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 Knoxville
Duct sealing in Knoxville typically runs $400 – $1,200 for a whole-home system, and most jobs are scheduled within a few business days. If your upstairs rooms never get warm in winter or your energy bills keep climbing despite a newer HVAC unit, the problem is often air leaking out of ducts before it ever reaches your vents.
We’ve worked in Knoxville homes since 2004, from the pre-1920 bungalows of Old North Kingston to the ranch houses lining Northshore Drive and Kingston Pike. Our crews dispatch from our Memphis office and serve Knoxville neighborhoods directly. We know the difference between a duct that needs cleaning and one that needs actual sealing or repair, and we won’t charge you for work that doesn’t fix the root problem. Call us at (361) 326-5060 for a free estimate with a written price before any work starts.
Why Hollis Air Duct Cleaning Is Knoxville’s Preferred Duct Sealing Company
Knoxville homeowners call us back because we show up inside the quoted window, price the job in writing before touching anything, and leave the site clean. That’s The Garrison Standard, and it applies to every job we run in Knox County.
Our technicians are background-checked and uniformed. You’ll know who’s walking into your home before they arrive. Every duct sealing job carries our 365-Day Done Right Promise in writing: if the seal fails or airflow doesn’t improve, we return and make it right at no charge, including a free second visit.
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 morning to schedule.
We understand Knoxville’s housing stock because we’ve worked inside it. We know the original sheet metal trunks in Fourth and Gill leak at every joint, and we know the flex runs in Fountain City ranches crush where previous owners ran them through tight crawl spaces. That local knowledge means we diagnose faster and fix it correctly the first time.
HVAC Duct Sealing in Knoxville
HVAC Duct Sealing in Knoxville addresses the conditioned air that escapes through gaps, disconnected joints, and corroded seams before it ever reaches your rooms. In this market, we see the problem most often in two types of homes: pre-1920 mill houses and bungalows with original sheet metal ductwork, and 1950s – 1970s ranches with aging flex runs. Sealing restores pressure balance so your system doesn’t overwork to compensate. A typical whole-home HVAC duct sealing job in Knoxville runs $400 – $900 for mastic sealing of accessible ductwork, or $700 – $1,200 if we need to replace crushed flex runs or corroded trunk sections.
When Sealing Beats Cleaning Alone
We regularly find Knoxville homeowners who paid for duct cleaning but still have hot and cold spots. The ducts were clean, but they were still leaking. Sealing comes after cleaning when the mechanical condition of the ductwork, not debris buildup, is the actual problem. We verify with static pressure testing before and after.
Mastic vs. Tape: What We Use
We seal with duct mastic and fiberglass mesh, not foil tape. Mastic remains flexible through Knoxville’s humidity swings and fills irregular gaps in pitted, corroded metal. Tape dries and peels. In older homes near the river, where corrosion has pitted the metal surface, mastic is the only sealant that adheres properly after mechanical prep.
Duct Repair in Knoxville
Duct Repair in Knoxville fixes the physical damage that sealing alone cannot address: crushed flex runs, separated trunk lines, corroded sections that have developed holes, and takeoffs that have pulled loose from the main plenum. We see this damage most often in homes that have had multiple owners, unpermitted renovations, or decades of humidity exposure in crawl spaces. A typical duct repair in Knoxville ranges from $300 – $600 for reconnecting or replacing a single branch run, to $800 – $1,500 for rebuilding sections of corroded trunk line or replacing multiple flex runs. We always provide a written price before starting.
Corroded Trunk Lines Near the River
Homes in neighborhoods close to the Tennessee River, including parts of South Knoxville and Island Home, often have trunk lines with corrosion from decades of valley fog and high humidity. Pitted metal won’t hold a seal until we mechanically clean the surface and apply mastic with reinforcement mesh. Sometimes the section is too far gone and needs replacement.
Crushed Runs from Renovations
In West Hills and Fountain City ranches, we find flex duct crushed under bathroom additions or kitchen remodels where a previous contractor ran new flooring over the duct. We replace the crushed section with properly sized flex or rigid duct and restore the original airflow path.
Trusted Brands We Service in Knoxville
Our Knoxville crews carry professional-grade equipment from Rotobrush, Nikro, and Abatement Technologies. We stock sealing mastic, fiberglass mesh, and replacement flex duct in common diameters so most repairs don’t wait on parts. For filtration upgrades after sealing, we install Honeywell and Aprilaire products that match the airflow characteristics of your newly sealed system. We don’t show up with hardware-store tape and hope it holds through a humid Knoxville summer.
