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 South Houston
Duct sealing in South Houston typically runs $400 – $950 for a whole-home system, and most jobs are scheduled within a few days of your call. We serve homeowners from the older ranch neighborhoods near Spencer Highway to the newer townhomes off Beltway 8, and our dispatch team coordinates from our Houston office to get crews to South Houston jobs on time.
We’re Hollis Air Duct Cleaning, part of the Garrison Partners family since 2004. Our Duct Sealing team knows South Houston’s homes inside and out. The post-war ranches along Avenue A, the bungalows near the ship channel, the gravel-road properties off Old Galveston Road – we’ve sealed ducts in all of them. The industrial haze from nearby refineries and the constant humidity here create a combination you won’t find in Pasadena or Pearland. That local knowledge matters because standard sealing methods fail when greasy, chemical-laden dust coats your duct walls. We degrease before we seal, and we test after. Call (361) 326-5060 for a free estimate.
Why Hollis Air Duct Cleaning Is South Houston’s Preferred Duct Sealing Company
South Houston homeowners have left us reviews mentioning the same things: we showed up in the window we promised, the price on the invoice matched the written quote, and the technician explained what he found before doing anything. That’s The Garrison Standard. We’re not the cheapest outfit you’ll find, and we don’t try to be.
Our Houston office dispatches crews to South Houston daily. We know the traffic patterns on Texas 3 and the back routes through residential neighborhoods. That matters when you’re scheduling around work or waiting for a technician with a written quote in hand.
Roy Castellanos leads our operation, and every technician who enters your home is background-checked, uniformed, and trained to leave the site clean. The 365-Day Done Right Promise covers every duct sealing job in writing: if the seal fails within a year, we return and make it right at no charge, including a free second visit.
We’ve earned our reputation in South Houston by doing what we said we’d do. No price bumps at the door. No disappearing acts. Just sealed ducts that hold.
Duct Insulation in South Houston
Duct Insulation in South Houston addresses a specific problem: the rigid metal ductwork in most 1950s – 1970s ranch homes here runs through attics that hit 120°F or higher in summer. Uninsulated or poorly insulated ducts bleed cooled air into that oven-like space before it ever reaches your vents. Your system runs longer, your bills climb, and the humidity that South Houston’s climate pushes into those ducts promotes condensation and mold.
Our crew wraps supply ducts with formaldehyde-free fiberglass insulation, sealed with vapor-barrier jacketing, to maintain the temperature of conditioned air from the air handler to the register. In homes with flexible ductwork – common in newer South Houston townhomes – we inspect for compression and kinks that reduce airflow, then insulate and seal the entire run.
When Insulation Beats Replacement
Many South Houston homeowners assume leaky ducts need full replacement. Often they don’t. If the metal is structurally sound, insulating and sealing the existing runs costs roughly half what replacement would run. We camera-inspect first, then give you a written price for either path.
Cost Range for Duct Insulation
Duct insulation in South Houston typically runs $600 – $1,400 for a whole-home system, depending on accessible attic space and linear footage. Homes with finished attics or tight crawlspaces take longer, and we price that upfront. No surprises when the technician arrives.
HVAC Duct Sealing in South Houston
HVAC Duct Sealing in South Houston closes the gaps, cracks, and disconnected joints that let conditioned air escape and unconditioned air enter your system. In a typical South Houston home, we find 20 – 30% airflow loss through leaks at plenum connections, boot-to-wall joints, and seams in rigid metal trunk lines. That waste shows up on your electric bill every month.
Our process starts with a negative pressure test to map every leak. We then clean and degrease the duct surfaces – critical in South Houston, where refinery fallout leaves an oily film that prevents standard mastic from bonding. We apply duct sealing mastic, reinforce with foil tape rated for high-humidity attics, and test again to confirm the system holds pressure.
Negative Pressure Testing Explained
We pressurize your duct system and measure airflow loss through a calibrated fan. This gives us a baseline in CFM, then a verified result after sealing. You see the numbers. No guesswork about whether the job worked.
Mastic vs. Tape in Humid Climates
We use water-based duct mastic for its flexibility and longevity in South Houston’s humidity, reinforced with foil tape at joints and boots. Cheap tape alone peels in attic heat. We don’t use it as a primary sealant.
Trusted Brands We Service in South Houston
We stock parts and sealing materials from Aprilaire, Abatement Technologies, and Guardsman for South Houston jobs, plus we carry Rotobrush rotary systems for pre-sealing cleaning. That local inventory means faster turnaround when your system needs attention. We don’t wait on warehouse shipments from Dallas or Austin. Our trucks leave the Houston office stocked with mastic, foil tape, insulation jacketing, and replacement boots sized for the rigid metal ducts common in South Houston’s older homes and the flexible ductwork found in newer construction. If your system uses Honeywell or Aprilaire filtration components, we inspect those during our sealing assessment and note any wear in our written report.
