Fast, Reliable Duct Repair & Sealing Across Greenwich
Duct repair and sealing in Greenwich, CT typically costs $275–$850 depending on system accessibility and material type, with most jobs completed in a single visit. If you’re losing heated or cooled air through leaks, gaps, or failing connections in your ductwork, we’re the team that fixes it properly the first time — no temporary patches, no subcontracted crews.
We drive to Greenwich regularly from our Bridgeport base, and we know the local housing stock intimately. From the Gilded Age estates of Back Country to the mid-century ranches in Cos Cob, we’ve repaired ductwork in homes where standard approaches simply don’t apply. Our Duct Repair & Sealing team brings commercial-grade equipment and two decades of field experience to every Greenwich job. Call (866) 531-5603 for a free estimate — we’ll give you an honest assessment and a firm quote before any work begins.
Why Elite Air Duct Cleaning Service Connecticut Is Greenwich’s Preferred Duct Repair & Sealing Company
Matthew Gonzalez handles your job personally — owner on-site, every time. That’s not a slogan; it’s how we’ve operated for 20 years. Greenwich homeowners don’t hire us to watch a rotating crew figure things out on their dime. They hire us because Matthew has seen — and fixed — duct systems in this town that most technicians wouldn’t recognize, let alone repair correctly.
Our reputation here is built on specifics. 663 verified reviews averaging 4.9 stars reflect consistent outcomes, not cherry-picked stories. Greenwich customers mention our thoroughness with older homes, our willingness to explain what’s actually wrong, and the documented before-and-after air quality reporting we provide as standard — something this market expects, especially in the 06831 zip code where estate sales and property transfers often require third-party verification.
Response time to Greenwich is typically same-day or next-day for standard repairs, and we schedule longer service windows for Back Country and mid-country estates where a single residence may require half a day or more. We don’t rush these jobs. The ductwork in a 12,000-square-foot Colonial Revival with four HVAC zones and 50 years of modifications can’t be assessed in 45 minutes.
Two decades of duct systems means we’ve developed real local knowledge: which Greenwich neighborhoods have original sheet-metal trunks with disintegrating liner, where coastal humidity creates condensation problems in crawlspaces, and why a “simple” flex duct repair in a finished attic on Round Hill Road often requires custom metal fabrication. That expertise saves our Greenwich customers money and repeated service calls.
Our Duct Repair & Sealing Services in Greenwich
Duct Sealing & Mastic Sealant Application
Air leakage is the single biggest efficiency killer in Greenwich duct systems, and the problem is worse here than in newer construction towns. In Back Country estates where multiple contractors have spliced new flex duct into original galvanized lines over decades, failed seals at trunk-to-flex connections create measurable static pressure imbalances across multi-zone systems. We don’t use duct tape — ever. Our mastic sealant application follows SMACNA standards and bonds permanently to metal, fiberglass, and properly prepared flex duct surfaces. For Greenwich’s irregular custom-routed ductwork, we hand-trowel mastic into gaps and transitions that tape products can’t seal, then verify with static pressure testing.
Flex Duct Repair & Replacement
Flex duct gets crushed in finished attics, kinked around structural beams, and degraded by temperature swings. In Greenwich’s estate homes, we frequently find modern insulated flex duct poorly connected to original trunk lines — like the 1920s Tudor on Round Hill Road where a previous contractor had used duct tape alone to splice flex into galvanized steel, dumping conditioned air into a finished attic and starving the second-floor zone. We removed that faulty splice, fabricated a custom metal transition, and sealed it with mastic. Proper flex duct repair in Greenwich often requires this level of custom work, not just swapping in a new length of hose.
Metal Duct Repair & Custom Fabrication
Greenwich’s concentration of historic and high-value homes means we repair more custom metal ductwork than most Connecticut operators. Original galvanized trunk lines in Gilded Age and Colonial Revival estates have been modified, extended, and re-routed through wine cellar mechanical rooms and finished third-floor spaces. When these lines corrode, separate at seams, or need new takeoffs, we fabricate transitions and patches on-site. Our Rotobrush and Nikro equipment includes the cutting and forming tools for this work — the same commercial-grade gear we use in light-commercial settings, not consumer-grade tools that can’t handle 26-gauge galvanized or rectangular duct transitions.
Duct Insulation & Condensation Control
Coastal humidity in Old Greenwich and Riverside creates a specific problem: uninsulated or degraded return ducts in unconditioned crawlspaces and basements condensate repeatedly, accelerating mold and mildew accumulation. We’ve repacked insulation on return ductwork in shoreline homes where the original fiberglass wrap had become a moisture sponge. For Greenwich’s climate — cold dry winters with constant heating airflow, followed by humid summers — proper duct insulation isn’t an efficiency upgrade. It’s moisture control. We use materials rated for the temperature and humidity swings this coastline experiences, not products meant for drier inland climates.
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.
Trusted Brands We Service in Greenwich
We carry and install components from Rotobrush, Nikro, Abatement Technologies, and Guardsman — brands we specify because they perform in demanding environments. For Greenwich’s larger estate systems, we stock transitional fittings, mastic compounds, and insulation wraps that match the non-standard dimensions common in retrofitted historic homes. That inventory means faster turnaround on repairs that would otherwise require special-order parts. When we’re sealing ductwork in a Back Country home with custom-fabricated transitions, we don’t wait two weeks for a fitting to arrive. We build it, seal it, and verify it — same visit.
