Duct Repair & Sealing Cost - Leakage Measured, Then Priced in Writing

How Much Does Duct Repair & Sealing Cost in Dallas?

Duct repair and sealing in Dallas, TX typically costs between $350 and $1,400 for most homes in 2026, with a per-vent or per-access-point range of $35 to $85 when the damage is isolated. The most common job we quote, sealing leaky ductwork in a 2,000 to 2,500 square foot home with mastic and mesh tape plus a pressure test, lands between $600 and $1,100. You’ll know your exact number before any work starts because we write the price down and it doesn’t move.

Before you commit to any contractor, understand one thing about Dallas specifically: your ductwork is working against a climate that punishes it. Attic temperatures in Plano, Garland, Mesquite, and across Dallas County routinely hit 140°F in July and August. That heat bakes the tape, dries out the mastic, and separates joints over time. The furnace cycles hard in January when the temperature drops forty degrees in a day. That thermal cycling, repeated year after year, is why Dallas homes leak more conditioned air than homeowners realize.

Key Takeaways:

• Most Dallas duct repair and sealing jobs fall between $350 and $1,400.
• Full-system sealing with mastic and a pressure test averages $600 to $1,100 for a typical single-family home.
• Dallas attic heat is the number one local driver of duct joint failure.
• Hollis Air Duct Dallas writes the price before work starts, and it does not move at the door.
• Every repair is covered by the 365-Day Done Right Promise, in writing.

Duct Repair & Sealing Cost Breakdown (2026)

Here’s what you can expect to pay in the Dallas market this year. These ranges reflect what we see across North Dallas, Oak Cliff, East Dallas, Richardson, and the surrounding suburbs. They assume a standard single-family home with a flex-duct or sheet-metal system and an accessible attic or crawlspace.

Service	Typical Dallas Range	What It Includes
Single duct joint repair	$75 – $150	One separated or torn joint, reconnected and sealed with mastic and mesh tape
Small leak sealing (1 – 3 access points)	$200 – $400	Isolated leaks at visible joints or plenum connections
Partial system sealing (4 – 8 vents)	$450 – $750	Sealing accessible duct runs, boots, and plenum connections
Full system sealing (entire home)	$600 – $1,100	All accessible ductwork sealed with mastic, mesh tape, and pressure-tested
Plenum repair or rebuild	$250 – $600	Damaged supply or return plenum repaired or re-fabricated
Flex duct replacement (per 10-ft section)	$85 – $160	Crushed, torn, or kinked flex duct removed and replaced
Return air repair	$150 – $400	Leaking or disconnected return duct sealed and reconnected
Whole-home duct replacement	$3,500 – $8,000	Full tear-out and replacement, typically when ducts are collapsed, moldy, or beyond sealing

Those numbers move based on a few things. If your attic is tight, with low clearance and obstacles, labor goes up. If your system is original to a 1970s ranch in Mesquite and the joints are held together with thirty-year-old duct tape that’s turned to dust, you’re looking at more access points and more time. If your home has a second story with a separate trunk line in a hard-to-reach chase, that adds cost too.

The single biggest variable in Dallas is whether the damage is a few separated joints or a system-wide leak pattern. A 2018 energy study in Texas found the average home loses 20 to 30 percent of conditioned air through duct leaks. In a Dallas summer, that’s real money leaving through your attic vents every month.

Repair vs. Replace: The Cost Decision

If sealing costs less than about 40 percent of replacement and your ductwork is structurally sound, sealing is the right call. In Dallas, that means a $700 sealing job beats a $6,000 replacement when the ducts are intact but leaky. Replacement makes sense when the ducts are crushed, moldy, saturated with rodent droppings, or so old that the inner liner is breaking down. We’ll tell you honestly which one you need, and the price is written down either way.

