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.
Before
After
Before
After
Before
AfterFast, Reliable Duct Sealing Across Friendswood
Duct sealing in Friendswood typically runs $450 – $1,200 per HVAC system depending on accessibility and the extent of leakage, with most multi-system homes in the area falling in the $900 – $2,400 range for complete sealing. We’re the Duct Sealing crew that serves Friendswood from our Houston dispatch office, and we know the difference between a quick patch job and sealing that survives our Gulf Coast humidity. Call (361) 326-5060 for a free written estimate.
Friendswood’s large-lot ranch homes and newer builds in West Ranch and Sterling Creek aren’t built like compact Clear Lake condos. Multiple systems, long trunk-line runs, and decades of coastal moisture mean duct leaks here cost you more than comfort. They cost you mold remediation, shortened equipment life, and energy bills that climb every summer. We seal ductwork by the book, price it in writing before we start, and back it with our 365-Day Done Right Promise.
Why Hollis Air Duct Cleaning Is Friendswood’s Preferred Duct Sealing Company
We’ve been part of the Garrison Partners family since 2004, and our Houston-area crews have handled enough Friendswood jobs to know the patterns. The 77546 ZIP code is full of homes where original flex duct from the 1980s has turned brittle, where Hurricane Harvey left hidden moisture in trunk lines, and where three-system houses need per-system pricing that doesn’t balloon at the door.
Our technicians are background-checked, uniformed, and expected to operate by The Garrison Code: arrive inside the quoted window, price in writing, complete the job by the book, leave the site clean. No exceptions. Every duct sealing job gets a written price before any work starts, and our 365-Day Done Right Promise means if the seal fails within a year, we come back 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. When you’re dealing with musty air after a tropical storm, you don’t wait until Monday.
Duct Insulation in Friendswood
Duct Insulation in Friendswood addresses the condensation that forms on cool duct surfaces when 90-degree, 80-percent-humidity attic air wraps around them. We install closed-cell foam insulation and reflective radiant barriers on accessible duct runs, typically after sealing leaks with mastic, to prevent the sweating that breeds mold in our climate. A standard Duct Insulation job in Friendswood runs $300 – $800 per system for accessible trunk lines and plenums, with costs rising if we need to open soffits or chase walls in two-story homes.
When Attic Condensation Demands Insulation
Friendswood’s year-round HVAC operation means ducts stay cold for months. Without proper insulation, that cold surface pulls moisture from Gulf Coast air like a glass of iced tea on a July porch. We see this most in original 1970s ranch homes with uninsulated sheet-metal trunk lines and in newer tight-built homes where attic ventilation can’t keep up. Insulation after sealing stops the cycle.
Insulation Materials for Coastal Humidity
We use products rated for high-humidity environments, not hardware-store wrap that delaminates in six months. Our crews explain what they’re installing and why, so you understand what you’re paying for before any material goes up.
HVAC Duct Sealing in Friendswood
HVAC Duct Sealing in Friendswood means finding and permanently closing the gaps, disconnected joints, and deteriorated seals that leak conditioned air into your attic, crawl space, or walls. We pressurize the system, locate leaks with smoke pencils and digital manometers, then seal accessible joints with UL-181 rated mastic and reinforced mesh. Inaccessible leaks get addressed through strategic access cuts or aerosol sealant injection. Per-system pricing for HVAC Duct Sealing in Friendswood typically ranges from $450 – $1,200, with whole-home multi-system jobs running $900 – $2,400.
Leak Detection Before Sealing
We don’t guess. Our techs run a negative pressure test to establish baseline leakage, then mark every compromised joint. In Friendswood’s older homes, we regularly find disconnected flex duct where original zip ties failed and gaps where trunk-line saddles separated under decades of vibration. You get a written report with photos.
Mastic vs. Tape in Humid Conditions
Foil tape fails in our climate. The adhesive degrades, the backing peels, and you’re leaking again within a season. We use water-based duct sealing mastic that remains flexible, bonds to metal and flex duct, and carries a UL-181 rating for air distribution systems. It’s slower to apply. It lasts.
