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.
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AfterHow Much Does Duct Repair & Sealing Cost in Los Angeles?
Duct repair and sealing in Los Angeles typically costs $450 to $2,800, with most single-family homes landing between $650 and $1,400 for a full seal-and-repair visit. Small fixes like reconnecting a single loose joint or patching one torn flex run usually run $180 to $400. Larger jobs involving multiple trunk-line leaks, attic re-routing, or sealing an older 1970s ranch home in the Valley can climb past $3,000, especially when access is tight.
That’s the short answer. What sets your actual number is how many leaks we find, how hard they are to reach, and whether the system needs both sealing and repair or just one. Morton’s Air Duct Cleaning provides a written price before any work starts, so you’ll know the exact figure before a single tool comes out of the truck.
Key Takeaways
- Most Los Angeles homes fall between $650 and $1,400 for duct repair and sealing combined.
- A single small leak patch runs $180 to $400; whole-home aero-sealing runs $1,200 to $2,800.
- Older homes in areas like Sherman Oaks, Highland Park, and Mid-City tend to have more leaks because of decades of attic heat.
- Every Morton’s visit comes with shoe covers, drop cloths, and a photo of the clean-up before we leave.
- Free estimates, written price upfront, and a 365-Day Done Right Promise on every job.
Duct Repair & Sealing Cost Breakdown (2026)
Here’s how the numbers shake out across the Los Angeles market for 2026. These ranges reflect real jobs we’ve priced and completed across LA County, not national averages pulled from a database.
| Service | Typical Price Range | Notes |
|---|---|---|
| Single leak patch or joint reconnection | $180 - $400 | Best for one isolated failure, often at a boot or collar |
| Sectional duct replacement (5-15 ft) | $300 - $700 | Torn flex runs, crushed sections, rodent-chewed segments |
| Whole-home mastic sealing | $650 - $1,400 | Hand-sealed at every accessible joint and seam |
| Aero-sealing (pressurized sealant) | $1,200 - $2,800 | Seals leaks you can’t reach by hand; best for 20+ year-old systems |
| Trunk line repair or re-route | $800 - $1,800 | Often needed when a remodel or HVAC upgrade leaves ducts mismatched |
| Attic or crawlspace duct re-support | $350 - $900 | Sagging ducts, disconnected hangers, kinked flex runs |
| Register boot sealing (per boot) | $45 - $85 each | Most homes have 10-20 of these; bundled discounts apply |
| Dryer vent sealing at the wall | $120 - $275 | Often paired with a dryer vent cleaning visit |
What pushes cost up
Attic heat in Los Angeles is the single biggest factor. Ducts running through a 140°F attic in the San Fernando Valley in August have been cooked for decades, and the tape and mastic that sealed them in 1988 are now powder. Homes built before 1985, and there are plenty of them in neighborhoods like Highland Park, Echo Park, and Pacoima, almost always need more work than a 2015 build in Playa Vista.
Access matters too. A leak you can reach standing up in a garage ceiling takes 20 minutes. A leak buried under blown-in insulation in a low-pitch attic above a Mid-City bungalow takes two hours and a second technician. That said, we never bill for time-wasting. Our written price is based on the scope we find, not the clock.
System size, duct type (rigid metal vs. flex), and the presence of asbestos-era materials in pre-1975 homes all affect the total. If you want to understand what a repair looks like in practice, our Duct Repair & Sealing in Los Angeles page walks through the actual process we follow.
What Affects Duct Repair & Sealing Pricing in Los Angeles
- Home age and neighborhood. A 1920s Craftsman in Koreatown and a 1990s tract home in Northridge are two different jobs. Older homes have more joints, more disconnected sections, and often no original mastic left to build on.
- Attic conditions and roof pitch. Low-pitch roofs with 12-inch clearance in the older parts of South LA make every repair slower. Steep-pitch roofs mean more careful staging to reach attic access safely.
