Whole-home duct cleaning
Dryer vent cleaning
Camera inspection
Sanitizing & deodorizingWhole-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.
Styles & brands we work with
- Whole-home duct cleaning
- Dryer vent cleaning
- Camera inspection
- Sanitizing & deodorizing
See the difference
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After
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Before
AfterHow Much Does Duct Repair & Sealing Cost in St. Louis?
Duct repair and sealing in St. Louis typically costs $350-$1,800, with most single-family homes landing between $450 and $900 for sealing leaks and reconnecting failed joints. Small fixes like re-taping a separated boot or sealing one accessible run often run $250-$450, while replacing damaged flex or sheet-metal sections across a whole system can push toward $2,500.
Those ranges cover labor, sealant, mastic, and standard fittings. The written estimate you get after an inspection sets the final price, because no two duct systems in St. Louis fail in the same way. Homes here deal with wide seasonal swings between humid summer air and dry winter heating, and that cycle finds every loose joint over time.
Duct Repair & Sealing Cost Breakdown (2026)
Here’s how the numbers break down by job type. These are typical St. Louis estimates for 2026, not quotes. Your written estimate after inspection is what counts.
| Job | Typical Cost Range | What It Covers |
|---|---|---|
| Sealing accessible leaks (mastic or tape) | $250-$550 | Taping and sealing gaps at boots, plenums, and accessible joints along exposed runs |
| Reconnecting a separated joint or boot | $200-$400 | Refastening and sealing a duct that has pulled loose at a register or transition |
| Repairing crushed or disconnected flex duct | $300-$700 | Replacing damaged sections of flex duct, retying, and sealing |
| Replacing a short run of sheet-metal duct | $450-$900 | Cutting out a damaged section and fitting a new one, sealed at both ends |
| Whole-system sealing (10-15 accessible connection points) | $700-$1,800 | Sealing a full set of boots, joints, and plenum connections throughout the accessible system |
| Duct repair combined with cleaning | $600-$2,000 | Cleaning first, then sealing and repairing the leaks found during cleaning |
| Extensive duct replacement (large home or attic system) | $1,500-$3,500+ | Replacing multiple damaged runs, often where flex duct has collapsed or been chewed through |
What drives cost up
The biggest cost driver is access. Ductwork buried in tight attic corners, behind finished ceilings, or under a low-clearance crawl space takes more labor than a clean, exposed basement run. Older homes in neighborhoods like Tower Grove South or Holly Hills often have original sheet-metal ducts with hand-cut joints that leak at every seam, so there’s more to seal. Homes with flex duct tend to cost more when sections have crushed or torn, because we’re replacing rather than just sealing. The size of the system matters too. A single-story ranch has fewer runs to work through than a two-story with two zones. And if you’re combining repair with cleaning or dryer vent work, the total adds up, but you’re paying for one visit instead of two.
We operate professional-grade Rotobrush and Nikro extraction systems, and we carry Air Duct Repair as a core part of what we do. That matters for pricing. When we clean St. Louis homes and find ducts that have pulled apart or collapsed, we can fix them on the same visit rather than leaving you to find a second contractor. One trip, one diagnosis, one repair.
What Affects Duct Repair & Sealing Pricing in St. Louis
Six things move the number up or down more than anything else:
- Home age and duct material. St. Louis has a broad mix of housing stock, from early-1900s city homes with original galvanized ductwork to newer subdivisions off Manchester Road with flex systems. Old metal ducts usually have more leaky joints to seal; newer flex has more sections that may need replacing rather than repairing.
- Access. Attics and crawl spaces in this climate get brutally hot and humid in summer and cold in winter, and low-clearance spaces slow the work. Ducts that are easy to reach take less time than ducts tucked behind coils, pipes, or framing.
- Number of leaks and problem spots. A single loose boot is a quick fix. A system that leaks at twenty joints needs sealing at every one, and labor adds up.
- Extent of damage. Sealing a gap is cheaper than replacing a crushed or disconnected run. Flex duct that an animal chewed through or that collapsed from a sagging hanger needs replacement, not just tape.
- System layout. Two-story homes with zoned systems, multiple return trunks, or equipment in a garage pull more ductwork than a compact single-story. More duct means more potential leak points and more time.
