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
AfterFast, Reliable Duct Repair & Sealing Across Rockville
Rockville homeowners lose conditioned air through leaky ductwork every day, and most never know it until their utility bill spikes or a room stays stubbornly cold. Duct repair and sealing in Rockville typically runs $340-$780 for a whole-system seal on a single-family home, with flex-duct replacement or metal-duct resealing quoted separately based on what the camera shows. Our crews are dispatched from our Washington, DC coordination office and carry the full Rotobrush and Nikro inventory needed for same-visit repairs in Rockville neighborhoods from Twinbrook to King Farm. Call (240) 255-4519 and we’ll put a written price in front of you before any panel comes off.
We’ve been working in Montgomery County since 2013. The housing stock here isn’t generic, and the duct problems aren’t either. Rockville’s three distinct building eras - 1950s post-war ramblers, 1960s-70s garden apartments, and 1990s-2000s planned communities - each produce failure modes we’ve documented across 52,000+ jobs. Our Duct Repair & Sealing team treats every home as its own inspection case, not a template.
Why CleanRun Air Duct Cleaning Rockville Is Rockville’s Preferred Duct Repair & Sealing Company
CleanRun is independently owned and operated under the Haven Standard, not a franchise network. Tomas Reyes has led the company since its founding, and every Rockville job is executed under the same standard: written price first, documented photo record last. Haven Standard Clause 1 requires the written price before any work starts. No exceptions. No “call for a quote.”
Our technicians are background-checked, uniformed, and identified by name before arrival - Haven Standard Clause 3: Verified Crews. The equipment roster includes Rotobrush, Nikro, Abatement Technologies, Honeywell, Aprilaire, and Guardsman. Customers can verify each brand independently. Every job concludes with a Documented Photo Record of every duct run, delivered as a standard deliverable, not an upsell.
The 365-Day Done Right Promise backs every Rockville job in writing. If the work isn’t right, we make it right. Not a policy subject to manager approval. A written guarantee.
We also offer a Free Second Opinion on any written estimate. Bring a competitor’s quote. We’ll put our number next to it, in writing, at no cost.
Our Duct Repair & Sealing Services in Rockville
Duct Sealing with Mastic Sealant
Mastic sealant is a water-based paste applied to metal duct seams and joints, reinforced with mesh tape at stress points. In Rockville’s Twinbrook neighborhood, we apply mastic to original 1950s sheet-metal trunks where thermal cycling has opened seams at elbows and wyes. The sealant cures to a flexible, durable finish that outlasts foil tape by decades. A typical mastic sealing job on a Twinbrook rambler’s supply trunk runs $280-$450, depending on linear footage and access.
Flex Duct Repair
Flex duct - the insulated flexible tubing common in 1990s-2000s construction - degrades from the inside out. In King Farm and Fallsgrove, we regularly find inner liner delamination that collapses the effective diameter and starves downstream registers. Mastic won’t fix this. We cut out the failed section and splice in new flex with mechanical collars and sealed joints. Flex duct repair in Rockville typically runs $180-$340 per run, with most homes needing two to four runs addressed.
Metal Duct Repair
Original sheet-metal ductwork in Twinbrook and West End ramblers suffers seam separation, corrosion at condensate collection points, and damage from decades of amateur modifications. We reseal seams with mastic and mesh, replace corroded sections with matching gauge metal, and restore proper slope for drainage. Metal duct repair in Rockville starts around $340 for localized work and can reach $680-$920 for extensive trunk rehabilitation.
Duct Insulation
Rockville’s humid continental climate pushes summer dew points above 65-70°F for weeks. Uninsulated or degraded duct insulation in attics and crawl spaces produces condensation that feeds mold colonization. We install foil-faced fiberglass insulation or closed-cell foam wrap, depending on access and existing conditions. Duct insulation in Rockville runs $2.80-$4.50 per linear foot, with most single-family homes falling in the $450-$780 range.
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.
Before
AfterTrusted Brands We Service in Rockville
Our equipment roster includes professional-grade tools from Nikro, Honeywell, and Aprilaire - brands customers can research independently before agreeing to any work. We stock common flex-duct diameters, mastic sealant, mechanical collars, and insulation materials on every Rockville truck, so most repairs don’t require a return visit for parts. For specialized components in older systems, our Washington, DC coordination office maintains next-day supplier relationships with regional HVAC distributors. You won’t wait a week for a collar size that should be on the shelf.
Common Duct Repair & Sealing Problems We See in Rockville Homes
- Original 1950s sheet-metal seams separating at elbows. Twinbrook ramblers were built with uninsulated galvanized trunks that expand and contract through Rockville’s hot summers and cold winters. After seventy years, the seams at 90-degree elbows and wye splits simply open up. The camera shows the gap; the blower motor shows the cost in elevated amp draw.
- Condensation and mold inside uninsulated runs. Rockville’s summer dew points stay above 65°F for weeks at a stretch. When that humid air contacts the cool surface of an uninsulated supply duct in a hot attic, water forms. It’s not a sales pitch. We’ve photographed active mold growth inside duct walls in Twinbrook homes where the homeowner had no respiratory symptoms yet - just a utility bill that kept climbing.
