Duct Repair & Sealing Cost - Tested First, Written Price Second

Every visit starts with

Whole-system duct and dryer vent check with before-and-after photos - you see exactly what came out of your vents

Worth knowing

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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Before & after – our own jobs

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How Much Does Duct Repair & Sealing Cost in Schertz?

Our Duct Repair & Sealing services in Schertz, TX typically run between $350 and $1,200 for most single-family homes, with the average job landing around $650. Heavily damaged ductwork – think collapsed flex duct in a Schertz attic that has been sitting at 140°F for several summers – can push that number toward $1,800 or higher when multiple runs need replacement rather than patching. At CleanRun, every price is written down before any work starts, so you know exactly where your job sits before we pull a single register cover.

Duct Repair & Sealing Cost Breakdown (2026)

The table below reflects actual pricing in the Schertz market as of 2026. These are the line items you will see on a CleanRun written scope – not ballpark guesses pulled from a national average that has never accounted for South-Central Texas heat load or the flex-duct construction common in Schertz homes built between 1995 and 2015.

A few things move the final number on a Schertz job more than anything else. First, access: an attic in July in Schertz can hit 145°F by 10 a.m., which slows work and adds labor time. Second, how many runs are actually leaking versus how many the customer suspects are leaking – a duct leakage test closes that gap before any repair dollars are committed. Third, the age of the duct system. Homes in Schertz’s Northcliffe, Savannah Heights, and Ashley Place neighborhoods built in the early 2000s often have flex duct that has been baking for 20-plus years; the inner mylar liner becomes brittle, and a “repair” that costs $120 per section is sometimes the wrong call when replacement at $220 buys another 15 years of service. That is the kind of thing we put in writing before work starts – not after.

What Affects Duct Repair & Sealing Pricing in Schertz

• Attic access and temperature: Most Schertz homes carry their duct systems in unconditioned attic space. The extreme summer heat – attic temps regularly exceed 130°F from May through September – means technicians can work in shorter windows, which extends labor hours on larger jobs. A crawlspace system in a pier-and-beam home in the older sections near Schertz-Cibolo-Universal City ISD adds a different challenge: confined quarters, occasional moisture, and limited tool maneuverability.
• Type of duct material: Flexible duct (flex duct) dominates Schertz residential construction built after 1985. It is easier to repair in short runs but cannot be re-seamed like sheet metal, so a torn inner liner means replacement rather than a patch. Sheet-metal duct systems, more common in commercial properties and homes built before 1975, cost more per linear foot to repair but hold a mastic seal reliably for decades.
• Number and severity of leak points: A single disconnected boot at a register is a 30-minute fix. A system where every supply-side connection has been leaking conditioned air into the attic for 10 years is a half-day job. We photograph each leak point before quoting – that photo record is part of the written scope, not a sales tactic.
• System size and layout: Schertz homes range from 1,400-square-foot patio homes in Fairways at Scenic Hills to 3,800-square-foot two-story builds in Homestead. A larger home with a longer duct run network and multiple zones will have proportionally more connection points to inspect and seal.
• Whether a duct leakage test is included: Schertz sits in Bexar County’s energy-code jurisdiction, and new construction requires duct leakage testing at rough-in and final inspection. For an existing home, a duct blaster test (which pressurizes the duct system and measures how much air escapes) gives you a before-and-after number in CFM (cubic feet per minute) – concrete proof of what the repair actually accomplished. Adding this test adds $150 to $300 to the job but eliminates the guessing.
• Repair versus replacement threshold: When more than 30% of a flex duct system needs individual section repairs, full replacement usually costs less per linear foot and comes with a longer serviceable life. We run that math in the written quote so the comparison is visible, not assumed.

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How to Save on Duct Repair & Sealing in Schertz

The single most useful thing a Schertz homeowner can do before spending money on duct repairs is get a written scope from at least two companies – one of which should include a duct leakage test so the scope of actual leakage is measured rather than estimated by eye. That number in CFM tells you whether you’re dealing with a minor sealing job or a system that has been hemorrhaging conditioned air for years. Without it, you’re pricing repairs against guesswork.

If you’ve already received a written estimate from another company, CleanRun offers a Free Second Opinion at no cost – we put our own number next to theirs in writing. That is not a promotional claim; it is documented in our standard practice and has been since 2013. Call (830) 402-5110 and ask for the written comparison.

