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.
Before
After
Before
After
Before
AfterFast, Reliable Duct Repair & Sealing Across Rockville
Duct repair and sealing in Rockville typically costs $280-$680 for most residential systems, with flex duct repair running $180-$420 per run and full mastic sealing of a galvanized trunk line at $340-$580. We dispatch crews to Rockville from our Washington, DC coordination office, and we schedule most repair visits within 3-5 business days. Call (240) 771-1508 for a written estimate before any work starts.
We’ve worked inside duct systems across every Rockville housing generation, from Twinbrook’s 1949-1956 cape cods to King Farm’s early-2000s planned communities. That range matters. A technician who only knows flex-duct townhomes will miss the two-generation failure pattern that defines Rockville’s older stock. Our crews carry equipment for both: metal trunk restoration tools for galvanized lines, and soft-bristle agitation systems for fiberglass-lined flex runs. We photograph every duct interior before we touch it, and we show you those images before we quote a price. Haven Standard Clause 1: written price before any work starts, no exceptions.
Why CleanRun Air Duct Cleaning Ashburn Is Rockville’s Preferred Duct Repair & Sealing Company
We’ve served Rockville homeowners since 2013, completing jobs in Twinbrook, East Rockville, King Farm, Fallsgrove, and the rural-edge properties off Darnestown Road and Travilah Road. Every one of those 52,000-plus homes received a written price before work began and a documented photo record when the crew left. That documentation is not a marketing promise; it’s a standard deliverable you receive as a PDF with timestamped before-and-after images of every duct run we accessed.
Our technicians are background-checked, uniformed, and identified by name before arrival under Haven Standard Clause 3: Verified Crews. We publish our Maryland license number on every page so you can verify it with the state. The equipment we bring to Rockville jobs includes Rotobrush agitation systems, Abatement Technologies negative-pressure extractors, and Guardsman sealants - brands you can look up independently before you agree to a price.
The 365-Day Done Right Promise applies to every Rockville job in writing: if the work is not right, we make it right. Not a policy subject to manager approval. A written guarantee signed by the technician and by Tomas Reyes, owner.
Our Duct Repair & Sealing Services in Rockville
Flex Duct Repair
Flex duct repair in Rockville runs $180-$420 per run depending on accessibility and liner condition. Most Rockville flex-duct problems trace to two sources: the 1970s-1980s fiberglass-lined take-offs grafted onto Twinbrook’s original metal trunks, which have now sagged, collapsed, or disconnected at the boot; and the modern flex-duct systems in King Farm and Fallsgrove, where tight attic bends have kinked or crushed the liner. Our crews inspect with a push camera before quoting, so you see the collapse or disconnect before we name a price. We replace damaged flex with new R-6 or R-8 insulated runs, secure with mechanical fasteners (not tape alone), and seal boot collars with mastic.
Mastic Sealant Application
Mastic sealing of metal trunk lines in Rockville costs $340-$580 for a typical single-system home. This is the correct treatment for Twinbrook’s original 1950s galvanized trunks, which were fabricated before modern pressure-sealing standards and now leak conditioned air into attics and crawl spaces at every seam and joint. We brush-apply water-based mastic (not tape) to all longitudinal seams, transverse joints, and branch take-offs, then pressure-test to verify seal integrity. On a recent job off Veirs Mill Road, our tech found the original trunk losing 28 percent of supply air through seam leaks; after mastic and boot re-securing, that dropped to 4 percent.
Air Leak Repair
Air leak repair in Rockville addresses the gaps between duct components and building envelope - register boots pulled away from drywall, plenum seams separated by thermal cycling, and return-air pathways drawing from wall cavities instead of ducted returns. Repair scope runs $220-$480 depending on leak count and access difficulty. In Rockville’s humid subtropical climate, unsealed return leaks are particularly costly: they pull 65-72°F dew-point attic air directly into the system, spiking indoor humidity and promoting mold colonization inside the ductwork. We seal with mastic and fiberglass mesh at the leak source, then verify with smoke pencil or pressure differential testing.