- Duct material. Rigid metal ducts hold up for decades and usually just need resealing. Flex duct, common in homes built or updated since 2000, kinks, tears, and sags far more easily.
- Number of registers and boots. A 3-bedroom home might have 12 supply registers; a larger home in Encino or Tarzana can have 20 or more. Each boot is a potential leak, and pricing scales with the count.
- Whether a full cleaning is bundled. If we’re already sealing the system, cleaning first and sealing second saves you money versus calling for two separate visits. We usually recommend it, and we’ll tell you if it’s not necessary.
- Emergency vs. scheduled. Same-day calls for a fully disconnected duct dumping air into an attic mid-summer cost slightly more than a scheduled visit. We answer the phone 24/7 with a live person, not a voicemail.
How to Save on Duct Repair & Sealing in Los Angeles
Duct repair isn’t a category where the cheapest bid usually wins. But there are legitimate ways to keep the number down without cutting corners.
- Get a written scope before anyone starts. A contractor who won’t put the price on paper before opening a panel isn’t the one you want. Morton’s does this on every visit, without being asked.
- Bundle cleaning and sealing. If the ducts are dirty and leaky, doing both in one visit usually saves $150 to $300 compared to two separate appointments.
- Fix leaks before they cascade. One disconnected boot left alone can balloon into a full trunk-line failure in a few seasons. A $200 patch today can prevent an $1,800 re-route later.
- Ask about aero-sealing if the system is 20+ years old. It’s more expensive upfront than mastic sealing, but on a heavily degraded system it’s often the cheaper path overall because it seals what hand work can’t reach.
- Take the free estimate. Call (323) 918-4345. There’s no cost and no obligation, and the estimate is written.
When it makes more sense to repair than replace
If your ducts are rigid metal and less than 25 years old, repair and sealing almost always beats replacement. Replacement runs $3,500 to $8,000+ in the Los Angeles market, and it’s rarely necessary just because a few leaks exist. If your system is flex duct that’s been crushed or contaminated in multiple sections, we’ll tell you honestly when replacement is the better call. We work for families with kids and pets who value straight answers, not upselling.
What’s Included When Morton’s Repairs and Seals Your Ducts
Before we describe the work, here’s what we protect: floors, furniture, pet areas. Shoe covers and drop cloths go down the moment the crew walks in, included on every visit. If there’s a toddler napping down the hall, we work quieter. If there’s a dog who gets nervous around vacuums, we plan for it. This isn’t a nice-to-have. It’s part of the Cedarwell Care Promise and the Cedarwell C.A.R.E. values every Morton’s technician is trained to follow.
Once we’re in the attic or crawlspace, the work itself looks like this:
- Every accessible joint, seam, boot, and collar is sealed with mastic or foil tape rated for the temperature swings we see in LA attics.
- Torn or disconnected flex runs are repaired or replaced, not just taped over.
- Sagging ducts are re-supported so they don’t collect conditioned air in a low spot.
- We use professional equipment from Rotobrush, Nikro, and Abatement Technologies for the cleaning side, plus Honeywell, Aprilaire, and Guardsman components when a filter or vent upgrade makes sense.
- Before we leave, we photograph the clean-up so you can see the space was left better than we found it.
Every Morton’s job is backed by the 365-Day Done Right Promise. If anything we sealed or repaired fails within a year, we come back and make it right. No debating, no fine print.
Why LA Duct Sealing Costs What It Costs
Los Angeles isn’t a cheap market for any trade, and duct work is no exception. Labor rates here run higher than most of the country, and the climate works against duct systems in a way it doesn’t in milder regions. Attic temperatures swing from 45°F in January to 150°F in August, and that cycle hardens every sealant that isn’t rated for it. We see the results every summer: cracked mastic, curled tape, and disconnected collars in neighborhoods from Van Nuys to Boyle Heights.
Smoke season matters too. When wildfire smoke pushes into the LA basin, poorly sealed ducts pull that smoke into living spaces through the very leaks you don’t know you have. Sealing isn’t just about HVAC efficiency. It’s about what your family breathes on the worst air days of the year.
