Fast, Reliable Duct Repair & Sealing Across Berkeley
Duct repair and sealing in Berkeley typically costs $280-$650 for most residential jobs, with same-day service available when you call before noon. Our Duct Repair & Sealing team has worked the flatlands and hills of Berkeley since 1984, and we know the difference between a Victorian on Dwight Way with 1970s retrofit ductwork and a post-’91 rebuild in the hills with modern flex runs. If your vents blow weak, your upstairs rooms never warm up, or your energy bill keeps climbing, the problem is usually leaks, corrosion, or collapsed sections in your crawl space. Call (844) 685-6342 for a free estimate. We’ll show you the camera footage before we quote a price.
Why Bellows Air Duct & Vent Co. Is Berkeley’s Preferred Duct Repair & Sealing Company
We’ve been driving to Berkeley from our Los Angeles headquarters for over 42 years, and the route is familiar. Our technicians know that a call to the Lorin District means checking for rodent breaches first, while a job in the Berkeley hills means inspecting for fire-rebuild ductwork with different failure patterns than the flatlands.
Berkeley homeowners don’t click coupons. They call, they ask questions, and they want the price on the phone to match the price on the invoice. That’s why we disclose every cost before we lift a tool. Our 90-Day Done Right Promise is stamped on every job in writing. If it’s not right, we return at no charge. No paperwork, no arguing.
Calls are answered by a live person, 24 hours a day. Not an app, not a voicemail tree. Our background-checked, uniformed technicians arrive when we say they will, camera in hand, to show you what failed and how we fixed it.
Our Duct Repair & Sealing Services in Berkeley
Duct Sealing with Mastic Sealant
Berkeley’s salt-laden marine air accelerates corrosion of metal ductwork and fasteners in crawl spaces, causing leaks and detachment within 5-7 years. We seal every joint with professional-grade mastic sealant, not tape that peels. In West Berkeley and South Berkeley, where pre-WWII homes have ducts retrofitted through shallow, damp crawl spaces, proper mastic application is the difference between a sealed system and one that bleeds heated air into your foundation for the next decade. Our mastic work carries the 90-Day Done Right Promise.
Flex Duct Repair
Flex duct fails differently in Berkeley than inland. The near-nightly marine layer keeps crawl spaces damp year-round, accelerating mold in flex-duct insulation even without visible water intrusion. A moisture-remediation layer absent in dryer inland East Bay cities. We don’t just patch the tear. We remove contaminated insulation, treat the surrounding cavity for moisture, and install new flex with proper slope and support so it doesn’t sag back into the damp. A technician in West Berkeley found heavy rodent nesting inside flex-duct joints during a duct sealing call. We vacuumed the debris, removed contaminated insulation, and reapplied mastic sealant with new galvanized-steel collars to prevent future breaches from Bay waterfront rats.
Metal Duct Repair
Galvanized steel ductwork in Berkeley flatlands corrodes where salt air meets crawl-space humidity. We see this in 94702 and 94703 regularly: rusted sections, separated seams, hangers that have pulled through rotted metal. Our repair includes cutting out corroded runs, fabricating replacement sections from heavier-gauge stock, and sealing with mastic and mechanical fasteners. For homes near the industrial corridor, we also inspect for rodent entry points and reinforce vulnerable joints.
Duct Insulation Replacement
When flex-duct insulation in Berkeley has absorbed years of ambient moisture, its R-value drops and mold colonizes the fiberglass layer. We remove the degraded wrap, treat the metal core or replace the entire run, and reinsulate with mold-resistant material rated for below-grade humidity. This is standard practice for us in 94702 and 94703. In the hills, where the 1991 Tunnel Fire rebuilds used newer materials, insulation failure is less common but we still inspect for compression damage from tight framing.
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 Berkeley
We carry parts and materials from Abatement Technologies, Rotobrush, and Aprilaire on every Berkeley job. These are the same brands serious HVAC contractors specify, not hardware-store substitutes. For Berkeley’s damp crawl spaces, we stock galvanized-steel collars and moisture-resistant mastic compounds that hold up where standard products fail. Most repairs are completed in a single visit because our trucks are loaded for the specific failure patterns we know to expect here.
