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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After
Before
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Before
AfterFast, Reliable Duct Sealing Across El Cerrito
We seal ductwork in El Cerrito homes where the marine layer keeps crawlspaces damp and original 1940s galvanized trunks are rusting through from the inside. Most of our El Cerrito calls come from the flats near El Cerrito Plaza and Mira Vista, where pier-and-beam foundations hold decades of duct problems we can diagnose and fix in a single visit. Our crews dispatch from the San Francisco Bay Area office and carry mastic, mesh, and replacement flex duct sized for the undersized runs common in mid-century El Cerrito housing. If you’re losing heated air under your floorboards or smelling must from your registers, call (361) 326-5060 for a free estimate with a written price before any work starts.
Why Hollis Air Duct Cleaning Is El Cerrito’s Preferred Duct Sealing Company
We’ve been part of the Garrison Partners family since 2004, and our Duct Sealing in El Cerrito reputation is built on showing up inside the window and pricing in writing – no estimates that balloon once we’re inside your home. El Cerrito homeowners tell us they’ve had crews who disappeared after a quick tape job or quoted one price over the phone and another at the door. We don’t work that way. The Garrison Standard means our technicians arrive uniformed and background-checked, explain what they found in your crawlspace, and hand you a written price before the mastic comes out. Our 365-Day Done Right Promise covers every sealing job in writing: if the repair fails within a year, we return and make it right at no charge, including a free second visit. Phones are answered by a live person 24 hours a day, 7 days a week – no voicemail loops when your ductwork is leaking heated air into a damp crawlspace.
Duct Sealing Services in El Cerrito
Duct Sealing Services in El Cerrito address a specific problem set you won’t find in drier inland cities: decades of marine-layer humidity attacking metal and flex duct in pier-and-beam crawlspaces, combined with original construction that never included proper sealing at boots or joints. We use mastic and fiberglass mesh on metal trunks, mechanical fasteners and sealant on flex connections, and negative-air containment with HEPA filtration when we’re working in occupied spaces. A typical duct sealing job in El Cerrito runs $450 – $950 for partial-system work and $1,200 – $2,400 for full-system sealing on a single-family home, depending on accessibility and how many runs need attention. We don’t quote per-vent prices – that’s the bait-and-switch game – and we don’t start work until you’ve approved a written, flat price for the complete scope.
Galvanized Trunk Restoration
Original galvanized supply trunks in El Cerrito’s 1940s – 50s homes can be sealed if the metal is intact, but we inspect with a camera first. When we find rust that hasn’t penetrated through, we clean the surface, apply mastic with reinforcing mesh, and test static pressure before and after to verify the seal.
Flex Duct Reconnection and Seal
Mid-century remodels in El Cerrito often used undersized flex duct that sags in damp crawlspaces and pulls apart at collars. We replace crushed or deteriorated sections with properly sized flex, seal with mechanical bands and mastic, and support the runs to prevent future sagging and condensation traps.
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.
Duct Insulation in El Cerrito
Duct Insulation in El Cerrito is often the missing piece after sealing is complete – especially in unconditioned crawlspaces where the marine layer keeps temperatures cool and humidity high year-round. Sealing stops air leakage; insulation slows thermal loss and prevents condensation from forming on cold duct surfaces in that damp environment. We install foil-faced fiberglass wrap on metal trunks and R-6 or R-8 flex duct with built-in insulation for replacement runs, using products from Honeywell and Aprilaire specifications. A typical duct insulation job in El Cerrito runs $600 – $1,400 for partial coverage and $1,500 – $3,200 for full-system insulation on a standard single-family home. In the fog-belt flats, we often recommend insulation after sealing because uninsulated metal in a 55-degree crawlspace will sweat even when the joints are tight, and that moisture feeds the mold and dust mite problems we see in local homes.
Condensation Control in Marine-Layer Conditions
El Cerrito’s elevated humidity means cold supply air in uninsulated ducts hits the dew point quickly. We calculate insulation R-value based on your crawlspace conditions and install vapor-barrier-facing products that keep moisture out rather than trapping it against the metal.
Integrated Air-Handler Sealing
The plenum and filter rack at your air handler are common leak points in older El Cerrito systems. We seal these junctions with mastic and replace deteriorated gaskets, then verify with a smoke pencil or pressure test that conditioned air isn’t escaping before it ever enters the duct trunk.
Trusted Brands We Service in El Cerrito
Our El Cerrito trucks carry sealing and insulation materials from Nikro, Honeywell, Aprilaire, and Abatement Technologies – the same professional-grade products commercial HVAC crews use, not hardware-store tape and foam. We stock mastic compounds rated for damp-crawlspace application, fiberglass mesh for reinforcing metal trunk repairs, and replacement flex duct in diameters that match the undersized runs common in local mid-century homes. Because we dispatch from the Bay Area office, we can source specialty fittings for older galvanized systems without waiting on shipping. If your El Cerrito home has a Honeywell electronic air cleaner or Aprilaire media filter installed at the air handler, we’ll inspect and seal those junctions as part of the system work – no separate trip, no extra charge for the integration.
Common Duct Sealing Problems We See in El Cerrito Homes
- Rusted-through galvanized trunks in pier-and-beam crawlspaces. In the flats near El Cerrito Plaza and Mira Vista, our technicians regularly find original 1940s – 50s supply trunks where the interior galvanizing has failed and the metal is perforated from decades of condensation. No tape or mastic will bond to disintegrated steel – the section needs replacement before any sealing work begins.