Metal Duct Repair
Metal duct repair in Rockville focuses on the aging galvanized trunk lines in pre-1960 housing and the transitional systems in 1970s-1980s East Rockville split-levels. Costs range from $260-$560 for spot repair (patching rust-through, reinforcing sagging sections) to $680-$1,200 for partial trunk replacement. We do not recommend sealing rusted or structurally compromised metal; we photograph the damage, show you the image, and quote replacement or lining options. Our crews carry sheet-metal fabrication tools to match existing trunk dimensions on-site.
Duct Insulation
Duct insulation in Rockville addresses the specific problem of unconditioned attic and crawl-space runs common in Twinbrook and East Rockville homes. Re-insulating a exposed trunk line with foil-faced fiberglass wrap runs $380-$720. Without proper insulation, Rockville’s summer dew points condense on cold supply ducts, dripping moisture onto ceiling drywall and seeding mold. We measure surface temperature differential and ambient dew point before quoting, then install insulation with sealed vapor barriers to prevent future condensation.
What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
BeforeAfterTrusted Brands We Service in Rockville
Our Rockville crews carry professional-grade equipment from trade-recognized brands: Rotobrush agitation systems for mechanical debris removal, Abatement Technologies negative-pressure extractors for controlled containment, and Guardsman sealants for permanent mastic applications. We also stock Aprilaire media filters and Honeywell zone dampers for integration jobs where repair reveals undersized or poorly zoned original systems. You can verify each manufacturer’s specifications independently; we name the equipment because we have nothing to hide about what touches your ductwork. Parts are stocked at our Washington, DC coordination office, so most Rockville repair jobs need no special-order delay.
Common Duct Repair & Sealing Problems We See in Rockville Homes
- Two-generation failure in Twinbrook: The original 1950s galvanized trunk lines were never pressure-sealed, and the 1970s-1980s flex-duct take-offs added during energy-crisis HVAC upgrades have now collapsed or disconnected at the boot. Sealing the old metal seams without first re-securing those flex branches just drives conditioned air into the crawl space. We map the full system with camera inspection before quoting any sealing scope.
- Rural-edge dust and pollen loading: Properties on unpaved approaches near Darnestown Road and Travilah Road pull heavy particulate into return-air intakes. Without MERV 11+ filtration at the air handler, that load settles into trunk interiors and re-enters living space every cycle. We inspect filter racks and recommend correct sizing as part of every repair visit.
- Wood-heat and outbuilding system contamination: Rural Rockville properties with supplemental wood heat draw creosote-tinged smoke and ash through returns, coating galvanized interiors and clogging flex-duct liners. Standard agitation tools cannot safely clear creosote residue; we use controlled solvent application followed by negative-pressure extraction, with full photo documentation of before and after conditions.
- Summer dew-point mold colonization: Rockville’s 65-72°F summer dew points condense on uninsulated or unsealed duct surfaces in attics and crawl spaces. A disconnected boot or collapsed liner left open across one humid season seeds mold that spreads through the entire system. We find these open points with camera inspection and seal them with mastic and mechanical fasteners, not temporary tape.
Pricing for Duct Repair & Sealing in Rockville, MD
| Service | Typical Range in Rockville |
|---|---|
| Flex duct repair (per run) | $180 - $420 |
| Mastic sealant, metal trunk (single system) | $340 - $580 |
| Air leak repair (multiple points) | $220 - $480 |
| Metal duct spot repair | $260 - $560 |
| Partial metal trunk replacement | $680 - $1,200 |
| Duct re-insulation (exposed trunk) | $380 - $720 |
These ranges reflect Rockville’s specific housing stock and access conditions. Twinbrook crawl-space jobs take longer than King Farm attic jobs; rural-edge properties with outbuilding systems require additional scope assessment. Every quote is written and itemized before work starts under Haven Standard Clause 1. We also offer a Free Second Opinion on any competitor’s written estimate: bring us their number, and we’ll put ours next to it in writing. Call (240) 771-1508 to schedule an inspection and receive your documented photo record and written price.
