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.
Fast, Reliable Duct Sealing Across Sharon Hill
If your Sharon Hill home has rooms that never heat evenly, utility bills that climb every winter, or a basement duct chase that whistles on windy days, the problem is likely air leaking from your ductwork before it ever reaches your vents. Duct sealing closes those gaps permanently. In Sharon Hill, where many homes still run on original or retrofitted ductwork from the mid-20th century, this is one of the most cost-effective improvements you can make to your HVAC system. Call (361) 326-5060 for a free estimate. Our Duct Sealing team dispatches from our Philadelphia office and serves Sharon Hill directly.
Why Hollis Air Duct Cleaning Is Sharon Hill’s Preferred Duct Sealing Company
We’ve been working in Delaware County long enough to know the difference between a Folcroft ranch and a Sharon Hill rowhome built in 1925. That matters because the ductwork is completely different, and so is the sealing approach. Our technicians are background-checked, uniformed, and trained to The Garrison Standard, which means arriving inside the quoted window, pricing in writing before any work starts, and leaving the site clean. Every repair we perform is backed by our 365-Day Done Right Promise. If the seal fails within a year, we come back and make it right at no charge, including a free second visit. Roy Castellanos leads our operation, and our phones are answered by a live person 24 hours a day, seven days a week. No voicemail loops, no callback queues.
Air Duct Sealing in Sharon Hill
Air Duct Sealing in Sharon Hill addresses a specific problem: conditioned air escaping through gaps, cracks, and disconnected joints in your duct system before it reaches your living spaces. In the borough’s older housing stock, we frequently find ductwork that was installed when coal heat was standard and later adapted for forced-air systems, often with seams that were never properly sealed or have dried out over decades. The result is heated or cooled air bleeding into basements, crawl spaces, and wall cavities while your thermostat keeps calling for more.
A typical whole-home duct sealing job in Sharon Hill runs $850 – $1,800 depending on system size, accessibility, and whether we need to address crushed or disconnected sections found during inspection. Homes near Chester Pike with full basements usually allow easier access than rowhomes with tight crawl spaces off Sharon Avenue, which can add labor time.
What the Sealing Process Involves
We start with a pressure test to measure total duct leakage, then seal accessible joints and seams with mastic, a thick, durable paste that remains flexible as metal expands and contracts. For smaller gaps in hard-to-reach chases, we apply aerosol sealant that travels through the duct system and bonds at leak points. We finish with a second pressure test so you see the improvement in writing.
When Sealing Becomes Essential
Sharon Hill’s humid summers and cold winters push HVAC systems hard year-round. If your second floor stays stifling in July despite the AC running constantly, or your first floor is frigid while the basement ductwork feels like a furnace, those are classic signs of significant leakage. We also recommend sealing before any new equipment installation. A tight duct system lets a properly sized unit perform as designed rather than compensating for losses.
Duct Sealing Services in Sharon Hill
Duct Sealing Services in Sharon Hill from Hollis Air Duct Cleaning cover everything from spot repairs on accessible basement runs to full-system sealing for homes with ductwork routed through unheated attics and crawl spaces. Many of the borough’s rowhomes on Bartram Avenue and Maple Avenue have ducts that pass through original chases with no insulation, meaning leaks don’t just waste energy, they pull in dust, fiberglass, and whatever else occupies those wall cavities. Our crews use professional-grade equipment from Rotobrush and Nikro, the same negative-air and rotary systems commercial contractors rely on, to access and seal these problem areas thoroughly.
We also handle Air Duct Cleaning in Sharon Hill and Dryer Vent Cleaning in Sharon Hill, which pairs well with sealing work. Cleaning first removes legacy coal ash, dust, and mold that sealing would otherwise trap inside the system.
Material and Method Selection
For Sharon Hill’s older metal ductwork, we prefer mastic over foil tape. Tape degrades in the temperature swings of unheated spaces; mastic lasts. On flex duct sections that have pulled loose from collars, we resecure with proper straps and seal the connection. We don’t use duct tape. Despite the name, it fails within months in HVAC applications.

Post-Sealing Verification
Every job ends with documentation. You receive the before-and-after pressure test results, a written summary of what was sealed, and your 365-Day Done Right Promise in writing. If airflow problems return or a seal fails, we come back at no charge.

