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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AfterFast, Reliable Duct Repair & Sealing Across League City
League City duct repair and sealing typically runs $340-$890 for most single-family homes, with flex-duct rebuilds in older tract housing landing toward the higher end. CleanRun crews are scheduled from our Houston office and carry Rotobrush inspection cameras, mastic sealant, and flex-duct replacement stock on every truck serving the League City market. Call (346) 253-1822 and we’ll put a written price in your hand before any panel comes off.
We’ve worked the full spread of League City housing - from 1990s-era subdivisions off FM 518 to newer builds near Victory Lakes and the shared-stack condos along NASA Parkway. The duct failures we find here don’t match what we see in drier inland suburbs. Gulf moisture, 140°F attic heat, and the lingering effects of Harvey’s Clear Creek flooding created a specific repair profile that generic duct companies often misdiagnose as a simple cleaning job.
Why CleanRun Air Duct Cleaning Pearland Is League City’s Preferred Duct Repair & Sealing Company
CleanRun has held the Haven Standard since 2013 - 52,000+ homes served, every one with a written price before work started and a documented photo record when the crew left. In League City specifically, our reputation rests on post-Harvey inspections that found what remediation crews missed: active mold colonies inside ductwork that was declared “dry” and never opened.
Our League City customers leave reviews citing the photo record. They mention technicians who showed them the separated mastic joint on their own phone screen before quoting the repair. Haven Standard Clause 1 - Written Price Before Any Work Starts - means no per-vent bait-and-switch and no “call for a quote” runaround. The price you sign is the price you pay.
Scheduling is coordinated from our Houston office, and we route trucks daily through League City, Webster, and Dickinson. Most League City appointments book within 48 hours. Technicians are background-checked, uniformed, and identified by name before arrival under Haven Standard Clause 3: Verified Crews.
We publish our license number on every page. We’re insured and bonded. And we offer a Free Second Opinion on any written estimate - bring a competitor’s League City quote and we’ll put our number next to it in writing.
Our Duct Repair & Sealing Services in League City
Duct Sealing
League City’s combination of elevated dew points and extreme attic heat destroys duct seals faster than inland markets. We seal supply and return plenums, register boots, and trunk-line connections with mastic sealant rated for the temperature swings these attics see. Every sealed joint is photographed before and after, and the photo record is delivered as part of the standard job file. A typical duct-sealing project in League City runs $340-$620 for a single-system home.
Flex Duct Repair
The 1990s-2000s tract homes that dominate League City’s housing stock were almost universally built with flexible duct routed through unconditioned attics. After fifteen to twenty-five summers above 140°F, the factory mastic on these flex-duct connections turns brittle and separates. We rebuild collapsed or disconnected runs with new flex duct, secure them with mechanical fasteners and mastic, and verify airflow at each register. Flex-duct repair in League City typically ranges from $180 per run to $740 for multiple-run replacement in a full system.
Metal Duct Repair
Older metal trunk lines in pre-1990 League City homes and some commercial buildings along Main Street develop corrosion at seams and support penetrations. We patch or replace damaged sections, re-seal with mastic, and insulate to prevent the condensation that Gulf moisture makes inevitable here. Metal duct repair starts around $280 for localized patching and runs to $890 for extensive trunk-line rebuilds.
Duct Insulation
Poorly insulated duct runs in League City slab-on-grade homes sweat during the long cooling season. That condensation feeds biological growth on nearby framing and inside the duct itself. We install closed-cell insulation wrap on exposed supply lines, paying special attention to runs passing through garage cavities and utility chases where Harvey floodwater penetrated. Insulation work in League City typically falls between $420 and $780 depending on linear footage and access.
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.
BeforeAfterTrusted Brands We Service in League City
CleanRun carries professional-grade equipment from Abatement Technologies, Rotobrush, and Aprilaire on every truck serving League City. We stock flex-duct, mastic, and register boots sized for the tract-home systems common here, so most repairs don’t wait on parts. Our technicians train on manufacturer specifications for each brand - no improvised tools, no shop-vac substitutions. You can look up every brand we name and verify what professional-grade duct repair equipment actually costs. That transparency is Haven Standard Clause 1 in practice.
Common Duct Repair & Sealing Problems We See in League City Homes
- Separated flex-duct joints from attic heat degradation. Factory mastic on 1990s-2000s flex duct turns to powder after repeated exposure to 140°F attic temperatures. We find separated connections pulling hot, fiberglass-laden attic air directly into living spaces on nearly every older service call in League City.
- Condensation-driven biological growth on evaporator coils and return plenums. Gulf moisture keeps League City dew points elevated year-round. Poorly insulated duct runs sweat, and that moisture feeds mold growth that a simple coil cleaning won’t stop without addressing the duct contamination source.
- Post-Harvey mold colonies in “remediated” floodplain homes. In Clear Creek-floodplain subdivisions, stormwater entered through utility chases and slab penetrations. Most remediation addressed visible drywall but never opened the HVAC plenum. We pop return-air grilles and find active mold in homes that were dried out, repaired, and relisted years ago.
