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.
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AfterFast, Reliable Duct Sealing Across Key Biscayne
We dispatch our Duct Sealing crews to Key Biscayne from our Miami office, and we know the island’s schedule: A/C runs almost every day, humidity rarely drops below 70%, and after a tropical storm passes, the phone starts ringing with musty-duct calls. If your home near Crandon Boulevard or your unit in the Key Colony towers smells damp even when the system is off, the problem is usually failed seals letting salt-laden air leak in at the joints. Call (361) 326-5060. We’ll give you a written price before any work starts, and every seal job carries our 365-Day Done Right Promise.
Why Hollis Air Duct Cleaning Is Key Biscayne’s Preferred Duct Sealing Company
We’ve been part of the Garrison Partners family since 2004, and our Miami South FL office has handled enough Key Biscayne jobs to know the difference between mainland duct problems and island duct problems. Our technicians are background-checked and uniformed, and they arrive inside the quoted window because The Garrison Standard doesn’t allow “on the way” texts that show up an hour late.
Key Biscayne homeowners call us back because we document everything. Before-and-after photos, moisture readings, written scope of work. When an insurer questions whether a duct was actually damaged or just dirty, our photo log answers the question before it’s asked. The 365-Day Done Right Promise means if a seal fails within a year, we return 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. Not a callback queue. Not “leave a message and we’ll get back to you Monday.” A real person who can schedule your estimate or dispatch a crew.
Air Duct Sealing in Key Biscayne
Air Duct Sealing in Key Biscayne is not the same job it is in Hialeah or Coral Gables. Here, sealing failures almost always show up as condensation and mold at the joints rather than the dry air-leak whistling mainland techs chase. The marine salt aerosol corrodes foil and galvanized seams, so the mastic itself fails first. A typical residential seal job on the island runs $450 – $850 for a single-family home, depending on duct accessibility and how much of the original 1970s-80s galvanized or flex duct needs attention. Condo units in shared vertical chases start around $350 per unit but require building-association coordination.
When Sealing Works Versus When Ducts Must Be Replaced
We seal ducts that are structurally sound but leaking at the seams. We replace duct sections that have been saturated by flood or storm intrusion and never properly dried. The difference matters for your health and your insurance claim. Our techs run a camera inspection and take moisture readings before recommending either path. We don’t seal over wet ductwork, because mastic traps moisture and mold blooms behind the bead. That’s the number-one call-back we see on the island, usually from a homeowner who hired a mainland crew that didn’t understand Key Biscayne’s post-storm reality.
Documentation for Insurance Claims
After a September storm pushed wind-driven rain through the roof vent of a stilt home near Key Colony, our tech found saturated flex duct in the return chase and a corroded foil seam on the air handler trunk. We ran a camera inspection, set up negative pressure with HEPA filtration, replaced the wet run, then sealed the remaining supply and return ducts with Guardsman mastic tested for salt-air exposure. The homeowner’s insurer accepted our before-and-after photo log and moisture readings, and the musty odor cleared within two days. We bring that same documentation discipline to every Key Biscayne job.
Duct Sealing Services in Key Biscayne
Duct Sealing Services in Key Biscayne require equipment and techniques chosen for marine conditions, not generic suburban work. We use professional-grade mastic from Guardsman and Abatement Technologies, applied with negative-air containment when working in shared condo chases. Rotary brush systems from Rotobrush clean the duct interior before sealing so the mastic bonds to metal, not to dust and biological film. A typical whole-system seal for a single-family home on Mashta Drive or Harbor Drive runs $450 – $850; condo units in towers like Grand Bay or Ocean Club run $350 – $600 per unit depending on riser access and association requirements.
Negative-Air Containment for Multi-Unit Buildings
Many Key Biscayne condos require building-association approval before any duct work begins because the ducts share vertical chases with neighbors. We coordinate directly with building management, set up Nikro negative-air machines with HEPA filtration, and seal our work area so contamination doesn’t migrate to adjacent units. This isn’t optional on the island. It’s how we protect your neighbors and your standing with the association.
Post-Storm Protocol
Hurricane season runs June through November, and after any significant storm we inspect for moisture intrusion before sealing. Wind-driven rain pushes through roof vents and A/C intakes on elevated homes, and saltwater-laden air enters duct systems even when floodwater doesn’t reach the living space. We dry, we document, we replace what’s wet, then we seal what’s sound. The sequence matters. Skip a step and you’re sealing mold inside your ducts.