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.
Trusted Brands We Service in Sharon Hill
Hollis crews work with professional-grade equipment and materials from Abatement Technologies, Guardsman, and Rotobrush, plus filtration products from Honeywell and Aprilaire. We stock mastic, aerosol sealant, and replacement fittings locally so Sharon Hill jobs don’t wait on parts. That matters in a borough where a crushed duct section behind a plaster wall might need a custom transition piece fabricated on site. Our Nikro negative-air machines keep dust contained during the work, particularly important in older homes where decades of accumulated particulate can disturb easily. When we recommend a filtration upgrade after sealing, we’re talking about products we’ve installed and warrantied, not catalog suggestions.
Common Duct Sealing Problems We See in Sharon Hill Homes
- Disconnected joints in crawl space runs. In rowhomes near the Darby border, we regularly find flex duct that has pulled completely away from supply boots in damp, low-clearance crawl spaces. The homeowner feels weak airflow upstairs while the crawl space stays comfortable. Sealing and resecuring these connections typically recovers 15 – 25% of lost capacity.
- Cracked mastic on original metal ductwork. Homes built before 1950 often have ducts that were sealed once, decades ago, with material that has dried and flaked away. Winter heating cycles expand and contract the metal, opening gaps that pull basement air into the system. We remove the old material and reseal with modern, flexible mastic designed for temperature cycling.
- Leaky return chases in unlined wall cavities. When Sharon Hill homes were converted from coal to forced air, contractors sometimes used wall studs as return pathways without proper duct lining. These chases draw air from inside walls, including dust, old insulation, and in some cases, residual coal soot. We seal accessible portions and recommend full duct lining where the condition is severe.
- Crushed sections from settling or renovation damage. In the borough’s older housing stock, particularly near Chester Pike, we’ve found supply lines flattened by settling foundations or previous owners’ DIY projects. These restrictions create backpressure that blows out seals elsewhere in the system. We replace damaged sections and seal the new connections properly.
Pricing for Duct Sealing in Sharon Hill, PA
A typical duct sealing job in Sharon Hill runs $850 – $1,800 for a whole-home system. Smaller spot repairs on accessible basement ductwork start around $350. What moves the price: how much of your system is accessible without cutting into walls, whether we find disconnected or crushed sections that need repair before sealing, and the overall linear footage of ductwork. Rowhomes with tight crawl spaces off Sharon Avenue or Bartram Avenue take more time than homes with full basements near the Folcroft line. We give you one flat price per system, agreed in writing before any work starts. No per-vent pricing, no add-ons once the technician is inside. Estimates are free. Call (361) 326-5060 to schedule.
We Also Serve Cities Near Sharon Hill
Our crews work throughout Delaware County. If you’re in Sharon Hill or nearby Darby, Folcroft, Glenolden, or Clifton Heights, we cover your area with the same written pricing and 365-Day Done Right Promise. Dispatch and scheduling are coordinated from our Philadelphia office.
Serving Sharon Hill, PA - Our Local Coverage Area
We’re based in the Sharon Hill 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 Sharon Hill
We typically schedule Sharon Hill appointments within 3 – 5 business days, with some next-day availability depending on the season. Our Philadelphia office dispatches crews directly to the borough. Call (361) 326-5060 to check current openings.
Yes. We work across the borough, from the rowhomes near Chester Pike and Bartram Avenue to the detached houses closer to the Glenolden border. The ductwork challenges differ by housing type, and our crews are familiar with both.
We don’t classify duct sealing as an emergency service, but our phones are answered by a live person 24/7. If a disconnected duct is causing a complete system failure in extreme weather, we’ll prioritize getting a technician to your Sharon Hill home as soon as possible.
Prices are consistent across our Delaware County service area. Sharon Hill’s older housing stock sometimes requires more repair work before sealing, which can push some jobs toward the higher end of our $850 – $1,800 range compared to newer construction in Folcroft or Glenolden. We price by the actual condition of your system, not your ZIP code.
Every duct sealing job is covered by our 365-Day Done Right Promise in writing. If any seal fails or airflow problems return within a year, Hollis comes back and makes it right at no charge, including a free second visit. There is no expiration fine print or service fee for warranty calls.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Sharon Hill as part of the Garrison Partners family since 2004.




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