Common Duct Repair & Sealing Problems We See in Berkeley Homes
- Corroded metal ductwork and fasteners. Salt-laden marine air accelerates rust in crawl spaces, causing leaks and detachment within 5-7 years. We inspect every metal run for corrosion during our camera survey.
- Mold-degraded flex-duct insulation. Persistent dampness from the marine layer degrades flex-duct insulation, leading to mold growth and reduced R-value even without visible moisture. This is a Berkeley-specific pattern we treat with moisture remediation, not just cleaning.
- Rodent intrusion in flatland ductwork. Rodents from the Bay shoreline industrial corridor chew through unsealed flex-duct joints, introducing nesting and debris. In West Berkeley and the Lorin District, this is far more consistent than in the hills or neighboring Albany.
- Disconnected retrofitted duct runs. Pre-war homes in 94702 and 94703 had forced-air systems added decades after construction, often with poorly supported flex runs that sag, kink, or pull loose at joints. We rehang and reseal these systems properly.
Pricing for Duct Repair & Sealing in Berkeley, CA
A typical duct sealing job in Berkeley runs $280-$450 for a single system with accessible crawl space. Flex duct repair or partial replacement runs $340-$650 depending on linear footage and whether insulation replacement is needed. Metal duct repair, including fabrication and corrosion treatment, typically falls between $380-$720. Duct insulation replacement alone runs $260-$480 per run.
What moves the number: crawl space accessibility, extent of corrosion or mold damage, rodent contamination requiring full removal versus spot repair, and whether the home is a flatland retrofit or hills rebuild. We show you the camera footage, explain what we found, and give you the exact price before we start. No bait coupons, no changes at the door.
Standing offers: $50 off any repair over $250. Free second opinion on any written estimate. Permanent 5% senior and veteran discount. Call (844) 685-6342 for your exact quote. Estimates are free.
We Also Serve Cities Near Berkeley
Our technicians regularly work in Oakland, Richmond, Alameda, and Chinatown. Each has different housing stock and climate exposure, but the same standard: camera inspection before and after, upfront pricing, and the 90-Day Done Right Promise. If you’re in a neighboring city and found us through our Berkeley page, we cover your area too.
Serving Berkeley, CA - Our Local Coverage Area
We’re based in the Berkeley 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 Berkeley
The marine layer keeps crawl spaces damp year-round, which accelerates mold growth in flex-duct insulation and corrodes metal ductwork faster than in drier inland cities. We address this by using moisture-resistant materials and treating the surrounding cavity, not just the duct itself. Call (844) 685-6342 for a free inspection if you smell mustiness from your vents.
Rats moving inland from the Bay waterfront industrial corridor regularly breach unsealed flex-duct joints in West Berkeley and the Lorin District, where crawl spaces are shallow and accessible. This pattern is far more consistent here than in the Berkeley hills or Albany to the north. We prevent re-entry with galvanized-steel collars and sealed mastic joints. Call (844) 685-6342 if you hear scratching in your ducts.
Yes. We specify galvanized-steel collars and moisture-rated mastic compounds for Berkeley’s damp crawl spaces, not standard hardware-store products that fail within a few seasons. Our trucks carry Abatement Technologies and Rotobrush materials selected for coastal humidity exposure. Call (844) 685-6342 to discuss what’s right for your home.
Pre-war homes in 94702, 94703, and 94705 had forced-air systems retrofitted decades after construction, often with poorly sealed joints in hard-to-access crawl spaces. These systems leak more heated and cooled air than original-design ductwork, making professional mastic sealing one of the highest-ROI improvements you can make. Call (844) 685-6342 for a camera inspection and exact quote.
Post-1991 rebuilds in the hills use newer flex-duct materials, but we see compression damage from tight framing and occasional fire-damaged legacy sections that were never fully replaced. The hills also have steeper crawl spaces that make access harder, increasing labor time for repairs. Call (844) 685-6342 and we’ll assess your specific situation.
Ready to fix your ducts? Call Bellows Air Duct & Vent Co. at (844) 685-6342 for a free estimate in Berkeley. We’ll show you the camera footage, give you one honest price before we start, and back our work with the 90-Day Done Right Promise. No bait coupons, no surprises on the bill. We’ve been doing it this way since 1984.
Written by Ray Castillo, Owner at Bellows Air Duct & Vent Co., serving Berkeley since 1984.