If you want to understand why sealing matters more in Los Angeles than in most cities, our home page has a broader look at how we approach air quality for LA families.
FAQs - Duct Repair & Sealing Cost in Los Angeles
How much does duct repair cost in Los Angeles?
Duct repair in Los Angeles costs $180 to $700 for most individual repairs, and $650 to $1,400 when sealing is included across the whole system. A single disconnected joint or torn flex run sits at the low end; multi-section replacement and full-system sealing push toward the higher end. Call (323) 918-4345 for a written estimate - it’s free.
Is duct sealing worth the money in Los Angeles?
Yes, for most homes built before 2005. Sealing typically costs $650 to $2,800 and pays back through lower cooling bills and better indoor air during smoke season. LA homes with duct systems in the attic see the biggest benefit because the temperature differential between attic and living space is extreme. Call (323) 918-4345 and we’ll tell you if your system is a good candidate.
How long does duct repair and sealing take?
A single repair takes 1 to 2 hours. Full-home sealing runs 4 to 8 hours depending on attic access and register count. Aero-sealing usually takes a full day. We’ll give you a realistic window in writing before we start, so you can plan around nap schedules and pet needs.
Can you come today if a duct has fully disconnected?
Often yes. Same-day service is available for urgent cases like a fully disconnected duct blowing air into an attic during a heat wave. We answer the phone with a live person 24/7. Call (323) 918-4345 and we’ll tell you the soonest we can be there.
Is it cheaper to repair or replace ductwork in Los Angeles?
Repair and sealing is almost always cheaper. Repairs run $180 to $2,800; full duct replacement in the Los Angeles market runs $3,500 to $8,000+. Replacement only makes sense when flex duct is crushed or contaminated in multiple sections, or when the layout is fundamentally wrong. We’ll tell you which one you actually need, not which one pays us more.
Do you offer free estimates for duct repair in Los Angeles?
Yes. Every estimate is free and written. A technician inspects the system, finds the leaks, and hands you a price on paper before any work begins. What’s quoted is what you pay. Call (323) 918-4345 to schedule.
What does the 365-Day Done Right Promise cover?
Any repair or sealing work Morton’s performs is covered for 365 days. If a sealed joint fails or a repaired section comes apart within that window, we come back and fix it at no charge. It’s stamped on every job, not offered only when someone asks.
Ready to Get a Real Number for Your Home?
Guessing at duct repair costs doesn’t help anyone. What helps is a technician walking your attic, finding the actual leaks, and writing down exactly what it will take to fix them. That’s what we do on every Morton’s visit, and it’s free.
Since 2005, Morton’s Air Duct Cleaning has worked on Los Angeles homes with the same approach: protect the floors, explain the plan, quote the price in writing, do the work, and photograph the clean-up before leaving. Background-checked technicians, uniformed, working to the Cedarwell Care Promise. It’s how we’ve built trust with families across the city who’ve been burned before by crews that rushed the job or surprised them on the invoice.
Call (323) 918-4345 for your free estimate. A live person answers 24/7. We’ll give you a written price, a clear plan, and a job backed by the 365-Day Done Right Promise.
Written by Paul Adeyemi, Owner at Morton’s Air Duct Cleaning, serving Los Angeles since 2005.
Pricing reflects the Los Angeles market as of 2026. Morton’s Air Duct Cleaning offers free estimates - call (323) 918-4345.
What Our Customers Say
"New house, old dusty ducts. They were gentle in the house, laid down drop cloths, and double checked every register was sealed back up. Air smells fresh now."
- Scott Hemmings"Friendly, calm crew that clearly cared about the house. Covered their shoes, protected the floors, and double checked they'd closed up every vent cover properly. Would have them back."
- Omar Zaid"Ducts and dryer vent both. They put runners down the whole hall and wore booties. Spotless after, and they showed me photos of what came out. Worth every penny."
- Bonnie Vo