- Shared-stack duct and dryer vent failures in condos and apartments. League City’s denser developments along NASA Parkway and near Baybrook Mall route multiple units through common chases. A separated duct in one unit pressurizes neighbors with lint, moisture, and conditioned air loss. We coordinate with building management and schedule access to minimize resident disruption.
Pricing for Duct Repair & Sealing in League City, TX
Here’s what duct repair and sealing actually costs in the League City market, based on jobs we’ve written prices for under Haven Standard Clause 1:
| Service | Typical Range in League City |
|---|---|
| Duct sealing (single system, mastic) | $340 - $620 |
| Flex duct repair (per run) | $180 - $340 |
| Multiple flex-duct replacement | $480 - $740 |
| Metal duct patching / repair | $280 - $620 |
| Metal trunk-line rebuild | $620 - $890 |
| Duct insulation (supply lines) | $420 - $780 |
| Return plenum rebuild (post-flood) | $380 - $650 |
Factors that move League City jobs toward the higher end: multiple attic access points in 1990s-era homes, post-Harvey mold remediation requiring HEPA containment, and shared-stack buildings where we coordinate access across multiple units. Every price is written and signed before work starts. No exceptions. Call (346) 253-1822 for a free estimate - we’ll inspect, photograph, and quote on the same visit.
We Also Serve Cities Near League City
CleanRun crews route daily through Webster, Dickinson, Friendswood, and Seabrook. Our Duct Repair & Sealing in League City schedule includes these surrounding markets, and we apply the same Haven Standard - written price first, photo record last - in every home we enter. If you’re in a nearby city and found this page searching for League City duct repair, we likely cover your address too. Call and we’ll confirm.
Serving League City, TX - Our Local Coverage Area
We’re based in the League City 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 - Duct Repair & Sealing in League City
Yes. In our experience inspecting League City homes in the Clear Creek floodplain, remediation crews rarely open HVAC plenums or flex-duct runs. In the Clear Creek-floodplain subdivisions off East Walker Street, we popped the return-air grille on a 2001 tract home and found standing debris and black mold deep inside the return plenum - the house had been “dried out” and relisted after Harvey without anyone touching the HVAC ductwork. Using negative pressure and HEPA filtration, our tech pulled a camera inspection through the flex runs and found mastic joints separated by years of 140°F attic heat, pulling hot, fiberglass-laden air straight into the living space. We rebuilt the return plenum with mastic sealant and re-sealed the supply and return ducts; the blower motor amp draw dropped noticeably on the next service call. If your home flooded, a dedicated duct inspection is warranted regardless of what the remediation report states. Call (346) 253-1822 for a free inspection.
League City’s specific geography drives this. The city sits between Galveston Bay and Clear Lake, so dew points stay elevated even by Houston standards - condensation forms on undersized or poorly insulated flex-duct runs here far more often than in drier inland suburbs. Combined with Harvey’s 2017 inundation of the Clear Creek floodplain, many 1990s-2000s tract-home duct systems absorbed floodwater and now carry active mold colonies rather than simple dust loads. The 140°F summer attic heat then degrades the mastic seals that were already compromised by moisture exposure. It’s a stacked failure mode we don’t see in Katy or The Woodlands. Our Duct Repair & Sealing team addresses both the seal degradation and any biological growth it enabled.
We coordinate directly with property management and schedule access across affected units. Shared-stack buildings along NASA Parkway and near Baybrook Mall require containment planning - a separated duct in one unit pressurizes the chase and affects neighbors. Our crew identifies the full stack routing with camera inspection, isolates the affected section with temporary dampers, and completes repairs during a single coordinated access window. We document the work with photos of the shared chase before and after, and we provide that record to both the unit owner and building management. Pricing for shared-stack repair typically runs $480-$920 depending on floors affected and access complexity.
Sealing alone won’t eliminate established mold, but unsealed ducts are often the recontamination source that makes coil mold return after cleaning. In League City’s humid climate, separated return ducts pull attic air laden with spores and organic material directly across the coil. We seal the duct system first, then assess whether coil cleaning or replacement is needed. The 365-Day Done Right Promise covers the full scope - if mold returns because we missed a leak path, we make it right. Most League City homes with coil mold need both duct sealing and coil treatment, running $620-$1,180 combined. Call (346) 253-1822 and we’ll scope it in writing.
Every CleanRun duct repair follows NADCA ACR guidelines for assessment, containment, and verification. For a typical League City job: we photograph every duct run with a Rotobrush inspection camera, identify separated joints or flood damage, establish negative-pressure containment if mold is present, rebuild or reseal with mastic and mechanical fasteners, then photograph again and test static pressure and airflow at each register. The before-and-after photo record, written scope, and static pressure readings are delivered as standard job documentation. The 365-Day Done Right Promise backs every repair in writing. Call (346) 253-1822 to schedule a documented inspection.
Written by Tomas Reyes, Owner at CleanRun Duct Repair & Cleaning, serving League City since 2013 under the Haven Standard.