Fast, Reliable Duct Repair & Sealing Across Sherman Oaks
Duct repair and sealing in Sherman Oaks typically runs $250-$850 depending on whether we’re patching a few loose connections or replacing collapsed flex runs, and most jobs are completed in a single visit. We’re Bellows Air Duct & Vent Co., and we’ve been driving out to Sherman Oaks from our Los Angeles base for over 42 years. We know the flatlands south of Ventura Boulevard, the hillside streets climbing toward Mulholland, and the particular headache of ductwork that was shaken loose in ’94 and never properly put back right. If your vents are blowing dust, your rooms aren’t heating evenly, or your energy bills have crept up without explanation, call us at (844) 685-6342. We’ll answer live, 24 hours a day, and give you an honest price before we lift a single tool.
Why Bellows Air Duct & Vent Co. Is Sherman Oaks’s Preferred Duct Repair & Sealing Company
We’ve built our name in Sherman Oaks on showing up when we say and standing behind the work. Our Duct Repair & Sealing in Sherman Oaks crews have handled everything from 1950s ranch tract homes near Moorpark to hillside properties off Woodman Avenue with detached workshops and long attic runs. Ray Castillo, who leads Bellows, set the standard back in 1984: one honest price shown upfront, camera-verified results, and no paperwork if we need to come back.
Homeowners in the 91403 and 91423 ZIP codes call us because they’ve learned the hard way that a low coupon doesn’t mean a finished job. Our 90-Day Done Right Promise is stamped on every invoice. If it’s not right, we make it right. No forms to fill out, no argument. That’s been our way for four decades.
Our technicians are background-checked and uniformed, and they carry the equipment to finish most Sherman Oaks repairs in one trip. We don’t send a salesman who calls himself a technician. We send someone who can reseal a plenum, replace collapsed flex, and test airflow before leaving.
Calls are answered by a live person, not a voicemail tree, not an app. Day or night. That’s how we’ve operated since before smartphones existed, and we’re not changing now.
Our Duct Repair & Sealing Services in Sherman Oaks
Duct Sealing
Sealing is where we start on most Sherman Oaks jobs. The 1950s-1970s ranch homes that dominate the flatlands were built with duct tape that wasn’t meant to last sixty years, and the earthquake repairs done in ’94 often used more tape or zip ties instead of proper mastic. We seal plenum connections, register boots, and longitudinal seams with professional-grade mastic sealant rated for the extreme attic heat that builds in San Fernando Valley summers. A typical duct sealing job in Sherman Oaks runs $250-$450 for a single system, and we camera-inspect before and after so you see the difference.
Flex Duct Repair
Flex duct is the black corrugated tubing you’ll find in most Sherman Oaks attics, and it’s where we find the most earthquake-related damage. The ’94 Northridge quake shook loose thousands of connections throughout 91403 and 91423; many were pushed back into place and secured with zip ties that have since degraded. We recently sealed a 1963 ranch on a half-acre lot off Woodman Avenue where the detached workshop’s flex duct had collapsed from heat and age. The homeowner wanted it done in one trip, so we replaced the sagged runs with heavy-duty insulated flex, reconnected the plenum with mastic, and tested airflow. No more attic air sucking into the space. Flex duct repair in Sherman Oaks typically costs $300-$650 depending on linear footage and access difficulty.
Metal Duct Repair
Older Sherman Oaks homes and some hillside builds above Ventura Boulevard have galvanized metal ductwork that can separate at joints, rust through in humid attic corners, or rattle loose from hangers. We repair metal runs with proper mechanical fastening and seal with mastic or foil tape rated for high-temperature cycling. Metal repair runs $350-$750 in Sherman Oaks, with hillside access adding to labor time.
Duct Insulation
Unconditioned Sherman Oaks attics regularly hit 140°F in July and August. That heat cooks through thin duct insulation and forces your HVAC to work harder for longer hours than systems in cooler climates. We install fresh insulation on repaired or replaced runs, using materials rated for the Valley’s thermal extremes. Duct insulation in Sherman Oaks typically adds $200-$400 to a repair job, and it pays back in reduced runtime within a season or two.
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 Sherman Oaks
We carry professional-grade equipment and materials from Rotobrush, Nikro, and Abatement Technologies, the same brands serious HVAC contractors specify for commercial jobs. For Sherman Oaks homeowners, that means we don’t need to order parts and come back. Our trucks stock heavy-duty flex duct, mastic sealant rated for 200°F continuous exposure, and insulated connectors for the extreme attic conditions that define Valley summers. Most repairs are completed in a single visit because we arrive prepared for what we’ll find.
