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 Leon Valley
Most duct repair calls we take from Leon Valley aren’t about sudden breakdowns. They’re about homes that have been breathing through failing ductwork for years without anyone pulling a panel to look. If you’re noticing weak airflow in back bedrooms, dust that returns within days of cleaning, or utility bills that climb each summer, the problem is often hidden in your attic duct runs. We dispatch crews to Leon Valley from our San Antonio office daily, and we carry the equipment to seal, repair, or replace duct systems on the same visit. Call (726) 600-7155 for a free written estimate.
Why CleanRun Air Duct Cleaning San Antonio Is Leon Valley’s Preferred Duct Repair & Sealing Company
We’ve worked in enough Leon Valley ranches off Bandera Road and Timberhill to know what the camera typically finds: fiberglass duct board that started delaminating sometime in the 1990s, or galvanized trunk lines with separated joints shedding conditioned air into 150°F attics. Our customers here tend to be homeowners who bought between 2015 and 2025, paid a premium for the location, and want documentation before they approve any work. We deliver that. Every job starts with a written price under Haven Standard Clause 1, and every duct run is photographed before and after. Our 365-Day Done Right Promise is backed in writing, not buried in a policy manual.
Tomas Reyes established CleanRun in 2013, and since then we’ve served more than 52,000 homes with the same protocol: written price first, documented photo record last. Technicians are background-checked and uniformed under Haven Standard Clause 3: Verified Crews. We publish our license number on every page because credentials should be verifiable, not claimed.
Our Duct Repair & Sealing Services in Leon Valley
Duct Sealing
Sealing is often the most cost-effective repair for Leon Valley’s original galvanized systems. Attic temperatures above 150°F degrade mastic and tape faster here than in shaded or newer construction, so we use modern mastic sealants rated for extended heat exposure and apply them to cleaned, prepped metal surfaces. A typical duct sealing job for a 1,800-square-foot Leon Valley ranch runs $450-$780, depending on how many branch runs need attention and whether the plenum itself has separated from the air handler. We seal every joint, every penetration, every damper slot. Then we pressure-test to verify the seal before we pack up.
Flex Duct Repair
Flex duct in Leon Valley’s older homes was often added during 1980s or 1990s HVAC upgrades, and it’s frequently crushed behind registers, chewed by rodents, or disconnected at the collar. Our crews carry replacement flex in R6 and R8 ratings, along with mechanical collars and tensioning straps. We don’t just reconnect; we inspect the full run with a borescope to find the damage you can’t see from the register. Flex duct repair in Leon Valley typically costs $180-$340 per run, with most homes needing two to four runs addressed.
Metal Duct Repair
Original galvanized sheet metal in 1950s-1970s Leon Valley homes can be repaired if the metal itself is intact. We cut out rusted or collapsed sections, fabricate replacement pieces on site, and seal with mastic and fiberglass mesh. When the trunk line is sound but branch takeoffs have failed, spot repair makes more sense than full replacement. Metal duct repair in Leon Valley generally ranges from $320 for a single branch repair to $1,200 for extensive trunk restoration. We photograph every cut, every patch, every seal.
Duct Insulation
Uninsulated or degraded duct wrap is common in Leon Valley’s postwar ranches, where builders often skipped insulation or used product that has since compressed or fallen away. We install new foil-faced fiberglass insulation with proper vapor barriers, sealed at every seam. For homes with duct board that can’t be salvaged, we may recommend full replacement with insulated flex or sheet metal wrapped to R8. Duct insulation work in Leon Valley runs $380-$950 depending on linear footage and attic accessibility.
Mastic Sealant & Air Leak Repair
Mastic is the standard for durable duct sealing, not tape. We apply it with brushes and trowels to every joint, seam, and penetration, then let it cure before restoring pressure. For air leak repair in Leon Valley’s aging systems, we often find that the leaks aren’t single large holes but dozens of small separations at factory seams and field modifications. We map them with a pressure pan test, seal systematically, and verify with a post-repair test. Mastic sealing as a standalone service in Leon Valley typically costs $380-$650 for a complete system.
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 Leon Valley
Our trucks carry professional-grade equipment from trade-recognized manufacturers: Rotobrush for mechanical agitation in duct runs, Abatement Technologies for negative-pressure HEPA containment, and Guardsman-rated sealants and insulation products. We stock common repair parts for Aprilaire and Honeywell air cleaner integrations, which are frequently paired with the original HVAC systems in Leon Valley’s 1960s and 1970s ranches. This means most repairs don’t wait on parts orders. Our Duct Repair & Sealing team can verify compatibility with your specific system before we quote.
