Duct Repair & Sealing in Dallas - Tested First, Written Price Second

Trusted Duct Repair & Sealing for Dallas Homeowners

If you’re wondering how much Duct Repair & Sealing costs, typical Dallas residential jobs run $350-$1,200, with sealing on the lower end and full flex-duct replacement at the higher end. CleanRun Air Duct Cleaning Dallas has documented every duct repair with before-and-after photos since 2013, and every job starts with a written price delivered before any work begins. Call (469) 405-6133 for a free estimate with no obligation.

Call (469) 405-6133

We’ve performed Duct Repair & Sealing in Dallas for more than 52,000 area homes since Tomas Reyes established CleanRun in 2013. Dallas presents specific challenges: summer attic temperatures regularly exceed 140°F, which degrades flex duct adhesive and causes metal duct seams to open. North Texas clay soil shifts foundations, which cracks duct runs where they pass through slab joints. And the 2015-2022 building boom in neighborhoods like Bishop Arts, Design District, and Trinity Groves left many homes with duct systems that were never properly sealed at the plenum (the main distribution box where all duct runs originate) in the first place.

Our crews document what they find. The camera shows a 3-inch debris build-up at the first elbow, or a 12-inch gap in mastic sealant that has been blowing conditioned air into your attic for three years. We show you the photo before we describe the repair. That’s Haven Standard Clause 1: Written Price Before Work Starts, backed by the 365-Day Done Right Promise in writing on every job.

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, crawl space, or wall cavities. In Dallas, we most commonly find failed seals at the plenum connection and at register boots (the metal box that transitions from the duct to your floor or ceiling vent) where summer heat cycling has degraded the original tape. CleanRun crews use professional-grade mastic sealant and metal-backed tape rated for Texas attic conditions, and every sealed joint is photographed before and after as part of the standard Documented Photo Record.

Flex Duct Repair

Flex duct, the insulated flexible tubing used in most Dallas homes built after 1985, collapses, tears, or disconnects at its collar connections over time. We regularly find flex duct that has been chewed by roof rats in Lakewood and Old East Dallas, or crushed by storage items in attics in Preston Hollow and Highland Park. Our crews replace damaged sections with new R-8 insulated flex duct, secure collars with UV-resistant zip ties and mastic, and verify airflow at the register with a digital manometer (a pressure gauge that measures air volume in cubic feet per minute).

Metal Duct Repair

Older Dallas homes in neighborhoods like Swiss Avenue, Kessler Park, and parts of Oak Cliff still have galvanized steel ductwork from the 1950s-1970s. These systems rust at seams, separate at slip joints, and develop whistle-inducing gaps. CleanRun repairs metal duct with custom-fabricated patch panels, sheet-metal screws, and two coats of mastic sealant. When sections are too deteriorated, we fabricate replacement runs on-site. Metal duct repair takes longer than flex duct work, but it preserves the durability that original systems were built for.

Duct Insulation

Duct insulation in Dallas attics degrades from radiant heat exposure, falling off in strips or compressing to the point where it no longer slows heat transfer. We install fresh R-8 fiberglass insulation with a reinforced foil vapor barrier, secured with mechanical fasteners rather than glue that will fail in the next summer. Proper insulation matters in Dallas because attic temperatures can swing from 40°F in January to 145°F in August, and uninsulated or poorly insulated ductwork loses 20-30% of its thermal energy before the air reaches your rooms.

Mastic Sealant Application

Mastic is a thick, water-based sealant that brushes or trowels onto duct seams and cures to a flexible, durable seal. Unlike foil tape, which can peel in heat, mastic remains adhered through decades of thermal cycling. CleanRun applies mastic to every seam, joint, and penetration in accessible ductwork, including the often-missed connection between the air handler and the plenum. We use mastic rated for 250°F continuous exposure, which exceeds any Dallas attic condition. The application is messy work, which is why many contractors skip it; we photograph every coated joint so you can verify it was done.

Air Leak Repair

Air leaks are the gaps and holes that bypass the duct entirely, pulling unconditioned attic air into your system or pushing your heated and cooled air into spaces where it does no good. We locate leaks using a smoke pencil (a device that releases a thin stream of non-toxic vapor to visualize airflow) and a digital pressure gauge that measures the difference between supply and return static pressure. Common leak points in Dallas homes include the filter slot, the air handler cabinet, and the return air pathway through wall cavities that were never properly sealed during construction. Repair typically involves sheet-metal patches, mastic, and expandable foam for larger penetrations.

