Whole-home duct cleaning
Dryer vent cleaning
Camera inspection
Sanitizing & deodorizingWhole-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.
Fast, Reliable Duct Sealing Across Cumming
Duct sealing in Cumming typically runs $450 – $1,200 for a whole-home job, depending on how many leaks your system has and whether we’re also repairing insulation and crushed flex runs. Most work is finished in a single day, and every price is written down before we touch anything. That means no surprises once our tech is standing in your crawlspace. If you live near Lake Lanier or in one of the newer subdivisions off Bethelview Road, call us at (762) 769-7145 and we’ll walk you through what your system actually needs.
We know Cumming’s housing stock because we’re in those attics and crawlspaces every week. Newer homes in developments around Post Road have long, complicated duct runs that collect construction dust and sometimes were never sealed properly from day one. Older lake-area homes off Buford Dam Road and Pilgrim Mill Road have duct systems that have fought humidity for 30 or 40 years. Different problems, same fix: a tight, sealed system that moves conditioned air where it belongs.
Why Hollis Air Duct Alpharetta Is Cumming’s Preferred Duct Sealing Company
The Garrison Standard is not a slogan. It’s a written expectation: arrive inside the quoted window, price the job in writing before any work starts, finish it by the book, and leave the site cleaner than we found it. Cumming homeowners call us because they’ve had the opposite experience with other outfits. A low teaser price that doubles once the van is parked in the driveway. A crew that leaves foam scraps and mastic smears in the attic. We’re built different, and the 365-Day Done Right Promise backs that up in writing. If the sealing fails within a year, we come back at no charge. That includes a free second visit, not a negotiated one.
Roy Castellanos runs the crew. He’s the one answering for every job, good or bad, and he’s the reason our techs show up background-checked, uniformed, and trained on the specific equipment we use. Nikro negative-air machines pull dust and debris out of your ducts during the prep work. Sealants and tapes are professional grade, not what you’d grab off a hardware store shelf. The result is a duct system that holds pressure and stops leaking conditioned air into your crawlspace or attic.
Styles & brands we work with




Duct Insulation in Cumming
Duct Insulation in Cumming is not a seasonal want. It’s a structural fix for homes where crawlspace-mounted air handlers pull lake-effect moisture from Lake Lanier into the duct liner, degrading it until the insulation is hanging in shreds and the metal underneath sweats. When our crew sees that, standard sealing alone won’t hold. The fix is to remove the failed liner, seal the metal joints properly, and reinsulate with closed-cell elastomeric rated for continuous high humidity. In Cumming, that work typically runs $300 – $700 per duct run, depending on run length and whether the old insulation is glued, wrapped, or both.
When Your Crawlspace Insulation Has Failed
You’ll know before you see it. Ducts in a vented crawlspace near the lake will start sweating in late spring, and that moisture ends up in your air. Musty smell at the vents, especially when the AC first kicks on. Water stains on the crawlside duct wrap. In older homes built in the 1970s and 80s, the liner may have been fiberglass with a thin foil face. Once that face delaminates, there’s no putting it back.
What Replacement Involves
We cut away the failed insulation, inspect the metal for rust or seam separation, seal what’s sound, and wrap with closed-cell insulation that does not absorb humidity the way old fiberglass does. The difference shows up in your next utility bill and in air that doesn’t smell like a damp crawlspace. We’ll show you before and after photos of your own ducts before we leave.
HVAC Duct Sealing in Cumming
HVAC Duct Sealing in Cumming is often the real fix behind the air quality complaints we hear, not the cleaning itself. When a supply trunk has separated at the plenum or a return duct was never fastened correctly, the system is pulling crawlspace air or dumping conditioned air under the house. Sealing means finding those failures and closing them with mastic and mechanical fasteners. Whole-home sealing in Cumming typically runs $450 – $1,200 for the duct system, with a camera inspection included so you see the leaks before and after.
Mastic and Foil Tape, Applied Correctly
Mastic is a thick, brush-on sealant that hardens into a flexible, airtight skin. Foil tape, the real UL-listed kind, handles seams and small joints. In Cumming’s humid climate, cheap foil tape lifts off fiberglass duct board within months. We use mastic as the primary seal and tape only as reinforcement, which is why our work holds up when a cheap fix fails.
Crushed and Disconnected flex runs
Newer subdivisions built since the 2000s often have flex duct running through tight attic kneewalls. Original hangers get loose, runs sag, and the duct eventually kinks or separates. Sealing alone can’t fix a crushed run. We replace the damaged section, rehang it properly, and then seal the connections. That’s the difference between paying once and paying twice.