Common Duct Repair & Sealing Problems We See in Greenwich Homes
- Disintegrating interior duct liner in 1960s–70s sheet-metal ducts. Mid-century ranches and split-levels in Cos Cob and eastern Greenwich neighborhoods often retain original ductwork with fiberglass interior liner that has degraded over 50–60 years. The material sheds particulate into the airflow, visible as fine dust at supply registers. We identify this with camera inspection and recommend repair or replacement before air quality testing confirms elevated fiberglass counts.
- Failed mastic seals at trunk-to-flex connections in estate ductwork. Back Country homes with multi-zone systems frequently show static pressure imbalances traced to connections that were never properly sealed, or where original mastic has cracked after decades of thermal cycling. We measure the imbalance, locate the leaks, and reseal with fresh mastic — then re-test to confirm the zone is balanced.
- Uninsulated return ducts in coastal crawlspaces condensating and molding. Old Greenwich and Riverside properties along Long Island Sound experience humidity infiltration that inland towns don’t match. Return ducts in unconditioned spaces become condensation surfaces, supporting biological growth that spreads through the supply side. We insulate and seal these runs, addressing the moisture source, not just cleaning the symptom.
- Successive renovation splices creating airflow chaos. In 06831 and mid-country zones, we’ve found galvanized trunk lines with three or four generations of flex duct additions, often in incompatible diameters and with no balancing dampers. The system “works” in the sense that air moves, but rooms are chronically uneven in temperature and the HVAC equipment runs longer than necessary. We map the system, identify the critical restrictions, and repair or reconfigure for proper airflow.
Pricing for Duct Repair & Sealing in Greenwich, CT
Here’s what duct repair and sealing costs in Greenwich’s market, based on the actual jobs we’ve completed:
| Service | Typical Range in Greenwich |
|---|---|
| Mastic sealant application (standard residential system) | $275–$450 |
| Flex duct repair/replacement (single run, accessible) | $180–$340 |
| Flex duct repair (finished attic, limited access) | $340–$550 |
| Custom metal fabrication and transition repair | $450–$850 |
| Duct insulation repack (return or supply run) | $220–$480 |
| Full-system assessment with static pressure testing | $150–$250 (credited toward repair) |
Greenwich’s estate homes run toward the higher end of these ranges due to system complexity, access difficulty, and the custom fabrication that irregular ductwork often requires. Mid-century ranches in Cos Cob typically fall in the middle. We provide exact quotes after inspection — no open-ended billing, no surprises. Estimates are free. Call (866) 531-5603 to schedule.
We Also Serve Cities Near Greenwich
We regularly repair and seal ductwork in Cos Cob (where mid-century sheet-metal systems are common), Riverside and Old Greenwich (coastal humidity specialists), and across the New York line in Port Chester and Rye Brook. If you’re in these communities and dealing with duct leaks, temperature imbalance, or post-renovation airflow problems, we cover your area with the same equipment and owner-led service.
Serving Greenwich, CT — Our Local Coverage Area
We’re based in the Greenwich 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 Greenwich
Failed connections between original galvanized trunk lines and later-added flex duct, often sealed originally with duct tape or inadequate mastic that has degraded over 20–40 years. We find these leaks with pressure testing and smoke sticks, then fabricate proper metal transitions and seal them with fresh mastic. Call (866) 531-5603 and we’ll locate your leaks — estimates are free.
We replace the damaged section with properly supported new flex duct, never just straightening and reusing crushed material that will restrict airflow permanently. In Greenwich’s finished attics — common in Back Country estate renovations — we often need to create access through knee walls or soffits, then restore finishes. We plan this work with you before cutting anything. For an exact quote on your specific access situation, call (866) 531-5603.
Yes — mastic is trowel-applied and conforms to any surface geometry, which is why we specify it for the non-standard transitions common in Greenwich’s retrofitted historic homes. Unlike tape products that fail on irregular surfaces or in damp crawlspaces, mastic bonds to properly prepared metal, fiberglass, and flex duct and remains flexible through decades of thermal cycling. We verify every sealed joint with static pressure testing before we leave.
We can, though the approach depends on liner condition. Where liner is actively shedding fiberglass into the airstream, we typically recommend removal and replacement with modern, non-shedding materials, or in some cases full duct replacement if the metal shell has also corroded. We inspect with a camera first so you know exactly what you’re dealing with. Call (866) 531-5603 to schedule a camera inspection in Cos Cob — we’ll show you what we see.
We plan access routes with you in advance, use existing mechanical rooms and service chases where possible, and protect finished surfaces with masonite or ram board when we must work in finished spaces. On the 1920s Tudor repair we mentioned, we accessed the attic splice through an existing closet, not through the plaster ceiling below. Matthew Gonzalez personally oversees this protection on every estate job — no exceptions. Call (866) 531-5603 to discuss access planning for your specific home.
Written by Matthew Gonzalez, Owner at Elite Air Duct Cleaning Service Connecticut, serving Greenwich since 2004.