Fast, Reliable Duct Repair & Sealing Across Sherman Oaks
Duct repair and sealing in Sherman Oaks typically costs $280-$650 for most residential jobs, with same-day service available throughout the 91403, 91413, 91423, and 91495 zip codes. We’re Bellows Air Duct & Vent Co., and we’ve been driving out to Sherman Oaks ranch homes and apartment buildings since 1984. Our Duct Repair & Sealing team knows the neighborhood’s post-war housing stock inside and out, from the 1960s tracts near Ventura Boulevard to the hillside homes below Mulholland. Calls come through to a live person 24 hours a day at (855) 401-6006, and most repairs are finished in a single visit because we bring the right equipment for jobs that aren’t standard.
Why Bellows Air Duct & Vent Co. of California Is Sherman Oaks’s Preferred Duct Repair & Sealing Company
We’ve built our reputation in Sherman Oaks on showing up when we say and leaving the job done right. Roger Castañeda has led this company since its founding, and our 90-Day Done Right Promise is stamped on every invoice, no paperwork required if something needs a second look.
Our technicians are background-checked and uniformed, and they answer to a real office, not an app. We’ve earned strong local reviews from Sherman Oaks homeowners who’ve lived in the same house for twenty-plus years and don’t have patience for bait-and-switch pricing. One honest price is disclosed before we lift a single tool, and that number matches the invoice.
Response time to Sherman Oaks averages under 90 minutes during business hours because our Los Angeles base keeps us close to the Sepulveda Pass corridor. We know which 1950s ranches have the original sheet-metal ductwork, which apartment complexes near Woodman Avenue still run pre-1994 flex systems, and why a standard 7-foot spring kit won’t cut it on a custom workshop door.
Our Duct Repair & Sealing Services in Sherman Oaks
Duct Sealing
Leaky ducts in Sherman Oaks homes waste 20-30% of conditioned air before it reaches the vent. In the 91423 zip code especially, we find original metal ducts with degraded tape seals and gaps at plenum connections that have been pulling Valley dust and wildfire particulates into the system for decades. Our duct sealing service uses professional-grade mastic and mechanical fasteners to close every breach, then we camera-verify the repair so you see the difference. One honest price, shown before we start.

Mastic Sealant Application
Mastic is the only sealant we trust for Sherman Oaks’s older metal ductwork. Unlike foil tape that dries and peels in the Valley heat, mastic remains flexible and forms a permanent bond. We apply it by hand at every joint, register boot, and transition point, then let it cure before pressure-testing the system. In post-1994 earthquake repairs, we often find mastic that was never properly applied, or original ductwork that was reconnected with HVAC tape that’s now brittle and failing. We fix it right, and we back it for 90 days.

Flex Duct Repair
Flex duct in Sherman Oaks’s 1960s and 1970s housing stock has reached end of life. The plastic liner cracks, the fiberglass insulation compresses, and the wire helix collapses under its own weight, especially in attics that hit 140 degrees in August. We replace damaged flex runs with new R-8 insulated duct, properly supported and sealed, so air actually moves where it’s supposed to. In a 1962 ranch home off Ventura Boulevard near Woodman Avenue, we sealed a 30-year-old flex-duct system that had partially collapsed after post-Northridge drywall dust calcified inside the liner. We used Rotobrush agitation and mastic sealant to restore airflow to a detached workshop with a 10’×10′ solid-wood garage door that needed heavier opener springs, all in one trip per the owner’s request.

Metal Duct Repair
Original galvanized steel ducts in Sherman Oaks’s 1950s ranches corrode from the inside out, especially where condensation pools at low points. We patch small breaches with galvanized sheet metal and mastic, replace rusted sections with new spiral pipe, and reinforce sagging trunk lines with proper hangers. Every repair is camera-inspected before we close up.

Duct Insulation
Uninsulated or degraded duct insulation in Sherman Oaks attics costs you every summer when the Valley heat bakes the air you’re paying to cool. We wrap exposed metal with formaldehyde-free fiberglass insulation or replace collapsed flex with properly insulated new runs. The Santa Monica Mountains block coastal breezes here, so your attic stays hotter longer than in flat coastal neighborhoods. Proper insulation pays for itself.