What Affects Duct Repair & Sealing Pricing in Dallas

• Attic accessibility. Homes in older Dallas neighborhoods like Lakewood and Casa View often have low-pitch roofs and tight attics. If a technician has to crawl on their stomach to reach a plenum, that’s labor time. In newer suburbs like Frisco and McKinney, attic access is often easier and the work moves faster.
• Number of access points. Every supply vent boot, every return, every plenum connection is a potential leak point. A 1,200 square foot home in Oak Cliff might have 8 to 10 access points. A 3,500 square foot home in Preston Hollow might have 20 or more. That’s the difference between a $450 job and a $1,100 job.
• Condition of existing ductwork. If the previous contractor used cheap cloth duct tape instead of mastic, that tape is brittle and gone within a few Dallas summers. You’re paying for removal of failed material before sealing can happen.
• Type of ductwork. Flex duct is cheaper to replace per section but fails faster in Dallas heat. Sheet metal lasts longer but costs more to repair when a joint separates because the metal itself may need reinforcement.
• Whether you need a pressure test. We pressure-test after sealing to verify the leak rate dropped. It’s included in full-system sealing jobs. If you’re doing a smaller repair and want documentation for an energy audit or home sale, a standalone test typically adds $100 to $150 in Dallas.
• Time of year. HVAC contractors in Dallas are busiest in June, July, and August. If your leak can wait until October or March, you may have more scheduling flexibility. Our written pricing doesn’t change with the season, but availability does.

How to Save on Duct Repair & Sealing

The cheapest way to save is to catch leaks before they multiply. A single separated joint at the plenum, if ignored, increases negative pressure that pulls more joints apart. What would have been a $150 repair becomes a $700 sealing job six months later. If you hear a whistling sound at a specific vent, feel weak airflow in one room, or notice dust blowing from one register, have it looked at.

Five practical ways to keep costs down:

• Get the price in writing before work starts. A contractor who won’t put a number on paper before the first tool comes out is a contractor who’ll find a reason to add charges. The Garrison Standard requires the price written down, every time.
• Seal all accessible ductwork at once. If you have four leaks repaired separately across three visits, you’re paying travel and setup time three times. Bundling the work into one full-system sealing job costs less per access point.
• Don’t pay for replacement when sealing will do. Some companies default to replacement because it’s a bigger ticket. If your ducts are intact but leaky, mastic sealing is the right fix and costs a fraction of replacement. We’ll show you the damage before we recommend anything.
• Ask about the warranty in writing. A repair without a written warranty isn’t a repair, it’s a gamble. Our 365-Day Done Right Promise covers every sealing job for a full year. If it fails, we come back at no charge, including a free second visit.
• Call for a free estimate. You’ll get a real number, not a range, and it won’t change when the technician arrives. Call (361) 309-6223 and a live person answers, 24/7. No voicemail loops.

Why Dallas Ductwork Fails Faster Than Most Markets

If you moved here from a cooler or more humid climate, you may wonder why your previous home’s ducts lasted thirty years without issue and your Dallas home needs attention at year fifteen. The answer is the attic.

Dallas summer attic temperatures reach 140°F or higher. Winter nights dip into the 20s. That’s a 100-plus degree swing, twice a year, on the materials holding your ductwork together. Metal expands and contracts. Flex duct’s outer jacket breaks down under UV exposure even inside a shaded attic. Mastic holds, but the joints around it move millimeter by millimeter until a gap opens.

We regularly see specific failure patterns across the metroplex. In Garland and Mesquite, where many homes were built in the 1980s and 1990s, the original flex duct has a gray outer jacket that degrades into a brittle shell. In Richardson and North Dallas, where 1970s sheet metal systems are common, we see separation at the plenum connections and at boot-to-floor transitions. In Coppell and Flower Mound, where homes are newer but attics are just as hot, we see poorly sealed initial installations from production builders who used tape instead of mastic.

The fix is the same in every neighborhood: find every accessible joint, clean it, seal it with mastic and mesh tape, and verify the result with a pressure test. That’s the repair standard we follow on every job, and it’s why the Duct Repair & Sealing in Dallas service exists as a dedicated offering rather than an add-on.

The 365-Day Done Right Promise, In Plain Terms

Every duct repair and sealing job we complete is covered in writing for 365 days. If a sealed joint separates, a repair fails, or the leak rate goes back up within that year, we return and make it right at no charge. There is no deductible, no service fee, no argument. The promise includes a free second visit. We don’t ask you to re-qualify, and we don’t prorate anything. That’s The Garrison Standard, and it’s in writing on every job.