Signs You Need Duct Repair & Sealing Right Now

• Rooms that won’t heat or cool evenly. If your south-facing bedroom in a Dallas summer stays 8-10°F warmer than the thermostat setting while the north rooms freeze, the duct run serving that room is likely disconnected, crushed, or leaking severely into the attic. This is one of the most common calls we get from homes in Addison and Farmers Branch, where 1980s and 1990s construction used undersized flex duct that has since deteriorated.
• Dust that returns within days of cleaning. When ducts leak on the return side, they pull attic dust, insulation fibers, and rodent droppings directly into your airflow. If you’re wiping white fiberglass dust off your furniture every Tuesday, your return ductwork has a breach. We’ve photographed this exact scenario in dozens of Dallas homes, particularly those with attic air handlers in neighborhoods like Lake Highlands and Casa View.
• Utility bills that spike without explanation. A 15-25% increase in your electric bill, especially during Dallas’s July-September cooling season, often traces to duct leaks that have worsened to the point where your HVAC system runs continuously to maintain temperature. The equipment works harder, wears faster, and still can’t keep up because half the cooled air is cooling your attic.
• Whistling or rushing air sounds from vents. These noises indicate high static pressure, usually caused by a duct that has partially collapsed or a seal that has blown open, forcing the same air volume through a smaller opening. The sound is a symptom; the underlying problem is that your system’s airflow is restricted, which strains the blower motor and can cause premature compressor failure in your outdoor unit.
• Visible duct damage in attic or crawl space. If you’ve been in your attic and seen flex duct hanging loose from its collar, insulation stripped away, or metal duct with rust streaks, the damage is already affecting your system’s efficiency and your indoor air quality. Dallas’s humidity, even in “dry” years, is enough to corrode metal and degrade flex duct adhesive when attic ventilation is inadequate.

Before

After

Our Duct Repair & Sealing Process - Step by Step

1. 1
   Written estimate delivered on-site. Our technician arrives in a marked CleanRun vehicle, introduces themselves by name, and inspects your accessible ductwork with a digital borescope camera (a flexible camera that feeds to a handheld screen, allowing us to see inside duct runs without dismantling them). We document visible damage, measure airflow at each register with a digital manometer, and deliver a written price before any work begins. Haven Standard Clause 1: no exceptions.
2. 2
   Photo documentation of existing conditions. Before touching a tool, we photograph the full length of every duct run we’ll be working on, the condition of insulation, and any specific damage points. These images become part of your job record and are delivered to you with the final invoice. This practice has been standard since Tomas Reyes completed CleanRun’s first job in 2013.
3. 3
   Repair and seal with trade-specified materials. Depending on the scope, we repair or replace damaged duct sections, apply mastic sealant to all seams and joints, replace degraded insulation, and verify collar connections with mechanical fasteners. We use equipment from Nikro for negative-pressure extraction if debris removal is needed, and our mastic and tape selections are rated for the temperature extremes of Dallas attics.
4. 4
   Post-repair testing and documentation. After repairs are complete, we re-measure airflow at each register and compare to pre-repair readings. We photograph every sealed joint, every repaired section, and every replaced insulation run. The post-repair photos are timestamped and included in your Documented Photo Record, so you can verify the difference between what was there and what we left behind.
5. 5
   Written warranty and job record delivery. You receive a printed invoice with the 365-Day Done Right Promise stated explicitly, your before-and-after photo record on a USB drive or via email link, and a summary of work performed. If anything we repaired fails within 365 days, we return and make it right at no charge. This is not a manager-discretion policy; it is a written guarantee on every job.

How Much Does Duct Repair & Sealing Cost in Dallas?

Duct Repair & Sealing Near Dallas - Our Service Area

CleanRun crews repair and seal ductwork throughout Dallas and the surrounding metro, including Duct Repair & Sealing in Mesquite, Duct Repair & Sealing in Garland, Irving, Richardson, Rowlett, Carrollton, Grand Prairie, Coppell, Plano, Forney, and Euless. Typical scheduling runs 2-4 days from call to arrival for non-urgent repairs; we do not promise same-day dispatch because duct repair requires proper diagnosis and material preparation, and rushing either produces sloppy work. For homes in Dallas proper, from Uptown and Knox-Henderson to Pleasant Grove and West Dallas, we’re familiar with the specific duct configurations common to each era of construction and can estimate accurately over the phone for most standard repairs.

Brands We Service for Duct Repair & Sealing

We’ve serviced duct systems connected to Honeywell air cleaners and zoning controls in hundreds of Dallas homes, and we stock replacement gaskets and collar adapters compatible with Honeywell’s whole-house media filters. When a Honeywell F100 or F200 air cleaner is integrated into the return duct, improper sealing around the filter cabinet is a common leak point; we verify these seals as part of our standard inspection protocol.

Aprilaire humidifiers and dehumidifiers, frequently installed in Dallas homes to manage the swing between winter dryness and summer saturation, require proper duct integration to function without leaking conditioned air. We’ve repaired and resealed countless Aprilaire bypass humidifier installations where the original contractor failed to seal the bypass duct collar, and we carry the specific transition fittings that Aprilaire systems require. Whether your duct system is connected to Honeywell, Aprilaire, or any other make of HVAC component, we can inspect, repair, and seal it to manufacturer specifications. Our equipment roster also includes Nikro and Abatement Technologies tools for jobs requiring negative-pressure extraction or containment.

Frequently Asked Questions - Duct Repair & Sealing in Dallas

Schedule Your Duct Repair & Sealing Service in Dallas Today

Call (469) 405-6133 to speak with a live person and schedule your free estimate. You’ll receive a written price before any work begins, a Documented Photo Record of every duct run we touch, and the 365-Day Done Right Promise in writing on every job. No coupons, no bait-and-switch, no per-vent pricing. Just documented evidence of what we found and what we fixed, at a price we agreed on beforehand.

Written by Tomas Reyes, Owner at CleanRun Air Duct Cleaning Dallas, serving Dallas, Duct Repair & Sealing in Mesquite, Garland, and surrounding communities since 2013.