Whole-system duct and dryer vent check with before-and-after photos - you see exactly what came out of your vents
That "$99 whole-house special" is a bait ad - the real number appears once they are in your hallway, or the "clean" is a shop-vac at the register. We photograph the inside of your ducts before and after instead.
Fast, Reliable Duct Sealing Across Brockton
Duct sealing in Brockton typically runs $800 – $2,400 for a whole-home system, depending on accessibility and the condition of the existing ductwork. Most Brockton homes we work on need sealing, not just cleaning, because decades of heating cycles and freeze-thaw stress have opened joints that a vacuum alone won’t fix. Call (361) 326-5060 for a written estimate before any work starts.
We serve Brockton from our Boston dispatch office, with crews running daily to neighborhoods from Campello and downtown to the post-WWII capes off West Elm Street. We’ve worked on enough triple-deckers, mill houses, and mid-century ranches here to know that Brockton ductwork has its own personality. The galvanized steel runs in a 1920s Pleasant Street triple-decker behave nothing like the flexible duct retrofits in a 1960s ranch near D.W. Field Park. That local familiarity matters when you’re deciding whether a joint needs mastic, a section needs replacement, or a converted coal chute needs to be sealed off entirely.
Why Hollis Air Duct Cleaning Is Brockton’s Preferred Duct Sealing Company
Hollis Air Duct Cleaning has been part of the Garrison Partners family since 2004. We operate under The Garrison Standard: written prices, written guarantees, and technicians who arrive uniformed, background-checked, and inside the quoted window. Our Duct Sealing team doesn’t negotiate at your door.
Our 365-Day Done Right Promise covers every sealing job in writing. If a sealed joint fails or a musty odor returns within a year, we come back at no charge, including a free second visit. No competitor in Brockton puts that in writing as standard practice.
Phones are answered by a live person 24 hours a day, 7 days a week. Scheduling is coordinated from our Boston office, but the crew that shows up knows Brockton’s housing stock cold: the coal-chute returns in Campello, the rusted galvanized steel in Montello, the crushed flexible ducts in south-side crawlspaces.
We price in writing before touching anything. The number on the page is the number on the invoice.
Duct Repair in Brockton
Duct Repair in Brockton usually means fixing disconnected joints, replacing rusted sections of galvanized steel, or rebuilding crushed flexible duct runs in tight crawlspaces. A typical repair in Brockton runs $350 – $950 for localized fixes, with whole-section replacements climbing toward $1,400 if we need to access basement chases or open wall cavities. We see the most repair calls from Campello, Montello, and the downtown triple-decker districts, where original ductwork from the 1920s – 1940s has simply reached the end of its service life.
Disconnected Return Joints
Our crew was called to a triple-decker on Pleasant Street in Campello where the homeowner complained of a musty odor and uneven heat. We found a disconnected return joint in the basement and a converted coal chute still acting as a return, with residual coal dust coating the interior. After a negative-pressure source removal cleaning and sealing the chute and joint with mastic, the odor was gone and the system held pressure. We used a camera inspection to confirm no other leaks.
Rusted Galvanized Steel Sections
Pre-1950 mill housing in Brockton often has original galvanized steel ductwork that corrodes from the inside out, especially in humid basements. We cut out the damaged section and splice in new metal with sealed collars, then pressure-test the repair to verify no leakage. The work takes half a day in most Brockton basements.
Air Duct Sealing in Brockton
Air Duct Sealing in Brockton addresses the leaks, gaps, and failed joints that pull unconditioned air into your system, waste energy, and reintroduce contaminants you’ve already paid to remove. A whole-home sealing job in Brockton typically costs $800 – $2,400, with simpler single-zone systems on the lower end and multi-story triple-deckers with converted coal chutes toward the higher end. Sealing is often the permanent fix after a cleaning, especially in Brockton’s older housing stock where vacuuming alone can’t stop a basement return from drawing in mold spores or coal dust.
Mastic Sealing of Accessible Joints
We brush on UL-181 rated mastic to every accessible joint, collar, and penetration. In Brockton’s 24/7 heating climate, tape alone fails within a season. Mastic remains flexible through freeze-thaw cycles and holds against the negative pressure of modern HVAC systems. We apply it thick enough to see, then document every sealed point with before-and-after photos for the homeowner.
Coal Chute Conversion Sealing
Brockton’s Campello and downtown triple-deckers frequently have old coal chutes repurposed as duct returns, so residual coal dust in the basement keeps re-contaminating the system unless those chutes are sealed. This quirk is common in Brockton but rare in Boston suburbs. We clean the chute interior with HEPA-contained vacuums, then seal it with rigid blocking and mastic to eliminate the contamination pathway permanently.