What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Key Biscayne
We stock Honeywell and Aprilaire filtration components and sealants at our Miami South FL warehouse, so Key Biscayne customers don’t wait for mainland shipping. Our equipment roster includes Rotobrush rotary brush systems for pre-seal cleaning, Nikro negative-air machines for condo containment jobs, and Guardsman mastic rated for salt-air exposure. When a Grand Bay association calls us for a multi-unit seal project, we don’t order parts after the estimate. We already have them. That means faster turnaround and fewer return trips, which matters when you’re coordinating with a building manager who has thirty other units to worry about.
Common Duct Sealing Problems We See in Key Biscayne Homes
- Sealing over ductwork that was never dried after flood or storm intrusion. The mastic traps moisture and mold blooms behind the bead. We see this on stilt homes near the bay where a tropical storm pushed rain through a roof vent three months ago and the homeowner never knew the ducts were wet.
- Standard foil tape on salt-aerosol-exposed galvanized or flex seams. The adhesive lifts within a season on Key Biscayne’s marine air. We use Guardsman mastic tested for salt-air exposure, applied after proper surface prep.
- Sealing a single unit’s ducts in a shared vertical chase without building-association approval. This can spread contamination to neighboring risers in Grand Bay or Ocean Club towers. We always coordinate with management and set up negative-air containment first.
- Ignoring the condensate pan and blower motor during a seal job. A sealed system with a still-wet air handler just re-wets the ducts on the next cooling cycle. We inspect and address the full air-handling unit, not just the duct seams.
Pricing for Duct Sealing in Key Biscayne, FL
A typical residential duct sealing job in Key Biscayne runs $450 – $850 for a single-family home and $350 – $600 per unit for condo work in shared-rise buildings. What moves the price: duct accessibility (crawl spaces under elevated homes take longer than attic access), how much of the original 1970s-80s galvanized or flex duct needs individual attention, whether negative-air containment is required for multi-unit coordination, and whether we’re sealing after storm damage that requires partial replacement first. We give you one flat price per system, agreed in writing before any work starts. No per-vent pricing. No invoice that balloons once the technician is inside. Estimates are free. Call (361) 326-5060 to schedule.
We Also Serve Cities Near Key Biscayne
Our Duct Sealing in Key Biscayne crews also handle jobs in Miami Beach, Miami, Coral Gables, and Hialeah. Each market has its own duct conditions: mainland Miami sees drier dust infiltration, Coral Gables has older Spanish-style homes with retrofit duct challenges, Hialeah deals with hard-water scale on condensate systems. We adjust our approach for each. But Key Biscayne’s year-round humidity, salt aerosol, and post-storm vulnerability are unique to the island, and our protocols here reflect that.
Serving Key Biscayne, FL - Our Local Coverage Area
We’re based in the Key Biscayne 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 Key Biscayne
We seal ducts that are structurally sound and properly dried; we replace sections that have been saturated and cannot be fully dried without mold risk. Our techs run a camera inspection and take moisture readings before recommending either path, and we document everything for your insurer. Call (361) 326-5060 for a free post-storm assessment.
Key Biscayne’s marine salt aerosol corrodes foil and galvanized seams, and year-round 70 – 80% humidity means sealing failures show up as condensation and mold rather than dry air leaks. Mainland duct sealers rarely encounter these conditions. We use Guardsman mastic rated for salt-air exposure and always inspect for moisture intrusion before sealing.
Yes, most Key Biscayne condo associations require approval and negative-air containment before duct work in shared vertical chases. We coordinate directly with building management, set up Nikro HEPA-contained work areas, and protect neighboring units from cross-contamination. We handle the paperwork so you don’t have to negotiate with the board yourself.
Our documentation, including before-and-after photos, moisture readings, and written scope of work, gives insurers the evidence they need to distinguish repairable seal damage from total replacement. We don’t guarantee approval, but our photo logs are designed to answer adjuster questions before they’re asked. Call (361) 326-5060 to discuss your specific situation.
Salt aerosol corrodes metal duct seams and degrades standard foil-tape adhesive within a single season, while constant humidity prevents the seasonal dry-out that lets mainland ducts shed moisture. We use mastic specifically tested for marine environments, applied after rotary-brush surface prep, and we never seal over corroded metal without addressing the underlying deterioration first.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Key Biscayne since 2004 as part of the Garrison Partners family.