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 Gateway
Gateway homeowners call us when their AC runs constantly but rooms stay uneven, or when that musty smell won’t clear no matter how many filters they change. We’re the Duct Sealing team at Hollis Air Duct Cleaning, and we serve Gateway from our South Florida dispatch office with crews that know this area’s housing stock inside and out. If you’re seeing fuzzy black spots on your ceiling registers or feeling weak airflow from certain vents, the problem usually starts in the attic, not the thermostat. Call (361) 326-5060 and we’ll send a uniformed tech who’ll show you exactly what’s happening before any work starts.
Why Hollis Air Duct Cleaning Is Gateway’s Preferred Duct Sealing Company
We’ve been in business since 2004 as part of the Garrison Partners family, and our 365-Day Done Right Promise means every duct sealing job in Gateway is backed in writing for a full year. We also offer Gateway Dryer Vent Cleaning services. If a joint we sealed fails or a musty odor returns, we come back at no charge, including a free second visit.
Our technicians are background-checked and uniformed, and they arrive inside the quoted window, not sometime between 8 and 5. The price is written down before any work starts, and it does not move at the door. That’s The Garrison Standard, and it’s how we operate in every Gateway home we enter.
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.
HVAC Duct Sealing in Gateway
HVAC Duct Sealing in Gateway typically addresses the flexible ductwork installed in mid-2000s to 2010s homes, where R-4 or R-6 insulation and minimal mastic at the boots has degraded under constant AC cycling. A typical sealing job in Gateway runs $450 – $850 for a single-system home, depending on how many joints need mastic and mesh, whether flex sections need re-support, and if we find disconnected returns pulling hot attic air into the system. Most Gateway homeowners need this service two to three years after handover, once builder-grade strapping sags and condensation starts pooling in low spots.
What We Seal and Why It Fails Here
We focus on the plenum, trunk-to-branch connections, boot-to-drywall collars, and any flex runs in unconditioned attics. Gateway’s year-round AC runtime, with dew points in the mid-70s from May through September, turns tiny gaps into steady moisture injection points. Tape-only patches fail within a season. We use mastic and fiberglass mesh at every joint, then re-support flex runs with proper strapping to eliminate low spots where condensation collects.
Camera Inspection Before We Touch Anything
We run a borescope through the system first. In Gateway’s newer gated communities, we’ve found crushed returns behind drywall and completely disconnected flex runs that the homeowner never knew existed. Sealing without looking is guessing. We don’t guess.
Duct Repair in Gateway
Duct Repair in Gateway often means replacing sections of compromised flexible ductwork that have become condensation traps, or reconnecting returns that have pulled apart at the collar. A typical repair in Gateway runs $300 – $650 per section, with full flex replacement on larger runs reaching $800 – $1,200 if the damage extends across multiple attic bays. Gateway homeowners usually need repair when they spot water staining around ceiling registers, feel hot air blowing from vents that should be cooling, or notice their AC running nonstop without reaching set temperature.
Sagging Flex and Standing Water
Builder-grade flex duct strapped too loosely creates belly sections where condensation pools. We’ve cut open flex in Gateway attics and found standing water, then mold, then the fuzzy black spotting that shows up on ceiling registers two rooms away. We remove the compromised section, install new flex with proper pitch and support, and seal every joint with mastic so it can’t happen again.
Disconnected Returns Pulling Attic Air
A disconnected return in a 140°F Gateway attic doesn’t just waste energy. It pulls humid, dusty air straight into your air handler and distributes it through every room. We verify airflow at each vent after repair to confirm the system is drawing from the house, not the attic.
Trusted Brands We Service in Gateway
Our crews carry professional-grade equipment from Rotobrush, Nikro, and Abatement Technologies, and we stock filtration products from Honeywell and Guardsman for Gateway jobs that need upgraded media after sealing or repair. We don’t run to the supply house mid-job. That means faster turnaround for Gateway homeowners and no return trips because a collar size or mastic type wasn’t on the van. Every technician arrives with the tools and materials to complete the work inside the quoted window, and if a job requires specialized filtration beyond our standard stock, we tell you before we start, not after we’re in your attic.
