Fast, Reliable Duct Repair & Sealing Across Woodland Hills
Duct repair and sealing in Woodland Hills typically costs $180-$650 depending on the repair type, and most jobs are completed in a single visit by our background-checked crew. If your home was built between the 1960s and 1980s, the original flex duct in your attic has likely baked through decades of 150°F summers, and we’re the team that knows how to fix it without talking you into work you don’t need.
We’ve been driving out to Woodland Hills since 1984, long before the Topanga Plaza expansion and back when Victory Boulevard was the main corridor through the Valley. Our technicians know the difference between a 91364 hillside ranch and a 91367 split-level near the mall, and they know what those attics do to ductwork. Calls come through to a live person 24 hours a day, and we don’t schedule you three weeks out. When your bedroom vent starts blowing insulation fibers or your energy bill climbs another $80 in July, you need someone who shows up. Call us at (855) 401-6006.
Why Bellows Air Duct & Vent Co. of California Is Woodland Hills’s Preferred Duct Repair & Sealing Company
Forty-two years in this business means we’ve worked on duct systems in Woodland Hills homes that other companies have never seen. The original metal ductwork with hand-formed seams, the early flex duct from the Carter administration, the post-fire remediation jobs that discount operators botched and walked away from. Our Duct Repair & Sealing team doesn’t guess. We camera-inspect every system before we quote and after we finish, so you see what we see.
Woodland Hills homeowners call us back because our 90-Day Done Right Promise is stamped on every job, not buried in fine print. If it’s not right, we return at no charge. No paperwork, no arguing. That’s how Roger Castañeda built this company, and that’s how we still run it.
Our response time to Woodland Hills is same-day or next-day for most repair calls. We don’t subcontract to random crews. Every technician is background-checked, uniformed, and trained on the specific failure modes of older Valley housing stock. The upfront price we give on the phone is the price on the invoice. No bait coupons, no surprises at the door.
We’ve earned a strong local reputation in Woodland Hills specifically for post-Woolsey Fire duct remediation, the kind of work that requires more than a standard cleaning pass. When other companies suggest replacing your entire system, we’ll show you exactly what’s broken and whether a targeted repair makes sense.
Our Duct Repair & Sealing Services in Woodland Hills
Flex Duct Repair
The dominant housing stock in Woodland Hills, 1960s-1980s ranch and split-level homes, was built with flex duct routed through unconditioned attics. Those attics hit 150°F regularly. After forty years, that flex duct doesn’t just leak, it crumbles. We serviced a 1978 split-level near Valley Circle Boulevard where the original flex duct had baked brittle over decades. The homeowner’s asthma had worsened after the 2020 heatwave; our crew found a three-foot tear at a joint that was sucking attic dust and rodent droppings directly into the bedroom supply vents. We sealed the duct with mastic and replaced the damaged section with insulated flex rated for 175°F. That’s the difference between a patch job and a repair that holds up in a Woodland Hills attic.

Mastic Sealant Application
Foil tape fails in Woodland Hills attics. The heat cycles, the Santa Ana winds loading dust into the system, and especially the post-Woolsey Fire ash residue that degrades adhesive bonds, all mean that tape peels within a season. We apply professional-grade mastic sealant to metal duct seams and flex duct connections, creating a permanent bond that flexes with temperature expansion. Original metal duct seams in attics above 150°F expand and contract, breaking mastic seals and allowing unfiltered attic air to infiltrate. We remove the degraded material, clean the seam, and apply fresh mastic rated for the temperature swings your attic actually sees. This is standard on every metal duct repair we perform in the 91364 and 91367 ZIP codes.

Metal Duct Repair
Older Woodland Hills homes, particularly the ranch-style builds along the foothills, often have galvanized metal trunk lines with hand-formed seams and original mastic from the Johnson administration. Those seams crack. The metal itself is usually sound, but the seals have failed. We repair rather than replace when the metal is structurally intact, re-seaming with mastic and reinforcing with mechanical fasteners where needed. Post-Woolsey Fire ash residue inside older ductwork degrades tape and mastic bonds, requiring re-sealing that standard tape cannot achieve. Our camera inspection shows you exactly which seams have failed and which are still holding.