We Also Serve Cities Near Rockville
Our crews repair and seal duct systems across Montgomery County and into adjacent communities. We regularly work in Rockville and nearby Potomac, Gaithersburg, Bethesda, and Germantown. Dispatch and scheduling are coordinated from our Washington, DC office, with local crews serving each area. If you’re unsure whether your property falls within our service radius, call (240) 771-1508 and we’ll confirm before booking.
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
Rural-edge properties on unpaved approaches near Darnestown Road and Travilah Road pull significantly more dust and spring oak and maple pollen into return-air intakes than filtered suburban environments like King Farm. Wood-heat households add creosote-tinged particulate that standard agitation cannot safely clear. We typically recommend a 2-3 year inspection interval for rural Rockville properties with these load factors, versus 4-5 years for townhomes on paved streets with no supplemental combustion heat. Call (240) 771-1508 and we’ll assess your specific system, filtration, and usage pattern.
Yes, if the metal is structurally sound. We camera-inspect first to check for rust-through, separation at seams, or physical damage from decades of thermal cycling. On sound metal, we brush-apply water-based mastic to all seams and joints, then pressure-test to verify seal integrity. We do not seal compromised metal; we photograph the damage and quote replacement or lining options. On a Twinbrook cape cod off Veirs Mill Road, our Duct Repair & Sealing tech found original 1950s galvanized trunk running through an unconditioned crawl space with collapsed 1970s fiberglass flex branches pulled loose at the boot. We ran camera inspection to map the disconnects, reconnected the flex runs, and mastic-sealed the trunk seams and boot collars - after which the supply registers in the back bedrooms finally held pressure and the musty crawl-space odor stopped bleeding into the living space.
It promotes condensation on cold supply surfaces and mold colonization inside the duct system. When unconditioned attic or crawl-space air at 65-72°F dew point contacts a 55°F supply duct, moisture condenses continuously during cooling cycles. That moisture feeds mold growth on fiberglass liners, mastic residue, and accumulated dust. Sealing the duct envelope and insulating exposed runs prevents this by keeping humid ambient air away from cold surfaces. We measure surface temperature and ambient dew point before quoting insulation scope. Call (240) 771-1508 for a system assessment.
We treat them as specialized contamination cases, not standard maintenance cleans. Creosote-tinged ash and smoke particulate require controlled solvent application followed by negative-pressure extraction with Abatement Technologies equipment; mechanical agitation alone risks spreading combustible residue. We photograph the interior condition before any chemical application, document the after condition, and provide written verification that the system is safe for continued use. Outbuilding systems with long duct runs may need分段 inspection due to access constraints; we discuss realistic scope before quoting. Call (240) 771-1508 to schedule.
No. We do not charge travel fees or reduce scope based on distance from our coordination office. What affects single-visit completion is the condition we find: a Twinbrook home with two-generation failure (collapsed flex branches plus unsealed metal trunk) requires more time than a straightforward mastic-sealing job, regardless of address. We camera-inspect before quoting and give you a realistic time estimate with the written price. If additional issues emerge during work, we photograph them, stop, and present a revised scope before proceeding. Haven Standard Clause 1 applies at every Rockville address. Call (240) 771-1508 to book.
Ready to stop losing conditioned air to your attic or crawl space? Call CleanRun at (240) 771-1508 for a free written estimate on duct repair and sealing in Rockville. We’ll inspect your system with a push camera, show you what we find, and deliver a documented photo record and itemized price before any work begins. Every job is backed by our 365-Day Done Right Promise and the full H.A.V.E.N. Standard.
Written by Tomas Reyes, Owner at CleanRun Duct Repair & Cleaning, serving Rockville since 2013.