- Combining services. Repair pairs naturally with cleaning. If the system needs both, doing them together usually costs less than two separate visits, and cleaning can’t be done properly without sealing what it exposes.
How to Save on Duct Repair & Sealing
There’s a simple principle here: the more we can find and access during a single visit, the better your number. Practical ways to bring the cost down:
- Get the whole system assessed at once. Finding every leak and problem spot in one inspection prevents the back-and-forth of fixing one thing now and discovering three more next month.
- Pair repair with cleaning. A cleaning visit already has the system opened up. Sealing and repairing on the same trip saves the labor of setting up twice.
- Address leaks early. A loose joint that gets sealed for $250 today can pull apart further and cost more later if the duct tears or separates.
- Ask for the written estimate and read what’s included. Know whether the quote covers sealant, fittings, and the number of leak points, so nothing gets added later.
Every job starts with a free estimate. We inspect what’s actually there, tell you what needs sealing versus replacing, and put the price in writing before work starts. Call (877) 349-6189 for a free estimate.
FAQs – Duct Repair & Sealing Cost
How much does duct sealing cost in St. Louis?
Duct sealing in St. Louis typically costs $250-$550 for accessible leaks on a single run, and $700-$1,800 for sealing a whole accessible system at every boot, joint, and plenum connection. The written estimate sets the final price. Call (877) 349-6189 for an exact quote, estimates are free.
Is it cheaper to repair or replace ductwork?
Repair is almost always cheaper than replacing a whole system, and it’s the right call when the ductwork is sound but leaking or a few sections are damaged. Whole-system replacement in St. Louis typically runs $1,500-$3,500+, while targeted repair and sealing usually lands at $250-$1,800 depending on scope. We diagnose first and only recommend replacement when the duct can’t be sealed or repaired effectively. Call (877) 349-6189 for a free estimate.
How much does it cost to fix a crushed flex duct?
Replacing a crushed or disconnected section of flex duct in St. Louis typically costs $300-$700, depending on the length of the run and how hard it is to reach. Sealing an accessible joint runs less, around $200-$400. Call (877) 349-6189 so we can look at the specific run and give you a written number.
Can duct cleaning and repair be done in one visit?
Yes, and in most cases we handle both on the same visit. We clean the system with professional-grade equipment, and where we find leaks or damage, we repair and seal them right then. Combining the two in St. Louis usually saves you the cost of a separate trip. Call (877) 349-6189 to schedule your estimate.
Does sealing ductwork actually lower energy bills?
Sealing leaky ducts can reduce the air your heating and cooling system wastes, but the exact savings depend on how much leakage you have and how your home is laid out, so we won’t quote a percentage. What we can do is seal the leaks that are there and show you the difference. Call (877) 349-6189 for a free estimate on sealing your St. Louis home’s ductwork.
We also work with trusted air-quality brands including Honeywell and Aprilaire, and we use Abatement Technologies equipment for proper containment during cleaning, so the work is contained and HEPA filtered where it matters. If you’re curious what a thorough job looks like before you commit, read up on Bellmont Air Duct Cleaning and how we approach the whole problem, not just part of it.
If your ducts are leaking, pulled apart, or crushed, the cost depends on how much needs sealing and how hard it is to reach. You’ll know what that number is before we start. Call (877) 349-6189 for a free estimate. We answer 24/7. Fast dispatch from 7am to 7pm, Sunday through Friday. Our technicians have up to 9 years of experience, and we bring the right professional-grade tools to a job rather than improvising. If it’s ducts, we clean, repair, and seal them. That’s all we do.
Written by the team at Bellmont Air Duct Cleaning.
Pricing reflects the St. Louis market as of 2026. Bellmont Air Duct Cleaning offers free estimates – call (877) 349-6189.
What Our Customers Say
"Did the dryer vent while they were here for a small add on price. The dryer now finishes a load in one cycle instead of two."
- Malik Bryant"Quoted per system rather than the bait and switch per vent pricing everybody else in town uses. The number I was told on the phone was the number on the invoice."
- Whitney Sutton"Fair price and thorough work. They ran about an hour and a half past the estimated finish time, so don't schedule anything tight after."
- Steve Norris