Trusted Brands We Service in Cumming
We work on all major duct and HVAC equipment brands, but a few show up more than others in Cumming homes. Honeywell and Aprilaire filtration systems are common in newer subdivisions where homeowners have added whole-home media filters. Nikro is the negative-air standard we run on our own equipment because it does the job in tight crawlspaces and attics without spreading dust through the house. If your system has any of these, our techs know the components and keep common parts on the truck, so a sealing job in Cumming doesn’t stall waiting for a part to ship.
See the difference
Before
After
Before
After
Before
AfterCommon Duct Sealing Problems We See in Cumming Homes
- Mastic joints cracking in vented crawlspaces. Lake Lanier’s moisture load cycles humidity up and down every single day, and brittle mastic eventually lets go. Our crews find this in homes along Buford Dam Road and Pilgrim Mill Road more than anywhere else in Cumming.
- Foil tape peeling off fiberglass duct board. Cumming’s muggy summers are brutal on adhesive-backed tape, especially on supply ducts in humid crawlspaces. Once it lifts, conditioned air escapes under the house and your AC works harder for nothing.
- Crushed flex runs in 1990s attic kneewalls. Builders hung flex duct with the cheapest straps available, and 25 years of attic heat does the rest. We find separated joints and collapsed sections in subdivisions all along Bethelview Road and Post Road.
- Return ducts pulling crawlspace air. When a return plenum isn’t sealed at the air handler, the system pulls whatever lives in the crawlspace, including moisture and mold spores, straight into your home’s air.
Pricing for Duct Sealing in Cumming, GA
Here are the honest numbers for Cumming. Basic sealing of a single-story, 1,500 – 2,200 square foot home runs $450 – $800 when the main issues are seams and small gaps. Homes with crawlspace-mounted air handlers, failed insulation, or multiple disconnected runs will land between $800 and $1,200. Duct insulation replacement typically runs $300 – $700 per run, depending on length and how difficult the access is. The price we quote over the phone and the price on the written estimate before work starts are the same number. Call (762) 769-7145 for a free estimate. There is no charge for the visit and no obligation.
We Also Serve Cities Near Cumming
Our crews serve Cumming and the surrounding area, including Alpharetta, Canton, Duluth, and Suwanee. If you’re in Cumming proper, we’ll schedule you directly. If you’re a few exits up 400 or over toward Lake Lanier, we’ll make the drive. See our Duct Sealing page for the full scope of work, or read more about our service area on the Cumming page.
Serving Cumming, GA - Our Local Coverage Area
We’re based in the Cumming 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 Cumming
Lake Lanier raises local humidity above what mastic and tape products were designed for in a vented crawlspace. The constant moisture cycling causes mastic to crack and foil tape to peel. That’s why we use closed-cell insulation and mastic rated for high humidity, and why our 365-Day Done Right Promise matters so much here. If it fails within a year, we return at no charge. Call (762) 769-7145 to have your crawlspace inspected before you pay for another round of sealing.
Yes, when the smell is coming from failed duct liner, disconnected returns, or air being pulled from the crawlspace, sealing and insulation replacement fixes it. We verified this on a 1980s ranch off Buford Dam Road where the supply trunk had separated at the air handler and the liner was hanging in shreds. After cleaning, sealing, reinsulating, and testing airflow, the musty odor was gone that same week. Call (762) 769-7145 for an inspection if you smell damp air at your vents.
Yes, often not because of age, but because of construction. Duct runs in newer subdivisions off Post Road and Bethelview Road can collect drywall dust, sawdust, and even food wrappers during the build. If the sealing crew was rushed or the duct hangers were not set properly, leaks will show up within the first few seasons. A camera inspection tells us what you’re dealing with. Call (762) 769-7145 and we’ll schedule one.
It shows exactly where the air is leaving the system: disconnected joints, rusted plenums, collapsed flex runs, and degraded liner. For older homes near Lake Lanier, we also see condensation damage and mold on the duct board. You’ll see the images yourself, not a summary. That’s how we price the job accurately and avoid surprises. Call (762) 769-7145 to set up an inspection.
It’s the best time to do it. The old system is out, the ductwork is exposed at the air handler, and seeping crawlspace air isn’t being masked by a new, more powerful blower motor. Sealing the existing ducts before the new unit goes in means the new system actually delivers what it’s rated for. Otherwise, you’re paying for efficiency that escapes under your house. Call (762) 769-7145 and we’ll coordinate with your HVAC contractor.
Written by Roy Castellanos, Owner at Hollis Air Duct Alpharetta, serving Cumming, GA with duct sealing, duct insulation, and air duct cleaning.