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 Catonsville
Duct sealing in Catonsville typically runs $450 – $1,200 for a whole-home job, depending on how much of the system needs attention and whether we’re working with original galvanized metal or newer flex runs. Our Duct Sealing crews serve Catonsville from our Baltimore office, and we know the local housing stock well enough to price it accurately before we start. If you’re smelling musty air from your vents months after the last heavy rain, or your energy bills have climbed without explanation, there’s a good chance your ducts are leaking conditioned air into damp crawl spaces and drawing that moisture back into your living space. Call (361) 326-5060 and we’ll send a technician with a camera, a moisture meter, and a written price.
Why Hollis Air Duct Cleaning Is Catonsville’s Preferred Duct Sealing Company
We’ve been working in Catonsville since 2004, and the Garrison Partners family has built our reputation here on showing up when we said we would and leaving the job site clean. Our technicians are background-checked, uniformed, and trained to The Garrison Standard, which means they arrive inside the quoted window, price the work in writing before touching anything, and document everything with photos. That discipline matters especially in Catonsville, where post-flood duct work often involves insurance claims and homeowners need paperwork that holds up. The 365-Day Done Right Promise covers every repair we make: if it fails within a year, we come back and make it right at no charge, including a free second visit. Phones are answered by a live person 24 hours a day, 7 days a week, so you’re not waiting through a callback queue when you’re dealing with wet ducts.
Duct Repair in Catonsville
Duct Repair in Catonsville usually means fixing sections of original galvanized sheet-metal trunk line or replacing damaged flex runs that past HVAC contractors added to older systems. We see this most often in the pre-1950s core along Frederick Road and in neighborhoods like Paradise and Catonsville Manor, where the original metalwork is solid but connections have loosened, seams have opened, or flood damage has compromised specific sections. A typical duct repair in Catonsville runs $280 – $650 for localized work, or $800 – $1,400 if we’re replacing multiple trunk sections or addressing water-damaged runs after a wet spring.
Galvanized Metal Restoration
Original galvanized ducts in Catonsville’s older homes can outlast the house itself if they’re kept dry and sealed properly. We mechanically clean the interior, treat any surface corrosion, and seal seams with mastic rated for metal substrates. The key is confirming the interior is dry first. Sealing over damp metal traps moisture and accelerates corrosion from the inside out.
Flex Run Replacement
The flex duct added during past HVAC upgrades in Catonsville’s 1950s-70s ranches and split-levels is often where we find the real damage. It’s lighter, cheaper, and far more vulnerable to flooding and rodent intrusion than the original metal. We replace compromised flex with new insulated flex or rigid metal where access allows, then seal all connections back to the trunk.
Air Duct Sealing in Catonsville
Air Duct Sealing in Catonsville addresses the leaks that let conditioned air escape into your attic, crawl space, or basement while pulling humid, musty air back into your supply. In Catonsville’s humid mid-Atlantic climate, this isn’t just an efficiency problem. It’s a moisture problem. Hot, muggy summers create condensation on cool duct surfaces in unconditioned spaces. Cold, damp winters do the same when warm air hits cold metal. That constant wet-dry cycle feeds mold and dust mites inside the system. A typical whole-home air duct sealing job in Catonsville runs $450 – $1,200, with smaller partial-system jobs starting around $280.
Mastic Sealing vs. Tape
We use duct sealing mastic, not foil tape, on every metal joint in Catonsville homes. Mastic is a thick, fiber-reinforced compound that brushes into seams and hardens into a permanent, flexible seal. Tape dries out, peels, and fails within a few years in the humidity Catonsville ducts experience. We apply mastic under negative pressure to verify the seal holds before we close the access.
Post-Flood Sealing Protocol
After water intrusion, we never seal ducts until camera inspection and moisture readings confirm the interior is dry throughout the run. In Catonsville’s tree-heavy older core, where floor ducts sit near damp crawl spaces, this step gets skipped by crews in a hurry. We document dryness with photos and meter readings before any sealant touches metal. Wet metal sealed is ruined metal.
Trusted Brands We Service in Catonsville
Our Catonsville crews work with professional-grade equipment from Rotobrush, Nikro, and Abatement Technologies, and we stock filtration and sealing products from Aprilaire and Guardsman for fast turnaround on local jobs. The rotary brush systems handle the mechanical cleaning that galvanized metal trunk lines need after years of sediment buildup. The negative-air machines let us contain debris and moisture during post-flood source removal. For homeowners who want upgraded filtration after we’ve sealed the leaks, we carry Aprilaire media air cleaners and Guardsman UV systems, installed with the same written pricing and 365-Day Done Right Promise that covers all our work.
Common Duct Sealing Problems We See in Catonsville Homes
- Blow-and-go cleaning that ignores standing water. After wet springs like 2018, we find crews who vacuumed the visible duct interior but never checked the low points of galvanized trunk lines where water pools. The mold reservoir stays. The musty smell returns within weeks, usually stronger than before.
