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 Gaithersburg
Duct repair and sealing in Gaithersburg typically runs $280-$850 depending on whether we’re reconnecting a single run or resealing an entire system, and most jobs are completed in one visit with a written price agreed before any work starts. Our crews dispatch from the Washington, DC office and carry common flex duct, metal collars, mastic sealant, and insulation stock sized for the Gaithersburg market. Call (240) 255-4519 for a free written estimate.
We’ve worked in Gaithersburg since 2013, and the duct problems we find here don’t match what we see in Bethesda or Silver Spring. Montgomery Village alone - one of the largest planned communities in the United States - contains thousands of homes built between 1966 and 1985 with original ductwork that predates modern materials and filtration standards. That concentration of aging systems in a single zip code shapes everything about how we approach Duct Repair & Sealing here.
Why CleanRun Air Duct Cleaning Rockville Is Gaithersburg’s Preferred Duct Repair & Sealing Company
Our Gaithersburg customers come back because we show them what we found. Every job ends with a Documented Photo Record - inside every duct run, before and after - delivered as a standard deliverable, not an upsell. The 365-Day Done Right Promise is backed in writing on every invoice: if the work is not right, we make it right.
We’ve served more than 52,000 homes since 2013, every one with a written price before work started and a photo record when the crew left. In Gaithersburg specifically, technicians are familiar with Montgomery Village’s ranch and split-level layouts, Kentlands’ neo-traditional crawlspace configurations, and the humidity patterns around Seneca Creek that accelerate duct degradation.
Haven Standard Clause 1 requires a written price before any work starts - no exceptions. Haven Standard Clause 3: Verified Crews means background-checked, uniformed technicians identified by name before arrival. Our license number is published on every estimate, not buried in a footer.
Dispatch and scheduling are coordinated from our Washington, DC office, with crews serving Gaithersburg locally. All calls are answered by a live person, 24/7.
Our Duct Repair & Sealing Services in Gaithersburg
Duct Sealing
Sealing is often the real fix in Gaithersburg’s older homes. In Montgomery Village colonials, we apply mastic sealant and metal collars to reconnect supply runs that have separated from the trunk line after decades of thermal cycling. In Kentlands and Lakelands, we reseal crawlspace flex-duct connections where Gaithersburg’s humidity has degraded tape and undone factory seals. A typical duct sealing job in Gaithersburg runs $280-$520 for partial-system work and $620-$850 for full-system sealing with trunk-line access.
Flex Duct Repair
Flex duct in Gaithersburg fails two ways. In Montgomery Village, original flex runs from the 1970s and 1980s have become brittle and collapse under negative pressure. In newer neighborhoods, condensation in conditioned crawlspaces delaminates the mylar jacket from the wire helix. We replace failed flex with new insulated duct sized to the original CFM load, secure it with metal collars and mastic (not tape), and photograph every connection. Flex duct repair in Gaithersburg typically costs $180-$340 per run.
Metal Duct Repair
Galvanized steel ductwork in Montgomery Village and surrounding 1960s-1980s Gaithersburg subdivisions rusts at seams, separates at drives, and collects debris in low spots where slope was compromised during original installation. We cut out failed sections, fabricate replacement metal to fit, and seal with mastic and fiberglass mesh. Metal repair runs $320-$580 depending on access and the extent of corrosion.
Duct Insulation
Uninsulated or degraded duct insulation in Gaithersburg’s humid climate wastes energy and creates condensation that feeds mold growth. We reinsulate trunk lines and plenums (the main distribution boxes) with foil-faced fiberglass or closed-cell foam board, depending on clearance and local code. Insulation work in Gaithersburg ranges from $240 for spot repair to $680 for full trunk-line reinsulation.
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 Gaithersburg
Our equipment roster includes Nikro negative-pressure extractors, Honeywell media air cleaners, and Aprilaire humidifier and filtration components - brands customers can look up independently before agreeing to a price. We stock common flex duct diameters, metal collars, and mastic sealant matched to the Gaithersburg market, so most repairs don’t wait on parts. For homes with Abatement Technologies HEPA filtration already installed, we coordinate repair work to maintain system integrity and warranty coverage.
Common Duct Repair & Sealing Problems We See in Gaithersburg Homes
- Original fiberglass duct liner shedding in Montgomery Village. The 1970s two-story colonials off Goshen Road and surrounding streets have furnace closets that trap humidity against duct board, degrading fiberglass liner until it sheds particulate into the airstream. A duct-cleaning-only job makes it worse until the liner is sealed or replaced.
- Disconnected or crushed galvanized runs in split-levels. Behind finished walls in 1966-1985 homes, supply runs separate from the trunk or get crushed during decades of maintenance access. Debris load often masks the leak until agitation tools expose it during cleaning.
- Condensation damage in Kentlands and Lakelands crawlspaces. Gaithersburg’s Seneca Creek humidity pockets push indoor relative humidity higher than surrounding upland areas. Poorly balanced duct systems in conditioned crawlspaces condense on cool duct surfaces, delaminating flex duct and undoing mastic seals within a single cooling season.