Roy Castellanos, who leads Hollis Air Duct Dallas, put it this way: a warranty that requires a fight isn’t a warranty. Ours is one sentence on the work order. It says what it covers and for how long. That’s it.

How the Sealing Process Works

You don’t need to know the trade to understand what we’re doing, but you should know enough to recognize whether a contractor is doing it right.

Step 1: Locate the Leaks

We start with a visual inspection of all accessible ductwork and a discussion of symptoms. Weak airflow in one room, dust around certain registers, a spike in your electric bill during a mild month, or a house that won’t hold temperature on the second floor. Then we use a pressure test or, on smaller jobs, a manual check of each joint to find where the air is escaping.

Step 2: Clean and Prep

Mastic won’t bond to dust or old adhesive. Each joint gets cleaned before sealing. On sheet metal, that means removing the old tape and wiping the surface. On flex duct, it means pulling back the insulation jacket, sealing, and re-securing it properly.

Step 3: Seal with Mastic and Mesh Tape

Mastic is a thick, paste-like sealant that cures into a flexible, durable bond. Unlike duct tape, which dries out and fails within a few Dallas summers, mastic moves with the ductwork as it expands and contracts. We apply it at every accessible joint, boot, and plenum connection, using mesh tape on larger gaps for reinforcement.

Step 4: Verify

After sealing, we verify the result. On full-system jobs, that means re-running the pressure test to confirm the leak rate has dropped. On smaller repairs, it means checking the fix directly. Either way, you get a written record of what was done and what it cost.

Our trucks carry Rotobrush rotary brush systems and Nikro negative-air machines for cleaning work, and our sealing work follows the same professional-grade standard. When filtration matters, we install and service Honeywell, Aprilaire, and Guardsman products. These are the same tools commercial crews use on office buildings and hospitals, not hardware-store gear.

How Much Does Duct Repair Cost in Dallas by Neighborhood?

Labor and material costs don’t vary much by zip code, but the age and style of housing stock do. Here’s what we see in the neighborhoods we serve most often.

North Dallas & Preston Hollow

Larger homes, often 3,000 to 5,000 square feet, with sheet metal ductwork from the 1960s through 1980s. Full-system sealing here runs $800 to $1,400 because of the access point count. Plenum repairs are common. These homes often have return air issues because the original systems were undersized for later additions.

East Dallas, Lakewood & Casa View

Homes from the 1920s through 1950s with retrofit ductwork. Attics are tight and access is difficult. Expect the labor side of a job to run 15 to 25 percent higher than a comparable home with an open attic. A partial sealing job that costs $550 in Frisco might run $650 to $750 here.

Garland, Mesquite & East Suburbs

1980s and 1990s construction with original flex duct nearing end of life. Common jobs are replacement of individual 10-foot flex sections at $85 to $160 per section, plus sealing of the remaining accessible joints. Many of these homes are at the point where full replacement is worth considering.

Frisco, Plano & Collin County

Newer construction, easier attic access, but production-builder shortcuts at installation. We see a lot of poorly sealed initial work in 2005 to 2020 homes. Sealing jobs here are often on the lower end, $500 to $900, because access is straightforward. The leaks are real even in newer homes.

Oak Cliff & South Dallas

Older homes with a mix of original and retrofit systems. Attic access varies. Frequently see separated return ducts and crushed flex from storage boxes placed on top of runs. Repair costs typically land in the $400 to $900 range depending on how much of the system is accessible.

What Happens If You Don’t Fix Leaky Ducts in Dallas?

A 20 percent duct leak in a Dallas summer isn’t just a comfort problem. It’s a recurring monthly charge on your electric bill. Here’s the math. If your summer cooling bill runs $250 a month and 20 percent of that air is leaking into the attic, you’re literally paying about $50 a month to cool your attic. Over a six-month cooling season, that’s $300. Over three years, that’s $900. A $900 sealing job pays for itself in three Dallas summers, and that’s before you factor in the wear on your HVAC system from running longer cycles to compensate for the lost air.