Common Duct Sealing Problems We See in Knoxville Homes
- Original sheet metal leaks in pre-1920 homes. Every joint and seam in Old North Knoxville and Fourth and Gill bungalows was originally sealed with fabric tape that has dried and failed. Conditioned air leaks into walls and crawl spaces year-round.
- Crushed or disconnected flex runs in post-war ranches. Fountain City and West Hills homes from the 1950s – 1970s often have flex duct that has been crushed by storage in attics or disconnected at takeoffs by previous owners.
- Corrosion from Tennessee River valley humidity. Ducts in homes near the river carry decades of exposure to fog and moisture, leaving pitted metal that resists adhesion until properly prepped.
- Biological coating from Smoky Mountain pollen. Spring pollen and fall leaf-mold spores create a film on duct interiors. Sealing over this contamination traps debris and the seal won’t bond to the surface.
Pricing for Duct Sealing in Knoxville, TN
A typical whole-home duct sealing job in Knoxville runs $400 – $1,200 depending on accessibility, the condition of the existing ductwork, and whether we’re sealing in place or replacing damaged sections. Mastic sealing of accessible metal trunk lines generally falls in the $400 – $700 range. Jobs requiring replacement of crushed flex runs or corroded trunk sections run $700 – $1,200.
What moves the price: crawl space height, the number of disconnected joints we find, whether we need to run new flex to replace crushed sections, and whether mechanical cleaning is required before mastic will adhere. We inspect with a camera first and give you a written price before any work starts. That price does not change at the door.
Call (361) 326-5060 for a free estimate. We’ll inspect your system, show you what we find, and give you an exact number.
We Also Serve Cities Near Knoxville
Our crews travel to Knoxville from our Memphis dispatch office and also serve Powell, Seymour, Louisville, and Clinton. The same written pricing, same 365-Day Done Right Promise, same background-checked technicians apply in every community we work.
Serving Knoxville, TN - Our Local Coverage Area
We’re based in the Knoxville 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 Knoxville
Original sheet metal ductwork in pre-1920 homes was sealed with fabric tape that fails after decades, and every joint leaks conditioned air into walls and crawl spaces. Newer homes use sealed duct systems from the start. We typically find 20 – 30% airflow loss in unsealed older systems. Call (361) 326-5060 for a camera inspection of your ducts.
Yes, but flex duct often needs repair first. We find crushed runs, disconnected takeoffs, and sections that have degraded from attic heat. We replace damaged flex with new material, then seal connections with mastic and proper supports. Call (361) 326-5060 and we’ll show you what your specific system needs.
Pollen from the Great Smoky Mountains coats duct interiors with a fine yellow-green film that prevents mastic from bonding to metal. We clean ducts with Rotobrush agitation under negative pressure before sealing. Sealing over contamination traps debris and the seal fails. Call (361) 326-5060 to schedule cleaning and sealing together.
River-adjacent homes often have corrosion from decades of valley fog and humidity. We mechanically clean pitted metal, apply mastic with fiberglass mesh reinforcement, and test static pressure to verify the seal holds. Severely corroded sections may need replacement rather than sealing. Call (361) 326-5060 for an inspection and written quote.
Yes, if you still have uneven temperatures or high energy bills after cleaning. Cleaning removes debris; sealing stops air loss. We’ve found that many Knoxville homeowners need both, especially in older homes where joints have separated or tape has failed. Call (361) 326-5060 and we’ll test your system to determine whether sealing will solve the remaining problem.
We worked a 1920s bungalow off Fourth and Gill where camera inspection showed the main trunk had separated at two joints and a branch run was crushed under a bathroom remodel. After source removal with Rotobrush agitation tools under negative pressure, we sealed the trunk with mastic and mesh and reconnected the branch with a new flex run, then verified the air handler was holding static pressure. The homeowner noticed the upstairs registers finally moved air like the downstairs ones. That’s the kind of result our Duct Sealing team delivers when we diagnose the real problem instead of selling a surface fix.
In Knoxville’s older homes, pre-1920 mill houses and bungalows in Old North Knoxville and Fourth and Gill, ducts near the Tennessee River carry decades of corrosion from river valley fog and humidity, so the real fix is often sealing and reconnecting crushed runs, not just cleaning them. We’ve learned to look past the dust and pollen to the mechanical condition of the duct itself. That’s what separates a temporary improvement from a permanent fix.
Ready to stop losing conditioned air to your crawl space? Call Hollis Air Duct Cleaning at (361) 326-5060 for a free estimate. We’ll inspect your ductwork with a camera, explain what we find in plain terms, and give you a written price before any work begins. Every job is backed by our 365-Day Done Right Promise: if it’s not right, we make it right at no charge.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Knoxville since 2004.