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
Before
After
Before
After
Before
AfterHow Much Does Duct Repair & Sealing Cost in Boulder?
Duct repair and sealing in Boulder typically runs $350 to $850 for a single accessible run, and most whole-home sealing jobs land between $800 and $2,400. Small fixes like reconnecting one joint or replacing a short flex section fall in the $350-$450 range, while repairs behind finished ceilings or under a slab push costs higher. We set the final price per job with a written estimate after we scope the actual ductwork, because Boulder homes vary so much in age and layout.
Those numbers reflect the local market as of 2026. Leaky, disconnected ductwork drains a forced-air system quietly: it cools the crawlspace instead of the bedroom, pulls attic dust into the supply, and drives up the run time on your furnace. We’d rather fix the ducts than clean around a problem, which is why we offer Boulder Duct Cleaning and repair as separate jobs under one contractor.
Duct Repair & Sealing Cost Breakdown (2026)
Here’s what the main line items cost in Boulder this year. Ranges assume average access; a run sealed deep inside a finished wall or a low-clearance crawlspace adds labor and may pull the price toward the top of each band.
| Line item | Typical 2026 range |
|---|---|
| Reconnect a single disconnected joint or boot | $350 – $450 |
| Seal visible joints and seams with mastic or foil tape on one run | $300 – $500 |
| Replace a section of torn or crushed flex duct | $400 – $700 |
| Rebuild damaged rigid metal trunk or branch | $550 – $900 |
| Whole-home duct sealing (aeroseal-style or manual mastic) | $800 – $2,400 |
| Add a return air path or fix undersized return | $600 – $1,200 |
| Repair behind finished drywall or ceiling (patch + access) | $500 – $1,500 in labor, above the duct repair itself |
| Insulate exposed runs in crawlspace or attic | $600 – $1,800 |
What pushes a job up? Access is the biggest lever. A run we can reach from a crawlspace hatch is quick work; a run above a vaulted ceiling means cutting access and patching it back. Older duct systems in Boulder’s pre-1960 housing stock often mix rigid galvanized trunk with later flex branches spliced in, so you may be sealing three different materials in one home. Duct design also matters: undersized returns and long runs to a second story need more than caulk, and those are the ones that climb into the four-figure range. Pulling a job down? A cluster of leaks in one accessible location can often be sealed in a single visit for the low end of the sealing band.
We build every estimate the same way: measure the run footage, note the material, and price the repair and sealing together so you see the whole scope before we start. If you’ve got air quality exposure – renovation dust, seasonal allergies, mold spores in a damp crawlspace – we can also quote air duct cleaning as part of the same visit, since we use Rotobrush contact-cleaning and Nikro negative-air HEPA equipment on every job.
What Affects Duct Repair & Sealing Pricing in Boulder
- Access to the duct run. Crawlspace and attic access is straightforward; runs buried in the floor assembly or above finished ceilings need drywall work, which adds labor. Boulder homes with flat-roof or low-pitch rooflines often have very tight attic clearance, so a technician has to work slowly in close quarters.
- Material mix. Rigid galvanized duct seals differently than flex; a run that’s had flex spliced into rigid trunk by a well-meaning homeowner takes longer to seal and to inspect.
- Number of leaks and disconnections. One boot pop is a small job. Twenty leaks across multiple trunks is a whole-home sealing scope with a test-and-verify step at the end.
- Whether the system is undersized. If a room never gets comfortable because the return is too small, that’s a design fix, not a seal-and-go job, and the price reflects it.
- Duct insulation condition. Exposed runs in a cold crawlspace lose heat before the air reaches the register. Re-insulating is worth quoting alongside repair if the wrap is torn or missing.
- Presence of a whole-home filtration system. Homes running Honeywell or Aprilaire filtration tie into the ductwork, and sealing around the filter cabinet and bypass is part of the repair. We’re trained on both systems and can check the cabinet seal while we’re there.
- The Boulder climate. Cold, dry winters and warm summers mean the system runs long hours; every leaky joint bleeds conditioned air for more of the year than in a mild climate, which is why sealing pays back faster here than the raw line item suggests.
One thing we always check while we’re in the ductwork: if you have a dryer vent run that’s separate from the HVAC ducts, that’s its own fire-safety item, and we treat it that way. Short, lint-clogged dryer ducts are a documented cause of residential fires, and a dryer vent cleaning is a standalone service, not an add-on we mention to run up the ticket.
