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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After
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AfterFast, Reliable Duct Sealing Across Sienna
We’re the Duct Sealing crew that serves Sienna from our Dallas-Fort Worth dispatch office, and we know this community’s homes inside out. Nearly every house here was built after 2000 in a master-planned setting, which means the ductwork is young but the problems are specific: construction dust, Gulf humidity, and attic heat that hits 140°F. We answer our phones live 24 hours a day at (361) 326-5060, and we’ll give you a written price before any work starts.
Our technicians are background-checked, uniformed, and trained to The Garrison Standard: arrive inside the quoted window, price it in writing, complete the job by the book, and leave the site clean. In Sienna, that standard matters because your HOA has rules about how attic vents and outdoor equipment must look, and because the real enemy here isn’t old metal ductwork – it’s mold and leaks in flex systems that never had a chance to dry out.
Why Hollis Air Duct Cleaning Is Sienna’s Preferred Duct Sealing Company
We’ve been in business since 2004 as part of the Garrison Partners family, and our reputation in Sienna is built on showing up when we said we would. Homeowners in neighborhoods like Heritage Park and Sawmill Lake call us because they’ve already dealt with the alternative: a low quote that ballooned once the technician was inside, or a crew that left drywall dust blowing through the registers.
Our response time to Sienna is coordinated through our Dallas-Fort Worth office, with crews dispatched specifically for this market. We don’t promise same-day miracles – duct sealing is scheduled work that deserves proper diagnosis – but we do promise a live person will answer your call, a written quote before any tool touches your system, and a 365-Day Done Right Promise that covers every repair in writing. If the work fails within a year, we come back at no charge, including a free second visit.
What Sienna homeowners tell us they value most is accountability. You know who’s walking into your home before they arrive. The price is written down and doesn’t move at the door. And our equipment roster – Rotobrush rotary brush systems, Nikro negative-air machines, and filtration from Honeywell and Aprilaire – is the same gear commercial crews use, not hardware-store rentals.
Air Duct Sealing in Sienna
Air Duct Sealing in Sienna is almost never about replacing ancient galvanized ductwork, because there essentially isn’t any. Instead, we seal disconnected flex duct runs in unconditioned attics, repair mastic joints fouled by construction debris, and stop the conditioned-air leaks that drive up your summer electric bills while pulling humid Gulf air into the system. A typical Air Duct Sealing job in Sienna runs $450 – $1,200 depending on how many runs need attention and whether we find mold that requires source removal first.
What We Find in Sienna Attics
The most common call we get is an upstairs bedroom that won’t cool evenly. In a two-story brick-and-stone home with flex ducts running through a 140°F attic, the long unsupported spans sag at wye connections and eventually separate. Conditioned air spills into the attic. Humid outside air gets sucked in. The temperature split between floors climbs to 6°F or worse, and your AC runs nonstop without ever catching up.
Sealing Versus Replacement
Most Sienna homes don’t need full duct replacement. The flex duct itself is often fine; it’s the connections, collars, and plenum seals that have failed. We use mastic and mesh tape at every joint, seal register boots to drywall with proper caulk, and verify our work with a duct blaster or smoke test. The goal is a tight system that moves air where it’s supposed to go, not into your attic.
Duct Sealing Services in Sienna
Duct Sealing Services in Sienna address the specific failure modes of post-2000 master-planned construction: mold colonization inside attic flex ducts near the air handler, seal abrasion from construction dust and drywall debris, and disconnected runs caused by thermal expansion in 140°F attics. Our Duct Sealing Services range from spot repair of a single disconnected run at $280 – $450 to whole-system sealing and rebalancing at $900 – $1,500 for larger homes with multiple zones.
Negative-Air Source Removal Before Sealing
We won’t seal over mold. If our camera inspection finds biological growth inside the flex duct – common near Sienna air handlers where 70°F+ dew points meet hot attic air – we perform negative-air source removal first. This uses a Nikro negative-air machine to pull contaminants out of the duct under controlled suction, with HEPA filtration so nothing recirculates into your living space. Only then do we seal.
Rebalancing After Sealing
A sealed duct system moves more air to the registers because it’s not leaking into the attic. That changes the pressure balance between supply and return. We measure airflow at each register after sealing and adjust dampers so every room gets its designed CFM. In Sienna’s large two-story homes, this step is what finally fixes the upstairs-hot, downstairs-cold problem.