Common Duct Sealing Problems We See in South Houston Homes
- Industrial grime breaking the seal. The refinery fallout along the ship channel coats duct interiors with a dark, sticky residue. Standard mastic applied over this film fails within months as the grease breaks the bond. We degrease every surface before sealing.
- Sandy road dust abrading joints. Properties on unpaved stretches off Old Galveston Road and similar gravel roads pull fine grit into return ducts. That sandblasting effect wears away sealant at boots and connections, reopening leaks we thought we’d closed.
- Attic heat degrading materials. South Houston attics regularly exceed 120°F in summer. Low-grade tape softens and peels. We use mastic rated for continuous high temperatures and foil tape with aggressive adhesive formulated for humid, hot environments.
- Older ranch homes with inaccessible duct runs. The 1950s – 1970s ranches near Spencer Highway often have ducts buried in soffits or framed into walls. We use remote cameras and flexible applicators to reach and seal these runs without destructive access cuts.
Pricing for Duct Sealing in South Houston, TX
Whole-home duct sealing in South Houston typically runs $400 – $950. Duct insulation adds $600 – $1,400. The final price depends on three factors: linear footage of ductwork, accessibility (attic crawl vs. open basement), and the condition of the duct surfaces – heavily contaminated ducts require degreasing before sealing, which adds labor.
We give you one flat price per system, agreed in writing before any work starts. No per-vent pricing. No add-ons at the door. The quote covers cleaning, degreasing if needed, sealing, insulation where specified, and post-job pressure testing. We also provide before-and-after photos of your own ducts so you can see what was done.
Call (361) 326-5060 for a free estimate. We’ll ask about your home’s age, square footage, and any symptoms you’ve noticed – uneven cooling, musty smells, rising bills – then schedule a technician to inspect and quote.
We Also Serve Cities Near South Houston
Our crews regularly work in South Houston and the surrounding communities: Pasadena to the east, Galena Park to the northeast, Deer Park to the southeast, and Pearland to the south. Each shares some of South Houston’s challenges – humidity, aging housing stock – but none face the same industrial particulate load from the ship channel refineries. That distinction matters in how we approach your job.
Serving South Houston, TX - Our Local Coverage Area
We’re based in the South Houston 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 South Houston
Every 5 – 7 years for homes on gravel or unpaved roads, compared to 7 – 10 years for paved suburban streets. The sandy dust off Old Galveston Road and similar stretches infiltrates return ducts and slowly abrades sealant at joints and boots. We inspect these properties more carefully during our initial assessment and may recommend more frequent pressure testing. Call (361) 326-5060 to schedule an inspection and get a written maintenance interval for your specific property.
No. Sealing alone won’t remove existing contamination. The dark, sticky residue from ship channel industrial activity must be removed through source cleaning and degreasing before sealing, or the odor will persist and the seal will fail. We perform both steps: full mechanical cleaning with rotary brushes and degreasing agents, then sealing with verified pressure testing. Call (361) 326-5060 for an inspection if you’re noticing chemical smells from your vents.
Yes, typically. Outbuilding systems in South Houston’s rural areas often use exposed flexible ductwork or metal runs with minimal insulation, pulling in more dust and heating up faster in direct sun. The sealing materials must be rated for wider temperature swings, and we often add extra insulation jacketing. We assess outbuilding systems separately and quote them as distinct systems. Call (361) 326-5060 to discuss your outbuilding setup.
Three reasons: original rigid metal ducts were assembled with snap-lock seams rather than sealed seams, attic insulation has compressed or degraded over decades, and retrofit work by previous owners often used incompatible materials. The 1950s – 1970s ranches near Avenue A and Spencer Highway are particularly prone to these issues. We camera-inspect to identify previous repairs and specify the right fix. Call (361) 326-5060 for a written assessment of your ranch home’s ducts.
High humidity causes condensation on cool duct surfaces, which degrades tape adhesives and promotes mold that breaks down organic sealants. We use synthetic, moisture-resistant mastic and foil tape rated for humid climates, and we verify that insulation vapor barriers are intact to prevent condensation formation. Homes near the ship channel with chronic humidity issues may benefit from supplemental dehumidification. Call (361) 326-5060 to discuss humidity control as part of your sealing project.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving South Houston since 2004.




Before
After
Before
After
Before
After