• Bundle duct repair with duct cleaning: If the duct system has both leakage issues and debris accumulation – both common in Schertz homes that have not been serviced since the original install – scheduling both services in a single visit reduces labor overhead. The technician’s access time is already committed; cleaning a duct run that has just been repaired costs less than two separate mobilizations.
• Ask for a duct leakage test before committing to repairs: Paying $150 to $300 for a pre-repair duct blaster test can save you from paying $800 to repair a section that turns out not to be leaking, or from under-committing on a system that needs more work than a visual inspection suggested.
• Check CPS Energy rebates: CPS Energy, which serves a portion of the greater San Antonio metro including parts of Schertz, has historically offered rebates for duct sealing and air barrier work when completed by a qualified contractor. Rebate programs change, so verify current availability at cpsenergy.com before scheduling.
• Time the job outside peak demand: Spring and fall are slower for HVAC-adjacent services in Schertz. Late October through February typically has more scheduling flexibility, and jobs booked with lead time rather than as emergency calls carry standard – not emergency – pricing.
• Don’t let a $79 coupon set the scope: Several companies market low entry prices for duct work in the San Antonio metro. In practice, that price does not include a written scope, a leakage test, photographic documentation, or any guarantee. The documented photo record CleanRun provides on every job – inside every duct run, before and after – is included in the quoted price, not sold as an add-on.

For a free written estimate on your Schertz home, call (830) 402-5110. The price you receive before work starts is the price on the invoice – Haven Standard Clause 1, no exceptions.

What the Work Actually Looks Like: A Schertz Job in Practice

In the Crossvine neighborhood in Schertz, a 2009 build came to us after the homeowner noticed two upstairs bedrooms running noticeably warmer than the thermostat setting – a temperature split of 6 to 8 degrees. Before quoting anything, the technician photographed the attic duct runs from the air handler to each supply register. The camera showed three flex duct sections with torn inner liners where the duct had been pushed against a rafter during an insulation re-blow, collapsing the airway by roughly 60%. A fourth section had a disconnected connection at the register boot, confirmed by a visible gap at the boot collar. Total measured leakage before repair: 142 CFM at 25 Pascals of pressure – about 18% of the system’s rated airflow escaping into attic space.

The written scope included replacement of the three damaged flex sections, reconnection and mastic sealing of the disconnected boot, and mastic sealing at four additional boot connections that showed minor gaps. Post-repair test: 31 CFM. The customer received a before-and-after photo record of every run and a post-repair leakage report as standard deliverables – not extras. Total job cost: $640, quoted in writing before the first section was touched.

That is what duct repair should look like in Schertz: a number before the work, a photo record after it, and a measurement that proves the repair did what it was supposed to do.

Duct Repair vs. Duct Replacement: When Each Makes Sense in Schertz

This is the question most Schertz homeowners don’t think to ask, and it’s the one that most determines whether a repair job is money well spent or money deferred. Here is the honest breakdown.

Repair makes sense when:

• The duct system is less than 15 years old and the damage is localized – one or two disconnected sections, a handful of boot leaks, or a single plenum connection that has separated.
• The total number of repair points is under 25 to 30% of the system’s connections.
• The flex duct inner liner is intact – it’s just the outer jacket or a connection collar that has failed.
• A post-repair leakage test projects a result below 8% total duct leakage, which is the CEC / IECC-aligned benchmark for acceptable performance.

Replacement makes more sense when:

• The system is original to a home built before 2000, the inner liner is brittle throughout (common in Schertz’s older Northcliffe-area homes), and repair costs per section begin to approach replacement cost per section.
• A duct blaster test shows total leakage above 25 to 30% of system airflow – at that point, individual section repairs rarely bring the system into acceptable range.
• The duct layout itself is contributing to comfort complaints (undersized trunk lines, right-angle elbows where sweeps were needed) and repair would preserve a flawed design.

CleanRun puts both numbers – repair cost and replacement cost – in the written quote when the system is borderline. That way the comparison is in writing, not in a conversation you have to remember later.

Understanding Duct Sealing Methods: Mastic vs. Aeroseal vs. Foil Tape

Not all sealing is the same, and the method used affects both the price and the longevity of the repair. Here is what each option means in plain terms.

