Trusted Duct Repair & Sealing for San Antonio Homeowners
Duct repair and sealing in San Antonio typically costs $180–$850 depending on the scope, with most single-room repairs completed in 2–3 hours and whole-system sealing taking a full day. At Liberty Bell Air Duct Cleaning Service San Antonio, Richard Anderson personally handles every duct repair call with 17 years of focused experience and the same commercial-grade equipment we use for our air duct cleaning work. We’re available for same-day service across San Antonio when your HVAC is blowing weak, your energy bills are climbing, or you’re noticing hot and cold spots that weren’t there before. Call (866) 769-1699 for a free, no-obligation estimate — Richard shows up with the tools, not a subcontractor.

San Antonio’s climate puts unique stress on ductwork. Our summers push attic temperatures past 140°F, baking flex duct and degrading mastic seals year after year. The limestone-heavy soil and seasonal shifting in neighborhoods from Alamo Heights to Helotes can crack duct board and pull metal seams apart. We’ve seen it across 456 completed jobs, and we’ve learned that duct problems don’t fix themselves — they inflate your CPS Energy bills and strain your compressor until something more expensive breaks. When Richard Anderson arrives at your door, you’re getting the person who’s sealed ducts in Terrell Hills bungalows, repaired crushed flex in Lakehills crawl spaces, and diagnosed airflow issues in Kirby ranch homes. That’s the difference between a specialist and a generalist.
What Our Duct Repair & Sealing Service Includes
Duct Sealing
Duct sealing closes the gaps, cracks, and disconnected joints that leak conditioned air into your attic, walls, or crawl space before it ever reaches your rooms. In San Antonio, we regularly find 20–30% air loss in homes built before 2010, especially in areas like Windcrest and Converse where original ductwork is reaching the end of its service life. Richard Anderson uses a two-part approach: first, a pressure-assisted smoke test to pinpoint every leak, then professional-grade mastic or aerosol sealant depending on access and duct material. We document before-and-after leakage rates so you see exactly what changed.
Flex Duct Repair
Flex duct — the insulated plastic tubing common in San Antonio tract homes — kinks, crushes, and tears more easily than homeowners realize, often where it passes through tight attic spaces or connects to ceiling boots. We replace damaged sections with new, properly sized flex duct rather than patching with tape that’ll fail in the next heat wave. In Live Oak and Timberwood Park, we’ve found rodent damage and UV degradation in attic flex that’s been cooking since the Bush administration. Richard sizes the replacement runs correctly, supports them with proper strapping every 4 feet, and seals with code-compliant collars — not the duct tape your uncle swore by.
Metal Duct Repair
Galvanized steel ductwork lasts longer than flex but suffers from seam separation, rust at condensation points, and vibration fatigue at blower connections. We repair metal duct with mechanical fastening — drives, S-locks, and standing seams — followed by fiberglass mesh and mastic for a permanent seal. In older San Antonio homes near Monte Vista or King William, we’ve restored original metal trunk lines that were leaking 40% of their airflow through corroded joints. When metal duct is too far gone, we’ll tell you straight and quote replacement rather than charging for a patch that won’t hold.
Duct Insulation
Uninsulated or degraded duct insulation in San Antonio attics is like pouring cold water into a hot skillet — your conditioned air warms up before it reaches the vent, forcing your AC to run longer and harder. We install fresh fiberglass duct wrap or replace the insulation jacket on flex duct with R-6 or R-8 material, depending on your attic configuration and local code requirements. In Lakehills and Helotes, where summer attic temperatures can exceed 150°F, proper insulation isn’t a luxury — it’s what keeps your system from fighting itself. Richard checks every inch of exposed duct during repair work and flags insulation gaps you might not know exist.
Mastic Sealant Application
Mastic is the thick, paste-like sealant that professionals use instead of tape for permanent duct joints — it remains flexible, won’t dry out, and creates a true airtight bond. We brush or trowel mastic onto every seam, collar, and connection we touch, then let it cure before pressurizing the system. In San Antonio’s climate, cheap foil tape fails within 2–3 years; mastic lasts the life of the duct. Richard applies it with the patience of someone who’s had to redo other contractors’ tape jobs — we don’t cut corners on the seal because we know you’ll call us back if it leaks.
Air Leak Repair
Air leaks in your duct system waste money and create pressure imbalances that pull dust, pollen, and attic insulation particles into your living space. We locate leaks using a calibrated duct blaster or theatrical smoke, then repair each one with the appropriate method for that location and material. In Terrell Hills and Alamo Heights, we’ve solved mysterious allergy symptoms and persistent dust problems simply by sealing return air leaks that were drawing from the attic. Every repair includes a final pressure test so you know the system performs before we pack up.
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.
