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.
Before
After
Before
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Before
AfterFast, Reliable Duct Sealing Across Sanford
Duct sealing in Sanford typically runs $450 – $1,200 for most homes, with shared-system buildings and older metal ductwork landing toward the higher end. We’re Hollis Air Duct Cleaning, and our crews work Sanford regularly, from Goldsboro bungalows to newer subdivisions like Celery Estates and RiverBend. Scheduling is coordinated from our Orlando office, but the technicians who show up at your door know Sanford’s housing stock and its specific problems. Call (361) 326-5060 for a free estimate with a written price before any work starts.
Why Hollis Air Duct Cleaning Is Sanford’s Preferred Duct Sealing Company
We’ve been in business since 2004 as part of the Garrison Partners family, and our Sanford customers come back because we price in writing and stand behind the work. The 365-Day Done Right Promise means if a seal fails within a year, we return and make it right at no charge, including a free second visit. That’s not a verbal assurance; it’s on every job sheet.
Our technicians are background-checked and uniformed. You know who’s walking into your home before they arrive. They show up inside the quoted window, work by The Garrison Code, and leave the site clean.
Phones are answered by a live person 24 hours a day, 7 days a week. No voicemail loops, no callback queues, no waiting until Monday.
We know Sanford’s specific headaches: shared return plenums in multi-unit buildings, original galvanized ducts in historic downtown homes, and the debris that gets pulled into systems after hurricane-season outages. That local knowledge changes how we scope the job.
Duct Sealing Services in Sanford
Duct Sealing Services in Sanford address the leaks, gaps, and failed joints that let conditioned air escape into attics, crawl spaces, and wall cavities. In this market, the problem is rarely a single obvious tear. It’s more often a dozen small leaks at plenum seams, register boots, and chase penetrations, especially in homes with shared systems or original metal ductwork. A typical whole-house duct sealing job in Sanford runs $450 – $1,200 depending on system size, access, and whether we’re working with flexible duct or rigid galvanized lines.
Leak Detection and Pressure Testing
We start with a pressure test to quantify what you’re losing. Our techs seal off the registers, pressurize the system, and measure the leakage rate. In Sanford’s older homes near the historic downtown, we regularly see 25 – 35% leakage, which means a quarter of your conditioned air never reaches the rooms. The test gives us a baseline and a way to prove improvement after the work.
Mastic Sealing and Joint Rebuild
For accessible leaks, we apply duct sealing mastic, a water-based compound that remains flexible after curing. Unlike tape, which dries and fails in Florida’s heat, mastic holds. On original galvanized ducts with surface rust, we prep the metal and use specialized compounds rated for corroded substrates. We don’t just slap sealant on dirty metal. The prep takes longer, but the seal lasts.
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 Sanford
Duct Insulation in Sanford protects against the condensation that forms when cool supply air runs through hot, humid attic spaces. In this climate, uninsulated or poorly insulated ducts sweat constantly. That moisture drips onto ceiling drywall, breeds mold, and degrades the mastic seals we just applied. A typical duct insulation job in Sanford, whether wrapping existing lines or replacing degraded fiberglass, runs $600 – $1,800 depending on linear footage and attic access difficulty.
Vapor-Barrier Wrapping
We use insulation with an intact vapor barrier, sealed at seams with appropriate tape. In Sanford’s nearly year-round cooling season, this matters more than in northern markets where ducts only run half the year. The vapor barrier faces the outside, toward the attic air, to prevent moisture migration into the insulation where it would compress the R-value and breed biological growth.
Condensate Line Inspection
While we’re in the attic, we check the condensate drain. A clogged drain pan overflows and soaks duct insulation from the outside, ruining it fast. We clear the line if needed and note any slope problems. It’s not technically insulation work, but it’s part of doing the job by the book.
Trusted Brands We Service in Sanford
Our equipment roster includes Rotobrush rotary brush systems for mechanical agitation inside ducts, Nikro negative-air machines for controlled debris extraction, and filtration and sealing products from Abatement Technologies and Guardsman. We stock common parts and materials locally, so most Sanford jobs don’t wait on shipping. When a Goldsboro multi-unit needs a custom plenum rebuild or a RiverBend home needs specific flex duct diameter, we source it fast and get back on schedule.
