Fast, Reliable Duct Repair & Sealing Across Kensington
Duct repair and sealing in Kensington typically costs between $180 and $650 depending on whether we’re patching a single flex-duct run or resealing an entire retrofit system, and most jobs are completed in one visit. We’re Bellows Air Duct & Vent Co. of New York, and we’ve been driving to Kensington since 1984 - long enough to know that the ductwork in these row houses doesn’t behave like anything you’ll find in a suburban manual. If your vents are blowing weak, your upstairs rooms won’t cool, or you’re paying Con Ed bills that don’t match your square footage, call us at (833) 348-8789. We’ll answer live, 24 hours a day, and give you an upfront price before we touch a single tool.
Kensington sits along the Coney Island Avenue corridor in central Brooklyn, ZIP 11218, a dense grid of pre-war brick row houses built mostly between 1910 and 1940. These homes were never designed for forced air. The duct systems we’re called to repair are mid-century retrofits, often improvised through closets, dropped ceilings, and party-wall cavities. That matters because standard repair protocols - the kind developed for tract homes in Long Island or New Jersey - routinely fail here. Our Duct Repair & Sealing team knows the difference. We’ve worked in the narrow attic spaces above Albemarle Road, threaded flex duct through the tight crawl gaps near Cortelyou Road, and navigated the subdivided units that turn a simple supply-trunk repair into a coordination job between two households. We don’t guess. We camera-inspect first, show you what we’re seeing, and then we fix it.
Why Bellows Air Duct & Vent Co. of New York Is Kensington’s Preferred Duct Repair & Sealing Company
We’ve served Brooklyn homeowners for over 42 years, and Kensington has been on our route map since the beginning. Lou Ferrante built this company on a straightforward idea: show the customer the problem before you quote the fix, quote the fix before you lift a tool, and stand behind the work for 90 days with no paperwork if something’s not right. That approach travels well in Kensington, where homeowners have seen enough bait-and-switch contractors to know the difference between a coupon price and a square deal.
Our response time to Kensington is same-day or next-day for most calls, and we schedule with an eye toward the parking realities along Coney Island Avenue and the side streets between Cortelyou and Ditmas. Our technicians are background-checked, uniformed, and equipped with Rotobrush and Nikro gear that fits the tight clearances these row houses demand. Every job gets a camera inspection before and after - a visual record, not a claim. And our 90-Day Done Right Promise is stamped on every invoice: if it’s not right, we return at no charge. No forms to fill out, no arguments.
We also offer a standing $50 Off Any Repair Over $250, a Free Second Opinion on Any Written Estimate, and a permanent 5% Senior and Veteran discount. The price we give on the phone is the price on the bill. We’ve never believed in surprise charges at the door, and we never will.
Our Duct Repair & Sealing Services in Kensington
Duct Sealing
Leaky ducts are the single biggest efficiency killer in Kensington’s retrofit systems. We use blower-door testing and smoke pencils to locate leaks in trunk lines, branch ducts, and register boots - then seal them with mastic or foil-backed tape rated for the application. In Kensington specifically, we see a lot of leakage at non-standard joints where original steam-radiator chases were repurposed as duct cavities. These aren’t catalog parts. They need a technician who recognizes the geometry and knows how to seal it without damaging the surrounding plaster or lath. We camera-verify every seal before we leave.

Flex Duct Repair
Flex duct doesn’t age gracefully in Brooklyn’s humidity, and Kensington’s tight attic spaces accelerate the problem. Crushed, torn, or disconnected flex runs are common above the second and third floors of row houses near Albemarle Road and Cortelyou. We replace damaged sections with insulated flex rated for the run length, support it properly to prevent sagging, and seal all connections with mastic. In some Kensington homes, the only access to a failed flex run is through a neighbor’s closet or ceiling - a scenario we’ve handled many times, always with written permission and coordination between tenants.

Metal Duct Repair
Where original galvanized trunk lines survive in Kensington’s retrofits, they often suffer from rust at low points, separated seams from thermal expansion, or damage from decades of amateur modifications. We patch small rust-throughs with galvanized sheet metal and sealant, re-seam separated joints with drive cleats and mastic, and replace sections that are too far gone. The metalwork in these old systems is rarely standard gauge or dimension, so we fabricate custom patches on site rather than forcing catalog parts to fit.

Duct Insulation & Mastic Sealant
Uninsulated or poorly insulated ducts in Kensington lose conditioned air to hot attics and cold exterior walls before it ever reaches the register. We wrap supply trunks and branch lines with fiberglass insulation jacketed with vapor barrier, sealed at all seams with mastic. For the non-standard joints common in retrofit systems, we use heavy-bodied mastic sealant from Abatement Technologies - the same product serious commercial contractors specify - because it flexes with thermal cycling and holds up under Brooklyn’s humidity spikes. We also account for the elevated diesel particulate along Coney Island Avenue, specifying insulation and filtration upgrades where soot degradation is a known risk.