- Cross-contamination in garden apartment shared chases. The 1960s-70s complexes along Veirs Mill Road and Route 355 often have duct chases that serve multiple units with no documented separation. A negative-pressure leak in one unit’s return can pull air from a neighboring kitchen or bath. Standard sealing without camera inspection misses this entirely.
- Flex-duct liner collapse in King Farm and Fallsgrove. The 1990s-2000s flex systems in these planned communities looked fine from the outside while the inner liner detached and bunched at turns, reducing effective diameter by half. The register still blows, but the room never reaches temperature. The blower works harder and fails sooner.
Pricing for Duct Repair & Sealing in Rockville, MD
We publish ranges because Haven Standard Clause 1 requires a written price before any work starts, and that price has to be grounded in something real. Here’s what duct repair and sealing costs in Rockville’s current market:
| Service | Typical Range |
|---|---|
| Mastic sealant sealing (whole supply trunk) | $280-$450 |
| Flex duct repair/replacement (per run) | $180-$340 |
| Metal duct repair (localized) | $340-$520 |
| Metal duct trunk rehabilitation (extensive) | $680-$920 |
| Duct insulation (per linear foot) | $2.80-$4.50 |
| Whole-system seal + inspection (typical rambler) | $340-$780 |
What moves a job to the higher end: limited crawl space or attic access, extensive corrosion requiring section replacement, or discovery of undocumented modifications from previous owners. What keeps it at the lower end: straightforward seam sealing with good access and intact original construction. Every estimate is free, and every price is written before work begins. Call (240) 255-4519 for an exact quote on your home.
We Also Serve Cities Near Rockville
Our crews work throughout Montgomery County, with regular jobs in Rockville, Gaithersburg, Bethesda, and Silver Spring. Scheduling and dispatch are coordinated from our Washington, DC office, but the technicians serving your home are the same background-checked, uniformed crews who know the local housing stock. Same written price standard. Same Documented Photo Record. Same 365-Day Done Right Promise.
Serving Rockville, MD - Our Local Coverage Area
We’re based in the Rockville 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 Rockville
Twinbrook’s 1950s ramblers and split-levels have original sheet-metal duct systems that have rarely been professionally serviced, combined with floor-level return grilles that pull in carpet fiber, pet dander, and - in homes where carports were enclosed as garages - combustion byproducts. The density of contamination and the age of the seams produce failure modes that simply don’t exist in King Farm’s 1990s flex-duct construction. We document this on every Twinbrook job with before-and-after photography of the duct interior. Call (240) 255-4519 for a free inspection and written estimate.
We start with a camera inspection to map the actual duct routing, which is often undocumented in 1960s-70s buildings along Veirs Mill Road and Route 355. Standard sealing without this step can pressurize leaks into neighboring units or pull return air from shared chases. Once we know where the ducts actually go, we seal at accessible points and recommend building-wide assessment if cross-contamination is confirmed. The written scope specifies exactly what we can address within your unit and what requires property-management coordination. Call (240) 255-4519 to schedule.
Metal duct repair addresses seam separation, corrosion, and joint failure with mastic sealant, mesh tape, and section replacement - the materials and techniques are standardized and durable. Flex duct repair addresses inner liner delamination and joint separation, which requires cutting out the failed section and splicing in new material with mechanical collars. Mastic alone won’t fix flex-duct liner collapse. The camera tells us which problem you have before we quote. Call (240) 255-4519 for a free camera inspection.
It’s real. Rockville’s summer dew points exceed 65°F for sustained periods, and when that humid air contacts the cool interior surface of an uninsulated supply duct in a hot attic or crawl space, condensation forms. We’ve photographed active mold growth in duct walls where the homeowner had no idea - only a utility bill that kept rising and a room that never cooled properly. The fix is proper insulation and sealing, not chemical fogging. Call (240) 255-4519 for a camera inspection that shows you what’s actually inside your ducts.
We coordinate access in advance, carry portable equipment that fits through standard doorways and elevators, and schedule during building-permitted hours. For garden apartments along Route 355 and Veirs Mill Road, we’ve developed protocols for loading dock access, stairwell protection, and unit-to-unit notification when shared chases are involved. The written scope includes the access plan so there’s no surprise on either side. Call (240) 255-4519 and we’ll walk through your building’s specific requirements before scheduling.
Schedule Your Duct Repair & Sealing in Rockville
Every Rockville job starts with a free estimate and ends with a Documented Photo Record of every duct run we touched. The written price comes first, under Haven Standard Clause 1. The 365-Day Done Right Promise backs the work in writing. Tomas Reyes has led CleanRun since 2013, and our crews have seen what Rockville’s three housing eras do to ductwork - from Twinbrook’s original sheet-metal trunks to King Farm’s failing flex runs. Call (240) 255-4519. A live person answers, 24/7. We’ll put a written price in front of you before any work starts.
Written by Tomas Reyes, Owner at CleanRun Duct Repair & Cleaning, serving Rockville since 2013.
Duct Repair & Sealing in Nearby Areas
