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 Gaithersburg
Duct repair and sealing in Gaithersburg typically runs $340-$890 for most residential systems, with full flex duct replacement on older townhomes reaching the higher end. Our crews are dispatched from our Washington, DC coordination office and carry Rotobrush and Abatement Technologies equipment to Montgomery Village, Kentlands, and Lakelands daily. Call (240) 771-1508 for a written estimate before any work starts.
We’ve been driving the I-270 corridor since 2013, and Gaithersburg’s mix of 1970s planned communities and newer vertical townhomes keeps our Duct Repair & Sealing team busy year-round. The city sits at roughly 500 feet on the Piedmont Plateau, which means more ground fog and higher interior humidity than lower suburbs toward DC. That moisture loads into aging duct systems differently here. We see it on every camera inspection.
Why CleanRun Air Duct Cleaning Ashburn Is Gaithersburg’s Preferred Duct Repair & Sealing Company
Gaithersburg homeowners have left us documented reviews mentioning the photo records specifically, the written prices, and the fact that our technicians arrive uniformed and named under Haven Standard Clause 3: Verified Crews. We don’t bury our license number in a footer. Tomas Reyes, who leads CleanRun, publishes it on every estimate because the homeowners we serve, research credentials before they call.
Our response time to Gaithersburg averages same-day scheduling for non-urgent work, with crews typically arriving within the agreed two-hour window. We know the difference between Montgomery Village’s original 1960s-to-1980s builds and the tighter duct chases in Kentlands townhomes. That local housing knowledge changes what equipment we load and what failure modes we expect before we open the first panel.
The 365-Day Done Right Promise applies in Gaithersburg exactly as it does everywhere we work, backed in writing on every job. If the repair isn’t right, we make it right. No manager approval needed. The H.A.V.E.N. Standard requires it.
Our Duct Repair & Sealing Services in Gaithersburg
Duct Sealing
Sealing in Gaithersburg means addressing systems that have run unsealed through decades of Piedmont humidity. We use mastic sealant and professional-grade tape, not hardware-store foil, and we photograph every joint before and after. On Montgomery Village units with original fiberglass duct board, sealing without first addressing delaminating interior surfaces traps particulate. We disclose what the camera shows before we seal.
Flex Duct Repair
Flex duct in Gaithersburg’s older townhomes fails differently than in newer construction. Above drop ceilings in 1970s Montgomery Village units, we regularly find accordion-kinked or crushed runs that have been moving reduced air for years. Our field protocol: camera first, photo documentation, then repair or replacement with Guardsman-supported materials. We never pressurize a hidden run without knowing what’s upstream. A typical flex duct repair or replacement in Gaithersburg runs $280-$620 per run, depending on chase access and length.
Metal Duct Repair
Metal trunk lines in Gaithersburg’s 1990s-and-newer builds, particularly in Lakelands and Kentlands, suffer seam separation and corrosion where humid attic air meets conditioned metal. We repair with proper sheet-metal practices, seal with mastic, and insulate where the original barrier has degraded. Metal repair typically falls between $340-$780 in this market.
Air Leak Repair
Leaks in Gaithersburg systems often hide behind humidity-caked debris. Rural-adjacent properties on unpaved roads near open land load ducts with dust and pollen that, combined with plateau humidity, forms a coating on duct walls. That coating can mask leaks during visual inspection. We test under negative pressure to find what cleaning alone won’t reveal. Air leak repair and sealing together typically range $420-$890 for a complete system.
Duct Insulation
Insulation replacement matters in Gaithersburg’s crawlspace and attic runs where the original wrap has compressed or absorbed moisture. We specify replacement R-value based on the chase location and photograph the installed product. Insulation work generally adds $180-$340 to a sealing job when bundled.
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 Gaithersburg
Our Gaithersburg crews carry Aprilaire and Honeywell components for common local HVAC configurations, and we stock Abatement Technologies filtration and sealing materials matched to the tighter duct chases in newer planned communities. Parts availability means most Gaithersburg jobs complete in one visit. We name the manufacturers so you can verify specifications independently before agreeing to any scope.
Common Duct Repair & Sealing Problems We See in Gaithersburg Homes
- Delaminating fiberglass duct board in Montgomery Village. Original 1966-to-mid-1980s duct board interiors shed glass fibers into supply and return air. Sealing over this material without replacement traps particulate. We photograph the delamination and show the homeowner before quoting removal.
