Fast, Reliable Duct Repair & Sealing Across Boston
Duct repair and sealing in Boston typically runs $280–$650 for most residential jobs, with same-week scheduling available throughout the city. We’re based in Lowell but regularly serve Boston homeowners — usually arriving within 45 minutes to an hour for appointments in Back Bay, Beacon Hill, and the North End. You can reach us at (877) 517-5646 for a free estimate.
We’ve spent 14 years working on duct systems, and Boston’s historic housing stock presents challenges you won’t find in newer markets. The brick rowhouses and brownstones built between 1800 and 1900 — Federal-era homes on Beacon Hill, Victorian brownstones in Back Bay, dense tenement blocks in the North End — were never designed for forced-air heating. When retrofits were added in the 1950s and 60s, contractors snaked uninsulated metal ducts through plaster-and-lath walls, floor cavities, and closet chases. Those systems are now 60–70 years old. Rust, collapsed flex runs, and failed seals aren’t exceptions here — they’re the norm.
Our Duct Repair & Sealing team treats these as whole-system problems, not patch jobs. Thomas Hernandez shows up as both owner and lead technician, with equipment built for remediation-grade work: Rotobrush rotary systems, Nikro negative-air machines, and Abatement Technologies HEPA containment. We don’t delegate to crews you haven’t met.
Why Titan Air Duct Cleaning Lowell Is Boston’s Preferred Duct Repair & Sealing Company
Boston homeowners have left us 389 verified reviews averaging 4.7 stars — not a handful of testimonials, but a track record you can verify. Many mention the same thing: Thomas arrives, diagnoses the actual problem, and fixes it without upselling equipment the house doesn’t need.
We’re in Boston regularly. From Lowell, we typically reach South Boston and the Seaport in under 40 minutes, Back Bay and Beacon Hill in 45–55 minutes, and the North End in about an hour depending on tunnel traffic. We schedule Boston appointments with buffer time for parking and building access — we know what it’s like finding a spot on Beacon Street or navigating a brownstone’s service entrance.
Our equipment matters here. Standard rotary brush rigs — the kind most residential crews carry — can’t reach duct runs that turn through three floors of original millwork. We bring Nikro high-powered reverse-air systems and flexible extension tools designed for exactly these configurations. Fourteen years, one specialty. Nothing else.
Our Duct Repair & Sealing Services in Boston
Duct Sealing with Mastic Sealant
Mastic sealant is our primary repair method for Boston’s older metal duct systems. The original retrofits in Beacon Hill and Back Bay brownstones used lap-jointed galvanized steel, sealed with cloth-backed tape that degrades after 40–60 years of thermal cycling. We remove failed tape, clean the joint surfaces, and apply water-based mastic rated for the temperature swings these systems see — from 120°F supply air in January to 55°F return air in summer when the masonry envelope is cooler than the humid outdoor air.
A typical mastic sealing job for a Boston brownstone’s main trunk and primary branches runs $280–$450. We pressure-test before and after so you see the actual leakage reduction.
Metal Duct Repair
Rust holes in uninsulated metal ducts are epidemic in Boston’s historic masonry buildings. The humid continental climate here drives moisture cycling through walls with no vapor barrier — summer dew points in the mid-60s°F meet winter air that’s bone-dry from heating, and the condensation inside cold duct runs corrodes steel from the inside out.
We recently repaired a leaking flex duct in a Beacon Hill brownstone where the 1950s retrofit had been run through a coal-chute chase. The original uninsulated metal trunk had holes from rust, and we sealed it with mastic and wrapped it with new insulation to stop the moisture damage that had rotted the adjacent lath. Metal duct repair with patch panels, custom transitions, and resealing typically runs $340–$580 in Boston, depending on access and extent of corrosion.
Flex Duct Repair & Replacement
Collapsed or crushed flex duct hides behind original millwork in Boston homes more often than you’d think. The 1950s retrofits used early flexible duct in tight chases where it was never meant to bend so sharply — or where later renovations compressed it. We find these with pressure-drop testing and borescope inspection, then replace with properly sized, insulated flex or convert to rigid where space allows. Flex duct repair or replacement in Boston typically runs $220–$420 per run.
Duct Insulation
Duct insulation is critical in Boston and often overlooked. The original retrofits left metal ducts bare inside masonry walls and floor cavities. In summer, those cold supply ducts sweat against humid air, promoting mold and dust-mite conditions that make annual or biennial cleaning more medically relevant here than in drier climates. We install fiberglass duct wrap with vapor-barrier facing, or closed-cell foam where space is tight. Duct insulation work in Boston brownstones typically runs $380–$650 depending on linear footage and access difficulty.
