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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AfterFast, Reliable Duct Repair & Sealing Across McLean
Duct repair and sealing in McLean typically runs $450-$1,800 per HVAC system depending on whether we’re sealing new flex-duct junctions in a custom estate or replacing corroded galvanized trunk lines in a 1960s ranch. Most McLean homes need a site assessment before any written price can be delivered, because the same street can contain both. Our Duct Repair & Sealing crews coordinate dispatch from our Washington, DC office and carry Rotobrush inspection cameras, mastic sealant, and metal fabrication tools on every truck serving McLean. Call (571) 520-6317 and we’ll put a written price in your hand before a single panel comes off.
Why CleanRun Air Duct Cleaning Herndon Is McLean’s Preferred Duct Repair & Sealing Company
We’ve worked in McLean since 2013, and the photo records from those jobs tell the story better than any marketing claim. One day we’re sealing ductwork in a 9,000 sq ft custom home with three-plus HVAC zones in Langley Oaks. The next, we’re repairing 50-year-old galvanized trunk lines in an unrenovated ranch two doors down in Chain Bridge Forest. That range makes template pricing dishonest and site assessment non-negotiable. We don’t quote over the phone for McLean duct repair. We send a technician with a camera.
Our McLean customers receive the same deliverables as every CleanRun job: a written price before work starts, under Haven Standard Clause 1; a Documented Photo Record of every duct run before and after; and the 365-Day Done Right Promise backed in writing. Our crews are background-checked, uniformed, and identified by name before arrival, per Haven Standard Clause 3: Verified Crews. Tomas Reyes, who leads CleanRun, reviews every McLean job file personally to confirm the photo record matches the written scope.
All calls route to a live person, 24/7. No automated queue. If you bring a competitor’s written estimate, we’ll deliver a free second opinion with our number beside it.
Our Duct Repair & Sealing Services in McLean
Duct Sealing
In McLean’s new construction estates, we seal hundreds of linear feet of ductwork before occupancy. The typical McLean replacement home produces drywall dust, insulation fibers, and sawdust that infiltrate poorly sealed junctions. We apply mastic sealant (a thick, fiber-reinforced paste that remains flexible after curing) and metal collars at every connection, then pressure-test the system to confirm leakage stays below 5%. For older homes near Dolley Madison Boulevard, we often find original tape and caulking has dried and failed, pulling attic air into the supply stream. Sealing those leaks usually drops energy bills measurably. A full duct sealing job in McLean runs $450-$950 per system for accessible trunk-and-branch layouts.
Flex Duct Repair
Flex duct, the ribbed plastic tubing common in McLean additions and retrofits, crushes easily and degrades in the DC metro’s humidity. We were called to a newly built 8,500 sq ft home in Langley Oaks where the homeowner complained of dust on every surface despite a new system. Our crew performed a camera inspection and found that the flex duct runs to the third-floor master suite had been crushed against a joist during construction, causing leaks that pulled attic insulation fibers into the supply airstream. We used mastic sealant and metal collars to repair six junctions, then verified with a pressure test that leakage dropped below 5%. Flex duct repair in McLean typically costs $280-$650 per run depending on accessibility and whether replacement sections are needed.
Metal Duct Repair
Original McLean colonials and split-levels from the 1960s-1980s often carry galvanized steel trunk lines that corrode at seams and joints. The metal fatigues, the original sealant fails, and the seams whistle. We fabricate replacement sections on-site, seal with mastic, and reinforce with metal drive straps. In homes near Chain Bridge Road, we’ve found trunk lines so deteriorated that partial replacement was the only honest option. Metal duct repair in McLean runs $600-$1,800 per system when trunk line replacement is involved, or $180-$400 for isolated seam sealing and reinforcement.
Duct Insulation
Unconditioned attic and crawl space runs in McLean lose efficiency through conduction, especially in summer when attic temperatures exceed 140°F. We install foil-faced fiberglass insulation or closed-cell foam sleeves on exposed metal and flex duct, sealed at seams with matching tape. Proper insulation reduces the load on multi-zone systems common in McLean’s larger homes, where three air handlers already draw significant power. Duct insulation in McLean typically adds $300-$700 per system to a sealing job.
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.
BeforeAfterTrusted Brands We Service in McLean
Our trucks carry professional-grade equipment from Rotobrush, Nikro, Honeywell, and Guardsman, brands any McLean homeowner can verify independently. We stock mastic sealant, metal fabrication supplies, and flex-duct replacement coils sized for the large multi-zone systems common in McLean’s new construction. That inventory means most repairs finish in one visit. We don’t return days later for parts.
