Duct Repair & Sealing in Alpharetta - Tested First, Written Price Second

Trusted Duct Repair & Sealing for Alpharetta Homeowners

Alpharetta Duct Repair & Sealing typically costs $280-$850 depending on whether you’re addressing minor register leaks or replacing collapsed flex runs in an attic, and most jobs are completed in a single visit with a written price agreed before any work begins. Since 2013, CleanRun Air Duct Cleaning Alpharetta has repaired and sealed ductwork in more than 52,000 homes across north metro Atlanta, every one with a documented photo record delivered at job completion. If your upstairs rooms never reach the thermostat setting, your energy bills have climbed without explanation, or you’ve found insulation blowing from a ceiling register, the duct system is the first place to look. Call (678) 679-7540 for a free estimate with a written price before any panel comes off.

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What Our Duct Repair & Sealing Service Includes

Duct Sealing

Duct sealing closes the gaps and separations where conditioned air escapes between the plenum (the main distribution box) and the individual duct runs that feed each room. In Alpharetta homes built during the 1990s and 2000s construction boom, we’ve found that up to 30% of heated or cooled air never reaches the registers due to seal failure at joints and connections. Our crews use mastic sealant and metal-backed tape rated for HVAC applications, applied after the duct interior is photographed to document the starting condition. Every sealed joint is pressure-tested before we close the access panel, and the after photos show the finished work.

Flex Duct Repair

Flex duct - the insulated flexible tubing common in Alpharetta attic installations - collapses, tears, or disconnects when support straps fail or rodents access the attic space. In neighborhoods like Windward and Avalon, we’ve replaced dozens of flex runs that had sagged into insulation, kinked at sharp turns, or been chewed through near roof penetrations. Our repair includes installing new support straps every four feet per manufacturer specification, replacing damaged sections with new R-8 insulated flex duct, and reconnecting to the plenum and register boot with mechanical fasteners rather than tape alone. The photo record shows the old run, the new materials, and the supported installation.

Metal Duct Repair

Sheet metal ductwork, found in older Alpharetta homes and in commercial-style residential systems, develops rust at seams, separates at drive cleats, or cracks from thermal expansion after years of cycling. We’ve repaired galvanized metal trunk lines in homes near downtown Alpharetta where condensation had corroded the bottom of horizontal runs. Our process includes cutting out damaged sections, fabricating replacement pieces on-site, and sealing with mastic and fiberglass mesh for a permanent repair. Metal repairs take longer than flex replacements but typically last the life of the HVAC system.

Duct Insulation

Duct insulation keeps conditioned air at temperature as it travels through unconditioned attic or crawl space environments. In Alpharetta’s climate, where attic temperatures reach 140°F in July and drop below freezing in January, under-insulated ducts lose efficiency in both seasons. We’ve reinsulated duct runs in homes throughout Crabapple and Milton where original R-4 insulation had compressed to R-2 or less. Our crews install new R-8 foil-faced insulation with all seams sealed and vapor barriers intact, then photograph the completed wrap before closing attic access.

Mastic Sealant Application

Mastic is a thick, fiber-reinforced paste that remains flexible after curing, making it the professional standard for sealing duct joints and seams. Unlike foil tape, which can fail when surfaces are dusty or oily, mastic bonds to galvanized metal, flex duct core, and existing sealant. In Alpharetta’s pollen-heavy spring environment, we’ve found mastic outperforms tape on exterior-facing duct boots where organic film accumulates. Our application includes brushing mastic 2 inches past each joint edge, embedding fiberglass mesh at stress points, and allowing full cure time before system restart. The photo record captures the applied mastic while still wet, confirming coverage.

Air Leak Repair

Air leaks occur where the duct system connects to the building envelope - at register boots, return air boxes, and filter grilles - as well as at damage points within the duct run itself. We locate leaks using a combination of visual inspection, smoke pencil testing at pressurized registers, and infrared camera scanning where access permits. In one Windward home, the smoke pencil revealed a 4-inch gap between the register boot and drywall that had been dumping conditioned air into the wall cavity for years. Repair includes sealing the leak, verifying with a second smoke test, and documenting the before-and-after pressure differential where equipment allows.

Brands We Service for Duct Repair & Sealing

We’ve worked on duct systems connected to Honeywell, Aprilaire, and Abatement Technologies air handlers and filtration equipment throughout Alpharetta and the surrounding north metro area. Honeywell’s TrueCLEAN and F100 systems require precise return air sealing to maintain their rated efficiency, and we’ve repaired dozens of undersized return boxes that were choking these units. Aprilaire’s steam humidifiers and dehumidifiers need dedicated duct runs with specific diameter and insulation requirements; we’ve replaced collapsed flex runs that were preventing these accessories from functioning. Abatement Technologies’ HEPA filtration systems operate at higher static pressure than standard HVAC, making duct sealing critical - a 10% leak in an Abatement system can drop filtration effectiveness by half. We stock fittings and adapters for these brands and can source OEM components when repairs require them.

