Duct Repair & Sealing in Cambridge, MA - Same-Day Service, Done Right the First Time

Fast, Reliable Duct Repair & Sealing Across Cambridge

Duct repair and sealing in Cambridge typically runs $180-$650 depending on access difficulty and material type, with most jobs completed in a single visit. We answer calls live 24 hours a day, and our technicians are usually on-site in Cambridge within hours, not days.

Call (844) 685-6342

We’ve been driving to Cambridge since 1984, and we know the difference between a quick fix and a proper repair. In a city where most housing was built before World War II as triple-deckers, Victorian multi-families, and brick row houses, ductwork was never part of the original plan. These homes were designed for steam radiators. When forced-air systems were retrofitted decades later, contractors routed ducts through old plaster walls, chimney chases, and cramped basement ceilings. That history lives in every access panel we open. Our Duct Repair & Sealing team carries flexible equipment and specialized techniques that standard suburban crews rarely need. We work around Cambridge’s tight clearances, alley-load entries, and parking constraints every day. If your ducts are leaking conditioned air into walls, pulling musty basement air upstairs, or simply not delivering airflow where it should, call (844) 685-6342. We’ll show you exactly what’s wrong with a camera inspection, quote one honest price before we start, and back the work with our 90-Day Done Right Promise in writing.

Why Bellows Air Duct & Vent Co. Is Cambridge’s Preferred Duct Repair & Sealing Company

Cambridge homeowners call us because we’ve earned their trust over four decades, not because we bought it with a coupon. Our reputation here was built one triple-decker at a time. We show up when we say we will. Our technicians are background-checked, uniformed, and trained to work in the tight, irregular spaces that Cambridge’s retrofitted duct systems demand.

Ray Castillo, who leads Bellows, has insisted since 1984 that every job include camera-verified results. Before we touch a tool, you see what we see. After we finish, you see the difference. No claim without proof. Our 90-Day Done Right Promise means if the repair fails, we return at no charge with no paperwork to argue over. We stand behind it.

Calls to our office are answered by a live person, 24/7. Not voicemail. Not an app. A real person who can dispatch a technician to Cambridge, check availability, and give you a straight answer about timing. Most repairs are completed in a single visit because our trucks carry the parts and materials these old systems actually need.

We understand Cambridge’s housing stock in a way that matters for your repair. We know that a “basement” in North Cambridge might be a dirt-floored crawlspace with a 4-foot ceiling. We know that duct runs in Inman Square often disappear into finished closets or behind drywall that a previous owner installed in 1987. We know that Central Square triple-deckers frequently share duct systems across floors with access panels that haven’t been opened in twenty years. That knowledge saves you time and money.

Our Duct Repair & Sealing Services in Cambridge

Duct Sealing

Leaky ducts waste 20-30% of conditioned air in a typical Cambridge home, and that percentage climbs higher in retrofitted systems with non-standard joints. We seal ductwork with mastic sealant and reinforced mesh tape, the combination that holds up against Cambridge’s freeze-thaw cycles where cheaper tape fails. In older metal duct systems common in Cambridge’s pre-1940 housing, we inspect every joint and seam, then apply sealant rated for the temperature swings these basements experience. A typical duct sealing job in Cambridge runs $250-$550 for a single-family or condo unit, with per-opening sealing at $45-$85 depending on accessibility. We offer $50 off any repair over $250.

Flex Duct Repair

Flex duct is vulnerable in Cambridge’s conditions. Rodents, moisture, and physical compression all take their toll, especially in the kneewall spaces and crawlspaces where so much of this city’s retrofitted ductwork was routed. We replace crushed or torn flex duct with new, properly supported runs, and we always check the surrounding conditions. If your flex duct is in an uninsulated Cambridge basement or crawlspace, we’ll tell you honestly whether repair alone is enough or whether insulation should be part of the conversation. Flex duct repair in Cambridge typically costs $180-$340 per run, with most jobs completed in under two hours.

Metal Duct Repair

Cambridge’s older metal duct systems, often galvanized steel routed through basement joists or repurposed chimney chases, develop rust at seams, separated joints from building settlement, and holes from decades of vibration. We repair these with proper sheet metal patches, sealed with mastic, not duct tape. Duct tape dries and fails; mastic flexes and endures. For metal duct repair in Cambridge, expect $220-$480 depending on the extent of damage and whether we need to fabricate custom fittings to match non-standard dimensions these old systems often require.