How to Save on Duct Repair & Sealing
The best way to keep duct repair costs down is to catch the leaks before they cascade into a bigger fix. A small disconnected joint left alone can blow insulation off nearby ductwork and lead to condensation and rust on the metal. Here’s what actually moves the number:
- Bundle sealing with cleaning. When we clean with Rotobrush contact equipment and then locate leaks, we’re already in the ductwork. Sealing on the same visit costs less than a separate trip out.
- Fix access first, then seal. If you know a run needs work, tell us upfront and we’ll build the access cost into one estimate rather than two.
- Get the written estimate before work starts. We price per job, so you’ll see the scope and the final number on paper before a technician lifts a tool. Estimates are free.
- Don’t wait for a comfort complaint. Sealing before the furnace runs all winter is cheaper than repairing ductwork that’s been flexing and leaking for two seasons.
- Ask about the duct cabinet seal. If you run a Honeywell or Aprilaire system, the cabinet seal at the filter is a common leak point – a small repair, not a whole-home scope.
- Check the dryer vent in the same visit. Not a duct repair saving directly, but a clogged dryer vent speeds up lint accumulation throughout the system, and clearing it prevents a bigger cleaning job later.
We also offer Guardsman-brand protective treatments as part of the full-service scope, so if you’re dealing with mold spores or heavy contamination in a damp crawlspace, the treatment and the sealing can be quoted together. For contamination-level situations, we have Abatement Technologies equipment on hand to handle fine particulates and mold spores that go beyond routine dust removal. Call (877) 550-7147 to talk through the scope before you commit to anything.
Can Duct Repair and Sealing Be Done the Same Day in Boulder?
Most single-run repairs and accessible joint sealing are same-day work if you call early. Whole-home sealing is usually scheduled as its own visit since it takes longer and needs a test step at the end to verify results. If you’re not sure which category your job falls into, call and we’ll help you figure it out.
The way to know is simple: if the problem is a disconnected joint, a torn flex section, or a boot that’s come loose from a register, it’s generally a same-day fix. If it’s a whole-house air leakage issue or an undersized return, that’s a scoped job. Call (877) 550-7147. We answer 24/7. Fast dispatch from 7am to 7pm, Sunday through Friday.
Does Duct Sealing Pay for Itself in Boulder?
Leaky ducts can lose a meaningful share of conditioned air before it reaches the room, and in Boulder’s cold winters and warm summers the system runs enough hours that the loss adds up on the utility bill. Sealing a moderately leaky system often pays back over a few seasons through lower run time, though we won’t promise a specific percentage because every home’s duct leakage is different.
What we can tell you is where the leaks are. Using a leak check before and after sealing, we can show you what was leaking and what’s been fixed. That’s not a sales pitch; it’s the only way to know the job worked. If you’re weighing sealing against a bigger repair, get the written estimate first and we can walk through the numbers together. A call to (877) 550-7147 gets the conversation started.
What’s the Difference Between Duct Repair and Duct Sealing?
Duct repair fixes broken ductwork – reconnecting separated joints, replacing crushed or torn sections, and rebuilding damaged rigid metal. Duct sealing closes the smaller leaks at joints, seams, and boots that aren’t fully broken but are leaking air. Most homes need both, and we quote them as one scope when that’s the case.
This matters for pricing because a broken run isn’t just sealed; it’s fixed first, then sealed, then tested. If your HVAC contractor told you to “just seal the ducts” and there’s a disconnected joint underneath, sealing alone won’t solve the problem. We clean and we repair, which means we identify structural problems before we leave a cleaned system in place.
When Should Duct Repair Be Skipped in Favor of Replacement?
Replacement beats repair when the ductwork is sized wrong for the system, when more than a third of the runs are crushed or disconnected beyond practical repair, or when the duct material is degraded to the point that sealing won’t hold. Every other case, repair is usually the better move. A whole-home duct replacement is a much larger project than sealing, and it’s not always necessary.
For homes running Honeywell or Aprilaire whole-home filtration, the ducts and the filtration cabinet are designed together. A partial replacement that doesn’t account for the cabinet can cause more leaks than it fixes. We work with both systems and will tell you plainly if replacement is the honest answer. Call (877) 550-7147 to review the scope.
Is Duct Sealing Worth It in Boulder’s Climate?