- Sealing ducts that are still wet inside. Mastic applied over damp galvanized metal traps moisture against the surface and accelerates corrosion. We’ve opened “sealed” ducts in Catonsville Manor homes to find rust holes where smooth metal had been just two years earlier.
- Insurer rejecting claims for lack of documentation. Insurance adjusters need proof that ductwork was non-salvageable, not just dirty. We provide dated photos, moisture meter readings, and camera footage showing standing water or saturated insulation inside the run. Without that documentation, homeowners eat the replacement cost.
- Flex runs added during past HVAC replacements that sag and pool condensation. In Catonsville’s 1960s split-levels, long flex runs with poor support create low spots where summer humidity condenses. The duct leaks at the sag, and the standing water never drains. We replace the sagging flex with properly supported runs and seal all connections.
Pricing for Duct Sealing in Catonsville, MD
Whole-home duct sealing in Catonsville typically runs $450 – $1,200. Partial-system sealing, where we’re addressing specific problem zones like a damp crawl-space trunk line or a set of leaky floor ducts, usually falls between $280 – $650. Duct repair, when we’re replacing damaged sections of metal or flex, ranges from $280 – $650 for localized work up to $800 – $1,400 for more extensive replacement. What moves the price: how much of the system we can access without cutting drywall, whether we’re working with original galvanized metal or newer flex, and whether post-flood conditions require source removal and drying before any sealing can begin. We give you one flat price per system, agreed in writing, before any work starts. No per-vent pricing. No add-ons at the door. Estimates are free. Call (361) 326-5060.
We Also Serve Cities Near Catonsville
Our Baltimore office dispatches crews throughout the metro area. We regularly do Duct Sealing in Catonsville and also serve Elkridge, Baltimore, Pikesville, and Randallstown with the same written pricing, background-checked technicians, and 365-Day Done Right Promise.
Serving Catonsville, MD - Our Local Coverage Area
We’re based in the Catonsville 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 Catonsville
We run a camera inspection of the full supply and return system and take moisture readings at multiple points inside the ductwork. If the interior is dry, the metal shows no active corrosion from prolonged wetness, and the insulation is intact and dry, we can mechanically clean and seal the existing ducts. If we find standing water, saturated insulation, or mold growth that has compromised the metal surface, we document it with photos and meter readings for your insurer and recommend replacement of those sections. Call (361) 326-5060 to schedule the inspection – estimates are free.
Yes, often they can, but only after we confirm they’re truly dry inside and out. Galvanized sheet metal in Catonsville Manor homes is heavier-gauge than modern flex and can withstand cleaning and resealing if it hasn’t sat wet for so long that the zinc coating has failed and rust has pitted through. We check with borescope cameras and moisture meters, then dry the runs with controlled airflow before applying mastic. If the metal is sound, sealing restores performance for years. If rust has compromised the integrity, we document it and replace the failed sections.
The smell is almost always mold or mildew growing inside ductwork that took on water and never dried properly. In the pre-1950s core near Frederick Road, original floor ducts and trunk lines run through crawl spaces that stay damp long after surface water recedes. Standard cleaning doesn’t reach the standing water in low spots of galvanized runs or the saturated insulation wrapped around them. We find the wet zones with cameras, remove the contaminated material under negative pressure, dry the remaining metal thoroughly, and seal only after moisture readings confirm the system is dry.
Insurers cover duct replacement when you can prove the damage was direct, physical, and made the ductwork non-salvageable. We provide that proof: dated photos of standing water inside the run, moisture meter readings above industry-standard thresholds, camera footage showing saturated insulation, and a written assessment distinguishing cleanable metal from material that must be replaced. Adjusters reject claims when contractors only say the ducts “seem wet” or provide a cleaning invoice with no documentation. Our process is built to give adjusters what they need to approve the claim.
Duct cleaning removes debris, dust, and mold from inside the ductwork. Duct sealing closes the leaks that let air escape and moisture enter. In Catonsville’s humid climate, you often need both: cleaning addresses what’s already inside, and sealing prevents new moisture from getting in through gaps at joints, connections, and access points. We frequently clean and seal in sequence, especially after flood events where leaks have allowed water intrusion. The combination is what stops the musty smell from coming back. Call (361) 326-5060 and we’ll assess whether your system needs one, the other, or both.
Ready to stop losing conditioned air to your crawl space and start breathing air that doesn’t smell like last spring’s flood? Call Hollis Air Duct Cleaning at (361) 326-5060 for a free estimate. We’ll send a background-checked, uniformed technician who arrives inside the quoted window, prices the work in writing before touching anything, and documents every step so you know what was done and why. Every job is backed by our 365-Day Done Right Promise: if it’s not right, we make it right at no charge, including a free second visit.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Catonsville since 2004.




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