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 South Riding
Most South Riding Dryer Vent Cleaning and duct repair calls we take follow the same pattern: a homeowner notices weak airflow upstairs, or dust that returns hours after cleaning, or a utility bill that climbed without explanation. The cause is rarely a single dramatic break. It’s fifteen to twenty years of slow degradation in flex duct runs that were never designed to last forever. In South Riding, where production builders finished entire neighborhoods between 1997 and 2008, that degradation is hitting all at once.
We’re local to Loudoun County, dispatching from our Washington, DC office, and we keep crews routed through South Riding regularly. Call (571) 487-7204 for a free written estimate. We’ll photograph the inside of your ductwork before we quote a dollar, so you see what we see.
Why CleanRun Air Duct Cleaning Leesburg Is South Riding’s Preferred Duct Repair & Sealing Company
We’ve worked in South Riding since the first wave of homes passed the ten-year mark and original ductwork started showing its age. Our Duct Repair & Sealing in South Riding reputation is built on documentation, not promises. Every customer receives a written price before work begins, under Haven Standard Clause 1, and a photo record of every duct run before and after.
Tomas Reyes established CleanRun in 2013. Since then we’ve served more than 52,000 homes, every one with the same protocol: written price first, documented photo record last. Our 365-Day Done Right Promise is backed in writing on every job, not just stated in marketing copy.
Technicians serving South Riding are background-checked and uniformed, operating under Haven Standard Clause 3: Verified Crews. We publish our license number and equipment roster so homeowners can verify credentials before they book. Calls are answered by a live person, 24/7.
Our Duct Repair & Sealing Services in South Riding

Flex Duct Repair
This is the service we perform most often in South Riding. The flex duct installed by NV Homes, Pulte, and Ryan Homes in the 2000s used fiberglass interior liners that begin to crumble at connection joints near the air handler right around year twenty. We pulled up to a colonial in the South Riding community off Riding Center Drive where the homeowner’s second-floor registers were barely moving air. Camera inspection showed the flex run at the air handler had a collapsed, liner-shredded elbow, so we isolated the supply and return ducts under negative pressure with HEPA filtration, cut out the failed section, and rebuilt it with new flex and mastic-sealed collars. Post-job static pressure dropped and the upstairs registers finally delivered balanced airflow. Typical flex duct repair in South Riding runs $340-$780 depending on how many runs are affected and whether the plenum needs resealing.

Duct Sealing
Unsealed joints and degraded tape at plenum connections leak conditioned air into attics, crawl spaces, and wall chases. In South Riding’s humid climate, those leaks also pull in unconditioned, moisture-laden air that raises indoor relative humidity and feeds microbial growth. Our Duct Repair & Sealing crews seal every accessible joint with mastic sealant, not duct tape, and pressure-test the system to verify results. Whole-system sealing for a typical South Riding colonial runs $580-$1,200.

Metal Duct Repair
Some South Riding homes, particularly earlier builds near South Riding Boulevard, used galvanized metal trunk lines with flex branch takeoffs. Metal ducts don’t crumble like flex liner, but they corrode at seams and can separate at transitions. We patch corroded sections, rebuild separated transitions, and seal with mastic rated for metal-to-flex connections. Metal duct repair in South Riding typically falls between $420-$960.

Duct Insulation & Mastic Sealant
Crawl-space homes in South Riding, common in neighborhoods east of Route 50, lose R-value when fiberglass duct insulation compresses or gets damp. We replace degraded insulation with new wrap and seal the vapor barrier with mastic. This matters especially in Loudoun County’s humid summers, where ground moisture wicks into returns running below floor level. Insulation replacement with sealing runs $280-$640 per affected run.

