Duct Repair & Sealing in Jacksonville - We Measure the Leak Before We Quote

Fast, Reliable Duct Repair & Sealing Across Jacksonville

Duct repair and sealing in Jacksonville typically costs $180-$650 depending on the scope, with most single-zone repairs completed in one visit. Bellows Air Duct & Vent Co. has served Duval County homeowners since 2012, and our Duct Repair & Sealing team knows the difference between a quick mastic seal and a full flex-duct replacement. Call (866) 995-4721 for upfront pricing and a free estimate.

Call (866) 995-4721

We’re based right here in Jacksonville, not dispatched from Orlando or Tampa. That matters when you’re staring at gray dust pouring from a supply vent in July and need someone who understands why 1970s flex duct fails differently here than anywhere else in Florida. Our technicians carry mastic, metal tape, and replacement flex duct on every truck, and most Jacksonville calls are scheduled same-day or next-day.

Why Bellows Air Duct & Vent Co. of Jacksonville Is Jacksonville’s Preferred Duct Repair & Sealing Company

Forty-two years in this trade means we’ve worked on duct systems in Arlington ranches built during the Nixon administration and in Southside split-entries thrown up during the Reagan boom. Jacksonville’s 1968 city-county consolidation triggered one of the largest suburban build-outs in U.S. history across Duval County’s 874 square miles, leaving an enormous inventory of 1970s-1990s flex-duct systems now 35-50 years old - all installed in unconditioned attics rather than basements, because Florida slab construction offers no alternative. Those attic-run ducts are uniquely punished by Northeast Florida’s St. Johns River basin humidity, where indoor relative humidity routinely exceeds the 60-70% threshold for mold colonization, making Air Duct Cleaning in Jacksonville essential and duct contamination and liner breakdown far more acute here than in inland or drier-climate cities of the same era.

We answer our own phones. Twenty-four hours a day, a live person at our Jacksonville office picks up - not a call center in another state, not an app that routes you to a chatbot. Our technicians are background-checked, uniformed, and equipped with camera inspection systems from Rotobrush so you see the damage before we touch it and the repair after we’re done. Every job carries our 90-Day Done Right Promise in writing: if it’s not right, we return at no charge, no paperwork, no arguing.

Gene Whitmore, who leads Bellows Air Duct & Vent Co., set the standard in 1984 that the price quoted on the phone is the price on the invoice. No bait coupons, no upsells at the door, no “we found something else” surprises. That standard still governs every duct repair we dispatch in Jacksonville.

Our Duct Repair & Sealing Services in Jacksonville

Flex Duct Repair

Flex duct is the weak link in most Jacksonville homes built between 1970 and 1995. The post-consolidation boom produced vast tracts of slab-on-grade ranch and split-entry homes across Arlington, Regency, Southside, and Mandarin - nearly all with original flex duct or early fiberglass duct board systems tucked into hot, humid attic spaces. As these systems age past 30-40 years, interior duct liner disintegration becomes the dominant failure mode. We repaired a 1970s split-entry in Mandarin where the flex-duct inner liner had crumbled into gray powder from decades of condensation cycling - installed stainless steel fasteners and sealed all joints with mastic to stop moisture intrusion. Our Jacksonville HVAC Cleaning and flex duct replacement uses Nikro-approved materials rated for Florida attic conditions, with all connections mechanically fastened before sealing.

Mastic Sealant Application

Metal tape fails. That’s not an opinion; it’s what we find on every callback from a competitor who used tape alone on a Jacksonville attic duct. Mastic sealant is a fiber-reinforced, water-based compound brushed onto joints and seams, then cured to a flexible, airtight membrane. In Jacksonville’s climate, where summer dew points stay above 75°F and attic temperatures hit 130°F, mastic outlasts tape by a factor of years. We apply mastic to every flex-to-metal connection, every supply boot, every return plenum seam. The material we use is specified by Honeywell for residential duct applications and carries a temperature rating well above Florida attic extremes.