Common Duct Sealing Problems We See in Sanford Homes
- Shared plenum leaks in multi-unit buildings. In dense downtown Sanford and Goldsboro, we regularly find that sealing only the visible supply and return ducts at the registers leaves the real leak paths open. The shared plenum seams and chase penetrations between units are where the conditioned air escapes, and they’re often buried in walls or ceilings.
- Wrong sealant on corroded galvanized metal. Original galvanized or bare sheet-metal ducts in early 20th-century Sanford homes have rust and debris that standard mastic won’t bond to. Using the wrong compound means the seal fails within a season as the metal continues to corrode underneath.
- Post-storm debris intake through compromised returns. After hurricane season power outages in Sanford, we often find that HVAC blowers have sucked in attic insulation and exterior debris through loose return connections. Sealing without cleaning and inspecting the full return path just traps that debris against the new seal.
- Dryer-vent stack sealing without full lint-path confirmation. On shared dryer-vent stacks in Sanford’s multi-unit buildings, sealing the run without confirming the full lint pathway from every unit can trap lint behind a new seal. That ramps up fire risk rather than reducing it.
Pricing for Duct Sealing in Sanford, FL
Whole-system duct sealing in Sanford typically costs $450 – $1,200. Single-family ranch homes with accessible attics and flex duct usually fall in the $450 – $750 range. Historic homes with original galvanized metal, shared systems requiring plenum work, or jobs needing extensive access through tight crawl spaces run $900 – $1,200. Duct insulation adds $600 – $1,800 depending on linear footage.
What moves the number: system size, duct material, access difficulty, and whether we’re addressing shared components. We don’t quote per-vent or teaser prices that balloon at the door. We give one flat price per system, agreed in writing before any work starts. You’ll see the same number on the invoice.
Call (361) 326-5060 for a free estimate. Our tech inspects, tests, and prices on-site. No obligation.
We Also Serve Cities Near Sanford
Our crews work throughout Seminole County and beyond. If you’re in Sanford or nearby Lake Mary, Oviedo, Longwood, or Winter Springs, we cover your area with the same written pricing and 365-Day Done Right Promise. Scheduling is coordinated from our Orlando office, with local technicians dispatched to your neighborhood.
Serving Sanford, FL - Our Local Coverage Area
We’re based in the Sanford 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 Sanford
Yes, and it’s often necessary. In Sanford’s multi-unit buildings, particularly near the historic downtown and in Goldsboro, we scope the work around common return plenums and shared vertical chases rather than treating your unit as an isolated system. We coordinate access with building management when needed, and we seal the shared seams that single-unit approaches miss. Call (361) 326-5060 to discuss your building’s layout.
Sanford’s humid subtropical climate means ducts sweat year-round, which degrades seals and breeds biological growth behind them. We use Abatement Technologies filtration and sealing products rated for high-humidity environments, and we always pair sealing with proper vapor-barrier insulation when ducts run through vented attics. The mastic compounds we select remain flexible in heat and humidity rather than drying brittle. Call (361) 326-5060 for specifics on your system.
Usually yes, but the prep is different. Original galvanized or bare sheet-metal ducts in Sanford’s early 20th-century homes often carry surface rust and debris that prevent standard sealant adhesion. We mechanically clean the metal, treat active corrosion, and use compounds formulated for compromised substrates. In some cases, partial replacement makes more sense than sealing failing metal. We price both options in writing before you decide. Call (361) 326-5060 for an inspection.
Yes, and they require different protocols. Shared dryer-vent stacks in Sanford’s denser housing must have their full lint pathway confirmed from every connected unit before any sealing occurs. Trapping lint behind a new seal creates fire risk. Our Duct Sealing team inspects the complete stack, cleans it if needed, and seals only after verifying clear airflow from all units. We document this on the job sheet.
Yes, if it’s done after proper cleaning and inspection. After Sanford’s frequent severe weather and power outages, we regularly find that blower motors have drawn attic insulation and exterior debris through compromised return ducts. Sealing without removing that debris traps it against the new seal and restricts airflow. Our process includes negative-air cleaning with HEPA filtration, camera verification, then sealing to NADCA standards. The homeowner in that 1920s Goldsboro bungalow told us the musty, humid smell in the hallway finally dropped, and the air handler stopped short-cycling on the shared side. Call (361) 326-5060 to schedule post-season inspection.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Sanford since 2004.