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 Sienna
We stock parts and filtration products from Honeywell, Aprilaire, and Abatement Technologies for Sienna customers, which means faster turnaround when your system needs a compatible component. Honeywell media air cleaners and Aprilaire whole-house dehumidifiers integrate directly with the high-efficiency systems common in Sienna’s newer homes, and Abatement Technologies HEPA filtration is what we deploy during mold remediation work. We don’t have to order and wait. The right part is on the truck, and if it’s not, our Dallas-Fort Worth office can have it to the crew before your appointment window.
Common Duct Sealing Problems We See in Sienna Homes
- Disconnected flex duct at wye connections. Sienna’s large two-story homes have long flex duct runs through unconditioned attics. When attic temperatures swing to 140°F, the plastic supports sag and the tape adhesive fails. The duct separates at the wye, spilling conditioned air into the attic and pulling in humid outside air through the return.
- Mold colonization near the air handler. The combination of 70°F+ summer dew points and 140°F attic temperatures creates condensation on the cold flex duct surface right where it leaves the air handler. This is a Sienna-specific problem you rarely see in drier inland subdivisions, and it produces the musty odor homeowners report from their registers.
- Seal failure from construction debris. Drywall dust and sawdust left in Sienna’s new-build duct systems abrades mastic seals and fouls the blower motor. The debris acts like sandpaper at every joint, accelerating seal failure within the first decade of occupancy.
- Flood-zone humidity intrusion. Sienna’s position in a recognized flood zone means post-storm humidity spikes and occasional duct contamination. After Hurricane Harvey in 2017, we performed repeated decontamination and resealing work in this community, and we still see moisture-damaged mastic from that era.
Pricing for Duct Sealing in Sienna, TX
Honest pricing starts with honest ranges. In Sienna’s market, a single disconnected flex duct run that needs reconnection and sealing runs $280 – $450. Spot sealing of multiple register boots and plenum connections runs $350 – $650. Whole-system duct sealing with negative-air cleaning, mastic application at all joints, and rebalancing for a large two-story home runs $900 – $1,500. We don’t quote per-vent teaser prices that balloon at the door. We inspect, we write the full price down, and that number doesn’t move once work begins.
What affects your specific cost: how many duct runs need attention, whether mold remediation is required before sealing, accessibility in your attic, and whether your system needs rebalancing afterward. Every estimate is free. Call (361) 326-5060 and we’ll schedule a look.
We Also Serve Cities Near Sienna
Our crews work throughout the greater metro area, and we regularly dispatch to Sienna from our Dallas-Fort Worth office. We also serve Houston, San Antonio, Dallas, and Fort Worth with the same written pricing, same background-checked uniformed technicians, and same 365-Day Done Right Promise. Each market gets local expertise; no generic playbook.
Serving Sienna, TX - Our Local Coverage Area
We’re based in the Sienna 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 Sienna
Sienna homes are newer but their duct systems face unique stress: 140°F attics, 70°F+ dew points, and construction debris left in flex ducts from the building phase. Older Houston neighborhoods often have galvanized metal ductwork that lasted decades; Sienna’s flex duct systems fail at connections and seals within 10 – 15 years because of Gulf humidity and thermal cycling, not age. Call (361) 326-5060 for a free inspection.
Duct sealing alone cannot fix active mold. We first perform negative-air source removal with HEPA filtration to remove biological growth, then seal the duct system to eliminate the condensation points that allowed mold to colonize. In Sienna’s climate, the root cause is usually humid outside air entering through leaks near the cold air handler. Sealing after cleaning prevents recurrence. Call (361) 326-5060 to schedule a camera inspection.
Sienna’s recognized flood zone status means post-storm humidity spikes and occasional duct contamination that accelerates seal degradation. After significant weather events, we inspect for moisture-damaged mastic and humidity-driven mold growth before sealing. Our crews are familiar with the specific recovery needs of this community. Call (361) 326-5060 if you’ve noticed odors or efficiency drops after recent storms.
We inspect with a camera, identify leaks and disconnections, perform source removal if mold is present, seal all joints with mastic and mesh tape, caulk register boots to drywall, and rebalance airflow. For a typical Sienna home, this takes 4 – 6 hours. You receive before photos, after photos, and a written 365-Day Done Right Promise. Call (361) 326-5060 for your specific quote.
Sienna’s HOA mandates screening of attic vents and outdoor HVAC equipment, which our crews respect on every job. We don’t modify exterior appearances or violate architectural standards. All our sealing work happens inside the duct system and attic, with no visible changes to your home’s exterior. Call (361) 326-5060 if you have specific HOA documentation requirements.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Sienna since 2004.