Common Duct Repair & Sealing Problems We See in Leon Valley Homes
- Delaminated fiberglass duct board. In homes built between 1955 and 1975, particularly in the Bandera Road and Timberhill areas, we regularly open air handler panels to find duct board where the fiberglass facing has separated from the core. Decades of attic heat cycling break down the adhesive binder. The board sheds fibers into supply and return ducts while restricting airflow at the elbows. It’s invisible from the register until you look.
- Disconnected or crushed flex runs. Flex duct added during later HVAC upgrades often fails at the collar or gets compressed behind furniture or built-ins. In Leon Valley, these hidden runs are frequently packed with decades of cedar pollen and limestone dust that the original system was never designed to filter effectively.
- Separated metal duct joints. Original galvanized trunk lines expand and contract through summer heat cycles. The mastic or tape applied in 1968 has long since failed. Conditioned air leaks into the attic, and in winter, northwest winds drive Ashe juniper pollen back through every gap into the system.
- Missing or degraded insulation. Attic temperatures in Leon Valley routinely exceed 150°F from June through September. Uninsulated or poorly insulated ducts lose 20-30% of cooling capacity before the air reaches the register. We see this most often in homes where the original insulation has fallen away or was never installed at the branch runs.
Pricing for Duct Repair & Sealing in Leon Valley, TX
We publish ranges because Haven Standard Clause 1 requires a written price before any work starts. Here is what duct repair and sealing typically costs in Leon Valley’s market:
| Service | Typical Range |
|---|---|
| Duct sealing (whole system) | $450 - $780 |
| Flex duct repair (per run) | $180 - $340 |
| Metal duct repair (spot/trunk) | $320 - $1,200 |
| Duct insulation (whole system) | $380 - $950 |
| Mastic sealing (standalone) | $380 - $650 |
These ranges reflect Leon Valley’s typical 1,400-2,200 square foot ranch stock with attic-mounted air handlers. Factors that move the needle: number of duct runs, accessibility (some attics in the older Bandera Road neighborhoods have limited headroom), whether the plenum itself needs replacement, and how much debris removal is required before sealing can begin. Every estimate is free, written, and delivered before we touch a panel. Bring a competitor’s quote; we provide a Free Second Opinion in writing.
We Also Serve Cities Near Leon Valley
Our crews work throughout the northwest San Antonio metro, including Leon Valley, Alamo Heights, Castle Hills, and Terrell Hills. Dispatch and scheduling are coordinated from our San Antonio office, with local routing that keeps Leon Valley appointments on regular rotation.
Serving Leon Valley, TX - Our Local Coverage Area
We’re based in the Leon Valley 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 Leon Valley
You probably can’t tell from the living room. The warning signs are weak airflow at distant registers, dust that returns within 48 hours of cleaning, or a faint fiberglass odor when the system first kicks on. We verify with a borescope inspection through the register or air handler panel, and we photograph what we find. If the facing has separated from the core, we quote replacement or repair in writing before proceeding. Call (726) 600-7155 to schedule a camera inspection.
Leon Valley sits on the northwest fringe of San Antonio, directly in the path of winter northwest winds that carry Ashe juniper pollen from the Hill Country cedar brakes and fine limestone dust from undeveloped Bexar County terrain. Your friend’s east-side home filters air that has crossed more developed, vegetated ground first. Your system works harder and traps more. The same geographic position that makes Leon Valley desirable for Hill Country access also makes its ducts a primary collection point for this debris. Sealing the duct system reduces infiltration; cleaning removes what’s already packed in.
We start with a pressure test to quantify leakage, then access the attic to clean and prep every joint. We apply mastic sealant with brushes and trowels to all seams, collars, and penetrations, reinforce with fiberglass mesh where needed, and install mechanical fasteners at flex connections. For original galvanized systems, we often find that the trunk is sound but branch takeoffs have failed; we repair those individually rather than replacing everything. We pressure-test again after sealing to verify improvement. The entire process is photographed, and the photo record is delivered with your invoice.
Most can be repaired if the metal hasn’t rusted through or collapsed. We cut out failed sections, fabricate replacements on site, and seal with mastic and mesh. Full replacement becomes necessary when the trunk line itself is compromised or when multiple branches have failed and spot repair would cost more than a new system. We make that call with the camera running and show you the footage before quoting either option. No work starts without a written price.
Original systems from the 1950s-1970s should be inspected every three to five years, with sealing performed whenever pressure testing shows leakage above 15% of total airflow. Homes with visible dust issues, weak airflow, or recent HVAC upgrades that strain older ductwork may need more frequent attention. The cedar pollen load in Leon Valley accelerates buildup, so we recommend pairing inspection with cleaning on that same cycle. Call (726) 600-7155 and we’ll put you on a maintenance schedule with documented records.
Written by Tomas Reyes, Owner at CleanRun Air Duct Cleaning San Antonio, serving Leon Valley since 2013.