What happens when you call
- 1
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.
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AfterTrusted Brands We Service in South Riding
Our equipment roster includes Rotobrush agitation systems, Nikro HEPA-negative-pressure extractors, and Honeywell and Aprilaire filtration components. We stock common flex duct diameters, mastic sealant, and collar fittings locally so South Riding jobs don’t wait on parts. If your system uses proprietary components, we’ll identify the manufacturer during the initial camera inspection and source accordingly. Every tool and material is named in your written scope before work begins.
Common Duct Repair & Sealing Problems We See in South Riding Homes

- Crumbling fiberglass liner at flex-duct joints. The signature failure mode of South Riding’s 2000s-era production housing. The interior liner delaminates and sheds particles into airflow, while the collapsing flex chokes supply to second-floor registers. We find this in roughly two-thirds of South Riding homes built between 2000 and 2006.
- Crawl-space returns wicking ground moisture. Homes on crawl-space foundations, concentrated in neighborhoods near South Riding Golf Club, pull humid air through compromised return seams. The damp interior liner becomes a substrate for microbial growth, especially during July and August when Loudoun County humidity peaks.
- Disconnected or crushed flex runs in chases. Production builders sometimes routed flex through tight framing chases where sagging or compression went unnoticed for years. These hidden disconnections silently rob airflow and can pull attic or crawl-space air directly into the supply stream.
- Failed builder-grade tape at plenum connections. The foil tape used at air-handler transitions dries and releases after fifteen to twenty years. Gaps as small as a quarter-inch leak hundreds of cubic feet of conditioned air monthly, and in South Riding’s climate, that leakage carries humidity and pollen into the system.
Pricing for Duct Repair & Sealing in South Riding, VA
We publish ranges because Haven Standard Clause 1 requires a written price before any work starts. Here is what duct repair and sealing costs in South Riding’s market:
| Service | Typical Range in South Riding |
|---|---|
| Single flex duct run repair/replacement | $340 - $780 |
| Whole-system duct sealing with mastic | $580 - $1,200 |
| Metal duct patch and transition rebuild | $420 - $960 |
| Duct insulation replacement per run | $280 - $640 |
| Air leak detection and spot sealing | $180 - $420 |
Final price depends on accessible duct length, number of affected runs, and whether the air handler must be disturbed to reach failed sections. Every estimate includes the camera inspection, the written scope, and the documented photo record. No per-vent pricing. No coupon bait. Call (571) 487-7204 for your exact number.
We Also Serve Cities Near South Riding

Our crews route through Loudoun County daily, serving South Riding alongside Leesburg, Ashburn, Sterling, and Herndon. The same written-price protocol, same documented photo record, same 365-Day Done Right Promise applies in every zip code we touch.
Serving South Riding, VA - Our Local Coverage Area
We’re based in the South Riding 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 South Riding

Check for weak airflow at second-floor registers, dust accumulation on vent grilles that returns within days of cleaning, or a musty odor when the system cycles. These symptoms point to crumbling fiberglass liner, the dominant failure mode in South Riding’s 2000-era production builds. A camera inspection confirms it without guesswork. Call (571) 487-7204 to schedule; estimates are free.
Crawl-space returns sit below grade where ground moisture concentrates, especially in Loudoun County’s humid summers. The damp environment degrades flex duct insulation and interior liner faster than slab-on-grade systems, and leaks in crawl-space returns pull that moist air directly into the air handler. South Riding’s clay-heavy soils hold moisture longer than free-draining substrates, compounding the issue in crawl-space neighborhoods. Sealing and insulating these returns is usually the fix, not just cleaning.
We start with a camera inspection of every accessible run, delivered to you as a documented photo record. If we find collapsed or liner-shredded flex, we cut out the failed section and rebuild with new material, mastic-sealed at every joint. If the duct is intact but leaking at connections, we seal with mastic and pressure-test. The written scope you approve beforehand states exactly which runs are being repaired versus sealed. No surprises after the truck arrives.
Yes. Cleaning removes accumulated debris but does not stop unconditioned, humid air from entering through leaks. In South Riding, where summer relative humidity regularly sustains microbial colonies inside ductwork, sealing is what keeps the system clean after the brushes leave. We recommend sealing at the same visit as cleaning when camera inspection shows joint gaps or tape failure. The combined service runs $780-$1,680 for a typical South Riding home.
CleanRun follows NADCA ACR, the Assessment, Cleaning, and Restoration standard, on every job. That means negative-pressure containment during any disturbance of duct liner, HEPA filtration on the work zone, and post-job verification that the system operates within design static pressure. Our documented photo record serves as the visual compliance documentation. If your home has failing flex duct, NADCA guidelines recommend repair or replacement before agitation cleaning to prevent further liner damage. We quote both steps in writing if needed.
Written by Tomas Reyes, Owner at CleanRun Duct Repair & Cleaning, serving South Riding since 2013.




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