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 Washington
Duct repair and sealing in Washington, DC typically runs $280-$680 for most residential jobs, with flex duct replacement in tight row-house chases landing at the higher end and straightforward mastic sealing of accessible metal trunk lines at the lower. Crews from our Washington Dryer Vent Cleaning office carry the hand tools, negative-pressure extractors, and per-unit documentation systems needed for the city’s dense, subdivided housing stock. Call (571) 520-6317 for a written estimate - we’ll scope the work on-site, photograph every run, and deliver your price before any panel comes off.
We’ve worked inside Washington homes since 2013. The housing here doesn’t behave like suburban Virginia or Maryland stock, and duct repair can’t be scoped like it. Our crews know the difference between a 1920s Petworth row house with a shared basement air handler and a 1950s Southwest Waterfront apartment building with original branch ducts. That familiarity changes what we bring, how long we plan, and what we find.
Why CleanRun Air Duct Cleaning Herndon Is Washington’s Preferred Duct Repair & Sealing Company
CleanRun has served more than 52,000 homes since 2013, and a significant share of those have been inside the District. Washington homeowners research before they call - we expect that. Every estimate starts with a written price under Haven Standard Clause 1, and every job ends with a Documented Photo Record of every duct run, delivered as a standard deliverable, not an add-on.
Our technicians are background-checked and uniformed under Haven Standard Clause 3: Verified Crews, and we identify each by name before arrival. Tomas Reyes leads operations, and the crews dispatched to Washington carry equipment from Rotobrush, Nikro, and Abatement Technologies - brands you can look up before agreeing to anything.
Scheduling and dispatch are coordinated from our Washington, DC metro office. We don’t route crews from two states away and hope they understand parking restrictions on Capitol Hill or the access rules in a Columbia Heights condo association. Local coordination means realistic arrival windows and technicians who show up with the right tools for plaster-lath walls and six-inch steam-riser chases.
The 365-Day Done Right Promise applies to every Washington job in writing. If the repair fails or the seal re-opens, we make it right. Not a policy subject to manager approval - a written guarantee on your job record.
Our Duct Repair & Sealing Services in Washington
Duct Sealing
Leaky ducts in Washington waste 20-30% of conditioned air before it reaches registers, according to Department of Energy estimates. In practice, we see worse. The retrofit ductwork crammed through closets and furred-down ceilings in 1890s-1930s row houses was never designed for forced air, and the joints - especially at flex-to-metal transitions - fail systematically. Our duct sealing crews use mastic sealant and mechanical fasteners, not tape, because tape degrades in the humid conditions of a Washington basement mechanical room. Every sealed joint is photographed before and after, and the photo record is delivered with your written scope.
Flex Duct Repair
Flex duct is the weak link in most Washington systems. The plastic liner tears at elbows, the insulation compresses where it was pulled too tight through chases, and the wire helix corrodes in damp basement conditions. In Capitol Hill and Petworth row houses, we regularly find flex sections routed through wall chases with under six inches of clearance alongside original cast-iron steam risers. Standard rotary brush systems cannot engage in those spaces. We hand-tool the repair, replace failed flex sections with properly sized material from Guardsman, and mastic-seal every connection. The job takes longer than a suburban tract home. The documentation shows why.
Metal Duct Repair
Original galvanized trunk lines in 1940s-1960s Washington apartment buildings rust at seams and separate at drive cleats. We repair with slip joints and sealed rivets, or section-replace when corrosion has penetrated. In subdivided row houses with shared air handlers, metal trunk repairs require per-unit isolation so work on one branch doesn’t pressurize neighbors’ ducts. We scope and document each unit separately. Landlord-tenant access rules apply, and we build that into the written estimate.
Duct Insulation
Washington’s humid subtropical climate produces summer humidity levels that exceed Richmond and Baltimore. In row houses with basement mechanical rooms and tight, under-insulated duct chases, condensation forms on cold supply ducts and breeds mold at joints. We install closed-cell insulation on accessible metal trunks and replace water-damaged flex duct with insulated product rated for the application. Insulation without sealing is incomplete - we address both, and we photograph the condition we found.
Mastic Sealant
Mastic is the only sealant we use on Washington jobs. Foil tape fails in humidity; mastic remains flexible and airtight. We brush-apply to joints, transitions, and penetrations, then mechanically secure where vibration is likely. In historic row houses with nonstandard duct configurations, mastic reaches places tape cannot. The work is slow. It is documented.
Air Leak Repair
Air leaks in Washington systems often occur at the plenum - the distribution box on top of the air handler - where temperature cycling has cracked seams or loosened connections. We repair plenum leaks with custom-fabricated metal patches or full section replacement, sealed and insulated. In multi-unit buildings, plenum leaks pressurize return pathways and draw odors between units. Per-unit balancing after repair is standard, not optional.
