Duct Sealing in Boston - Tested First, Written Price Second

Fast, Reliable Duct Sealing Across Boston

Duct sealing in Boston typically costs $800 – $2,400 per system depending on accessibility, and most jobs are completed in one day with written pricing agreed before any work begins. We’re Hollis Air Duct Cleaning, part of the Garrison Partners family, and our Boston office dispatches crews to triple-deckers in Dorchester, rowhouses in Back Bay, and colonials in West Roxbury with the same standard: arrive inside the window, price it in writing, leave the site clean. Call (361) 326-5060 for a free estimate – we’ll look at your layout and give you a number that doesn’t move at the door.

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Why Hollis Air Duct Cleaning Is Boston’s Preferred Duct Sealing Company

We’ve been in business since 2004, and our Boston crews know the difference between a standard suburban ranch and a 1920s triple-decker with flex duct snaked through a closet chase. That matters because duct sealing in Boston is rarely a simple tape-and-go job – it’s often about separating shared returns, rebalancing airflow between floors, and documenting pressure changes you can’t see with your eyes.

Our technicians are background-checked and uniformed, and we follow The Garrison Code on every job: written price before work starts, 365-Day Done Right Promise backed in writing, and a free second visit if the repair fails. Phones are answered by a live person 24 hours a day, 7 days a week – no voicemail loops, no callback queues.

We serve Boston from our local metro office, with crews regularly working in Somerville, Cambridge, Chelsea, and Everett. Whether your system is in a converted attic in Jamaica Plain or a basement mechanical room in South Boston, we’ve likely sealed something similar.

Duct Repair in Boston

Duct Repair in Boston often starts with a homeowner noticing uneven heating between rooms, or a system that runs constantly without catching up. In this city’s housing stock – triple-deckers built between 1880 and 1930, brick rowhouses with retrofitted HVAC, mid-rise pre-war apartments – the problem is rarely a single failed component. It’s usually decades of patchwork repairs, corroded metal at uninsulated attic joints, or flex duct that has pulled loose from its collar.

Our crews use Rotobrush rotary systems and Nikro negative-air machines to access and clean the line before sealing, because mastic won’t bond to dust-coated metal. We document the repair with before-and-after photos and a written report you keep.

Corroded Metal and Rust-Through

Boston’s freeze-thaw cycles and coastal humidity attack uninsulated ductwork in attics and basements. We cut out corroded sections, splice in new galvanized metal or insulated flex, and seal with mastic rated for the temperature swing. The price is written before we cut.

Disconnected Flex and Collar Failures

In older retrofits, flex duct was often jammed through chases with inadequate support. Sagging creates turbulence and leaks. We rehang with proper strapping, replace crushed sections, and seal every joint with mechanical fasteners plus mastic – not duct tape, which fails in Boston’s humidity within a season.

Air Duct Sealing in Boston

Air Duct Sealing in Boston is fundamentally different from sealing in newer construction because the ductwork was often an afterthought. In triple-deckers, you frequently find shared returns between units, supply runs that were cobbled together across renovations, and no central chase designed for HVAC. Sealing here means addressing the whole system path – supply and return – or you risk pulling unconditioned air, odors, or even smoke from adjacent units.

We use professional-grade sealing mastic and mechanical connections, with camera verification and blower-door testing to prove the result. Every job gets a written price before we start and falls under our 365-Day Done Right Promise.

Shared Return Separation

In Boston’s triple-deckers, the return side is often a shared plenum or a party-wall chase rather than individual per-unit returns. Sealing the supply ducts without sealing the shared return leaves cooking odors and smoke migrating between units – a code and health problem unique to this housing type. We seal shared returns with mastic and mechanical connections, then rebalance supply and return for each unit independently.

Pressure Testing and Documentation

Because you cannot see inside plaster walls, we run a blower-door test before and after sealing to measure actual leakage reduction. You get the numbers in writing. If the improvement doesn’t meet our standard, we keep working until it does – that’s The Garrison Standard.

We were called to a three-unit triple-decker in Dorchester where the top-floor tenant complained of cigarette smoke in the bedroom. A camera inspection showed the second-floor return was physically connected to the third-floor return through an old party-wall chase, so we sealed the shared return with mastic and a mechanical connection, then rebalanced supply and return ducts for each unit. After the work, the third-floor tenant reported no smoke, and our blower-door test showed return leakage dropped enough that the upper unit’s system was no longer pulling air from below.

Trusted Brands We Service in Boston

Our Boston crews carry equipment and parts from Rotobrush, Nikro, and filtration brands including Aprilaire and Guardsman. We stock mastic, mechanical fasteners, and insulated flex duct sized for the narrow chases common in Boston’s older buildings. That means faster turnaround – we don’t wait for parts to ship while your system leaks conditioned air into the attic. For homeowners in historic districts or with specialized filtration needs, we also source Abatement Technologies products when the job calls for HEPA-level containment or negative-air isolation during the work.

Common Duct Sealing Problems We See in Boston Homes

• Shared returns in triple-deckers letting odors migrate between units. One neighbor’s cooking or smoke ends up in another’s bedroom because the return plenum was never properly separated. We seal and rebalance each unit independently.
• Duct tape failing on plaster-embedded chases within a single season. Boston’s coastal humidity and freeze-thaw cycles destroy non-NADCA-approved sealants. We use mastic rated for the temperature swing and mechanical backup.
• Uninsulated attic and basement runs corroding from condensation. Pre-1930 rowhouses have metal duct in unconditioned spaces that sweats in summer and rusts in winter. Sealing over active corrosion traps moisture – we replace corroded sections first, then seal.
• Supply-only sealing that ignores the return side. A homeowner pays for sealing but still feels drafts because the return leaks pull basement air or neighbor’s air. We test and seal the complete loop.

Pricing for Duct Sealing in Boston, MA

We Also Serve Cities Near Boston

Our Duct Sealing crews work throughout the metro area, including Somerville, Cambridge, Chelsea, and Everett. Same standard, same written pricing, same 365-Day Done Right Promise. If you’re unsure whether your address falls in our service radius, call (361) 326-5060 and we’ll confirm.

FAQs About Duct Sealing in Boston