Mastic sealant is a water-based paste – gray, thick, and applied by brush or glove to duct connections. It dries flexible, bonds to sheet metal and flex duct collars, and is the standard for duct sealing work in the residential HVAC industry. It is the appropriate choice for accessible joints at register boots, plenum connections, and flex duct takeoffs. Price impact: low to moderate. Longevity: 20-plus years when properly applied.

Aeroseal works from the inside of the duct system. The HVAC system’s registers are sealed off, a computer-controlled applicator injects an adhesive polymer mist under pressure into the duct network, and the particles accumulate at leak points – sealing gaps that are physically inaccessible from the outside (inside wall cavities, above sealed ceilings, at duct joints embedded in framing). The process is pressure-tested before and after; the machine prints a before-and-after leakage report. Price: $900 to $1,600 for a whole-system Aeroseal treatment in Schertz. It is the right tool when leaks are confirmed but cannot be physically reached for mastic application.

Foil tape (UL 181B-FX rated) is appropriate as a supplement to mastic – not a replacement for it. Foil tape alone on a flex duct collar joint can fail at the high attic temperatures Schertz experiences in summer. Any contractor using only foil tape on primary duct connections is cutting a corner you will pay for again in three to five years.

On CleanRun jobs in Schertz, the method used on each connection is noted in the written scope. You don’t have to take our word for it – the photos show the material applied at each point.

Signs Your Schertz Home Needs Duct Repair

Most duct leaks in Schertz don’t anneal themselves as a visible problem – they show up as energy bills and comfort complaints. The following are specific indicators worth acting on rather than monitoring.

• Rooms that don’t match the thermostat: A temperature split of 4 degrees or more between the thermostat location and a specific room is a meaningful signal. In two-story Schertz homes, the upper level consistently running 6 to 10 degrees hotter than the first floor often points to supply-side duct leakage in the attic above that floor.
• Electric bills that don’t match the square footage: CPS Energy’s average residential bill for a 2,200-square-foot home in the Schertz area during peak summer months (June through August) runs roughly $180 to $260, depending on equipment age and thermostat habits. If your bill is consistently 30% above that range with no obvious explanation, duct leakage is a reasonable candidate.
• Excessive dust on supply registers: When conditioned air leaks out of a duct and attic air is pulled in to replace it (negative pressure), fine insulation particles and attic dust enter the duct stream. If your registers accumulate visible dust within two to three weeks of cleaning, the duct system may be drawing from attic space rather than returning to the air handler cleanly.
• HVAC system short-cycling: A system that reaches temperature and shuts off, then restarts within a few minutes, can indicate that supply air is not reaching the rooms it’s designed to condition – causing the thermostat to read satisfied while the occupied rooms remain warm. Duct leakage is one of several causes; a duct blaster test will confirm or rule it out.
• Visible duct damage after attic work: In Schertz, the most common cause of sudden duct disconnection is attic insulation work. Insulation contractors working above flex duct runs – or HVAC technicians accessing equipment without protective boards – routinely displace or damage duct connections. If you had attic work done in the last two years and comfort problems followed, a duct inspection is the logical next step.

What CleanRun Documents on Every Schertz Duct Repair Job

The Documented Photo Record is not a feature we added – it is how CleanRun has operated since the first job in 2013. Every duct run is photographed before any work begins. Every repair point is photographed after the work is complete. The customer receives this record as a standard deliverable when the job closes.

On duct repair and sealing jobs specifically, the documentation includes:

• Pre-repair photographs of each identified leak point, tagged by location (e.g., “Master bedroom supply boot, north wall”).
• Photographs of the sealant or repair material applied at each point, showing coverage and method.
• Where a duct leakage test is included: the pre-repair and post-repair CFM readings, printed from the test equipment and included with the job record.
• The written scope of work – the same document you approved before work started – with technician notes on what was found at each location.
• The 365-Day Done Right Promise confirmation in writing, stating that if any repaired connection fails within 365 days of the job date, CleanRun returns and corrects it. No manager approval required – it is written into every job record.

This is what makes a written price meaningful: the documentation that confirms the work was done and done correctly is delivered alongside it. For more on what a full-service duct repair engagement includes, see our Duct Repair & Sealing in Schertz service page.