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 Boston
We stock parts and materials for the equipment we encounter most in Boston’s mixed housing stock: Honeywell electronic air cleaners and media filters, Aprilaire whole-house humidifiers and ventilation controls, and Abatement Technologies HEPA filtration and negative-air systems. For sealing and repair work, we source mastic, foil tape, and insulation from commercial-grade suppliers — not the hardware-store products that fail in two seasons. If your system includes these brands, we likely have what we need on the truck. If it’s a non-standard configuration from a 1960s retrofit, we fabricate transitions on-site. Either way, Boston customers don’t wait for parts orders from out of state.
Common Duct Repair & Sealing Problems We See in Boston Homes
- Rust holes in uninsulated metal ducts from decades of condensation cycling inside historic masonry walls. Boston’s humid summers and heated winters create year-round moisture stress that suburban basements with open ductwork simply don’t experience.
- Collapsed or crushed flex duct in tight chases behind original millwork, often discovered only when we pressure-test the system. These runs may have been damaged during a renovation 30 years ago and never detected.
- Failed mastic tape at lap joints in original retrofits, causing supply air to leak into wall cavities and return air to pull in attic dust and plaster debris. In Boston’s densely packed rowhouses, this also means you’re heating or cooling your neighbor’s wall void.
- Non-standard duct diameters — 5×10 rectangular, 8×6 oval, custom transitions — that require fabricated sheet metal rather than off-the-shelf fittings. We bring a brake and shear for exactly this reason.
Pricing for Duct Repair & Sealing in Boston, MA
| Service | Typical Range in Boston |
|---|---|
| Mastic sealing (main trunk + branches) | $280–$450 |
| Metal duct repair with patching/replacement | $340–$580 |
| Flex duct repair or replacement (per run) | $220–$420 |
| Duct insulation (wrap or foam) | $380–$650 |
| Full system assessment with pressure testing | $150–$220 (credited toward repair) |
What moves the price: access difficulty (single grille vs. full basement), extent of corrosion or damage, whether we need to fabricate custom transitions for non-standard sizes, and whether insulation removal is required. We don’t quote over the phone for complex Boston brownstone jobs — we need to see the access points and test the system. Estimates are free. Call (877) 517-5646 to schedule.
We Also Serve Cities Near Boston
We regularly work in South Boston, where newer condo conversions present different challenges than Back Bay brownstones; Chelsea, with its mix of triple-deckers and industrial-to-residential conversions; Winthrop, where salt air accelerates metal duct corrosion; and Cambridge, with its own stock of pre-1900 housing and Harvard/MIT institutional HVAC systems. Same technician, same equipment, same 4.7-star standard.
Serving Boston, MA — Our Local Coverage Area
We’re based in the Boston 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 Boston
Yes, in most cases. We evaluate the metal condition first — if the steel is structurally sound despite surface rust, mastic sealing and insulation wrapping restores performance for another 20+ years. If corrosion has perforated the duct walls, we patch or replace sections. Call (877) 517-5646 and we’ll inspect before quoting — estimates are free.
Usually yes. We seal from accessible points on your side and use pressurized smoke testing to verify that shared-wall leaks are stopped. In rare cases where the leak is mid-wall with no access, we coordinate with building management. We’ve done this in Boston’s dense tenement blocks before — there’s almost always a workable approach.
Yes, significantly. The musty smell comes from mold and dust mites thriving in cool, humid duct surfaces — exactly what happens when uninsulated metal runs through masonry walls in Boston’s humid summers. Sealing stops air leaks, and insulation prevents surface condensation. We’ve had customers report noticeable improvement within 48 hours of completion.
Yes. This is standard in Beacon Hill and Back Bay brownstones. We use high-powered reverse-air-sweep equipment and flexible borescope tools to reach duct runs far beyond the access point. In some cases we create a small additional access in a closet or service chase, which we patch and finish to match. Thomas has solved this exact problem dozens of times.
Yes. We fabricate custom transitions and fittings on-site with our sheet metal brake. Non-standard diameters from 1950s retrofits are common in Boston — 5×10 rectangular, 8×6 oval, 7-inch round — and we don’t try to force off-the-shelf parts that won’t seal properly. Call (877) 517-5646 for an exact assessment — estimates are free.
Written by Thomas Hernandez, Owner at Titan Air Duct Cleaning Lowell, serving Boston and surrounding communities since 2010.