Common Duct Sealing Problems We See in Gateway Homes
- Condensation pooling in sagging flex runs. Gateway’s builder-grade R-4 and R-6 flex duct was strapped with minimal support, and the constant AC cycling in this climate creates low spots where water collects. We re-support with proper strapping and pitch so water drains instead of pooling.
- Tape-only patches failing under humidity. Foil tape on flex duct joints degrades within a season in Gateway’s mid-70s dew points. We remove old tape and apply mastic with fiberglass mesh, which flexes with thermal expansion and maintains its seal year after year.
- Disconnected returns in unconditioned attics. The aggressive AC runtime in Gateway creates pressure pulses that loosen collar connections over time. A disconnected return pulls 140°F attic air into the system, raising humidity and feeding microbial growth throughout the ductwork.
- Post-construction debris in newer homes. Gateway’s rapid build-out in the 2000s and 2010s left drywall dust, wood scraps, and insulation fragments in ductwork that builders never cleaned. That debris traps moisture at joints and accelerates seal failure.
Pricing for Duct Sealing in Gateway, FL
A typical HVAC duct sealing job in Gateway runs $450 – $850 for a single-system home with accessible attic ductwork. Duct repair, including section replacement of compromised flex, runs $300 – $650 per section, with larger full-run replacements reaching $800 – $1,200. What moves the price: how many joints need mastic and mesh, whether we find disconnected returns or crushed sections requiring repair, if the attic access is tight or obstructed, and whether you need upgraded filtration after we finish. We give you one flat price per system, agreed in writing before any work starts. No per-vent pricing, no add-ons at the door. Estimates are free. Call (361) 326-5060 for an exact quote on your Gateway home.
We Also Serve Cities Near Gateway
Our South Florida dispatch office coordinates crews across the region, and we regularly schedule Duct Sealing in Gateway alongside work in Jacksonville, Miami, Tampa, and Orlando. Each job follows The Garrison Standard: written price, written guarantee, background-checked uniformed technicians, and the 365-Day Done Right Promise.
Serving Gateway, FL - Our Local Coverage Area
We’re based in the Gateway 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 Gateway
Gateway’s mid-2000s-to-2010s builder-grade flex duct was commonly installed with R-4 or R-6 insulation and strapping that sags within a few years, so in Gateway’s year-round AC runtime the low spots become condensation pools and the first visible sign is fuzzy black spotting on ceiling registers at about the two-to-three-year mark. The builder’s tape-only joints also fail under constant humidity cycling. Call (361) 326-5060 for a free inspection and written estimate.
The fuzzy black spots are mold growing on condensation that pools in sagging flex duct sections, almost always in homes two to three years past handover where builder-grade strapping has loosened in Gateway’s hot, humid attic conditions. We were called to a home off Gateway Boulevard in a newer gated section where the homeowner had black speckling around three ceiling registers and a musty smell in the primary bedroom; our tech ran a camera inspection and found sagging builder-grade flex with standing condensation in two low spots. We cut out the compromised sections, sealed the joints and boots with mastic and mesh, re-supported the runs with proper strapping so they couldn’t pool again, and then performed source removal under negative pressure with HEPA filtration on the air handler side. The musty odor cleared within a day and the registers stayed dry through the rest of the summer. Call (361) 326-5060 if you’re seeing similar spotting.
Duct sealing fixes the moisture source that’s feeding the smell, but if mold has already established in the flex, sealing alone won’t remove it. In Gateway’s climate, we typically recommend sealing first to stop the condensation, then source removal with negative-air HEPA extraction to clear biological growth from the intact ductwork. We price both phases in writing before starting either. Call (361) 326-5060 for an assessment of your specific system.
Yes, typically 15 – 30% in Gateway homes with significant leakage, because your AC stops cooling the attic and starts cooling the rooms you actually live in. The bigger savings here is system longevity: constant runtime in 90°F+ months burns out compressors prematurely when half the cooled air is escaping into the attic. Call (361) 326-5060 for a leakage test and written estimate.
The builder should have used mastic and mesh at every boot and collar instead of foil tape, installed R-8 flex minimum with proper support strapping at 4-foot intervals to prevent sagging, and run a post-construction duct cleaning before handover to remove drywall dust and debris. They should also have verified airflow balance room-to-room and confirmed no returns were drawing attic air. Most didn’t. We fix what they skipped. Call (361) 326-5060 for a written plan to correct it.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Gateway since 2004.