Duct Insulation

Uninsulated or degraded duct insulation is a hidden energy drain in Jacksonville homes. When the R-value of attic duct insulation drops below R-6, the temperature differential between conditioned air and attic air drives condensation on the duct exterior - which then drips onto ceiling drywall, breeds mold, and rots framing. We replace damaged insulation with formaldehyde-free fiberglass wrap or closed-cell foam insulation, depending on the duct type and attic access. In riverfront neighborhoods like Ortega and along the Intracoastal, where salt air accelerates metal corrosion, proper insulation also protects the duct exterior from ambient moisture.

Metal Duct Repair

Older Jacksonville homes with galvanized steel ductwork, common in pre-1970 construction near Springfield and Riverside, suffer from seam separation and rust-through at low points where condensate collects - issues our Jacksonville Dryer Vent Cleaning team also encounters with aging metal systems. We cut out damaged sections, fabricate replacement pieces on-site, and seal with mastic and mechanical fasteners. Unlike flex duct, metal duct repair is permanent when done right - and we back it with our 90-Day Done Right Promise.

Air Leak Repair

A 10% duct leak in a Jacksonville attic doesn’t just waste money. It pulls 130°F, 70% RH air into your system, overworks your AC, and deposits moisture on every interior surface downstream. We pressure-test duct systems, identify leak points with smoke pencils and thermal imaging, and seal them permanently. Most leak repairs run $180-$340 and are completed in a single visit.

Trusted Brands We Service in Jacksonville

We stock repair materials from Nikro, Honeywell, and Aprilaire - including parts for Lennox service in Jacksonville - the same brands serious HVAC contractors specify for commercial installations. Our Jacksonville warehouse carries flex duct in standard diameters, mastic sealant, mechanical fasteners, and replacement insulation so we’re not waiting on a parts run while your attic hangs open. For homeowners with Aprilaire whole-home air cleaners or Honeywell zone control systems integrated into their ductwork, our technicians understand how to repair ducts without disrupting those components. Fast turnaround matters in July, and local inventory is how we deliver it.

Common Duct Repair & Sealing Problems We See in Jacksonville Homes

• Gray powder from supply vents. Technicians servicing older homes along the Arlington corridor or the Ortega/Mandarin riverfront areas frequently find flex duct whose inner liner has crumbled into a gray powder - a failure mode driven by decades of condensation cycling in 130°F attics - that homeowners assume is ordinary dust but is actually degraded fiberglass and polymer duct material being circulated as breathable particulate through the living space. This requires flex duct replacement, not cleaning.
• Mold at supply boots. Jacksonville’s humid subtropical climate, amplified by the broad St. Johns River flood plain and Atlantic Intracoastal proximity, keeps summer dew points persistently above 75°F - meaning even a small duct air leak pulls moisture-laden attic air into the system and condenses it on interior surfaces, feeding biological growth. Supply boots are the first failure point.
• Disconnected flex joints. Thermal cycling in unconditioned attics loosens the adhesive and zip-tie connections used in original 1970s-1980s installations. Disconnected flex joints are common in Arlington and Ortega riverfront homes, where temperature swings between winter lows and summer highs stress materials beyond their design limits.
• Collapsed flex duct sections. In homes with original ductwork across Southside and Regency, we’ve found entire flex duct runs collapsed by attic insulation weight or crushed by workers who crawled over them during roofing or pest control work. Collapsed sections create total airflow blockage to one or more rooms.

Pricing for Duct Repair & Sealing in Jacksonville, FL

We Also Serve Cities Near Jacksonville

Our service area extends throughout Northeast Florida. We regularly dispatch to Jacksonville neighborhoods and surrounding communities including Oakleaf Plantation, Bellair-Meadowbrook Terrace, Fruit Cove, and Orange Park. Same-day availability varies by location and season; call for current scheduling.

FAQs - Duct Repair & Sealing in Jacksonville