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 Washington
Our Washington crews carry professional-grade equipment from Rotobrush, Nikro, and Abatement Technologies - negative-pressure extractors, rotary agitation systems, and HEPA-filtered vacuums that meet NADCA-equivalent standards. We stock Guardsman flex duct and mastic in common diameters so most repairs don’t wait on parts. For controls and dampers, we source Honeywell and Aprilaire components. You can verify every brand before we start; the equipment list is part of your written scope.
Common Duct Repair & Sealing Problems We See in Washington Homes
- Retrofit ductwork in nonstandard chases. The forced-air systems installed in 1960s-1980s row houses run through closets, furred-down hallway ceilings, and wall chases never designed for ductwork. Standard rotary agitation tools cannot fully engage in these spaces, so joints and flex connections get missed during maintenance and re-leak within seasons.
- Shared air handlers in subdivided buildings. A single basement unit feeding multiple condos or rentals means duct repair must be scoped per-unit. Sealing one branch without balancing airflow can starve upper-floor registers while overcooling basement units. We document each branch separately.
- Condensation and mold at duct connections. Washington’s sustained summer humidity, combined with tight, under-insulated chases alongside old steam risers, produces moisture that degrades mastic and separates flex seams. Sealing without addressing moisture is temporary work. We treat it as standard, not an upsell.
- Plaster dust infiltration in shared wall chases. In Capitol Hill and Petworth, supply ducts routed through the same chases as original cast-iron steam risers collect decades of fine plaster dust. This particulate packs into flex duct connections, restricts airflow, and accelerates liner degradation. Hand-tool cleaning and repair is often the only effective approach.
Pricing for Duct Repair & Sealing in Washington, DC
A typical mastic sealing job on accessible metal ductwork in Washington runs $280-$420. Flex duct repair or replacement in tight row-house chases runs $380-$680 depending on linear footage and access difficulty. Full duct insulation on exposed basement trunk lines runs $450-$720. These are whole-system prices, not per-vent teaser rates that balloon once the truck arrives.
What moves the number: access conditions (crawl space versus finished basement), number of flex sections requiring replacement, whether per-unit balancing is needed in multi-unit buildings, and the extent of moisture damage requiring insulation replacement. We do not quote over the phone. A technician visits, inspects every run with a camera, and delivers a written price before any work starts - Haven Standard Clause 1, no exceptions.
Bring a competitor’s written estimate. We’ll deliver a free second opinion, our number next to theirs, both in writing.
| Service | Typical Range in Washington |
|---|---|
| Mastic sealing, accessible metal ducts | $280-$420 |
| Flex duct repair/replacement, standard access | $380-$550 |
| Flex duct repair, tight chase (under 6 in. clearance) | $480-$680 |
| Metal duct section repair/replacement | $320-$580 |
| Duct insulation, exposed basement trunk | $450-$720 |
| Plenum repair with per-unit rebalancing | $520-$780 |
We Also Serve Cities Near Washington
Our Duct Repair & Sealing in Washington crews also work in Arlington, Alexandria, Bethesda, and Silver Spring. Dispatch is coordinated from the Washington, DC metro office, with local knowledge of each jurisdiction’s permit and access requirements.
Serving Washington, DC - Our Local Coverage Area
We’re based in the Washington 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 Washington
Yes. We scope and document each unit separately, work within landlord-tenant access rules, and rebalance airflow so sealing one branch doesn’t starve neighbors. The written estimate breaks out per-unit work so all parties have a record. Call (571) 520-6317 to schedule a site visit - estimates are free.
The retrofit ductwork in these neighborhoods runs through wall chases with under six inches of clearance alongside original cast-iron steam risers. Standard rotary equipment cannot engage, so we hand-tool the work, replace failed flex sections, and mastic-seal in confined spaces. A job that takes two hours in an open suburban basement can take four in a Petworth row house. The photo record shows the difference.
Rarely. We access ducts through existing registers, basement mechanical rooms, and removable panels. Historic-preservation restrictions limit envelope alterations, and we work within them. If wall opening is necessary, we document why in writing and include it in the scope with your approval - but most sealing is accomplished without it.
Washington’s humid subtropical climate produces sustained summer humidity that exceeds neighboring cities, and row-house duct chases are often uninsulated and poorly ventilated. Condensation forms on cold supply ducts, mold colonizes at joints, and that moisture degrades new seals if not addressed. We treat antimicrobial application as standard on nearly every job, not an optional upsell. Call (571) 520-6317 for an inspection - estimates are free.
Yes, if your building has a shared return pathway or leaky plenum connections. Unsealed returns create pressure imbalances that draw air between units. Proper sealing and per-unit balancing isolates your air stream. We test for cross-flow during the repair and document the before-and-after pressure readings. The photo record includes what we found.
Schedule Your Duct Repair & Sealing in Washington
Our Duct Repair & Sealing team is ready to inspect your Washington home, deliver a written price, and complete the work with full documentation. Every job includes the Documented Photo Record, the 365-Day Done Right Promise, and the H.A.V.E.N. Standard. Call (571) 520-6317 to speak with a live person and schedule your free estimate.
Written by Tomas Reyes, Owner at CleanRun Duct Repair & Cleaning, serving Washington since 2013.
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