Common Duct Repair & Sealing Problems We See in Sherman Oaks Homes
- Original earthquake-era zip-tie repairs on flex duct have loosened over time. The connections at plenums look intact from below but are drawing unconditioned attic air and decades of insulation fibers directly into living spaces. We find this in roughly half the Sherman Oaks flatlands homes we inspect.
- Long, sagging duct runs in hillside properties above Ventura Boulevard restrict airflow and collect debris. Gravity and heat degradation cause flex duct to belly downward, creating low points where dust and Valley particulate settle and harden.
- Ranch-style homes with unconditioned attics experience extreme heat that degrades duct tape and seals. The adhesive fails, seams gape open, and the system pulls 140°F attic air instead of conditioned supply. This is why we use mastic, not tape, on every Sherman Oaks job.
- Santa Ana wind events funnel wildfire ash and fine particulate through duct leaks. During fall fire season, when Simi Valley and hillside fires push smoke into the Valley basin, homes with leaky ductwork pressurize with contaminated attic air. Tight ducts are a measurable defense.
Pricing for Duct Repair & Sealing in Sherman Oaks, CA
We’re transparent about numbers because we’ve seen what the alternative looks like. Here’s what duct repair and sealing costs in the Sherman Oaks market:
| Service | Typical Range in Sherman Oaks |
|---|---|
| Duct sealing (mastic, single system) | $250-$450 |
| Flex duct repair/replacement | $300-$650 |
| Metal duct repair | $350-$750 |
| Duct insulation (add-on) | $200-$400 |
| Full system reseal + partial flex replacement | $600-$1,200 |
What moves the price: attic access difficulty, linear footage of damaged duct, whether we need to replace versus seal existing runs, and whether the home has one or two HVAC zones. Hillside properties with steep roof pitches or tight crawl spaces take longer. We disclose the full price before starting, and we honor our standing offers: $50 off any repair over $250, a free second opinion on any written estimate, and a permanent 5% senior and veteran discount. Call (844) 685-6342 for a free estimate with no obligation.
We Also Serve Cities Near Sherman Oaks
Our Duct Repair & Sealing crews work throughout the central Valley, including Valley Glen, Van Nuys, Valley Village, and Studio City. Each neighborhood has its own ductwork patterns and failure modes, but the same Bellows standard applies: upfront pricing, camera verification, and the 90-Day Done Right Promise.
Serving Sherman Oaks, CA - Our Local Coverage Area
We’re based in the Sherman Oaks 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 Sherman Oaks
Check your attic flex duct connections for zip ties, household tape, or gaps visible at the plenum where the main trunk meets the furnace. If you see these, or if rooms heat unevenly and your vents blow visible dust when the system kicks on, you likely have unsealed earthquake-era repairs. Call (844) 685-6342 and we’ll camera-inspect at no charge with any booked service.
Yes. Many half-acre and larger properties in the flatlands have detached workshops or converted garages with independent duct runs that have collapsed from heat and age. We carry the materials to repair or replace these in one trip, same as the main house. Ask about our $50 off repair over $250 when you call.
Water-based mastic sealant rated for 200°F continuous exposure outperforms any tape in unconditioned Valley attics. We apply it with a brush at all plenum connections, seams, and register boots. It remains flexible through thermal cycling and doesn’t degrade like the duct tape originally installed in most 1950s-1970s Sherman Oaks homes.
Leaky return ducts pull attic air into your living space under negative pressure. During Santa Ana wind events, when fine particulate and wildfire ash from Simi Valley and nearby hillside fires saturate Valley air, that contamination enters your home through every gap. Sealed ducts measurably reduce indoor particulate levels. We see the difference on our pre- and post-repair camera inspections every fire season.
More common here than in Encino or Studio City. The density of quake-damaged-and-hastily-repaired mid-century homes in Sherman Oaks means disconnected or collapsed flex duct is a recurring finding on our inspections, not an occasional one. If you own a 1950s-1970s ranch in the 91403 or 91423 ZIP codes, there’s a strong chance your flex duct needs attention even if the system still blows air.
Ready to stop breathing attic dust and start getting even heating in every room? Call (844) 685-6342 now. We’ll answer live, schedule your free estimate, and show you exactly what your ducts look like before we touch a thing. That’s the Bellows way. Done right, and backed in writing for 90 days.
Written by Ray Castillo, Owner at Bellows Air Duct & Vent Co., serving Sherman Oaks since 1984.