Trusted Brands We Service in Brockton
Our equipment roster includes Nikro negative-air machines for contained source removal, Honeywell and Aprilaire filtration components, and Abatement Technologies HEPA vacuums. We stock common sealing materials and collar fittings locally, so Brockton jobs don’t wait on parts shipments. For filtration upgrades paired with sealing work, we size and install Honeywell and Aprilaire media cabinets to fit the existing return plenum without duct modifications. Every tool on the van is professional-grade, not hardware-store gear, and our technicians explain what each piece does before starting work.
Common Duct Sealing Problems We See in Brockton Homes
- Sealing only accessible joints while leaving hidden disconnected runs in basements or crawlspaces. This continues to pull in coal dust and mold spores, especially in Campello triple-deckers where returns run through unfinished basement chases. We camera-inspect every run before declaring the job complete.
- Using tape or non-NADCA approved sealants that fail under the 24/7 heating cycles of Brockton’s cold winters. Standard foil tape dries and separates within one heating season. We use only UL-181 rated mastic, applied to manufacturer thickness, documented in your job photos.
- Overlooking converted coal chutes used as returns, so sealing those chutes without cleaning the residual coal dust first just traps contaminants that later re-enter the system. This is the Brockton-specific failure we see most often from crews who don’t know the local housing stock. We HEPA-vacuum before we seal.
- Ignoring rust-through on galvanized steel ducts in humid Brockton basements. Sealing a rusted section is temporary at best. We mark every thin spot during inspection and recommend replacement where the metal won’t hold mastic.
Pricing for Duct Sealing in Brockton, MA
Here’s what duct sealing costs in Brockton’s market:
| Service | Typical Range |
|---|---|
| Localized duct repair (single joint/section) | $350 – $950 |
| Whole-home duct sealing, standard ranch/cape | $800 – $1,600 |
| Whole-home duct sealing, triple-decker/multi-zone | $1,400 – $2,400 |
| Coal chute sealing with HEPA cleaning (Campello/downtown) | $600 – $1,200 add-on |
What moves the price: accessibility (crawlspace vs. full basement), number of zones, whether we need to open walls or chases, and the condition of existing materials. Rusted steel costs more to prep than intact flexible duct. We give one flat price per system, agreed in writing before work starts. No per-vent pricing, no add-ons at the door. Call (361) 326-5060 for a free estimate with exact numbers for your Brockton home.
We Also Serve Cities Near Brockton
Our crews run regularly to Brockton and the surrounding towns: Holbrook, Abington, Sharon, and Norwood. Each job carries the same written price guarantee, 365-Day Done Right Promise, and live-answer scheduling, whether we’re sealing ducts in a Sharon colonial or a Norwood split-level.
Serving Brockton, MA - Our Local Coverage Area
We’re based in the Brockton 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 About Duct Sealing in Brockton
Because cleaning removes debris but doesn’t close the gaps that let it back in. In Brockton’s triple-deckers and mill housing, disconnected returns in basements and converted coal chutes draw in coal dust, mold spores, and humid basement air the moment the system restarts. Sealing closes those pathways permanently. Call (361) 326-5060 for a written quote on cleaning plus sealing.
Yes, and we do it regularly. We HEPA-vacuum the chute interior first to remove residual coal dust, then block and seal the opening with rigid materials and mastic. Sealing without cleaning first traps contaminants that eventually re-enter the system. We document the work with camera inspection and photos.
Brockton’s cold, damp New England winters mean heating systems run 24/7 from October to April, pulling dust and combustion byproducts through ducts; the humid summers and frequent freeze-thaw cycles also promote mold and mildew growth inside ductwork, especially in basements and crawlspaces. Sealants must withstand constant thermal expansion and high humidity. We use mastic rated for these conditions, not tape that separates in the first freeze-thaw cycle.
We pressurize the system and use smoke pencils to trace visible leaks, then run a duct inspection camera through every return and supply to find hidden disconnects. In Brockton’s triple-deckers, we especially check basement chases and former coal chutes where returns often have undocumented splits. We show homeowners the camera footage before and after sealing.
Yes. These homes typically have flexible duct retrofits from the 1970s – 1990s, which crush in tight attic spaces and separate at metal collars. We replace damaged flex duct where needed and seal all joints with mastic. The work usually takes less time than triple-decker jobs, so pricing falls in the lower half of our range.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Brockton since 2004 as part of the Garrison Partners family.




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