- Humidity-caked debris hiding leaks on rural-adjacent properties. Dust and pollen from unpaved roads near Gaithersburg’s open land combine with plateau humidity to form a coating on duct walls. Leaks only reveal under negative-pressure testing. Cleaning without testing misses the actual problem.
- Collapsed flex duct above 1970s drop ceilings. On a Montgomery Village townhome call off Stedwick Road, our tech found an original 1976 fiberglass duct board trunk whose interior had delaminated, plus an accordion-kinked flex run crushed above a drop ceiling - both feeding a supply register that barely moved air. We performed camera inspection, documented the collapsed run with photos for the homeowner before pressurizing anything, then replaced the kinked flex and sealed the plenum with mastic. After repair, static pressure at the air handler dropped and the blower motor’s amp draw returned to spec.
- Microbial growth in unsealed humid systems. Gaithersburg’s 500-foot elevation and frequent ground fog keep interior humidity higher than lower DC suburbs. Unsealed return plenums in basements and crawlspaces draw that moisture into the system, supporting growth that sealing alone won’t address.
Pricing for Duct Repair & Sealing in Gaithersburg, MD
| Service | Typical Range in Gaithersburg |
|---|---|
| System-wide duct sealing (mastic, joints, plenum) | $420-$780 |
| Flex duct repair / replacement (per run) | $280-$620 |
| Metal duct repair (seams, sections) | $340-$780 |
| Air leak detection + repair bundle | $420-$890 |
| Duct insulation replacement (add-on) | $180-$340 |
| Full system: sealing + multiple flex repairs + insulation | $890-$1,680 |
Every Gaithersburg estimate is written and delivered before work starts, per Haven Standard Clause 1. No exceptions. The price covers the full system, not per-vent arithmetic that balloons on the invoice. We also provide a Free Second Opinion on any competitor’s written estimate. Bring it. We’ll put our number next to it.
What moves the price: chase access (drop ceilings vs. open attic), material type (fiberglass duct board removal costs more than flex replacement), and whether negative-pressure testing reveals hidden leaks beyond the visible scope. We document everything with photos. You’ll see what we saw.
We Also Serve Cities Near Gaithersburg
Our crews work Gaithersburg daily and rotate to Rockville, Germantown, Potomac, and Bethesda from the same dispatch. The equipment and standards stay identical. The local housing knowledge changes. Germantown’s ranch-style single-families fail differently than Gaithersburg’s vertical townhomes. We load the truck accordingly.
Serving Gaithersburg, MD - Our Local Coverage Area
We’re based in the Gaithersburg 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 Gaithersburg
Every 2 to 3 years, not the generic 5-to-7-year rule. Dust and pollen loading from unpaved surfaces is substantially higher than in paved suburban cores, and Piedmont humidity cakes that debris onto duct walls where it traps moisture and masks leaks. Call (240) 771-1508 and we’ll put a written maintenance interval in your job record based on what the camera shows.
The original 1970s installations used first-generation flex duct with minimal support, run through narrow chases designed for the drop-ceiling aesthetic of that era. Decades of thermal cycling and occasional service traffic compress the material at elbows and supports. We find accordion-kinks on roughly one in three Montgomery Village calls. Camera inspection before any pressurization is mandatory on our protocol.
Yes. At roughly 500 feet on the Piedmont Plateau, Gaithersburg captures more precipitation and ground fog than lower-elevation DC suburbs. That moisture loads into unsealed return systems and supports microbial growth that sealed systems resist. The urgency isn’t theoretical. We photograph the difference between sealed and unsealed plenums in the same neighborhood.
Sealing alone fixes air loss at joints and plenum connections. It does not fix delaminating duct board interiors that shed fibers into the airstream. On Montgomery Village homes with original board, we typically recommend board replacement or encapsulation in the same scope, with sealing performed on the new material. We show the camera evidence and quote both options in writing.
Yes, including detached workshops, garage HVAC, and converted barn structures with ducted heating or cooling. These systems often use flex duct run in unconditioned space, exposed to wider temperature swings and higher debris loading. We inspect, photograph, and quote them under the same written-price protocol. Call (240) 771-1508 with the outbuilding square footage and we’ll schedule a camera inspection.
Ready for a written estimate? Call (240) 771-1508. A live person answers. We’ll schedule camera inspection, deliver a written price before any work starts, and leave you with a Documented Photo Record of every duct run. The 365-Day Done Right Promise applies in full. Tomas Reyes and the team at CleanRun have operated this way since 2013.
Written by Tomas Reyes, Owner at CleanRun Duct Repair & Cleaning, serving Gaithersburg since 2013.