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 Katy
Duct sealing in Katy typically costs $450 – $1,200 for a whole-home seal depending on system size and accessibility, and most jobs are completed in a single visit. If your home was built in the last five years in one of Katy’s master-planned communities west of the Grand Parkway, there’s a strong chance your ducts were never properly sealed at handover. We see it constantly.
We’re the Duct Sealing crew for Hollis Air Duct Cleaning, and we serve Katy from our Houston dispatch office. Our technicians are background-checked, uniformed, and arrive inside the quoted window. Calls are answered by a live person, 24 hours a day, 7 days a week. If you’re in Cinco Ranch, Old Katy, or the new developments stretching toward Fulshear, we’ll quote your job in writing before any work starts. Call (361) 326-5060 for a free estimate.
Why Hollis Air Duct Cleaning Is Katy’s Preferred Duct Sealing Company
We’ve been in business since 2004 as part of the Garrison Partners family, and our track record predates most local competitors in the Houston metro. That longevity matters in a market like Katy, where construction crews rotate fast and warranty work often gets passed between subcontractors who never return.
Our 365-Day Done Right Promise covers every duct sealing job in writing. If the seal fails within a year, we come back at no charge, including a free second visit. No negotiation, no runaround. Katy homeowners tell us this matters because they’ve already dealt with builders who disappeared after closing.
We price every job in writing before touching your system. The number on the page is the number at the door. Our technicians follow The Garrison Code on every job: arrive inside the window, price in writing, complete the work by the book, leave the site clean. You’ll know who’s arriving before they walk in.
Duct Sealing Services in Katy
Duct Sealing Services in Katy address a specific problem that worsens with every cooling season: conditioned air bleeding into your attic through gaps, joints, and failed seams instead of reaching your rooms. In Katy’s humid subtropical climate, your HVAC runs at high capacity most of the year. Every cubic foot of cooled air that escapes into a 140-degree attic is money you’re paying to cool plywood and insulation. A typical whole-home duct seal in Katy runs $450 – $1,200, with larger two-story homes in master-planned communities toward the higher end and smaller ranch homes in Old Katy toward the lower.
Leak Detection and Static Pressure Testing
We start with a pressure pan test and visual inspection of accessible ductwork. Many Katy homes, especially new builds, show open joints at trunk lines and boot takeoffs that builders never sealed. We measure static pressure at the air handler to quantify exactly how much air you’re losing before we quote the repair.

Mastic Sealing and Mechanical Fastening
We seal joints with a Guardsman-rated mastic sealant applied over fiberglass mesh, not duct tape, which deteriorates in Katy’s attic heat within two years. Metal connections get mechanical fastening plus sealant. Flexible ductwork gets support strapping to prevent sagging, which creates new leaks over time.