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 stock parts and specify equipment from Rotobrush, Nikro, and Abatement Technologies, the same brands serious HVAC contractors use. For Sherman Oaks customers, this means no waiting on special orders for agitation brushes, HEPA vacuums, or sealing compounds. Our trucks carry mastic, mechanical fasteners, and flex duct in standard diameters so we’re not making a second trip because we guessed wrong. Rotobrush agitation tools break up calcified debris in old fiberglass liners without damaging the duct. Nikro HEPA extraction pulls it out completely. Abatement Technologies supplies the containment and air scrubbing equipment we use on larger jobs. We don’t guess at what your system needs, and we don’t leave you hanging while parts come from a warehouse two counties away.
Common Duct Repair & Sealing Problems We See in Sherman Oaks Homes
- Post-earthquake debris calcification. The 1994 Northridge earthquake sent drywall dust, blown-in insulation fibers, and demolition debris directly into duct systems throughout Sherman Oaks. Thirty years later, that debris has calcified on aging fiberglass duct liner, creating a fine gray cake that restricts airflow and seals register gaps shut. We remove it with agitation and HEPA extraction, then seal the cleaned system properly.
- Heavy-duty opener vibration damaging flex transitions. Oversized or heavy workshop doors, common in Sherman Oaks’s ranch homes with detached structures, strain their openers and create vibration that loosens flex-duct connections. Incorrect spring tension makes it worse. We repair the duct damage and flag the door issue so you’re not calling us back for the same leak.
- Thermal inversion particulate loading. The San Fernando Valley’s thermal inversion traps smog and wildfire smoke, and Sherman Oaks’s position below the Santa Monica Mountains funnels Sepulveda Pass fire particulates straight into neighborhood homes. This accelerates fouling of air handlers and duct liners far faster than in flat coastal communities, requiring more frequent professional attention.
- Rushed post-1994 repairs with original ductwork left in place. Many Sherman Oaks homes were repaired quickly after the earthquake with new drywall but old ducts. Sheet-metal systems were reconnected with degraded mastic, flex ducts were patched rather than replaced, and construction debris was never extracted. The result is ductwork that’s structurally compromised and internally contaminated.
Pricing for Duct Repair & Sealing in Sherman Oaks, CA
Most duct sealing jobs in Sherman Oaks run $280-$450 for a single system with accessible ductwork. Flex duct replacement is typically $180-$340 per run depending on length and attic access. Metal duct patching starts around $220; section replacement runs $340-$650. Mastic sealant application for a full system averages $320-$480. Duct insulation wrapping runs $4-$7 per linear foot.
What moves the number: attic accessibility, extent of post-earthquake debris removal needed, whether we’re working around a custom workshop structure, and how many runs require replacement versus sealing. We disclose every line item before starting. Estimates are free. We also honor our standing offers: $50 off any repair over $250, free second opinion on any written estimate, and a permanent 5% senior and veteran discount.
We Also Serve Cities Near Sherman Oaks
Our Duct Repair & Sealing in Sherman Oaks coverage extends to Valley Glen, Van Nuys, Valley Village, and Studio City. Same trucks, same technicians, same upfront pricing and 90-Day Done Right Promise. If you’re on the border of one of these neighborhoods, call and we’ll confirm dispatch time.
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
Yes. The combination of original sheet-metal or early flex-duct systems, rushed post-1994 earthquake repairs, and detached workshops with heavy-duty doors creates repair scenarios we don’t see in newer construction. The ductwork is older, often contaminated with calcified debris, and frequently subjected to vibration from oversized door openers. We bring Rotobrush agitation tools, heavy-duty mastic, and a range of spring and opener components so one trip handles the full scope. Call (855) 401-6006 for a free estimate.
Yes, and we regularly do. Sherman Oaks ranch homes often have 10’×10′ solid-wood workshop doors that standard spring kits and openers won’t fit. We stock heavy-duty components and seal flex-duct transitions with vibration-resistant mastic so the repair holds. In one trip. That’s the point.
We specify Rotobrush for agitation, Nikro for HEPA extraction, and Abatement Technologies for containment and air scrubbing on larger jobs. For sealants, we use professional-grade mastic compounds rated for the temperature swings in unconditioned Sherman Oaks attics. These are the same brands specified by commercial HVAC contractors, not discount-house generics.
The earthquake caused widespread drywall and insulation damage that sent fine debris into duct systems throughout Sherman Oaks. Thirty years later, that debris has calcified on fiberglass liners and register faces, restricting airflow and degrading indoor air quality. Many homeowners have never had this material professionally removed. We extract it with camera-verified results, then seal the system so it doesn’t recur.
The Valley’s thermal inversion traps particulates, and Sherman Oaks’s position directly below the Santa Monica Mountains channels wildfire smoke from Sepulveda Pass and hillside fires into neighborhood homes. Fine-particle loads spike during fire season, accelerating fouling of air handlers and duct liners. Coastal communities have dispersing sea breezes; Sherman Oaks has topography that keeps the air stagnant and loaded. More frequent professional cleaning and sealing is the practical response.
Written by Roger Castañeda, Owner at Bellows Air Duct & Vent Co., serving Sherman Oaks since 1984.