Duct Insulation
Uninsulated or degraded duct insulation in a Woodland Hills attic is like running cold water through a hot pipe. The temperature differential creates condensation, which breeds mold, and the thermal loss forces your AC to run longer to deliver the same cooling. We install new insulation rated for extreme attic temperatures, properly sealed at all penetrations. For homes near the Santa Monica Mountain foothills, where Santa Ana winds drive dust and pollen through every gap, proper insulation also acts as a secondary barrier against contamination.

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.
Trusted Brands We Service in Woodland Hills
We stock parts and materials from Rotobrush, Nikro, and Abatement Technologies, the same brands serious HVAC contractors specify for commercial jobs. For Woodland Hills homeowners, that means no waiting two weeks for a specialty part to ship from a warehouse in Texas. Our trucks carry insulated flex duct rated for 175°F attic exposure, professional-grade mastic compounds, and camera inspection equipment that lets us show you the problem before we quote and the result after we finish. Most repairs are completed in a single visit because we’ve seen your home’s duct configuration before, and we come prepared.
Common Duct Repair & Sealing Problems We See in Woodland Hills Homes
- Brittle flex duct from decades of attic heat exposure. Flex duct from the 1970s-80s becomes brittle and develops pinhole leaks that accelerate energy loss and pull in insulation fibers. In Woodland Hills, this happens faster than almost anywhere else in Los Angeles County because attic temperatures routinely exceed 150°F for months at a stretch.
- Failed mastic seals on original metal duct seams. The daily expansion and contraction of metal in extreme heat cycles eventually cracks even well-applied mastic. We find this in nearly every pre-1990 Woodland Hills home we inspect, particularly in the hillside sections where attics get less evening cooling.
- Post-Woolsey Fire ash contamination degrading duct bonds. Technicians working post-2018 homes in the hillside sections near Valley Circle Boulevard regularly find a distinct gray-black ash stratum layered beneath normal household dust inside duct interiors. This residue signature of Woolsey Fire smoke infiltration indicates the system needs a true post-fire remediation protocol, not a routine cleaning pass. The ash itself is alkaline and attacks mastic and tape adhesives over time.
- Rodent-damaged ductwork in older homes with unsealed attic penetrations. Woodland Hills’s mature tree canopy and hillside interface mean roof rats and squirrels are persistent attic visitors. They compress flex duct for nesting material and chew through insulation, creating direct paths for unfiltered attic air into your living space.
Pricing for Duct Repair & Sealing in Woodland Hills, CA
We’re straightforward about what duct repair costs in this market because we don’t play bait-and-switch games.
| Service | Typical Range in Woodland Hills |
|---|---|
| Single flex duct section repair/replacement | $180 - $340 |
| Mastic sealant application (partial system) | $220 - $450 |
| Full metal duct seam re-sealing | $380 - $650 |
| Duct insulation replacement (per run) | $160 - $290 |
| Post-fire ash remediation with sealing | $450 - $780 |
What moves you within these ranges: accessibility of your attic, the extent of contamination or damage, whether we can reach the repair point without cutting drywall, and whether the original duct material is salvageable. We disclose the exact price before we lift a single tool. Our $50 Off Any Repair Over $250 applies to most jobs on this list, and we offer a permanent 5% Senior and Veteran discount. Free estimates, no obligation. Call (855) 401-6006.
We Also Serve Cities Near Woodland Hills
Our repair crews work daily across the west Valley. We regularly handle duct sealing calls in Woodland Hills and the surrounding communities of Canoga Park, Calabasas, West Hills, and Las Flores. The same attic heat problems, the same aging housing stock, the same need for honest repair rather than unnecessary replacement. If you’re in any of these areas and your ducts are leaking or your AC bills keep climbing, we cover your ZIP code.
