Fast, Reliable Duct Repair & Sealing Across Miramar
Duct repair and sealing in Miramar typically costs $180–$650 depending on whether we’re sealing accessible joints with mastic or replacing degraded flex runs in a 140°F attic, and most Miramar jobs are completed same-day. If you’re seeing uneven cooling, dust plumes from vents, or your AC runs constantly without catching up, the problem is often gaps in ductwork hidden above your ceiling—not the HVAC unit itself. Call Apex Air Duct Cleaning Service Miami at (833) 628-3661 for a free inspection and honest assessment of what your system actually needs.

We’ve worked Miramar’s east-side streets long enough to know the pattern: 1960s and 1970s CBS ranch homes with decades of layered duct patches, unsealed splices, and insulation that’s cooked to powder in attics that never cool down. Our Duct Repair & Sealing team doesn’t guess—we inspect with cameras, seal with professional-grade mastic, and repair with the same Rotobrush and Nikro equipment we use on commercial jobs across South Florida.
Why Apex Air Duct Cleaning Service Miami Is Miramar’s Preferred Duct Repair & Sealing Company
Owner Michael Brown has spent 11 years in this single trade, and he’s the technician who shows up at Miramar doors—not a rotating subcontractor learning the neighborhood on your dime. That matters in a city where the housing stock tells a specific story, and where misdiagnosing a flex-to-metal splice gap as “just needs cleaning” wastes your money and leaves the real problem festering.
Our 867 verified reviews at 4.9 stars include repeat calls from Miramar homeowners who initially hired us for cleaning and brought us back when they realized their “clean” ducts were still leaking. We’re familiar with the grid around Miramar Parkway, the older sections off SW 68th Avenue, and the specific attic conditions that degrade ductwork faster here than in communities with newer construction and milder microclimates.
From cleaning to repair to sanitizing—handled in one visit. No managing multiple contractors, no finger-pointing between the crew that cleans and the crew that supposedly seals.
Our Duct Repair & Sealing Services in Miramar
Duct Sealing with Professional Mastic
In Miramar’s 33023 ZIP, we regularly find that previous HVAC crews—or homeowners themselves—connected new flex duct to original galvanized trunk lines without applying mastic sealant. That 1-inch gap blows 140°F attic air straight into your living space for years. We cut the joint clean, apply Honeywell mastic sealant rated for high-humidity environments, and re-insulate the connection properly. A sealed splice in a Miramar attic isn’t a luxury; it’s the difference between an AC cycle that runs 25 minutes versus 37.
Flex Duct Repair & Replacement
Flex duct insulation in Miramar attics breaks down faster than almost anywhere in the continental U.S. Eleven months of annual AC use, combined with attic temperatures that peak at 140–150°F, turns the vapor barrier brittle and the insulation into settled powder. We replace degraded flex runs with properly sized new duct, seal every connection with mastic, and suspend the line correctly so it doesn’t sag and create new debris traps. We recently sealed a flex-to-metal splice inside a 1972 ranch home on a quiet street off SW 68th Avenue. The previous HVAC crew had just jammed a new flex run into the original trunk line without mastic, leaving a 1-inch gap that had been blowing unfiltered attic air—140°F and humid—into the living room for years. Our tech cut the joint clean, applied Honeywell mastic sealant, and re-insulated the connection, dropping the homeowner’s next AC cycle by 12 minutes.
Metal Duct Repair
The galvanized steel trunk lines in Miramar’s 1960s–70s ranches were built to last, but the seams and takeoff connections weren’t. We repair separated seams, corroded sections, and damaged takeoffs using professional metalworking techniques—not foil tape that’ll fail in six months of Miramar humidity. When a metal trunk is structurally sound but leaking at every joint, we seal from the inside with mastic or apply external sealant wraps depending on access and condition.
Duct Insulation Restoration
Condensation inside uninsulated or poorly insulated duct runs is a chronic Miramar problem. When your 55°F conditioned air hits a 95°F duct wall in a humid attic, water forms, drips onto drywall, and gets mistaken for a roof leak. We restore or replace insulation with materials rated for South Florida’s sustained heat and humidity, eliminating the condensation cycle that seeds mold growth in hidden plenum gaps.

What happens when you call
- 1
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 Miramar
We work with Honeywell, Aprilaire, and Abatement Technologies for sealants, filtration components, and air quality accessories—brands specified by commercial restoration contractors, not big-box consumer lines. For Miramar customers, this means we stock the right mastic compounds, filter media, and replacement fittings locally, so we’re not ordering parts that delay your job. Our Rotobrush and Nikro negative-pressure systems are the same units we deploy on commercial duct cleaning jobs across Miami-Dade and Broward, which means when we inspect your Miramar home, we’re seeing problems with equipment that reveals what consumer-grade cameras miss.