Yes, generally. Boulder’s dry air and temperature swings put a lot of demand on a forced-air system, and leaky ducts leak in both heating and cooling season. A crawlspace duct that’s leaking in January sends warm air into a cold space; the same leak in July wastes cool air. Sealing protects against both directions.
One thing to flag: if your crawlspace is damp, sealing a duct system that sits in moisture can trap the problem rather than fix it. In those cases we may recommend a cleaning with Nikro negative-air HEPA equipment and a Guardsman protective treatment before sealing, so the ducts are clean and dry when they’re closed up. We’ll explain the order of operations when we scope the job.
Safety: What to Know Before Touching Your Ductwork
Most duct sealing is careful, low-risk work, but a few parts of a forced-air system are genuinely dangerous to handle without training. A gas furnace’s flue connection and the heat exchanger are not a place to run foil tape or mastic around. Sealing a flue or a combustion-air path can cause carbon monoxide to back-draft into the home – a serious hazard. If you see a disconnected flue or evidence of combustion gas near the ductwork, stop and call a licensed gas technician, not a duct repair crew. We don’t touch gas lines or flues; we flag them and get the right trade out, and we recommend you do the same.
The second thing: never enter a crawlspace or attic with exposed electrical connections, and never run a consumer vacuum into ductwork that may be contaminated with mold. A wet/dry shop vac will aerosolize mold spores into the living space. Contamination-level situations need negative-air HEPA equipment, which is exactly what our Nikro systems are for.
Duct Repair & Sealing Cost FAQs
How much does duct sealing cost in Boulder?
Duct sealing in Boulder typically costs $800 to $2,400 for a whole-home scope, and $300 to $500 for a single run. The price depends on how many leaks we find and whether the runs are accessible. Call (877) 550-7147 for a free estimate – the written number is the final price.
How much does duct repair cost in Boulder?
Duct repair in Boulder typically ranges from $350 to $900 depending on what’s broken. A single disconnected joint or a boot repair is usually around $350-$450. Rebuilding a damaged metal trunk can run $550-$900. Call (877) 550-7147 – estimates are free and we’ll scope the actual run.
Is it cheaper to repair or replace ductwork in Boulder?
Repair is almost always cheaper than replacement when the ducts are structurally sound and sized correctly. Replacement is only the better answer when the system is undersized, most runs are crushed, or the duct material is worn out. Whole-home replacement is a much bigger project, so get a written estimate for repair first – we’ll tell you honestly if replacement is the right call.
Can you seal ducts in a crawlspace or attic in Boulder?
Yes. Crawlspaces and attics are where most duct leaks live, and sealing them there is standard work. In Boulder, tight attic clearances and cold crawlspaces add some labor cost but don’t change the approach. We bring the right equipment for a low-clearance environment.
Does duct sealing require a permit in Boulder?
Most duct sealing and repair is not a permitted activity, but a full duct system replacement or a major alteration often is. Ask the City of Boulder building department to confirm before work starts. We can walk you through what we’re doing so you can ask the right question. Call (877) 550-7147 to discuss scope.
Get a Free Duct Repair & Sealing Estimate in Boulder
If you’ve got a room that never gets comfortable, a crawlspace full of ductwork you haven’t looked at, or a system that’s blowing dust into the house, sealing and repairing the ducts is a practical place to start. We clean with Rotobrush and Nikro equipment, we repair what we find, and we’re trained on Honeywell and Aprilaire systems so the fix fits the home. Our technicians have up to 9 years of experience with duct repair and sealing work.
Call (877) 550-7147 to schedule a free estimate. We answer 24/7. Fast dispatch from 7am to 7pm, Sunday through Friday. If your call comes in outside those hours, we’ll book it into the next opening. If you’re looking for our full range of services in Boulder, we’re glad to send the same crew to scope cleaning, repair, and dryer vent work together.
Pricing reflects the Boulder market as of 2026. Boulder Duct Cleaning offers free estimates – call (877) 550-7147.
What Our Customers Say
"Ran a negative air machine on the whole system rather than the shop vac on a stick that the cheap outfit down the road uses. Showed me the before and after photos from inside the trunk line and it was genuinely disgusting."
- Megan Parker"Found a disconnected run in the crawlspace while they were in there and told me about it rather than cleaning around it."
- Marisol Castillo"My wife's allergies had been bad in this house since we moved in. It's been two months since they did the ducts and it's noticeably better. Not a miracle, but real."
- Eric Pruitt