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.
Duct Insulation in Katy
Duct Insulation in Katy protects against a problem most homeowners don’t notice until their upstairs bedrooms stay hot all summer: attic heat transferring through thin duct walls and warming your cooled air before it reaches the register. In Katy’s climate, uninsulated or poorly insulated ducts in vented attics can raise supply air temperature by 8 – 15 degrees. A typical duct insulation job in Katy runs $600 – $1,800 depending on linear footage and whether we’re reinsulating existing ducts or wrapping newly sealed lines. Many homeowners combine sealing and insulation in one visit.
Vapor Barrier Wrapping
Katy’s humidity condenses on cold duct surfaces, especially in spring and fall when attic temperatures swing. We use insulation with an intact vapor barrier facing the duct, sealed at seams with matching tape. Without this barrier, moisture migrates into the insulation, compresses it, and breeds mold.
Replacement of Water-Damaged Insulation
We regularly find collapsed or mold-stained insulation in Katy homes where roof leaks or poor attic ventilation preceded us. We remove the damaged material, treat the duct surface, and install new insulation. This isn’t cosmetic. Wet insulation has an R-value near zero and actively damages your ducts.
Trusted Brands We Service in Katy
We carry professional-grade equipment and materials from Rotobrush, Nikro, and Guardsman, the same tools commercial crews use in hospitals and schools. For filtration and sealing products, we stock Honeywell and Aprilaire components. We keep common sealants, mastics, and insulation wraps on our Katy-area vans so we’re not making a supply run on your time. If your system uses specific boot sizes or trunk dimensions common in local builder specs, we likely have the fitting in stock. Fast turnaround matters when your upstairs bedrooms are 85 degrees in July.
Common Duct Sealing Problems We See in Katy Homes
- New construction with unsealed joints. Builders in Katy’s master-planned communities often leave trunk-to-boot connections open, especially on second-floor runs that are harder to inspect. Attic heat and Katy Prairie silt get drawn into these gaps, so your system moves dirt instead of conditioned air.
- Sealing over construction debris. Some warranty crews or handymen seal leaks without first removing drywall dust and silt. The sealant bonds to dirt, not metal, and fails within months. Worse, it bakes the debris into the seam where you can’t clean it.
- Flexible ductwork sagging in humid attics. Katy’s attic humidity softens the wire helix in cheap flex duct. It droops, kinks, and tears at the support points. Sealing the ends doesn’t help when the middle is crushed flat.
- Sealing the wrong components first. We’ve found new homeowners or their warranty crews who caulked registers and the air handler cabinet while leaving trunk leaks wide open. The system looks sealed but still bleeds air into the attic, and the debris load never gets addressed.
Pricing for Duct Sealing in Katy, TX
Whole-home duct sealing in Katy typically runs $450 – $1,200. A single-story ranch in Old Katy with accessible attic space and metal ductwork usually falls at the lower end. A two-story home in Cinco Ranch or west of the Grand Parkway with extensive flexible duct runs, multiple trunk lines, and construction debris removal needed can reach the upper range. Duct insulation adds $600 – $1,800 depending on linear footage.
What moves the price: accessibility (crawl space vs. walk-in attic), amount of construction debris requiring source removal, whether we’re sealing existing ducts or also replacing damaged flex lines, and whether insulation is included. We give one flat price per system, agreed in writing before work starts. No per-vent pricing, no add-ons at the door. Call (361) 326-5060 for a free estimate with exact numbers for your home.
We Also Serve Cities Near Katy
Our crews work throughout the west Houston corridor. We regularly seal ducts in Katy, Fulshear, Richmond, Sugar Land, and Stafford. Scheduling is coordinated from our Houston office, with local technicians dispatched to your area. Same flat-price, written-quote standard applies in every community we serve.
Serving Katy, TX - Our Local Coverage Area
We’re based in the Katy 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 Katy
Because Katy sits on the Katy Prairie, new-home construction churns up fine silt and clay that gets pulled straight into HVAC intakes long before you move in. Many builders also leave trunk joints and boot takeoffs unsealed, especially on second-floor runs. We regularly seal ducts in homes still under builder warranty. Call (361) 326-5060 for an inspection – estimates are free.
Signs include rooms that never reach the thermostat setting, excessive dust on registers, or utility bills higher than neighbors with similar homes. We confirm leaks with a pressure pan test and static pressure measurement at the air handler. Many new Katy builds show 20 – 30% air loss through unsealed joints. Call (361) 326-5060 to schedule testing.
Yes. Katy’s humid subtropical climate means your HVAC runs heavily most of the year, and humid attic air gets pulled into leaky ducts, condensing on cold surfaces and promoting mold. Sealing prevents this infiltration. Proper sealing with vapor-barrier insulation is especially critical here compared to drier climates. Call (361) 326-5060 for a humidity-specific assessment.
No. Sealing closes gaps but doesn’t clean debris. We recommend source removal first, then sealing. We were called to a just-closed two-story in the master-planned communities west of the Grand Parkway where the family kept finding drywall dust on every register and the upstairs bedrooms never got comfortable. Camera inspection showed open joints at the trunk and boot takeoffs bleeding conditioned air into the attic, with construction silt packed in the supply and return ducts. We sealed the seams with a Guardsman-rated sealant, ran agitation tools under negative pressure with HEPA filtration, and the static pressure at the air handler dropped so the system finally balanced. Many homeowners also ask us about Katy Dryer Vent Cleaning during this same visit. Call (361) 326-5060 to discuss the right sequence for your home.
Absolutely. Old Katy’s 1970s – 80s ranch homes often have original metal ductwork that’s actually easier to seal permanently than modern flex duct. The joints may have loosened over decades, but the metal itself lasts. We test, clean if needed, seal with mastic, and reinsulate. Many older homes see the biggest comfort improvement because they’ve been leaking the longest. Call (361) 326-5060 for an estimate.
Ready to stop paying to cool your attic? Call Hollis Air Duct Cleaning at (361) 326-5060 for a free, written estimate on duct sealing in Katy. We’ll quote your job flat-price before any work starts, back it with our 365-Day Done Right Promise, and show up when we said we would. That’s The Garrison Standard.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Katy since 2004.




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