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 San Antonio
Duct repair and sealing in San Antonio typically costs $280-$650 for most residential jobs, with flex duct replacement running $180-$340 per run and whole-system mastic sealing ranging $450-$850 depending on access and plenum condition. We’re CleanRun Air Duct Cleaning San Antonio, and our crews work the full metro from our San Antonio office - Monte Vista to Stone Oak, the Helotes corridor out to Converse and Universal City. If your back bedroom won’t cool, your summer bills are climbing, or a camera inspection during cleaning showed separated seams or crushed flex, we’ll put a written price in front of you before any panel comes off. Call (726) 600-7155.
Why CleanRun Air Duct Cleaning San Antonio Is San Antonio’s Preferred Duct Repair & Sealing Company
We’ve been in San Antonio homes since 2013 - 52,000 of them - and every single job started with a written price and ended with a Documented Photo Record of every duct run. Not a policy. A deliverable you can scroll through on your phone.
Our technicians are background-checked, uniformed, and identified by name before arrival - Haven Standard Clause 3: Verified Crews. The H.A.V.E.N. Standard governs every interaction, and our 365-Day Done Right Promise is backed in writing on every job, not just stated in marketing copy. If the work isn’t right, we make it right.
We don’t do $79 coupons or shop-vac noise. We do documented evidence: before-and-after photos, written scope, written warranty. For San Antonio homeowners who bought between 2015 and 2025 and research before they call, that’s usually enough.
Our Duct Repair & Sealing Services in San Antonio
Duct Sealing
San Antonio duct sealing has to be specified for two conditions most national advice ignores: a 150°F attic for four months, and a winter cedar-pollen load that doesn’t exist in Houston or Dallas. We test every sealed system under positive pressure during the December-February Ashe juniper peak, because a leak that’s harmless in October pushes cedar pollen straight into your return plenum all winter. Our crews use mastic sealant and mechanical banding on every joint, not foil tape that peels off after 20 summers. A typical whole-system mastic sealing in San Antonio runs $450-$850.
Flex Duct Repair
We pulled a crushed 6-inch flex run out of a 1948 Craftsman bungalow off West Hollywood in Monte Vista after the homeowner complained the back bedroom never matched the front of the house. Camera inspection showed the run had been stepped on during a 1990s attic re-deck and the seam tape had failed decades ago. We replaced the run, mastic-sealed the collar at the air handler, and banded every remaining joint - the static pressure drop across the supply plenum corrected and the rear bedroom finally tracked within 2°F of the thermostat. Flex duct replacement in San Antonio typically runs $180-$340 per run depending on length and attic access.
Metal Duct Repair
Original 1940s-60s metal trunk lines in Monte Vista and Lavaca homes have pinhole leaks and separated seams where the old fiberglass wrap has crumbled. They leak into unconditioned attic air that hits 150°F+ in summer, which means your AC is cooling hot attic air that never reaches the register. We cut out corroded sections, fabricate replacement trunk with Pittsburgh-seamed galvanized, and seal with two-part epoxy mastic rated for metal expansion. Metal repair in San Antonio typically runs $320-$580 per section.
Mastic Sealant Application
Foil tape fails in San Antonio attics. Period. The adhesive degrades, the backing cracks, and by year 15 you’ve got gaps pulling 150°F air into your supply. We apply fiber-reinforced water-based mastic with a minimum 1/16-inch wet thickness, brushed into every seam and collar joint. On older return plenums, we embed fiberglass mesh tape before the second coat. Mastic-only sealing runs $280-$520 for most San Antonio homes.
Duct Insulation
When flex duct insulation has compressed or the vapor barrier is torn, the R-value drops and condensation forms on the exterior in San Antonio’s humid shoulder seasons. We replace damaged insulation with new flex duct or apply closed-cell insulation wrap to metal trunk lines, depending on what’s actually in your attic.
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 San Antonio
Our equipment roster includes Rotobrush for camera inspection and debris removal, Nikro negative-pressure extraction systems, and Abatement Technologies HEPA containment. We stock mastic, banding, and replacement flex in common San Antonio diameters - 6-inch, 8-inch, 10-inch, 12-inch - so most repairs don’t wait on parts. Guardsman epoxy compounds for metal repair are on every truck. You can look up every brand independently; we name them so you can.
Common Duct Repair & Sealing Problems We See in San Antonio Homes
- Original metal trunk lines in Monte Vista and Lavaca. The 1940s-60s galvanized steel has pinhole corrosion at the bottom of horizontal runs where condensation pooled for decades. The fiberglass wrap crumbles to dust when touched. These systems need section replacement, not just sealing.