Whether your system uses Guardsman UV air purifiers, any of the brands above, or equipment from Carrier, Trane, Lennox, or another manufacturer, we can assess the ductwork and deliver a written repair scope. Our crews carry adapters and transition fittings for the most common plenum configurations found in Alpharetta homes built from the 1980s through new construction.

Before

After

Signs You Need Duct Repair & Sealing Right Now

• Uneven temperatures between rooms. If the master bedroom in your Alpharetta home runs 8°F warmer than the hallway thermostat in summer, the duct run serving that room is likely leaking, blocked, or disconnected. This isn’t a thermostat problem; it’s a distribution problem that repair can fix without replacing the HVAC unit.
• Unexpectedly high energy bills. A duct system leaking 20% of its air into the attic forces the heat pump or furnace to run longer to satisfy the thermostat. We’ve seen Alpharetta homeowners with $40-$60 monthly summer cooling increases traced to a single separated flex duct in a hot attic.
• Dust or insulation debris at registers. When you find gray fiberglass or attic insulation on the register fins or the floor beneath, the duct boot has separated from the ceiling or wall, creating a vacuum that’s pulling debris from the building cavity. This indicates both an air leak and an indoor air quality issue.
• Hissing or whistling sounds when the system runs. Audible leaks at joints or gaps mean pressurized air is escaping at velocity. In metal duct systems, this often occurs at failed drive cleats; in flex systems, at torn outer jackets. The sound is the symptom; the energy loss and uneven conditioning are the costs.
• Musty odors when the HVAC cycles on. Leaks in return ductwork can pull attic air, crawl space moisture, or wall cavity odors into the conditioned air stream. In Alpharetta’s humid climate, we’ve traced musty smells to return leaks pulling from damp crawl spaces, not duct contamination requiring cleaning alone.

Our Duct Repair & Sealing Process - Step by Step

1. 1
   System inspection and leak identification. We start with the HVAC system running, checking each register for proper airflow and using a smoke pencil to identify leaks at boots, joints, and accessible seams. In accessible attics, we photograph the visible ductwork before touching anything, establishing the baseline condition for the photo record.
2. 2
   Written scope and price delivered before work begins. Based on what we find, we prepare a written repair scope with line-item pricing for each repair or replacement needed. Haven Standard Clause 1 requires this price be delivered and agreed in writing before any work starts. There is no “call for a quote” - the quote is in your hands, with no obligation until you approve it.
3. 3
   Repair execution with documented progress. Approved repairs proceed with the system shut down and locked out. We photograph each repair stage - the damaged section, the repair in progress, the completed work - so the photo record shows not just before and after, but what was done in between.
4. 4
   Pressure verification and airflow testing. After sealing or replacement, we restore system power and verify airflow at each affected register. Where we have sealed joints, we recheck with the smoke pencil to confirm no leakage. Metal repairs and mastic applications are allowed cure time before pressurization.
5. 5
   Photo record delivery and written warranty. The complete photo record, including all before, during, and after images, is delivered as part of the standard job documentation. Every repair is backed by the 365-Day Done Right Promise: if the work is not right, we make it right, backed in writing on every job.

How Much Does Duct Repair & Sealing Cost in Alpharetta?

Duct Repair & Sealing Near Alpharetta - Our Service Area

CleanRun Duct Repair & Cleaning serves Alpharetta and the surrounding north metro communities including Duct Repair & Sealing in Roswell, Duct Repair & Sealing in Johns Creek, Milton, Duluth, Dunwoody, Norcross, Sandy Springs, Suwanee, Cumming, Holly Springs, and Woodstock. Most Alpharetta appointments are scheduled within 2-3 business days, with same-week availability for active air leaks or disconnected ducts that have left a home without heating or cooling in a living area. Our technicians are dispatched from a north Fulton County location, and drive times to Windward, Crabapple, Avalon, and downtown Alpharetta neighborhoods are typically under 30 minutes. We also handle home air quality and full system cleaning throughout this service area.

Frequently Asked Questions - Duct Repair & Sealing in Alpharetta

Schedule Your Duct Repair & Sealing Service in Alpharetta Today

Call (678) 679-7540 to schedule your free estimate. A live person will answer, gather the details of what you’re experiencing, and schedule an inspection at your convenience. You’ll receive a written price before any work begins, a documented photo record of every repair, and the 365-Day Done Right Promise in writing. No coupons, no bait-and-switch, no surprises - just the repair your duct system needs, done once and done right.

Written by Tomas Reyes, Owner at CleanRun Duct Repair & Cleaning, serving Alpharetta since 2013.