Duct Insulation

Cambridge sits in the humid Charles River basin, and that geography creates a specific problem: condensation inside uninsulated ductwork in poorly ventilated basements and crawlspaces. The combination of muggy summers and freeze-thaw winters drives repeated condensation cycles that promote mold and mildew colonization inside duct cavities. We insulate ductwork with formaldehyde-free fiberglass wrap or closed-cell foam where appropriate, creating a thermal barrier that stops condensation before it starts. Duct insulation in Cambridge runs $3.50-$6.00 per linear foot, with typical partial-system jobs falling between $300-$700.

Mastic Sealant Application

Mastic is our preferred sealant for Cambridge’s older metal duct systems because it remains flexible through temperature extremes that crack lesser products. We apply it with a brush or spray depending on access, then embed mesh tape at stress points for reinforcement. In Cambridge’s retrofitted systems, where ducts often pass through irregular chases and tight joist bays, mastic’s ability to seal around complex geometries makes it the practical choice. Mastic sealant work is typically bundled with broader sealing or repair jobs, with standalone small-area application starting around $150.

Air Leak Repair

Air leaks in Cambridge duct systems often occur at the worst possible locations: behind finished walls, above dropped ceilings, or in the inaccessible corners of old chimney chases. We locate these leaks with blower-door-assisted pressure testing and infrared scanning, then repair them with the least invasive access method possible. Sometimes that means a small access cut. Sometimes it means working through an existing panel. We always discuss the approach with you before cutting anything. Air leak repair in Cambridge ranges from $200 for accessible single leaks to $600+ for multiple leaks requiring diagnostic time and selective access.

Trusted Brands We Service in Cambridge

We carry professional-grade equipment and materials from Nikro, Honeywell, and Aprilaire, the same brands serious HVAC contractors specify for demanding installations. Our trucks stock flexible duct in common diameters, mastic sealant, reinforced mesh tape, and insulation materials sized for the non-standard dimensions we encounter in Cambridge’s older housing. That inventory means we don’t make two trips. When we find a failed Honeywell zone damper in a Cambridge triple-decker or an Aprilaire media cabinet with a separated duct connection, we repair it with parts that match the original specification. Fast turnaround matters in a city where many residents work long hours and need the job done in the window they have available.

Common Duct Repair & Sealing Problems We See in Cambridge Homes

• Leaking mastic seals in basement joist duct runs. Cambridge’s freeze-thaw cycles crack aged sealant that was applied decades ago in unconditioned basements. We scrape out the old material and reseal with modern, flexible mastic rated for the temperature swings these spaces experience.
• Hidden access panels behind drywall or in closets, left unrepaired. In retrofitted systems throughout Central Square and North Cambridge, previous contractors or homeowners covered access panels during renovations. Unsealed joints behind these panels leak conditioned air continuously. We locate the panels, restore access, and seal what we find.
• Condensation and mold in uninsulated flex duct routed through crawlspaces. The Charles River basin’s humidity penetrates poorly ventilated crawlspaces where flex duct was often routed as a retrofit shortcut. We repair or replace damaged duct and recommend insulation where the environment demands it.
• Rodent damage in flex duct runs near exterior walls and foundation gaps. Cambridge’s dense housing and mature tree canopy support active rodent populations. We repair gnawed flex duct with new material, then seal the duct system against re-entry where building conditions allow.

Pricing for Duct Repair & Sealing in Cambridge, MA

We Also Serve Cities Near Cambridge

Our technicians work throughout the metro area. If you’re in Somerville, Brookline, Medford, or Boston and dealing with leaky ducts, hidden access panels, or retrofitted systems that never seem to deliver proper airflow, we cover your area too. We know the similar housing stock in Somerville’s triple-deckers, the converted Victorians in Brookline, and the mixed-era construction in Medford. Our Cambridge service area extends to these neighboring communities with the same response standards and upfront pricing. Call to confirm coverage for your specific address.

FAQs - Duct Repair & Sealing in Cambridge