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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After
Before
After
Before
AfterFast, Reliable Duct Sealing Across Exton
Duct sealing in Exton typically costs $450 – $950 for a whole-home system, and most jobs are completed in a single visit. We seal supply and return ductwork with mastic and metal-backed tape, then pressure-test to confirm the fix holds.
We’ve been driving the Route 100 corridor long enough to know which Exton subdivisions were built in which phase of Chester County’s growth boom. The split-levels near Whitford Hills, the colonials off Ship Road, the townhome clusters closer to the Main Street at Exton shopping district – our crews have sealed ducts in all of them. Roy Castellanos and our team dispatch from our Philadelphia office, and we schedule Exton homeowners within a window we actually keep. When you call (361) 326-5060, a live person answers, day or night. No callback queues, no “we’ll get back to you Monday.”
Why Hollis Air Duct Cleaning Is Exton’s Preferred Duct Sealing Company
Exton homeowners don’t hire us because we’re the cheapest. They hire us because the price we write down before work starts is the price on the invoice. No per-vent add-ons, no “we found another problem” surprises once the van is in your driveway.
Our reputation here was built on showing up inside the quoted window, in uniform, with background-checked technicians who know the difference between a 1987 flex-duct run and a 2004 retrofit. We’ve sealed ducts in finished basements from Marchwood to Franklin Ridge, and in attics over homes near the historic village core where farmhouse-era properties got retrofitted with forced-air systems that never quite fit right.
Our Duct Sealing in Exton work is covered by the 365-Day Done Right Promise. If a seal fails within a year, we come back and make it right at no charge. That includes a free second visit, not a negotiation.
Calls are answered by a live person 24 hours a day, 7 days a week. Scheduling is coordinated from our Philadelphia office, with crews serving Exton locally.
Duct Sealing Services in Exton
Duct Sealing Services in Exton address the specific failure patterns of 20 – 40 year old builder-grade flex duct and joint connections that dominate this market. The job involves locating leaks with a pressure test, sealing joints and seams with mastic compound and metal-backed tape (not the gray cloth tape that peels off in humid attics), and verifying results with a post-seal pressure test. Most Exton homeowners need this when rooms won’t heat or cool evenly, utility bills spike without explanation, or a renovation disturbed original duct runs.
Pressure Testing and Leak Detection
We pressurize your duct system and measure airflow loss to find the gaps you can’t see. In Exton’s finished basements, leaks often hide behind drywall where original installers cut corners on joint sealing. The test gives us a baseline number in CFM, and we don’t leave until that number drops.
Mastic Sealing and Metal-Backed Tape Application
Mastic is a thick, flexible sealant that fills gaps and remains pliable as ducts expand and contract. We apply it by hand at every joint, boot, and penetration, then reinforce with metal-backed tape rated for temperature cycling. This outlasts the adhesive tapes that fail after a few seasons in Exton’s humid summers.
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.
Duct Insulation in Exton
Duct Insulation in Exton solves a problem that’s especially costly in homes with attic or crawlspace runs: heated or cooled air bleeding into unconditioned spaces before it reaches your vents. We wrap supply ducts with formaldehyde-free fiberglass insulation, seal the vapor barrier, and secure it so it won’t sag or compress. Exton homeowners typically need this when second-floor rooms stay cold in winter despite the furnace running constantly, or when summer humidity condenses on cold duct surfaces in the attic.
Attic Duct Insulation Upgrades
Attic temperatures in Chester County swing from below freezing to over 130 degrees. Uninsulated or poorly insulated ducts lose 20 – 30% of their thermal energy in that environment. We use insulation rated for the temperature extremes Exton attics see, sealed with a proper vapor barrier to prevent condensation and mold.
Crawlspace and Basement Run Protection
Finished basements in Exton often have ductwork in soffits or bulkheads that pass through cooler, damper zones. Insulating these runs prevents condensation that drips onto ceiling tiles and promotes mold growth. We inspect the full path and insulate where the building envelope leaves ducts exposed.
Trusted Brands We Service in Exton
Our equipment roster includes Nikro negative-air machines for containment during sealing work, Honeywell and Aprilaire filtration components we integrate after sealing to protect the clean system, and Abatement Technologies HEPA equipment for jobs where disturbed construction debris requires extra care. We stock parts and materials locally for Exton customers, so we’re not waiting on shipments when your appointment arrives. The tools are professional-grade, not hardware-store gear, and our technicians explain what each piece does while it’s running in your home.
Common Duct Sealing Problems We See in Exton Homes
- Failed flex-duct connections at main trunks. The builder-grade flex duct installed in Exton’s 1980s – 2000s subdivisions degrades at the collar connections after two decades of thermal cycling. We cut back to solid material and reattach with proper supports so the duct doesn’t sag and separate again.
- Leaky returns pulling in attic dust and pollen. Exton’s heavy spring pollen season and fall leaf debris get drawn into return ducts through gaps in attic floor penetrations. Sealing these returns improves indoor air quality and reduces the load on your filtration system.
- Renovation-disturbed ductwork in finished basements. Homeowners in neighborhoods like Marchwood and Franklin Ridge have finished their basements over original duct runs, often compressing or kinking flex duct in the process. We locate the restriction and restore proper airflow without tearing out finished ceilings.
- Agricultural dust and mold spores in older systems. Many Exton subdivisions were built over former farmland, and we’ve found fine agricultural dust and mold spores lingering in ductwork decades after construction, particularly in neighborhoods off Route 100. Sealing the system prevents these particles from recirculating.
Pricing for Duct Sealing in Exton, PA
A typical whole-home duct sealing job in Exton runs $450 – $950. Smaller townhomes or partial-system repairs start around $350. Full-system sealing with insulation wrapping in a larger single-family home can reach $1,200 – $1,500 if attic access is limited or extensive remediation is needed.
What moves the number: the linear feet of ductwork, accessibility (finished basements and tight attics take longer), whether insulation replacement is included, and the severity of leaks found during pressure testing. We give you a written price before any work starts, and that price does not move at the door. One flat price per system, no per-vent pricing, no add-ons once we’re inside.
We also handle Air Duct Cleaning in Exton and Dryer Vent Cleaning in Exton if your system needs more than sealing. Call (361) 326-5060 for a free estimate.
We Also Serve Cities Near Exton
Our crews work throughout Chester County, including Downingtown, West Chester, Malvern, and Lionville. The same written pricing, same 365-Day Done Right Promise, same background-checked technicians apply in every town we serve.
Serving Exton, PA - Our Local Coverage Area
We’re based in the Exton 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 About Duct Sealing in Exton
We typically schedule Exton appointments within 3 – 5 business days, and our crews arrive inside the quoted window. Call (361) 326-5060 to check current availability.
We seal ducts across all Exton neighborhoods, from the townhomes near Main Street at Exton to the single-family homes in Marchwood, Franklin Ridge, and Whitford Hills, plus the older properties near the historic village core. If your home has ductwork, we can seal it.
We do not classify duct sealing as an emergency service, but our phones are answered by a live person 24/7 to schedule urgent appointments when a system failure has left you without heat or cooling. If the situation requires immediate temporary repair, we’ll prioritize your booking.
Exton pricing is comparable to Downingtown and Lionville, slightly below Main Line towns like Malvern where older homes with plaster walls and hard-to-access systems drive labor time up. A typical Exton whole-home seal runs $450 – $950.
Every duct sealing job is covered by our 365-Day Done Right Promise in writing. If a seal fails within one year, Hollis returns and makes it right at no charge, including a free second visit. This applies to all Exton work and is not prorated or limited to materials.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Exton and Chester County under The Garrison Standard.