Common Duct Repair & Sealing Problems We See in McLean Homes
- Post-construction debris in new flex duct. McLean’s teardown-and-rebuild cycle fills brand-new ductwork with drywall dust, sawdust, and insulation fibers. These particles clog flex duct and return-air layouts, forcing leaks at poorly sealed joints that standard cleaning won’t fix. We camera-inspect every new system before occupancy.
- Liner delamination in aging flex duct. Original 1960s-1980s colonials with early-generation flex duct develop liner separation and microbial growth from DC’s humid summers, where relative humidity regularly exceeds 70% from June through August. Cleaning won’t reattach a failed liner; section replacement and sealing is the honest repair.
- Disconnected runs in multi-zone systems. Large McLean homes with three or more air handlers often have crushed or disconnected duct runs hidden behind finished walls. The homeowner feels “some rooms don’t cool,” but the cause is invisible without camera inspection. Sealing alone won’t restore airflow to a disconnected run.
- Failed original seals on galvanized trunk lines. Fifty-year-old metal duct in unrenovated McLean ranches carries dried tape, cracked caulking, and corroded seams. The leaks pull attic air, dust, and pollen from McLean’s dense tree canopy directly into the supply stream. Mastic sealant and metal collar reinforcement are the standard repair.
Pricing for Duct Repair & Sealing in McLean, VA
McLean’s housing stock demands per-system pricing, not per-vent gimmicks. A single 9,000 sq ft home with three HVAC zones and hundreds of linear feet of ductwork bears no resemblance to a 2,200 sq ft ranch with one system. We assess on site, then deliver a written price before any work starts.
| Service | Typical Range in McLean |
|---|---|
| Duct sealing, accessible trunk-and-branch | $450-$950 per system |
| Flex duct repair (per run) | $280-$650 |
| Metal duct repair, seam sealing and reinforcement | $180-$400 |
| Metal trunk line partial replacement | $600-$1,800 per system |
| Duct insulation added to sealing job | $300-$700 per system |
What moves a job toward the higher end: finished-wall access requiring careful remediation, multiple HVAC zones with independent duct networks, and post-construction repair where debris must be extracted before sealing. What keeps costs down: accessible basement or attic runs, single-zone systems, and straightforward resealing of original junctions. Every estimate is free. Every price is written. Call (571) 520-6317.
We Also Serve Cities Near McLean
Our crews work throughout Fairfax and Loudoun counties. We regularly perform Duct Repair & Sealing in McLean and also serve Herndon, Sterling, Reston, and Ashburn with the same written-price, photo-documented standard. Dispatch and scheduling are coordinated from our Washington, DC office.
Serving McLean, VA - Our Local Coverage Area
We’re based in the McLean 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 McLean
Each zone operates as an independent duct network with its own air handler, plenum (the distribution box where conditioned air splits to each run), and return-air path. Sealing one zone leaves leaks in the others, and the total linear footage in a large McLean estate can exceed 400 feet. We price per system, inspect each zone separately with a Rotobrush camera, and deliver a written scope for every network. Call (571) 520-6317 to schedule assessment of all zones.
We pressurize the duct system and use a calibrated fan to measure total leakage, then run a Nikro inspection camera through every run to locate specific failure points. In McLean’s new construction, we most often find crushed flex duct at joist crossings and unsealed junctions where subcontractors connected lines before drywall went up. The camera shows the damage; the pressure test quantifies it. Both go in your photo record.
We remove failed original tape and caulking, clean corroded seams to bare metal, apply mastic sealant reinforced with fabric mesh, and secure with metal drive straps or collars. In severe cases near Dolley Madison Boulevard and Chain Bridge Forest, we’ve found trunk lines with pinhole corrosion that require section replacement. We fabricate replacements on-site, seal all connections, and pressure-test before closing. The photo record shows every seam.
Yes, if the smell originates from microbial growth on duct liner surfaces where humid attic air enters through leaks. McLean’s mature tree canopy and the DC metro’s 70%+ summer humidity create ideal conditions for this. Sealing the leaks stops the moisture source. If liner delamination or heavy contamination is present, we recommend repair or section replacement rather than sealing alone. Camera inspection determines which approach is honest.
Every CleanRun job concludes with a Documented Photo Record: before-and-after images from inside every duct run, delivered as a standard job record. We also pressure-test sealed systems to verify leakage below 5%. The 365-Day Done Right Promise means if the work isn’t right, we make it right, backed in writing, not subject to manager approval. Haven Standard Clause 1 requires the written price before work starts; the photo record and pressure test verify the work matched that scope. Call (571) 520-6317 for a free estimate.
Written by Tomas Reyes, Owner at CleanRun Air Duct Cleaning Herndon, serving McLean since 2013.