Common Duct Repair & Sealing Problems We See in Miramar Homes
- Unsealed flex-to-metal splices in 140°F attics. The incremental updates common in Miramar’s 33023 housing stock left thousands of homes with flex duct jammed onto old galvanized trunks without mastic. Those gaps leak conditioned air, draw in attic dust and biological growth, and create condensation events every time the AC cycles off.
- Multi-generation duct patches creating internal debris traps. When a 1960s metal system gets partially replaced with 1980s flex, then patched again in the 2000s, the internal diameter changes at every junction. Dust, pollen, and roof debris accumulate in these stepped transitions, blocking airflow and harboring mold that standard cleaning can’t reach.
- Degraded flex duct insulation causing condensation “roof leaks.” We get calls from Miramar homeowners convinced they need a roofer, when the water stain on their ceiling is actually condensation dripping from a flex run whose insulation has cooked to nothing in a decade of attic heat.
- Original fiberglass duct board crumbling at plenum connections. The 1965–1972 Miramar ranches with original fiberglass duct board see the material delaminate where it meets the air handler, creating gaps that bypass filtration entirely and pump unconditioned attic air through every vent.
Pricing for Duct Repair & Sealing in Miramar, FL
Here’s what duct repair and sealing costs in Miramar’s market:
| Service | Typical Range in Miramar |
|---|---|
| Mastic sealing of accessible joints (per joint) | $180–$280 |
| Flex duct repair/replacement (per run, attic access) | $320–$480 |
| Metal trunk line seam repair (per section) | $280–$420 |
| Duct insulation restoration (per run) | $240–$380 |
| Full system inspection with camera scope | $150–$200 (credited toward repair) |
What moves you up or down within these ranges: attic accessibility (Miramar’s low-slope ranch roofs vary), the extent of degraded material requiring removal, and whether we’re working around active mold that needs containment. Homes in 33023 with multiple generations of unsealed patches typically need more labor than a single-era system. We don’t quote over the phone for hidden attic conditions—we inspect first, show you what the camera sees, and give you a fixed price before any work starts. Estimates are free. Call (833) 628-3661 to schedule.
We Also Serve Cities Near Miramar
Our service radius covers Miramar plus Andover, West Park, Hollywood, and West Hollywood—the same technician, same equipment, same direct accountability from Michael Brown whether we’re sealing ductwork off Hollywood Boulevard or replacing flex runs near West Park’s municipal boundary.
Serving Miramar, FL — Our Local Coverage Area
We’re based in the Miramar 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 — Duct Repair & Sealing in Miramar
Because cleaning doesn’t seal gaps. In Miramar’s 33023 homes, we commonly find flex-to-metal splices that were never mastic-sealed—the previous crew cleaned around the leak but didn’t close it, so conditioned air still escapes into the attic and unfiltered attic air still enters your living space. Call (833) 628-3661 for a camera inspection that’ll show you exactly where the separation is.
Older galvanized trunks in Miramar ranches have riveted seams and takeoff connections that move and corrode differently than modern snap-lock duct; they require metal-specific repair techniques and heavier mastic application to accommodate thermal expansion in 140°F attics. Modern flex systems fail at the connections; Miramar’s legacy metal fails at the seams.
We can seal and reinforce limited delamination, but once fiberglass duct board crumbles at the plenum connection—a common failure in 33023’s 1960s stock—we typically recommend transitioning to a properly sealed metal or flex connection, since patched fiberglass in a humid Miramar attic degrades again within 2–3 years.
We see this constantly in Miramar’s incremental-update housing stock. DIY splices usually lack proper support hangers, correct diameter transitions, and mastic sealing; we remove the amateur work, size the replacement correctly for your system’s CFM requirements, and seal to code. The fix usually pays for itself in reduced AC runtime within a single South Florida summer.
Every 18–24 months for 33023’s 1960s–70s housing stock, given the 11-month AC season and attic conditions that accelerate seal failure. Newer homes in western Pembroke Pines can stretch to 3 years; Miramar’s legacy splices in unconditioned attics simply don’t get that margin. Call (833) 628-3661 to set up an inspection—estimates are free, and we’ll show you what the camera finds before recommending any work.
Written by Michael Brown, Owner at Apex Air Duct Cleaning Service Miami, serving Miramar and South Florida since 2013.