Brands We Service for Duct Repair & Sealing
We’ve worked extensively with Abatement Technologies air filtration and duct access components, particularly in homes where the original builder installed their HEPA-rated return air systems. Richard Anderson knows their collar dimensions, filter rack specifications, and the common failure points where their metal transitions meet flex duct — we’ve repaired dozens in San Antonio’s 1990s-era subdivisions and stock the hardware to match their gauge and fit.
Our Rotobrush and Nikro cleaning systems see daily use, but they’re also diagnostic tools: the camera attachments let Richard inspect duct interiors before sealing, spotting damage that smoke tests alone won’t reveal. Whether your home has Abatement Technologies, Rotobrush, Nikro, or any other make of duct material or HVAC connection, we can assess, access, and repair it. No brand is too obscure, and no system is too old for an honest evaluation.
Signs You Need Duct Repair & Sealing Right Now
- Your energy bills jumped without explanation. A sudden 15–25% increase in your CPS Energy bill often traces to duct leakage your AC is compensating for by running longer cycles. We’ve traced $80/month overcharges to a single disconnected return duct in a Leon Valley attic — the homeowner assumed their aging compressor was the culprit.
- Some rooms never reach the thermostat setting. Hot spots in summer or cold spots in winter usually mean restricted or leaking supply runs, not a failing HVAC unit. In San Antonio’s two-story homes, we commonly find crushed flex duct above the second-floor hallway that’s starved the back bedrooms for years.
- You see dust collecting rapidly near vents. Excess dust right after cleaning often signals a return air leak pulling attic debris into the system. Richard has found gaps as large as 4 inches between return plenums and ceiling joists in Kirby and Windcrest homes — the filter never had a chance.
- Your ductwork is 15+ years old and has never been inspected. Flex duct degrades, mastic dries, and metal corrodes on a predictable timeline. In San Antonio’s heat, that timeline accelerates. If your home was built before 2010 and the ducts are original, you’re likely operating with significant leakage whether you’ve noticed symptoms or not.
- You hear whistling, rattling, or whooshing from vents or walls. Air escaping through gaps creates turbulence you can hear — a high-pitched whistle from a supply boot, a rattle from a loose metal seam, or a whoosh from a disconnected flex run. These sounds are your ductwork telling you where it’s failing.
Our Duct Repair & Sealing Process — Step by Step
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System inspection and airflow assessment. Richard Anderson arrives with a manometer, anemometer, and inspection camera to measure static pressure, airflow at each vent, and visual condition of accessible ductwork. We don’t guess — we measure. This baseline tells us whether you’re dealing with leakage, blockage, or design issues.
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Leak detection and damage documentation. We pressurize the duct system and use theatrical smoke or a duct blaster to locate every leak, then photograph damage for your records. In San Antonio’s tight attics, we’ll also note insulation condition, pest intrusion, and any safety hazards like exposed wiring near metal duct.
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Repair plan and upfront pricing. Before touching tools, we explain what we found, show you the photos, and provide a written estimate with line-item costs. No surprises, no pressure. You’ll know exactly what each repair costs and why we’re recommending it — whether it’s a single flex replacement or whole-system sealing.
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Professional repair with commercial-grade materials. Richard performs all work personally using mastic, mechanical fasteners, replacement flex duct, and insulation matched to your system. We don’t send a crew you haven’t met — when the owner shows up, so does 17 years of hands-on experience. Professional equipment, the same tools used in commercial settings, brought to your San Antonio home.
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Post-repair testing and verification. We re-test static pressure and airflow to confirm improvement, then walk you through the results. If we sealed your ducts, we’ll show you the before-and-after leakage comparison. Your invoice includes warranty terms and our direct line for any follow-up questions.
How Much Does Duct Repair & Sealing Cost in San Antonio?
A typical single leak repair or flex duct replacement in San Antonio runs $180–$340, while whole-system duct sealing for an average 2,000-square-foot home generally falls between $450–$850 depending on attic accessibility and the extent of leakage found. Metal duct repairs with seam rebuilding and corrosion treatment typically range $280–$520, and adding or replacing duct insulation runs $2.50–$4.00 per linear foot for R-6 material in standard attic conditions.

| Service | Typical Range in San Antonio |
|---|---|
| Single leak repair / small flex replacement | $180 – $340 |
| Metal duct seam repair with mastic | $280 – $520 |
| Whole-system duct sealing (avg. home) | $450 – $850 |
| Duct insulation replacement (per linear foot) | $2.50 – $4.00 |
| Multiple-zone repair with access challenges | $600 – $1,200 |
Several factors move your price within these ranges. Attic accessibility is the big one — a truss attic with 6 feet of headroom in Live Oak takes half the time of a 120°F Cape Cod crawl space in Alamo Heights. The material and age of your ductwork matters too; brittle 1980s flex duct often requires more replacement than repair, while well-installed metal duct may need only targeted sealing. We also factor in whether your system needs a full pressure test with a duct blaster ($75–$125 if done standalone, included free with whole-system sealing) or if visual inspection and smoke testing suffice.