Permit Requirements for Duct Work in Schertz, TX

Schertz falls under the City of Schertz Building & Development Services division for residential permitting. For most duct repair and sealing work – patching existing runs, sealing connections, replacing individual flex duct sections – a permit is generally not required under the Texas Mechanical Code, because the work is classified as maintenance and repair rather than new installation or system alteration. However, if the project involves replacing more than 50% of the duct system, altering the layout, or modifying equipment connections, a mechanical permit from the City of Schertz may be required.

CleanRun confirms permit requirements during the scoping process and notes any applicable code requirements in the written scope before work begins. If a permit is required, that is stated in the quote – not discovered after the invoice is issued.

FAQs: Duct Repair & Sealing Cost in Schertz

How much does duct sealing cost for a typical Schertz home?

For a 2,000-square-foot Schertz home with standard attic-mounted flex duct, duct sealing using mastic sealant at accessible connection points typically runs $350 to $700. If the leaks are inside walls or above sealed ceilings and require Aeroseal treatment, expect $900 to $1,400 for the same size home. The price depends on the number of leak points, access difficulty, and whether a duct leakage test is included in the scope. Call (830) 402-5110 for a written estimate – the price is on paper before any work starts.

Is duct repair worth it, or should I just replace the whole system?

Repair is worth it when the total repair cost is less than 40 to 50% of full replacement cost and the remaining duct system is in serviceable condition. In Schertz homes built after 1995, a localized flex duct repair at $150 to $280 per section makes sense when the rest of the system is intact. When a duct blaster test shows 25% or more total leakage and the flex liner is brittle throughout, replacement at $3,500 to $5,500 for a 2,000-square-foot home typically delivers better cost-per-year value than a repair-heavy approach. CleanRun provides both numbers in the written quote when the system is borderline, so you can make the comparison on paper.

How long does duct repair take in a Schertz home?

A single disconnected boot or a two-section flex duct repair takes 1 to 2 hours. A whole-home mastic sealing job on a 2,200-square-foot Schertz house – covering 10 to 14 register boot connections, both plenums, and any damaged sections – typically runs 3 to 5 hours in the attic. An Aeroseal whole-system treatment adds roughly 2 hours for setup, injection, and post-test. Attic access and summer temperatures in Schertz extend labor time on jobs scheduled May through September.

Does duct repair require a permit in Schertz, TX?

For standard maintenance-level repairs – patching, sealing, or replacing individual flex duct sections – a permit is generally not required under the Texas Mechanical Code in Schertz. For projects that replace more than 50% of the duct system or alter the equipment connections, a mechanical permit from the City of Schertz Building & Development Services may apply. CleanRun identifies permit requirements during scoping and notes them in the written quote before work begins.

Can duct sealing actually lower my energy bills in Schertz?

Yes, with a specific range: the U.S. Department of Energy estimates that duct leakage accounts for 20 to 30% of heating and cooling energy loss in a typical home. In Schertz, where cooling loads run high from May through October, a system leaking 18 to 25% of conditioned air into the attic before it reaches living spaces can add $60 to $120 per month to a summer electric bill compared to a sealed system of identical equipment efficiency. Post-repair duct leakage tests document the before-and-after CFM reduction, giving you a measured number rather than an estimated one.

How do I know if a duct repair company in Schertz is quoting a fair price?

The most reliable check is a written scope from at least two companies that includes the same line items: which sections are being repaired, what method (mastic, Aeroseal, replacement), whether a pre- and post-repair leakage test is included, and what guarantee applies to the work. A quote that does not specify the repair method or the number of connections being sealed is not a comparable price – it’s an opening number. CleanRun offers a Free Second Opinion on any written estimate: call (830) 402-5110, share the other quote, and we put our number next to it in writing.

CleanRun serves homeowners across Schertz and the surrounding communities from our base here in the area. If you’re unsure what your duct system needs, a written inspection scope is the starting point – not a sales call. You can learn more about the full range of services we provide on our home page, or go directly to our Duct Repair & Sealing in Schertz service page for a detailed look at how each job is scoped and documented.

To schedule a written estimate or request a Free Second Opinion on an existing quote, call CleanRun at (830) 402-5110. A live person answers every call. The written price comes before any work starts – that is Haven Standard Clause 1, and it applies to every job, including yours.

Written by Tomas Reyes, Owner at CleanRun Air Duct Cleaning Schertz, serving Schertz since 2013.

Pricing reflects the Schertz market as of 2026. CleanRun Air Duct Cleaning Schertz offers free estimates – call (830) 402-5110.