- Failed tape seals on retrofitted flex connections. Previous homeowners or handymen often used duct tape (the cloth-backed kind, not UL-181 rated) on flex-to-metal connections. It dries and falls off. We find this repeatedly in Gaithersburg’s 1990s-era additions and basement finish-outs.
Pricing for Duct Repair & Sealing in Gaithersburg, MD
We publish ranges because Haven Standard Clause 1 requires a written price before any work starts - and that price should not be a surprise.
| Service | Typical Range in Gaithersburg |
|---|---|
| Single flex duct repair/replacement | $180 - $340 |
| Partial duct sealing (up to 5 runs) | $280 - $520 |
| Metal duct section repair | $320 - $580 |
| Full-system duct sealing with trunk access | $620 - $850 |
| Duct insulation (spot to full trunk) | $240 - $680 |
What moves the number: access (crawlspace vs. finished basement), material type (flex vs. metal vs. duct board), and whether we find secondary damage like mold or collapsed runs once the camera goes in. We photograph everything and review it with you before setting the final written price. No per-vent pricing. No teaser coupons. Free Second Opinion on any written estimate from a competitor - bring us their number and we’ll put ours next to it in writing.
We Also Serve Cities Near Gaithersburg
Our service area extends to Rockville, Bethesda, and Silver Spring, with crews dispatched from the Washington, DC office. Duct conditions vary by municipality - Rockville’s housing stock skews newer, Bethesda’s pre-war homes present different access challenges, and Silver Spring’s mid-century apartments have their own duct configurations. We adjust our repair approach 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
Montgomery Village’s 1966-1985 homes still run original galvanized and fiberglass-lined duct systems, and the furnace-closet layout in its 1970s two-story colonials traps humidity against duct board, causing liner shedding that techs rarely see at this rate in Rockville or Germantown. Because Montgomery Village is one of the largest planned communities in the U.S., this aging-duct condition is concentrated in a single zip code rather than scattered across the region. Kentlands and Lakelands homes, built late 1980s-2000s, face different issues - poorly balanced crawlspace systems and condensation - but their duct materials are newer and less prone to structural failure. Call (240) 255-4519 for an exact quote - estimates are free.
We run a camera inspection and a static pressure test; a disconnected run shows zero airflow at the register and a pressure anomaly at the trunk, while a dirty but connected run maintains pressure with restricted flow. During cleaning, agitation tools sometimes expose a disconnection that debris had been masking - the vacuum suddenly pulls from a gap instead of the register, and the camera confirms it. We photograph the finding and show you before quoting repair. Call (240) 255-4519 for an exact quote - estimates are free.
Yes. Gaithersburg sits at the Piedmont’s edge with Seneca Creek running through it, creating localized low-lying humidity pockets that push indoor relative humidity higher than surrounding upland areas during the region’s notoriously muggy summers. This elevated moisture load accelerates mold colonization inside ductwork and degrades tape-based seals within a season. We use mastic sealant and mechanical fasteners (metal collars, screws) rather than tape for this reason, and we verify seal integrity with a smoke test before leaving. Call (240) 255-4519 for an exact quote - estimates are free.
Cleaning removes debris from inside the duct runs; sealing repairs the physical envelope - reconnecting separated joints, closing gaps, and restoring pressure integrity. In Gaithersburg’s Montgomery Village homes, we often find both needs: decades of debris accumulation plus disconnected or shedding liner that cleaning alone cannot fix. We assess with camera inspection and quote each scope separately so you know what each deliverable costs. The Documented Photo Record shows you exactly what was cleaned versus what was repaired. Call (240) 255-4519 for an exact quote - estimates are free.
We can seal degraded liner with a water-based duct liner coating or encapsulant, applied after cleaning and negative-pressure HEPA extraction, which stops shedding and restores a smooth interior surface. If the liner is too degraded or the duct board is structurally compromised, we replace the affected section with new metal duct. On a Montgomery Village two-story colonial off Goshen Road, our crew pulled registers during a standard clean and found the original fiberglass duct liner shedding into the airstream, with two supply runs disconnected at the trunk and one crushed flex run behind the air handler. We ran camera inspection, isolated the failed runs under negative pressure with HEPA filtration, rebuilt the connections with mastic sealant and metal collars, then re-insulated the trunk line - the homeowner’s second-floor airflow came back and the shedding stopped. Call (240) 255-4519 for an exact quote - estimates are free.
Ready to see what’s actually inside your ducts? Call CleanRun Air Duct Cleaning Rockville at (240) 255-4519 for a free written estimate. Every Gaithersburg job starts with a written price before work begins, includes a Documented Photo Record of every duct run, and is backed by our 365-Day Done Right Promise. Bring a competitor’s written quote - we’ll put our number next to it, no charge.
Written by Tomas Reyes, Owner at CleanRun Air Duct Cleaning Rockville, serving Gaithersburg since 2013.