Duct Sealing in Randallstown - Tested First, Written Price Second

Fast, Reliable Duct Sealing Across Randallstown

Duct sealing in Randallstown typically runs $450 – $1,200 for a whole-house job, with most homeowners in the $600 – $850 range depending on how much of the original 1950s – 1970s galvanized steel ductwork is still in place. We dispatch from our Baltimore office and carry the mastic, mesh, and negative-air equipment needed to seal the rusted joints and failed seams that are standard in this market. Call (361) 326-5060 for a written estimate before any work starts.

Call (361) 326-5060

We’ve worked the ranch homes off Liberty Road, the split-levels near Randallstown’s west side, and the rural properties out toward Reisterstown Road where longer drives and outbuilding duct runs create their own sealing headaches. Randallstown’s post-WWII housing boom left thousands of homes with unlined galvanized steel ducts that have now passed 60 years in service. That metal traps debris at every joint, and Baltimore’s humid summers condense on the cold surface, feeding rust and popping tape seals within a season. Our Duct Sealing team knows where to look because we’ve sealed ducts in this specific housing stock for years.

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

Hollis Air Duct Cleaning, founded in 2004 as part of the Garrison Partners family, brings The Garrison Standard to every Randallstown job: written price, written guarantee, and technicians who arrive inside the quoted window in uniform. We don’t compete on teaser coupons. We compete on showing up, pricing it before we touch it, and leaving the site clean.

Our 365-Day Done Right Promise covers every duct sealing job in writing. If the seal fails within a year, we return and make it right at no charge, including a free second visit. No negotiation, no runaround.

Phones are answered by a live person 24 hours a day, 7 days a week. When you call (361) 326-5060, you reach a human who can schedule your estimate, not a callback queue that dumps you to Monday.

Our technicians are background-checked and uniformed. You know who’s walking into your home before they arrive. They carry professional-grade equipment from Nikro and Abatement Technologies, the same negative-air machines and rotary tools commercial crews use, and they explain what they’re doing in plain terms while they work.

Duct Repair in Randallstown

Duct Repair in Randallstown most often means addressing the rusted sheet-metal screw joints in original 1960s return trunks, especially on the west side where humid summer air has condensed on cold galvanized metal for decades. When screws rust through, the joint separates, air leaks into wall cavities or the basement, and your blower motor short-cycles trying to maintain pressure. A typical duct repair in Randallstown runs $280 – $650 depending on how many joints need attention and whether sections of trunk line require replacement.

Rusted Joint Rebuilds

We remove the failed fasteners, clean the mating surfaces down to bare metal, and bridge the seam with fiberglass mesh embedded in duct sealing mastic. The mastic remains flexible after curing, so thermal expansion doesn’t re-crack the seal the way foil tape does.

Sectional Replacements

When rust has eaten through the galvanized wall itself, typically at the bottom of horizontal runs where condensate pools, we cut out the damaged section and splice in new galvanized or insulated flex duct. We price this in writing before cutting anything.

Air Duct Sealing in Randallstown

Air Duct Sealing in Randallstown targets the conditioned air you’re already paying to heat or cool, then losing through gaps at plenum collars, register boots, and the rusted screw joints that plague original 1950s – 1970s systems. A full-system seal in Randallstown typically costs $450 – $1,200, with simpler single-zone ranch homes at the lower end and multi-level split-levels with complex trunk-and-branch layouts toward the top. We seal with mastic and mesh at every accessible joint, then pressure-test to verify the improvement.

Return Trunk Priority

The return side operates under negative pressure, so leaks here pull basement air, wall cavity dust, and combustion byproducts into your breathing stream. In Randallstown’s older galvanized systems, the return trunk is almost always the worst leak path. We seal it first.

Supply Boot Sealing

Register boots in plaster or drywall often separate from the trunk line over decades of thermal cycling. We seal the boot-to-trunk joint and the boot-to-floor interface, stopping the attic or crawl space air that bypasses your filter entirely.

Trusted Brands We Service in Randallstown

We stock sealing materials and filtration components from Honeywell, Aprilaire, and Abatement Technologies for Randallstown customers, which means no waiting on special orders for standard jobs. Our Nikro negative-air machines create contained work environments in occupied homes, and our rotary agitation tools from Rotobrush break loose debris dams before we seal, so we’re not trapping contamination behind fresh mastic. When a Randallstown homeowner needs a filtration upgrade after sealing, we have Aprilaire media cabinets and Honeywell electronic air cleaners on the truck. Fast turnaround matters here because once you’ve opened a humid, rusted duct system, you don’t want it sitting exposed while parts ship.

Common Duct Sealing Problems We See in Randallstown Homes

• Rusted sheet-metal screws at original 1960s return-trunk joints on the west side fail first. The screw hole itself keeps leaking even after mastic bridges the seam, so we remove the old fastener, fill the hole, and re-secure with corrosion-resistant hardware before sealing over.
• Unlined galvanized ducts in Baltimore-humid summers condense at cold joints. Tape-and-mastic seals pop loose within a season unless the metal is dried and primed first. We run a dehumidification pass before applying sealant on badly sweating systems.
• Longer service drives on the rural edges mean outbuilding and detached-garage duct runs get sealed last. These leaky runs create lint pathways and pressure imbalances that pull unfiltered air into the main house system. We include them in the scope, not as an afterthought.
• Original plenum collars separate from furnace cabinets after decades of vibration. The gap is often hidden by insulation wrap, and it can leak 15 – 20% of total airflow into the mechanical room before any duct joint is addressed.

Pricing for Duct Sealing in Randallstown, MD

We Also Serve Cities Near Randallstown

Our crews work Duct Sealing in Randallstown and the surrounding communities regularly: Pikesville to the south, Owings Mills to the northeast, Reisterstown to the northwest, and Catonsville to the southeast. Same written pricing, same 365-Day Done Right Promise, same live-answer scheduling at (361) 326-5060.

FAQs About Duct Sealing in Randallstown