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.
Fast, Reliable Duct Sealing Across Lewisville
If your Lewisville home has rooms that never cool evenly, utility bills that spike every July, or a persistent layer of attic dust on your return vents, the culprit is probably leaky ductwork. In Lewisville, where summer temperatures push past 100°F for weeks at a stretch and your AC runs almost nonstop from June through September, even a 15% duct leakage rate can add hundreds of dollars to your annual cooling costs. Our Duct Sealing team dispatches from our Seattle coordination office and serves Lewisville homeowners with the same discipline we bring to every job: arrive inside the quoted window, price it in writing before touching anything, and leave the site clean. Call (361) 326-5060 for a free estimate.
Why Hollis Air Duct Cleaning Is Lewisville’s Preferred Duct Sealing Company
We’ve been part of the Garrison Partners family since 2004, and that track record matters in a market where fly-by-night operators come and go. Lewisville homeowners know the difference between a crew that shows up in a branded van with uniformed technicians and one that rolls up in an unmarked truck with a magnetic sign.
Our 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 to schedule your duct sealing in Lewisville.
Every technician we send to Lewisville is background-checked and uniformed. You’ll know who’s walking into your home before they arrive, and they’ll know your neighborhood, whether that’s the newer construction in Castle Hills or the established ranch homes off Mill Street.
We price every job in writing before work begins. The number doesn’t move at the door. That’s The Garrison Standard, and it’s how we’ve built our reputation across North Texas.
Air Duct Sealing in Lewisville
Air Duct Sealing in Lewisville addresses a problem most homeowners don’t know they have until the utility bill arrives or the back bedroom stays stubbornly hot. The process involves locating gaps, cracks, and disconnected joints in your supply and return ductwork, then sealing them with mastic compound or metal-backed tape rated for HVAC use. In Lewisville’s climate, where attic temperatures can exceed 140°F in July, unsealed ducts pull that superheated air directly into your living space while leaking cooled air into the attic. A typical whole-house duct sealing job in Lewisville runs $1,200 – $2,800 depending on system size and accessibility, with most single-family homes falling in the $1,500 – $2,200 range.
Leak Detection and Assessment
We pressurize your duct system and measure airflow loss to find exactly where your conditioned air is escaping. In Lewisville’s older east-side neighborhoods near the I-35E corridor, we regularly find 1970s-era flex duct that has pulled loose at the collar connections, creating gaps large enough to lose 20 – 30% of your system’s output.
Mastic Sealing and Reinforcement
Once we’ve mapped every leak, we apply duct sealing mastic, a thick, fiber-reinforced compound that remains flexible for decades. Unlike duct tape, which dries and fails within a few years in North Texas attic heat, mastic creates a permanent bond that holds through Lewisville’s extreme seasonal temperature swings.
Duct Sealing Services in Lewisville
Duct Sealing Services in Lewisville from Hollis cover everything from spot repairs on disconnected runs to complete system resealing for homes with widespread deterioration. We also handle Air Duct Cleaning in Lewisville and Dryer Vent Cleaning in Lewisville when your system needs more than sealing alone. Most Lewisville homeowners schedule duct sealing after noticing hot rooms, excessive dust, or cooling bills that climbed 30 – 40% without explanation. A typical sealing job takes 4 – 6 hours for a standard single-story home, with pricing starting around $1,200 for partial sealing and ranging to $2,800 for comprehensive whole-system work with hard-to-access attic runs.
Return Duct Sealing
Return leaks are the hidden efficiency killer. When your return pulls air from a hot, dusty attic instead of from your living space, your AC works harder and your indoor air quality suffers. In Lewisville’s Valley Ridge area, we’ve found that even newer homes sometimes have return plenums that were never properly sealed at the platform connection.

Supply Register and Boot Sealing
The gap between your drywall and the metal boot behind each register is a common leak point that forces cooled air into your wall cavities. We seal these with foam-backed gasket material and mastic, ensuring every CFM you pay for actually reaches your rooms.