To avoid overpaying, get at least one estimate that includes a written scope and post-repair verification. We’ve been called to redo “sealing” jobs where a competitor brushed mastic on two visible joints and called it complete — the homeowner’s bills never dropped. Our estimates are free, detailed, and include the testing that proves the work worked. Call (866) 769-1699 for an exact quote on your San Antonio home — estimates are free, and Richard will show you exactly what you’re paying for.
Duct Repair & Sealing Near San Antonio — Our Service Area
We serve San Antonio proper and the surrounding communities with typical response times of 45 minutes to 1.5 hours depending on traffic and time of day. Our regular service area includes Duct Repair & Sealing in Lackland Air Force Base, Duct Repair & Sealing in Leon Valley, and Duct Repair & Sealing in San Antonio itself, plus Alamo Heights, Helotes, Terrell Hills, Kirby, Windcrest, Converse, Live Oak, Lakehills, and Timberwood Park. Whether you’re in a historic Monte Vista bungalow with original metal duct or a new build in Far West Side with flex that’s already kinked, we’ll get there with the right equipment and the person who knows how to use it.
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.
Frequently Asked Questions — Duct Repair & Sealing in San Antonio
Duct repair and sealing is the process of fixing physical damage to your HVAC ductwork and closing air leaks at joints, seams, and connections so conditioned air reaches your rooms instead of escaping into walls or attics. At Liberty Bell Air Duct Cleaning Service San Antonio, we handle everything from crushed flex duct replacement to metal seam rebuilding to whole-system mastic sealing, always with post-repair testing to verify results. Your air quality is the only thing we do — not a side service we offer between other jobs. Call (866) 769-1699 for a free estimate.
Most single repairs or small sealing jobs take 2–3 hours, while comprehensive whole-system sealing for an average San Antonio home requires 6–8 hours and is typically scheduled as a full-day appointment. Richard Anderson works methodically — we don’t rush the mastic curing time or skip the final pressure test just to finish faster. Call (866) 769-1699 to schedule a time that works for your household.
Single repairs typically run $180–$340, whole-system sealing averages $450–$850, and metal duct work falls in the $280–$520 range depending on accessibility and material condition. We provide written, itemized estimates before starting any work, and our initial inspection is free. Call (866) 769-1699 for an exact quote — estimates are free.
Yes — we’ve serviced hundreds of systems with Abatement Technologies components and use Rotobrush and Nikro equipment daily for inspection and cleaning work that informs our repairs. Richard Anderson knows the specifications, common failure modes, and proper repair techniques for these brands and all standard duct materials. Whether you have these brands or any other make, we can help.
We prioritize urgent calls — complete duct disconnections, AC shutdowns traced to duct collapse, or situations where leakage is causing compressor strain — and aim for same-day response when our schedule allows. For true HVAC emergencies after hours, we recommend contacting your heating and cooling contractor first; we’re your duct specialist, not a general HVAC service, and we’ll coordinate with them if duct issues are involved. For same-day duct repair assessment, call (866) 769-1699 early in the day.
Yes — all duct repairs carry a one-year workmanship warranty covering materials and labor, with extended coverage available for whole-system sealing packages. If a seal we applied fails or a repaired section develops a new leak at the same location, we return and fix it at no charge. 456 customers reviewed us. 4.9 stars is what consistent, owner-operated work looks like.
Clear a path to your attic access, HVAC closet, and any crawl space openings; remove fragile items from shelves directly below attic pull-down stairs; and have your recent CPS Energy bills handy if you’re concerned about efficiency loss. Richard will need to run your system during testing, so plan for brief periods when the AC or heat will be on. We’ll handle ladders, drop cloths, and cleanup — you don’t need to do anything else. Call (866) 769-1699 to book your appointment.
Schedule Your Duct Repair & Sealing Service in San Antonio Today
One specialist. Every service. No subcontractors. When Richard Anderson arrives at your San Antonio home, you’re getting 17 years of focused duct expertise, commercial-grade equipment, and a repair that’s tested and verified before we leave. Call (866) 769-1699 now for your free, no-obligation estimate — we’ll assess your system, explain what we find in plain language, and give you upfront pricing you can compare. Your indoor air quality is too important to trust to a rotating crew with commodity tools.
Written by Richard Anderson, Owner at Liberty Bell Air Duct Cleaning Service San Antonio, serving San Antonio since 2007.