Trusted Brands We Service in Friendswood
Our equipment roster includes Rotobrush rotary brush systems for pre-sealing cleaning, Nikro negative-air machines for containment during mold remediation, and filtration and insulation products from Abatement Technologies and Guardsman. We stock common sealing and insulation materials locally for Friendswood jobs, which means faster turnaround when you’re dealing with post-storm contamination or preparing a home for sale in West Ranch or Sterling Creek. Our Houston office coordinates scheduling and parts, and crews serve Friendswood directly without the delays of out-of-town dispatch.
Common Duct Sealing Problems We See in Friendswood Homes
- Multiple systems, partial sealing. A typical Friendswood home has two or three HVAC units, but some contractors quote and seal only the easiest one. We price per system and document every unit, because leaving one system leaking means you’re still losing efficiency and inviting humidity into the others.
- Mold in trunk-line first feet after storms. After tropical weather, we find mold growth concentrated where cool supply air meets warm attic air near the plenum. Sealing over this without cleaning traps spores. We inspect with cameras first, remediate if needed, then seal.
- Brittle original flex duct in 1970s – 1990s homes. The vinyl outer layer degrades in our UV-exposed attics and humidity-cycled conditions. We identify sections that need replacement versus sealing, and we don’t charge sealing prices for replacement work.
- Low-grade sealants that fail in humidity. Cheap caulk and tape products soften, crack, or lose adhesion under Friendswood’s temperature swings and moisture loads. We use only rated, tested materials with documented performance in Gulf Coast conditions.
Pricing for Duct Sealing in Friendswood, TX
Honest pricing means no per-vent teaser rates that triple once the van is in your driveway. Here’s what duct sealing costs in Friendswood:
| Service | Typical Range |
|---|---|
| Single-system HVAC duct sealing | $450 – $1,200 |
| Two-system home, complete sealing | $900 – $1,800 |
| Three-system home, complete sealing | $1,200 – $2,400 |
| Duct Insulation (per system, accessible) | $300 – $800 |
| Camera inspection with written report | $150 – $250 (credited toward sealing) |
Factors that move the needle: accessibility (crawl space vs. walk-in attic), extent of mold remediation needed before sealing, number of disconnected joints requiring reconnection versus simple sealing, and whether we need to create access points in finished spaces. We write the price down before any work starts. It does not move at the door. Call (361) 326-5060 for a free estimate on your specific home.
We Also Serve Cities Near Friendswood
Our crews regularly handle duct sealing in Webster, League City, Pearland, and Alvin. League City and Clear Lake homes tend toward single-system setups with shorter runs, so their pricing and scope differ from Friendswood’s multi-system reality. Wherever you are in the area, we apply the same standard: written price, documented work, 365-Day Done Right Promise.
Serving Friendswood, TX - Our Local Coverage Area
We’re based in the Friendswood 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 Friendswood
Extreme humidity keeps duct surfaces cold and wet for months, which degrades tape adhesives and causes metal-to-flex connections to work loose. In older Friendswood homes with original 1970s – 1990s ductwork, we regularly find that leaks have worsened gradually as materials fatigued in the moisture cycle, making sealing more extensive than a simple patch job. Call (361) 326-5060 and we’ll assess what your specific system needs.
Per-system pricing prevents the bait-and-switch where a low quote covers only one unit and the others get added at premium rates once work begins. Friendswood’s large ranch and two-story homes often have separate upstairs, downstairs, and primary-suite systems, so we price each unit individually and total them in writing before starting. You’ll know the full cost before we touch anything.
You should receive a written invoice itemizing each system sealed, before-and-after pressure-test results showing leakage reduction, photos from camera inspection, and a copy of our 365-Day Done Right Promise. We provide this on every Friendswood job because ductwork is hidden, and documentation is how you verify you got what you paid for.
Sealing prevents humid outside air from entering the system and re-wetting partially dried ductwork after flooding or storm-driven rain. In neighborhoods near Clear Creek, we’ve seen sealed systems recover faster and develop less secondary mold than unsealed ones, because controlled airflow replaces the moisture-laden infiltration that feeds microbial growth. We recommend inspection after any significant water intrusion event.
Yes, we seal both sides, because return leaks pull hot, humid attic air directly into your system while supply leaks waste the air you already paid to cool. Sealing only one side leaves half the problem unaddressed and can actually worsen pressure imbalances that draw more humidity into the ductwork. Our written scope covers both on every system we touch.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Friendswood and the greater Houston area since 2004.