$2,400, still delivered as one flat price per system agreed before work starts.
Several factors move the price within these ranges. Attic accessibility matters: truss-framed attics with limited clearance take longer to navigate safely than open crawl spaces. The extent of existing damage affects material needs; a home with original builder-grade foil tape failure throughout requires more labor than one with a single disconnected joint. System age and configuration play a role, as older units may need adapter fittings to connect new duct properly.
What you should not pay for: per-vent pricing that balloons as the crew “discovers” additional problems, or teaser rates that exclude the actual sealing work. CleanRun’s written price covers the complete scope. We also offer a Free Second Opinion on any written estimate from another contractor; bring their quote and we’ll put our number next to it in writing.
Every estimate in Ashburn is free and includes the diagnostic pressure test. Call (240) 771-1508 to schedule.
Duct Repair & Sealing Near Ashburn - Our Service Area
CleanRun crews work daily across Loudoun and Fairfax counties, with Duct Repair & Sealing in Ashburn as our central service hub. We regularly reach Duct Repair & Sealing in Sterling and Duct Repair & Sealing in Herndon within standard scheduling windows, and extend to Leesburg, Reston, Chantilly, Centreville, Gaithersburg, Vienna, Germantown, Potomac, and Tysons Corner for scheduled appointments. Most Ashburn-area jobs are scheduled within a few business days, with written confirmation of arrival window provided when you book.
Serving Ashburn, VA - Our Local Coverage Area

We’re based in the Ashburn 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 Ashburn
Duct repair and sealing fixes the physical leaks, disconnections, and damage in your ductwork, while duct cleaning removes accumulated debris from intact ducts. A leaking duct system cannot be fully cleaned because the vacuum seal required for negative-pressure extraction is compromised, and cleaned ducts will immediately re-contaminate if intake leaks pull attic air through the return side. We often recommend sealing first, then cleaning, for homes with both issues.
Most residential duct sealing jobs in Ashburn are completed in four to six hours, with flex duct or metal repairs adding one to two hours per run depending on accessibility. Larger homes with multiple zones or complex attic layouts may require a full day. Your written scope includes the estimated duration before you approve the work, and we do not leave until the post-repair pressure test confirms results.
Typical single-system duct sealing in Ashburn runs $850-$1,400 as a flat price, with individual repairs like flex duct replacement at $280-$450 and metal duct repair at $320-$580. The exact figure depends on system size, accessibility, and damage extent, which is why we perform a free diagnostic and deliver a written price before any work begins. Call (240) 771-1508 for an exact quote on your home.
Yes. We regularly encounter Aprilaire whole-home ventilation systems integrated with ductwork in Ashburn homes, and our crews are trained to seal and repair around these units without compromising their designed airflow rates. We also service duct configurations paired with Rotobrush-cleaned systems and Abatement Technologies filtration equipment. Whether your system includes these brands or any other make, we can assess and repair the ductwork properly.
We do not classify duct repair as an emergency dispatch service, but we do answer calls live 24/7 and schedule urgent appointments as quickly as diagnostic and crew availability allow. A completely disconnected main trunk line in summer or winter warrants prompt attention, and we will prioritize these situations within our scheduling capacity. Call (240) 771-1508 to discuss your timeline.
Every job is backed by the 365-Day Done Right Promise in writing: if the repair fails or the seal leaks within one year, we return and make it right at no additional cost. This is a written guarantee included in your job record, not a policy subject to manager approval. Haven Standard Clause 1 and the Done Right Promise together mean the price and the accountability are both fixed before we start.
Clear a path to your attic access, crawl space entry, and utility room, and ensure pets are secured away from work areas. You do not need to move furniture or cover belongings; our crews use drop cloths and containment as needed. Have your recent utility bills available if you’d like us to correlate consumption patterns with our leakage findings, and bring any competitor’s written estimate if you want our Free Second Opinion.
Schedule Your Duct Repair & Sealing Service in Ashburn Today

Call (240) 771-1508 to book your free estimate. You’ll speak with a live person, schedule at your convenience, and receive a written price before any work begins. Every repair includes a documented photo record of every duct run and the 365-Day Done Right Promise in writing. No per-vent pricing, no surprise charges, no vacuum noise.
Written by Tomas Reyes, Owner at CleanRun Air Duct Cleaning Ashburn, serving Ashburn since 2013.




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