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 Alvin
Duct repair and sealing in Alvin typically runs $280-$750 for most homes, with flex duct replacement and full-system mastic sealing at the higher end. We dispatch crews to Alvin from our Houston coordination office, and most Alvin homeowners get a written quote within 24 hours of calling. If your registers are blowing weak, musty, or noticeably warm air, the problem is usually a disconnected or degraded duct run in the attic, not the HVAC unit itself. Call (346) 253-1822 and we’ll put a camera inside before we quote a dollar.
We’ve worked in Alvin since 2013, from the older ranch neighborhoods near Mustang Bayou to the newer builds off Highway 35. The housing stock here tells a consistent story: original flex duct installed in the 1960s through 1980s, cooked by attics that hit 150°F in July, and in too many homes, flooded during Harvey with backflow that left a dried silt line inside the lower duct runs. Our Duct Repair & Sealing team doesn’t guess at what’s wrong. We photograph every run before we touch it, deliver a written price before we start, and leave you with a documented record of what we found and what we fixed.
Why CleanRun Air Duct Cleaning Pearland Is Alvin’s Preferred Duct Repair & Sealing Company
Alvin homeowners are specific about who they let into their homes. We’ve earned that trust by showing what other companies only describe. Every job since 2013 has started with a written price and ended with before-and-after photos of every duct run. No exceptions.
Our crews know Alvin’s housing patterns. The 1960s-1980s ranch homes near Chocolate Bayou corridor still carry original flex duct that degrades predictably. Post-Harvey rebuilds throughout Brazoria County often have ductwork that looks new but hides dried sediment colonies from flood backflow. We know to check for the silt residue line. Standard visual inspections miss it. Our camera doesn’t.
Haven Standard Clause 3: Verified Crews means every technician is background-checked, uniformed, and identified by name before arrival. Tomas Reyes, our owner, built this standard into the company from the first job. The 365-Day Done Right Promise backs every repair in writing. If it’s not right, we make it right. Not a policy subject to manager approval. A written guarantee.
All calls are answered by a live person, 24/7. Scheduling is coordinated from our Houston office, but the crew that arrives at your Alvin home knows the local conditions. They’ve seen the crushed flex behind air handlers. They’ve measured the static pressure drop after proper mastic sealing. They don’t sell. They document, quote in writing, and fix what they find.
Our Duct Repair & Sealing Services in Alvin
Flex Duct Repair
Flex duct is the black corrugated tubing you’ll find in most Alvin attics from the 1970s and 1980s. It degrades. The insulation sags. The inner liner tears. The collar disconnects from the plenum and dumps your conditioned air into 150°F attic space. We replace damaged flex runs with new R-8 insulated duct, secure with mechanical fasteners, and seal every joint with mastic. In a 1970s ranch near Mustang Bayou, our tech found the original flex crushed behind the air handler, with a visible silt residue line from Harvey backflow coating the liner. We performed source removal under negative pressure, replaced the damaged flex run, and sealed the plenum and joints with mastic. The static pressure dropped and the musty odor cleared within a day.
Mastic Sealant Application
Mastic is a thick, fiber-reinforced sealant brushed onto duct joints, plenum connections, and register boots. It outlasts tape by decades, especially in Alvin’s humidity. Duct tape dries and fails. Mastic stays flexible. We apply it to every metal-to-metal and metal-to-flex joint after repair work. For Alvin homes with post-Harvey repairs, mastic sealing is often the difference between a system that holds pressure and one that leaks 20-30% of its airflow into the attic. We use Guardsman-brand mastic rated for high-humidity applications.
Duct Insulation
Uninsulated or degraded duct insulation in Alvin attics creates condensation. Cold supply air hits 150°F metal. Water forms. Mold follows. We wrap repaired or replaced duct runs with fresh insulation, vapor-sealed at seams, to stop the sweating cycle that plagues Alvin’s year-round HVAC operation. This is especially critical for metal duct systems in older homes near the historic downtown core, where original fiberglass wrap has compressed to nothing after forty years of heat cycling.
Metal Duct Repair
Some Alvin homes, particularly pre-1970s builds and custom construction, use galvanized metal ductwork. We repair separated seams, replace rusted sections, and seal with mastic. Metal ducts in Alvin’s humidity are prone to corrosion at seams and register boots. Our Rotobrush inspection cameras show the damage before we cut anything. We quote the repair in writing. Then we fix it.
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 Alvin
We stock parts and materials from Abatement Technologies, Aprilaire, and Guardsman for Alvin jobs, with equipment including Rotobrush inspection systems and Nikro negative-pressure extractors. These aren’t proprietary names. You can look them up. We name them because we want you to verify what we’re using before you agree to a price. For Alvin’s humidity and heat conditions, we specify materials rated for Gulf Coast applications, not generic stock. That means faster turnaround on repairs and no waiting for special-order sealants when your system is leaking 25% of its airflow into the attic.