Beyond cost, leaky return ducts pull air from the attic into your living space. That’s 140°F air in July, plus dust, insulation fibers, and whatever else is up there. Leaky supply ducts push conditioned air into the attic, which over time can lead to moisture issues when warm humid air meets cold surfaces. The fix is straightforward, and the cost is predictable when you work with a company that prices in writing.

FAQs – Duct Repair & Sealing Cost

How much does duct sealing cost in Dallas?

Duct sealing in Dallas typically costs $600 to $1,100 for a full-system job on a standard single-family home. Smaller partial jobs run $200 to $400 for 1 to 3 leak points. The range depends on the number of access points and attic accessibility. Call (361) 309-6223 for a free estimate, and you’ll get a written price before any work starts.

Is duct sealing worth the cost?

Yes, in Dallas, where a 20 percent duct leak can cost you $300 to $600 per year in wasted cooling alone, sealing typically pays for itself within 2 to 4 years. If you’re also losing heated air in winter, the payback is faster. The 365-Day Done Right Promise covers the work for a full year, so the repair is guaranteed in writing.

How much does it cost to replace flex duct in Dallas?

Flex duct replacement in Dallas runs $85 to $160 per 10-foot section, including materials and labor. A full trunk-line replacement in a typical home runs $3,500 to $8,000. Replacement makes sense when the duct is crushed, torn, or the inner liner is breaking down. If the duct is intact but leaky, sealing is the cheaper fix, and we’ll tell you which one you need.

Can you fix ductwork the same day?

Yes, most single-joint repairs and small sealing jobs are done same day. Full-system sealing on a larger Dallas home may take 4 to 8 hours, which is still typically a single visit. Call (361) 309-6223 and a live person answers 24/7. We’ll tell you the timeline when we schedule, and the price is written before we touch anything.

Does duct sealing help with high electric bills in Dallas?

Yes, sealing duct leaks that account for 20 to 30 percent of system airflow loss typically reduces cooling costs by $300 to $600 per year in Dallas, based on average local electricity rates and a $200 to $300 monthly summer bill. The exact savings depend on how leaky your system is, which the pressure test tells us before and after the work.

Do you offer free estimates for duct repair in Dallas?

Yes, estimates are free, and the price is written down before any work starts. It does not change when the technician arrives, and there are no add-on charges. Call (361) 309-6223 to schedule. A live person answers, 24/7, no voicemail loops.

Why Dallas Homeowners Call Hollis Air Duct Dallas

You’ve probably dealt with a contractor who didn’t show, or showed late, or quoted one number and handed you a different invoice. The Garrison Standard exists because that experience is too common in this trade. Here’s what it means in practice.

We arrive inside the quoted window. The price is written down before we start, and it does not move. The technicians are background-checked and uniformed, so you know who’s walking into your home before they arrive. The job is completed by the book, using professional-grade equipment from Rotobrush, Nikro, and Abatement Technologies. The site is left clean. And the work is covered by the 365-Day Done Right Promise in writing.

Roy Castellanos leads the Dallas operation, and he holds the team to those specifics. Not adjectives. Specifics. Calls are answered by a live person 24 hours a day, 7 days a week. If you call at 2 a.m. with a duct emergency, a human picks up.

Our home page has more about the full range of services, including air duct cleaning and dryer vent cleaning. If you’re not sure whether you need repair, sealing, or full replacement, call (361) 309-6223 and we’ll help you figure it out over the phone, no charge.

Get Your Written Estimate

The only way to know what duct repair and sealing will cost in your Dallas home is to have someone look at your specific system. The estimate is free. The price is written down before any work starts. It doesn’t move. And if the work fails within a year, we come back at no charge.

Call (361) 309-6223 now. A live person answers, 24/7. You’ll get a straight answer, a written price, and a repair that’s covered for a full year.

Written by Roy Castellanos, Owner at Hollis Air Duct Dallas, serving Dallas since 2004.

Pricing reflects the Dallas market as of 2026. Hollis Air Duct Dallas offers free estimates – call (361) 309-6223.