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.
Trusted Brands We Service in Kensington
We stock parts and specify equipment from the brands that HVAC professionals actually trust: Rotobrush for duct cleaning and agitation tools that fit tight residential runs, Nikro for high-velocity vacuum and extraction equipment, and Honeywell for zone controls and air-quality accessories. For Kensington customers, this means we don’t order parts from a catalog and make you wait a week. Our trucks carry the common fittings, sealants, and flex sizes these row-house retrofits demand. Most repairs are completed in a single visit because we’ve seen these systems before and we know what breaks.
Common Duct Repair & Sealing Problems We See in Kensington Homes
- Subdivided row-house access issues. A single supply trunk originally serving one family now straddles two or three legal apartments, and repairing it requires written access through a neighbor’s unit. Technicians unfamiliar with Brooklyn’s conversion-era housing often damage party-wall cavities trying to force access from the wrong side.
- Mastic failure in humid drop ceilings. Improper mastic application on non-standard joints in dropped-ceiling plenums fails under Brooklyn’s summer humidity, causing recurring leaks that homeowners mistake for new problems. We use the right product for the joint type and verify cure conditions.
- Diesel soot accelerating insulation degradation. Kensington’s location along the dense Coney Island Avenue corridor exposes homes to elevated particulate loads that standard residential filters don’t catch. Duct insulation installed without accounting for this contamination breaks down faster and leaks sooner.
- Steam-radiator retrofit chaos. Original 1910s-1930s homes with no ductwork were later fitted with forced air through any available cavity, resulting in sharp turns, crushed flex, and supply runs that terminate in closets or behind radiators. Standard repair estimates routinely underestimate the scope of these systems.
Pricing for Duct Repair & Sealing in Kensington, NY
We’re upfront about numbers because nobody likes a surprise on the bill. Here’s what duct repair and sealing typically runs in Kensington’s market:
- Single flex-duct repair or replacement: $180-$340
- Mastic sealing of branch lines and register boots: $220-$450
- Metal duct patch or seam repair: $260-$480
- Duct insulation wrap (per trunk or branch run): $180-$350
- Full system resealing with blower-door verification: $550-$950
- Complex multi-unit access repair (subdivided row house): $400-$650
What moves the needle: access difficulty, whether we’re working through a neighbor’s unit, the condition of existing insulation, and whether the system needs filtration upgrades to handle Coney Island Avenue particulate loads. We disclose the full price before we start - every time. Estimates are free, and our $50 Off Any Repair Over $250 applies automatically. Call (833) 348-8789 for your exact quote.
We Also Serve Cities Near Kensington
Our service area covers the central Brooklyn neighborhoods that share Kensington’s housing stock and challenges. We regularly repair ductwork in Flatbush, Borough Park, Brooklyn broadly, and Park Slope - each with its own retrofit quirks, but all within the same pre-war row-house tradition. If you’re searching for Duct Repair & Sealing in Kensington or any of these nearby communities, we’re the same drive away. Same technicians, same camera inspection, same 90-Day Done Right Promise.
Serving Kensington, NY - Our Local Coverage Area
We’re based in the Kensington 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 Kensington
Because many Kensington row houses were originally single-family homes later subdivided into two- or three-family dwellings, and the retrofit ductwork was installed before those legal boundaries existed. A supply trunk serving your second-floor apartment may run through a closet or ceiling that now belongs to the first-floor tenant. We coordinate written access, schedule around both households, and complete the repair without disturbing either tenant’s space. Call (833) 348-8789 to discuss access logistics for your building - estimates are free.
Heavy-bodied mastic sealant, applied with a brush or caulking tube and reinforced with fiberglass mesh at stress points. Foil tape alone fails on the non-standard joints and thermal expansion cycles common in Kensington’s improvised ductwork. We specify mastic rated for the joint type and verify it’s cured properly before pressurizing the system. For a sealant assessment on your specific setup, call us at (833) 348-8789.
The dense diesel traffic along Coney Island Avenue elevates particulate levels that standard residential filters don’t capture, accelerating contamination and insulation degradation in low-filtration retrofit systems. We see faster duct soiling and more frequent insulation failure in homes within a block or two of the corridor. Upgrading filtration and inspecting insulation condition during repair visits prevents repeated callbacks. Ask about filtration upgrades when you call (833) 348-8789.
Yes. We’ve replaced crushed and disconnected flex duct in attic clearances as tight as 18 inches above Kensington’s third-floor ceilings. Our Rotobrush tools and compact Nikro vacuums fit where standard equipment won’t, and we support new flex properly to prevent the sagging that caused the original failure. Most attic flex repairs run $220-$400 and finish in one visit. Call (833) 348-8789 to schedule a camera inspection.
Because there was no ductwork at all until someone retrofitted forced air decades after construction. Installers routed supply and return runs through any available cavity - old chimney chases, closet soffits, dropped ceilings, party-wall gaps - resulting in sharp turns, uneven airflow, and access points that make no sense on paper. We recently sealed a flex-duct leak in a Coney Island Avenue row house where the original steam-radiator system had been retrofitted with forced air, and the supply run serving the second-floor apartment was only accessible via a closet in the first-floor unit. Using Rotobrush tools and mastic sealant, we restored airflow without disturbing either tenant’s space. These systems require a technician who reads the house, not the manual. Call (833) 348-8789 if yours needs attention.
We’re here when you need us. Calls are answered by a live person, 24 hours a day - not a voicemail, not an app. Lou Ferrante and our team at Bellows Air Duct & Vent Co. of New York have served Brooklyn homeowners for over 42 years, and we know Kensington’s row houses because we’ve worked in them for decades. Whether you’ve got a single leaky register boot or a subdivided building with ductwork crossing unit boundaries, we’ll camera-inspect, quote upfront, and stand behind the work for 90 days. No bait coupons. No price changes at the door. Just a square deal, done right.
Call (833) 348-8789 now for your free estimate.
Written by Lou Ferrante, Owner at Bellows Air Duct & Vent Co. of New York, serving Kensington since 1984.