What happens when you call
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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 Lewisville
Hollis technicians carry professional-grade equipment from Rotobrush and Nikro on every Lewisville job, and we stock sealing products from Guardsman and Abatement Technologies for fast turnaround without waiting on parts shipments. Rotobrush rotary brush systems let us clean duct surfaces before sealing, ensuring mastic bonds properly rather than adhering to dust and debris. Nikro negative-air machines maintain containment during the work, protecting your home’s interior. For filtration upgrades after sealing, we source Honeywell and Aprilaire products that match your system’s airflow requirements. When you need Duct Sealing in Lewisville, you’re getting commercial-grade tools and materials, not hardware-store substitutes.
Common Duct Sealing Problems We See in Lewisville Homes
- Cedar pollen infiltration through attic duct leaks. After December-February cedar fever season peaks, Lewisville residents in older east-side neighborhoods call us with allergy symptoms that won’t quit indoors. The giveaway is loose joints in 1970s-era attic flex duct pulling unfiltered pollen directly from the attic space.
- Disconnected flex runs in post-2000 subdivisions. Castle Hills and Valley Ridge homes have modern duct systems, but the flexible branch lines can pull loose from collars during our frequent spring hail and windstorms, dumping conditioned air into attic insulation.
- Sheet-metal trunk deterioration in historic Old Town ranches. Homes near Mill Street and the Old Town district often have original 1950s-70s metal trunk lines where seams have opened and tape has dried out, creating continuous leakage along the entire run.
- Return platform gaps pulling 140°F attic air. In Lewisville’s brutal summers, an unsealed return plenum can suck superheated attic air into your system for months, raising your electric bill and overworking your compressor.
Pricing for Duct Sealing in Lewisville, WA
Honest pricing starts with honest ranges. In Lewisville’s market, partial duct sealing for a specific problem area typically runs $1,200 – $1,700. Whole-system sealing for a standard 1,500 – 2,500 square foot home with accessible attic ductwork falls between $1,800 – $2,500. Larger homes, multi-story layouts with complex attic runs, or systems requiring significant access work can reach $2,800. What moves the needle: how much of your ductwork is accessible, whether we need to remove insulation to reach leaks, and whether your system also needs cleaning before sealing will hold. We give you one flat price per system, agreed in writing before any work starts. No per-vent pricing, no teaser coupon that balloons once we’re on site. Call (361) 326-5060 for an exact quote on your Lewisville home. Estimates are free.
We Also Serve Cities Near Lewisville
Our crews work throughout the Dallas-Fort Worth Metroplex and beyond, with regular service to Seattle, Spokane, Tacoma, and Vancouver. Scheduling and dispatch are coordinated from our Seattle office, but the technicians who arrive at your Lewisville home live and work in your region. They know the local housing stock, the local climate patterns, and the local building codes that affect how duct sealing gets done right.
Serving Lewisville, WA - Our Local Coverage Area
We’re based in the Lewisville 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 Lewisville
We typically schedule Lewisville appointments within 3 – 5 business days, with flexibility for urgent situations like complete disconnections that are dumping conditioned air into your attic. Call (361) 326-5060 and we’ll find the next available slot that works with your schedule.
Yes, we seal ducts from Castle Hills and Valley Ridge in the newer western sections to the historic ranch homes off Mill Street and throughout the Old Town district, plus all corridors along and near I-35E. Our technicians are familiar with the distinct ductwork styles in each area.
We prioritize calls where a major disconnection has occurred and your system is non-functional or pulling dangerous attic temperatures into your home. Our phones are answered by a live person 24/7, and we’ll assess urgency and schedule accordingly.
Lewisville pricing sits in line with the broader DFW Metroplex market, though homes in older east-side neighborhoods sometimes run slightly higher due to access challenges with 1970s-era attic layouts. We don’t inflate prices based on zip code. Your written quote reflects your specific system, not your neighborhood.
Every Hollis duct sealing job is backed by our 365-Day Done Right Promise. If any sealed joint fails or leaks recur within a full year, we return and make it right at no charge, including a free second visit. That’s written on every invoice, not implied.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Lewisville with The Garrison Standard since 2004.




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