Common Duct Repair & Sealing Problems We See in Alvin Homes
- Original flex duct collapsed from attic heat cycling. The 1960s-1980s ranch homes throughout Alvin’s older neighborhoods still run original flex through brutally hot attics. The inner liner degrades, the insulation compresses, and the duct collapses behind air handlers or at sharp bends. We find this with a camera, replace the run, and seal the connection.
- Harvey backflow silt lines in lower duct runs. Homes in the Mustang Bayou and Chocolate Bayou flood plains often show a distinctive silty residue line inside lower supply and return runs. It dried after the flood and became a substrate for mold. Standard cleaning without camera inspection and agitation tools misses it. We document it, remove it under negative pressure, and seal the system to prevent recontamination.
- Condensation mold on uninsulated metal ducts. Alvin’s near-constant humidity and year-round HVAC operation cause duct surfaces to cycle between sweating-cold and superheated-dry. Mold grows at seams and registers even when the system looks clean. Insulation and proper sealing break this cycle.
- Disconnected collar joints dumping air into the attic. The vibration of Alvin’s hard-working HVAC systems loosens mechanical fasteners over years. We find supply boots hanging open, blowing $400 worth of cooled air into attic space monthly. We reconnect, mechanically fasten, and mastic-seal every joint.
Pricing for Duct Repair & Sealing in Alvin, TX
Here’s what duct repair and sealing costs in Alvin’s market, based on jobs we’ve completed across Brazoria County:
| Service | Typical Range in Alvin |
|---|---|
| Single flex duct run replacement | $280-$420 |
| Mastic sealing, whole system (up to 10 runs) | $450-$650 |
| Duct insulation wrap, supply and return | $380-$580 |
| Metal duct section repair/replacement | $320-$520 |
| Full system: inspection, repair, sealing, insulation | $680-$1,100 |
Factors that move the price: accessibility of attic space, extent of flood-related contamination requiring source removal, and whether the plenum itself needs resealing or replacement. We deliver a written price before any work starts, every time, under Haven Standard Clause 1. No per-vent pricing. No add-ons after the van arrives. Bring a competitor’s written estimate and we’ll provide a Free Second Opinion, our number next to theirs.
Call (346) 253-1822 for an exact quote. Estimates are free.
We Also Serve Cities Near Alvin
Our crews work throughout Brazoria County and northern Galveston County, including Alvin, Manvel, Friendswood, Pearland, and Santa Fe. Scheduling is coordinated from our Houston office, with local dispatch to each community. The same written-price standard, the same documented photo record, the same Haven Standard applies whether we’re working in Alvin’s historic core or a new build in Manvel.
Serving Alvin, TX - Our Local Coverage Area
We’re based in the Alvin 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 Alvin
Musty odors from supply registers, visible debris at register openings, or uneven cooling after the system runs are the common signs. We confirm it with a camera inspection. In Alvin’s flood-affected neighborhoods, especially near Mustang Bayou and Chocolate Bayou, we regularly find a dried silt residue line inside lower duct runs that standard visual inspections miss. The camera shows it clearly. We document what we find, quote removal and sealing in writing, and deliver before-and-after photos as part of the standard job record. Call (346) 253-1822 to schedule an inspection.
Because a leaking duct system undoes any cleaning within months. In Alvin’s 1960s-1980s ranch homes, original flex duct has degraded, collars have loosened, and conditioned air is dumping into 150°F attics. Cleaning the debris doesn’t fix the airflow loss or the attic air being drawn back into the system. We seal first, then clean if needed. The static pressure test proves the result. Haven Standard Clause 1 requires the written price to cover the actual fix, not just the visible symptom.
Yes, after source removal of the contamination. Sealing over active mold traps moisture and worsens the problem. We use negative-pressure extraction and agitation tools to remove mold colonies from the duct surface, then apply mastic sealant to prevent recontamination at joints and seams. In Alvin’s humidity, this two-step process is standard, not optional. The 365-Day Done Right Promise covers our sealing work if moisture re-enters from a new source.
Uneven temperatures room to room, weak airflow at distant registers, musty odors that return within weeks of cleaning, or utility bills that spike without explanation. These point to disconnected, crushed, or leaking duct runs, not just debris buildup. We run a camera and a static pressure test to distinguish between a cleaning need and a repair need. The written quote reflects what we find, not what we hope will work.
Alvin holds the U.S. record for 24-hour rainfall, 43 inches during Tropical Storm Claudette in 1979, and the combination of extreme moisture history and summer attic temperatures above 150°F demands sealants rated for high-humidity, thermal-cycling conditions. We specify Guardsman mastic and mechanical fasteners, not tape, because tape adhesive fails in Alvin’s attics within two to three years. The sealing work we do is designed to survive both the moisture and the heat. That’s why we back it with the 365-Day Done Right Promise, in writing, on every job.
Written by Tomas Reyes, Owner at CleanRun Air Duct Cleaning Pearland, serving Alvin since 2013.