Duct Sealing in Chelsea - Tested First, Written Price Second

Fast, Reliable Duct Sealing Across Chelsea

Duct sealing in Chelsea typically runs $450 – $1,200 for a whole-house system, with most triple-decker jobs falling between $650 and $950 depending on how many runs need attention. We dispatch crews from our Boston office and carry the tools and materials to seal galvanized, flex, and duct-board systems in the older homes that dominate this city. If your second-floor unit never gets warm or your basement air handler smells musty every July, the problem is usually leaks in the ductwork, not the furnace itself. Call (361) 326-5060 for a free estimate; we’ll put the price in writing before any work starts.

Call (361) 326-5060

We’ve been sealing ducts in Chelsea since 2004, and we’ve learned that this city’s housing stock doesn’t behave like the newer suburbs. The triple-deckers in Prattville and Cary Square, the pre-war multi-families near Bellingham Square, the converted industrial lofts along the waterfront – they all have specific failure patterns that a crew fresh from a cookie-cutter development won’t recognize. Our technicians are background-checked, uniformed, and trained on The Garrison Code: arrive inside the window, price in writing, complete the job by the book, leave the site clean. That’s the standard on every Duct Sealing in Chelsea job we take.

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

Chelsea homeowners know the difference between a crew that treats their building like a generic job and one that understands what a 1920s triple-decker demands. We’ve sealed ducts in the unheated attics of Cary Square, the damp basements of Prattville, and the converted mill spaces near the Mystic River. Our reputation here is built on showing up when we said we would and leaving the system tighter than we found it.

Our phones are answered by a live person 24 hours a day, 7 days a week. No voicemail loops, no callback queues, no waiting until Monday to schedule. When you call (361) 326-5060, you talk to a human who can book your appointment, explain what the technician will do, and email you a confirmation with your technician’s name and photo. Background-checked, uniformed, accountable.

The 365-Day Done Right Promise covers every sealing job we do in Chelsea. If the seal fails, if a connection loosens, if airflow drops back to where it was, we come back and make it right at no charge. That includes a free second visit. It’s not a verbal assurance; it’s written on every invoice.

Dispatch and scheduling for Chelsea are coordinated from our Boston office, but the crews serving you live and work in the metro area. They know the traffic patterns on Route 1 and Everett Avenue, the parking constraints near Bellingham Square, and the access challenges of a triple-decker with a narrow driveway. That local knowledge saves time on the job, which saves you money.

Duct Repair in Chelsea

Duct Repair in Chelsea is rarely a simple patch job. The galvanized steel runs in pre-1950 triple-deckers have had decades to rust through, especially where they pass through unheated attics and crawl spaces. We start every repair with a camera inspection to see what we’re dealing with: crushed returns, disconnected branch takeoffs, rust holes pulling attic air into the supply side, or duct board that’s soft from moisture damage.

A typical duct repair in Chelsea runs $280 – $650 for a single run or section replacement. If the damage is extensive – multiple rusted sections, a collapsed trunk line, or mold-contaminated duct board – the repair can reach $800 – $1,400. We always inspect before we quote. The price you approve in writing is the price you pay.

Crushed or Disconnected Runs

Triple-deckers share trunk lines between units, and vibration over decades can shake branch takeoffs loose. We find this constantly in Chelsea attics. A disconnected return doesn’t just waste heated air; it pressurizes the wall cavity and pulls in dust, insulation fibers, and whatever else is back there. We reconnect with mechanical fasteners and seal with mastic rated for the temperature swing these attics see.

Rusted Galvanized Replacement

Once a galvanized duct wall rusts through, mastic won’t hold. The metal is too thin and too uneven. We cut out the damaged section and splice in new galvanized or switch to insulated flex duct where space allows. In Prattville, we’ve replaced entire attic trunks that had turned to lace from the inside out. The tenant’s heat finally reached the back bedroom. The musty smell cleared.

Air Duct Sealing in Chelsea

Air Duct Sealing in Chelsea is often the critical step that makes cleaning worth doing. You can pull decades of debris out of a duct system, but if the supply side is still leaking 30% of its air into an unheated attic, you’re heating the rafters and paying for it. We seal after we clean, not before, because sealing over contaminated ducts traps mold spores and construction dust against the fresh mastic.

Whole-system air duct sealing in Chelsea typically costs $450 – $1,200. A small single-family or one unit in a triple-decker with accessible ductwork runs toward the lower end. Larger systems, multiple floors, or jobs requiring attic or crawl-space access push toward the higher end. We itemize everything in writing before we start.

Mastic and Mesh Application

We use Guardsman reinforcement mesh embedded in water-based duct mastic for seams and joints. This isn’t foil tape from the hardware store; it’s a permanent, flexible seal that moves with the metal as it expands and contracts through Chelsea’s temperature swings. The mesh prevents the mastic from cracking when the furnace kicks on and the duct goes from 40 degrees to 140 in minutes.

Pressure Testing After Sealing

After we seal, we test. A manometer measures static pressure at the air handler and at key supply registers. If the pressure differential hasn’t improved, we haven’t found all the leaks. In Cary Square triple-deckers, we’ve found leaks at register boots that looked tight but were pulling air through the drywall cutout. We seal what others miss because we test what we seal.

Trusted Brands We Service in Chelsea

Our vans carry professional-grade equipment from Rotobrush, Nikro, and Abatement Technologies, plus sealing and filtration products from Honeywell, Aprilaire, and Guardsman. For Chelsea’s older housing stock, that means we have the rotary brush systems to agitate debris out of rectangular galvanized trunk lines, the negative-air machines to maintain containment in occupied multi-family buildings, and the mastic and mesh to seal joints that have been leaking since the Eisenhower administration. We don’t make a separate trip for materials. The van arrives stocked, the job finishes in one visit, and your written price doesn’t change because we “had to order something special.”

Common Duct Sealing Problems We See in Chelsea Homes

• Rusted galvanized attic runs. In Prattville and Cary Square triple-deckers, pre-1950 galvanized duct routed through unheated attics sweats all winter. The condensation rusts the metal from the inside until it leaks heated air into the rafters. Sealing mastic alone won’t bond to rust scale; the damaged section has to be cut out or sleeved.
• Disconnected shared trunk takeoffs. Triple-deckers often have one main supply trunk with branch ducts to each floor. Vibration and thermal cycling shake these branches loose over decades. Sealing the registers on one floor does nothing if the break is in the common trunk above the ceiling.
• Mold at the air handler. Chelsea’s humid summers and poorly ventilated basements breed mold on duct board and flex duct near the furnace. Sealing over contaminated material traps spores and makes the problem worse. We clean first, treat if necessary, then seal clean surfaces.
• Attic air infiltration through return leaks. A rusted return duct in an unheated attic doesn’t just lose air; it pressurizes the cavity and pulls in fiberglass insulation, rodent droppings, and dust from the 1920s. What you smell when the heat kicks on is often attic, not duct.

Pricing for Duct Sealing in Chelsea, MA

We Also Serve Cities Near Chelsea

Our crews seal ducts across the metro area, including Chelsea, Everett, Revere, Malden, and Boston. The same written price, the same 365-Day Done Right Promise, the same background-checked technicians at every stop.

FAQs About Duct Sealing in Chelsea