- Failed foil tape in 1970s-90s north-side tract homes. Stone Oak and the Helotes corridor were built with cheap flex duct and foil tape that peels off after 20+ summers in 150°F attics. Joints that were sealed at install are wide open by the time we inspect. Mastic is the only fix that lasts.
- Crushed flex from attic traffic. San Antonio’s housing stock includes decades of HVAC contractors, cable installers, and homeowners who’ve stepped on duct runs. A 6-inch flex crushed to 3 inches delivers half the design airflow. Camera inspection finds it without tearing up drywall.
- Caliche dust abrasion inside return plenums. Periodic southwesterly dust events push fine limestone particulate into older, poorly sealed return systems. That grit abrades mastic and seam tape from the inside. Sealing without source removal buries the problem. We photograph the abrasion pattern so you can see why.
Pricing for Duct Repair & Sealing in San Antonio, TX
Here’s what duct repair and sealing actually costs in the San Antonio market:
| Service | Typical Range |
|---|---|
| Single flex duct run replacement | $180 - $340 |
| Mastic sealing, whole system (up to 12 runs) | $450 - $850 |
| Metal trunk section repair/replacement | $320 - $580 |
| Return plenum rebuild with mastic | $380 - $620 |
| Duct insulation replacement (per run) | $140 - $260 |
What moves you within these ranges: attic access (crawl vs. walkable), number of joints to seal, whether we find additional damage during camera inspection, and whether the air handler needs repositioning for proper collar alignment. We put the exact number in writing before any work starts - Haven Standard Clause 1. No exceptions. Free estimates. Call (726) 600-7155.
We Also Serve Cities Near San Antonio
Our Duct Repair & Sealing in San Antonio crews regularly work Converse, Universal City, Schertz, and Helotes - the same trucks, same written pricing, same Documented Photo Record. Dispatch and scheduling are coordinated from our San Antonio office.
Serving San Antonio, TX - Our Local Coverage Area
We’re based in the San Antonio 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 San Antonio
San Antonio sits at the southern edge of the Edwards Plateau - ground zero for Ashe juniper pollen, the source of the regionally infamous “Cedar Fever” that strikes December through February. Unlike Houston, where duct sealing is mainly an energy issue, San Antonio HVAC systems pull cedar pollen through return-air grilles all winter long, and any leak in your return plenum dumps that pollen straight into your living space on every heating cycle. A duct system that’s “fine” in October fails under winter pollen load here in a way it doesn’t in Houston or Dallas. Call (726) 600-7155 and we’ll pressure-test your returns during the actual cedar season.
We run a camera through every accessible duct run from the register or plenum end - a 6-millimeter borescope on a 50-foot push rod that records 1080p video. In that 1948 Craftsman off West Hollywood, the camera showed the crushed flex 14 feet from the register without a single piece of drywall removed. The homeowner watched the feed in real time. We deliver the video as part of your Documented Photo Record. Call (726) 600-7155 to schedule a camera inspection.
No. Foil tape fails in San Antonio attics; we remove it where we find it. Proper sealing involves cleaning the joint surface, applying fiber-reinforced mastic with a brush to a minimum 1/16-inch wet thickness, embedding mesh tape at stress points, and mechanical banding at collars and transitions. For metal trunk lines, we use two-part epoxy mastic rated for thermal expansion. The whole system gets a positive-pressure smoke test before we sign off. A typical whole-system seal takes 4-6 hours for a crew of two. Written price before we start: $450-$850 for most San Antonio homes.
Most property managers in Converse, Live Oak, and Universal City have adopted duct cleaning as a standard unit-turnover requirement, but sealing is only specified when inspection shows failed joints or crushed runs - which is common in military rental stock with high tenant turnover and repeated attic access by various contractors. We offer a combined clean-and-inspect package with written photo documentation that satisfies most property management requirements. If sealing is needed, we quote it separately with the same written upfront price. Call (726) 600-7155 for property management scheduling.
Properly applied mastic sealant with mechanical banding lasts 20+ years in a San Antonio attic, including 150°F summer peaks. Foil tape, by contrast, typically fails in 10-15 years. We warranty our sealing work for 365 days under the Done Right Promise, and we photograph every joint so you have a baseline for future comparison. If you’re buying a home in Stone Oak or the Helotes corridor built in the 1990s, assume the original foil tape is failing now and budget $450-$850 for resealing. Call (726) 600-7155 for a free inspection and written quote.
Ready to see what’s actually inside your ductwork? Call CleanRun Air Duct Cleaning San Antonio at (726) 600-7155. We’ll put a written price in front of you before any work starts, photograph every run before and after, and back it all with the 365-Day Done Right Promise. No coupons. No shop-vac noise. Just documented evidence you can see.
Written by Tomas Reyes, Owner at CleanRun Air Duct Cleaning San Antonio, serving San Antonio since 2013.