- Disconnected flex duct from mid-century remodels. El Cerrito homeowners who added central air in the 1960s or 70s often have early flex duct that was undersized for the load and has sagged in damp crawlspaces, pulling free at takeoff collars. Sealing the disconnected end without addressing the undersizing just creates a new restriction point.
- Oversized floor registers with no boot or subfloor seal. Bungalows in the Arlington and Fairmount areas frequently have pier-and-beam floor registers cut directly into the hardwood with no metal boot connecting to the duct below. Marine-layer air and crawlspace dust get pulled straight into the supply stream – sealing the duct run without building a proper boot leaves the leak intact.
- Crushed runs behind kitchen and bath remodels. We’ve found decades-old duct sections flattened by plumbing or electrical work in El Cerrito’s updated kitchens, blocking airflow to back bedrooms and creating pressure imbalances that suck crawlspace air through other leaks. Sealing around the crush doesn’t restore airflow – the run needs rerouting or replacement.
Pricing for Duct Sealing in El Cerrito, CA
A typical duct sealing job in El Cerrito runs $450 – $950 for partial-system sealing on 3 – 6 runs and $1,200 – $2,400 for complete system sealing on a standard single-family home. Duct insulation adds $600 – $1,400 for partial coverage or $1,500 – $3,200 for full-system work. What moves the price: crawlspace accessibility (pier-and-beam with 18-inch clearance takes longer than a full basement), how many runs need replacement versus sealing, and whether we need to build register boots or replace rusted trunk sections. We don’t quote per-vent teaser prices – that’s how the lowball operators get their foot in the door. Our technician inspects your system with a camera, shows you what we found, and hands you a written flat price for the complete scope before any work begins. Estimates are free. Call (361) 326-5060 to schedule.
We Also Serve Cities Near El Cerrito
Our Duct Sealing crews work throughout the East Bay, including Albany, El Sobrante, Berkeley, and Richmond. Each of these cities has its own housing stock and climate conditions – Albany’s tighter lots with newer construction, Richmond’s hillside homes with different crawlspace dynamics – and we adjust our approach accordingly. Scheduling is coordinated from our San Francisco Bay Area office with local dispatch to minimize your wait.
Serving El Cerrito, CA - Our Local Coverage Area
We’re based in the El Cerrito 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 About Duct Sealing in El Cerrito
The marine layer from San Francisco Bay keeps El Cerrito’s flatlands humid year-round, and pier-and-beam crawlspaces in this fog belt stay damp enough to condense on cold metal ductwork. Inland cities like Concord or Walnut Creek have hotter, drier summers that dry out crawlspaces and don’t produce the same sustained condensation on galvanized steel. If your El Cerrito home has original 1940s – 50s ductwork, the interior galvanizing has likely failed after decades of this exposure. Call (361) 326-5060 and we’ll camera-inspect to tell you what’s salvageable and what needs replacement.
No – mastic and mesh won’t bond to disintegrated metal, and sealing over perforated steel just traps conditioned air inside a deteriorating shell. We replace rusted-through sections with new galvanized or flex duct, then seal the new connections properly. Our written estimate separates replacement from sealing so you know exactly what each costs before we start. Call (361) 326-5060 for a free inspection.
Sealing closes leaks where air escapes; insulation wraps the duct to prevent thermal loss and condensation on the exterior surface. In El Cerrito’s damp climate, we often recommend both: sealing first to stop air loss, then insulation to prevent the cold-duct sweating that feeds mold growth in marine-layer conditions. A typical combined job in El Cerrito runs $1,500 – $3,800 depending on system size. We price each component separately in writing so you choose what fits your budget.
Yes – we use source-removal methods with agitation tools under negative-air containment and HEPA filtration, which aligns with NADCA guidelines for work in occupied homes. For El Cerrito’s older systems, this means we don’t just seal over dust and debris; we clean accessible trunk lines first so the sealant bonds to metal, not grime. Our technicians document before-and-after conditions with photos you can review. Call (361) 326-5060 to ask about our process on your specific system.
Camera inspection is the only way to know for certain. If the metal is intact with isolated leaks at joints and boots, sealing solves the problem. If we find rusted-through trunk sections, crushed runs that can’t be restored, or flex duct that’s disintegrated from mold, replacement is the only durable fix. At a 1948 bungalow off Fairmount Avenue near El Cerrito Plaza, our tech ran a camera inspection through the original galvanized supply trunk and found a crushed run behind the kitchen remodel, plus a rusted-through section under the hall bath. After source removal with agitation tools under negative pressure and HEPA filtration, we sealed the disconnected trunk with mastic and mesh, then reconnected the crushed run back to the air handler. The homeowner’s dust complaints and uneven room temperatures in the back bedrooms cleared up within a week. We’ll show you the camera footage and explain exactly what sealing can and can’t fix on your system. Call (361) 326-5060 for a free estimate.
Ready to stop losing heated air into a damp crawlspace? Call Hollis Air Duct Cleaning at (361) 326-5060 for a free duct sealing estimate in El Cerrito. We’ll inspect your system with a camera, show you what we found, and hand you a written flat price before any work begins – backed by our 365-Day Done Right Promise in writing.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving El Cerrito and the Bay Area since 2004.