Duct Sealing in Largo - Tested First, Written Price Second

Fast, Reliable Duct Sealing Across Largo

Duct sealing in Largo typically costs $350 – $850 for a whole-home system, and most jobs are completed in a single visit. If your registers blow weak, your AC runs nonstop, or your power bill climbs through summer, the problem is often leaking duct joints pulling hot attic air or humid underbelly air into the system.

Call (361) 326-5060

We’ve worked in Largo long enough to know the Pinellas peninsula isn’t generic Florida. The salt-laden breeze off the Gulf, the sandy soil under mobile home parks off Ulmerton Road, and the original galvanized ductwork in 1960s block ranches all create failure patterns you won’t find in Orlando or Tampa. Our crews serve Largo from our Miami-area dispatch office, with scheduling coordinated for Pinellas County windows. When you call (361) 326-5060, a live person answers, and we quote a written, flat price before any work starts.

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

Hollis Air Duct Cleaning has been part of the Garrison Partners family since 2004, and our Duct Sealing in Largo reputation is built on showing up inside the window and pricing in writing. Largo homeowners aren’t looking for the lowest teaser quote; they’re looking for the quote that doesn’t move once the van is in the driveway.

Our 365-Day Done Right Promise covers every duct sealing job in writing. If the seal fails or the leak returns within a year, we come back and make it right at no charge, including a free second visit. No negotiation, no “let us check the notes.”

Every technician is background-checked and uniformed. You know who’s walking into your home before they arrive. And our phones are answered by a live person 24 hours a day, seven days a week. No voicemail loops, no callback queues, no waiting until Monday for a scheduling question.

We know the neighborhoods: the 55+ parks along Ulmerton Road, the mid-century ranches south of East Bay Drive, the condo clusters near Largo Central Park. That local knowledge means we know where to look for the leak before we open the first ceiling panel.

Duct Repair in Largo

Duct Repair in Largo often starts with a homeowner noticing weak airflow at the far end of the house, or a musty smell every time the AC cycles. In this market, the repair usually involves collapsed flex runs, rusted galvanized trunk lines, or joints that have separated where salt corrosion weakened the metal. A typical duct repair in Largo runs $280 – $620 depending on whether we’re replacing a single compromised run or rebuilding a section of trunk line.

Collapsed Flex Runs in Older Homes

Original flex duct in Largo’s 1970s and 1980s ranches has often sagged or been crushed by attic traffic. We inspect with a camera, remove the damaged section under negative-air containment, and install new insulated flex with mechanical fasteners and mastic sealant, not tape.

Rusted Galvanized Trunk Lines

The salt air that blows through Pinellas County corrodes galvanized steel from the inside out. When we find pinholes or flaking metal in a trunk line, we cut out the compromised section and transition to new duct board or sheet metal with a corrosion-resistant coating.

Air Duct Sealing in Largo

Air Duct Sealing in Largo is the preventive step that stops conditioned air from escaping into your attic, crawl space, or underbelly. Most Largo homes lose 20 – 30% of their cooled air through leaks at the plenum, trunk line connections, and register boots. In a climate where your AC runs eight months a year, that’s real money. Whole-system duct sealing in Largo typically runs $350 – $850, with larger homes or multiple attic zones toward the higher end.

Mastic Sealing at Joints and Plenums

We use fiber-reinforced mastic applied with a brush or trowel at every joint, not foil tape. Tape fails within a season on salt-residue-coated metal. Mastic remains flexible, fills small gaps, and creates a permanent seal that holds against the pressure changes of a Florida summer.

Register Boot and Return Air Sealing

Leaks where the duct meets the ceiling register are invisible but costly. We seal the boot-to-drywall connection and the boot-to-trunk connection, then verify with a pressure test so you know the seal held before we leave.

Trusted Brands We Service in Largo

Our Largo crews carry professional-grade equipment from Rotobrush, Nikro, and Abatement Technologies, and we stock sealing and filtration products from Honeywell, Aprilaire, and Guardsman. That means most repairs don’t wait on parts. When we find a failed section in a Largo attic, we can often replace and seal it same visit. We specify Guardsman-backed mastic for underbelly and humid-area applications because it holds adhesion where standard compounds lift. For homeowners in the East Bay Drive corridor or the condo communities near Largo Central Park, that local parts availability means one visit, one flat price, no return trip to finish the job.

Common Duct Sealing Problems We See in Largo Homes

• Salt-corroded joints on original galvanized ductwork. The sea breeze that keeps Largo pleasant also deposits microscopic salt crystals on attic metal. Over years, this residue prevents tape adhesion and accelerates rust at joints. We see this in nearly every pre-1990 ranch between East Bay Drive and Ulmerton Road.
• Underbelly moisture intrusion in mobile home parks. In Largo’s 55+ communities off Ulmerton Road, sandy soil wicks Gulf humidity directly into flex duct runs. The wire helix rusts from the outside in, the inner liner collapses, and mold colonizes from the bottom up. Standard attic-focused sealing misses this entirely.
• Condensation at poorly insulated trunk lines. Largo’s year-round high humidity means any duct surface below dew point sweats. Water pools at low spots, degrades mastic, and restarts leaks we just sealed. We always verify insulation integrity before sealing.
• Beach sand and pollen accumulation at register boots. Pinellas beach sand is fine silica that settles in duct low points. Combined with pollen from the area’s heavy oak and pine canopy, this grit abrades seals and provides a food source for microbial growth. Source removal comes before sealing, always.

Pricing for Duct Sealing in Largo, FL

We Also Serve Cities Near Largo

Our crews work throughout central Pinellas County, including Largo, Clearwater, Seminole, Dunedin, and Pinellas Park. The same written pricing, same 365-Day Done Right Promise, same background-checked technicians apply in every city we serve.

FAQs About Duct Sealing in Largo