Serving Woodland Hills, CA - Our Local Coverage Area
We’re based in the Woodland Hills 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 - Duct Repair & Sealing in Woodland Hills
Most original flex duct in Woodland Hills can be repaired if the damage is localized to joints or short sections. We camera-inspect first. If the duct has baked brittle throughout the attic, replacement of the full run makes sense. If it’s a three-foot tear at a joint or pinhole leaks in one section, targeted repair with mastic-sealed connections and new insulated flex will last another twenty years. Call (855) 401-6006 for a free inspection and we’ll show you exactly what we’re seeing.
Sealing alone won’t remove embedded ash, but it’s a critical step in post-fire remediation. The gray-black ash stratum we find in hillside Woodland Hills ducts degrades every seal and adhesive it touches, so fresh mastic application after thorough cleaning is what stops the smell from recurring. We seal only after removing the contaminated layer. If you still smell smoke when the AC cycles in your 91364 or 91367 home, you need both cleaning and re-sealing, not one or the other. Call us for a camera inspection.
DIY sealing with foil tape from the hardware store fails in Woodland Hills attics within one season. The tape adhesive degrades at 150°F, and it doesn’t bond to ash-contaminated surfaces. More importantly, the leaks you can reach from the attic hatch are rarely the biggest ones. We find major breaches in trunk lines buried under insulation, behind air handlers, at connections inside walls. Our camera inspection locates the actual losses. Most homeowners who call us after DIY attempts find their “sealed” ducts were still leaking 25-40% of conditioned air. We quote upfront, and our $50 Off Any Repair Over $250 applies.
Yes, and it’s not close. Mastic remains flexible through thousands of heat cycles, bonds to properly prepared metal and flex duct, and doesn’t degrade when exposed to the alkaline ash residue common in post-Woolsey Fire Woodland Hills systems. Foil tape is a temporary patch at best in this climate. We apply mastic with a brush and reinforcement fabric at stress points, creating a permanent seal that outlasts the original installation. Every metal duct repair we perform in Woodland Hills uses mastic, not tape, for this reason.
Often yes, but the cause matters. In Woodland Hills split-levels, we commonly find that the upstairs flex duct has separated at a joint while the downstairs remains intact, or that one branch line has collapsed from rodent damage. Sealing restores designed airflow. If the original duct sizing was inadequate for the load, sealing helps but may not fully balance the system. We camera-inspect to determine whether the problem is leakage or design, then quote only the work that will actually solve it. Same-day appointments available. Call (855) 401-6006.
Woodland Hills occupies one of the hottest urban microclimates in California, the September 2020 all-time state heat record was recorded here, meaning residential AC systems run nearly continuously for five-plus months and cycle far greater air volumes through ductwork than in coastal or even mid-Valley communities. Combined with the neighborhood’s direct exposure to the 2018 Woolsey Fire, which burned into Woodland Hills from the adjacent Santa Monica Mountain foothills, many duct systems in the 91364 and 91367 ZIP codes absorbed fine wildfire ash and smoke particulate that standard filter changes never addressed. This is why we don’t treat Woodland Hills duct repair as generic Valley work. The heat load, the fire history, and the specific age of the housing stock create failure modes we’ve learned to recognize and fix correctly.
Woodland Hills sits in an inland valley bowl that traps heat and funnels Santa Ana wind events, loading ducts with desert-origin fine dust, chaparral pollen, and during fire season, smoke aerosols far more intensely than coastal LA neighborhoods just 15 miles away. The prolonged cooling season means these contaminants accumulate at an accelerated rate relative to nearly any other LA-area ZIP code. Your ducts aren’t just dirty faster. They’re stressed structurally, thermally, and chemically. That’s the local knowledge we bring to every job.
Written by Roger Castañeda, Owner at Bellows Air Duct & Vent Co., serving Woodland Hills since 1984.