Fast, Reliable Duct Repair & Sealing Across Lomita
Duct repair and sealing in Lomita typically runs $280-$650 for most residential jobs, with mastic sealant work on older metal trunk lines falling in the $320-$480 range. We’re usually on site within the hour for Lomita calls, and most repairs are finished same day. Call (844) 685-6342 for a free estimate.
We’ve been driving to Lomita since 1984, back when most of these homes were already thirty years old. Our technicians know the difference between a 1950s California bungalow off Narbonne Avenue and a 1960s tract home near Eshelman Avenue, and we know what kind of ductwork each one hides in its attic. The marine layer rolls in heavy here, and the port traffic along PCH and Western Avenue leaves its mark on everything, including the air moving through your vents. That’s not a talking point. It’s what we find every time we scope a Lomita duct system.
Why Bellows Air Duct & Vent Co. Is Lomita’s Preferred Duct Repair & Sealing Company
Bellows has been serving South Bay homeowners for over 42 years, and Lomita has always been part of our route. We’re not a dispatch service routing calls to whoever’s available. Our technicians are background-checked, uniformed, and employed by us. They answer to a live person at our office, 24 hours a day, not an app or a voicemail tree.
Our Duct Repair & Sealing team carries the equipment to repair galvanized metal trunk lines, replace collapsed flex duct, and apply professional-grade mastic sealant on site. Every job gets a camera inspection before we start and after we finish, so you see what we saw and what we fixed.
We offer a 90-Day Done Right Promise on every repair. If something’s not right, we make it right. No paperwork, no arguing. That’s been our policy since Ray Castillo founded the company, and it’s non-negotiable.
Our standing offers include $50 off any repair over $250, a free second opinion on any written estimate, and a permanent 5% senior and veteran discount. We also run an $89 seasonal tune-up for homeowners who want to catch problems before they turn into repairs.
Our Duct Repair & Sealing Services in Lomita
Mastic Sealant Application
Mastic sealant is the right fix for most leaking joints in Lomita’s older galvanized ductwork. Unlike duct tape, which fails within a year of temperature swings and attic moisture, mastic forms a permanent flexible bond that expands and contracts with the metal. A typical mastic sealing job in Lomita runs $320-$480 for a standard single-system home, depending on how many joints need treatment and whether we need to access them through the attic or crawl space. We apply it by hand to every seam, takeoff boot, and register connection, then verify the seal with a pressure test before we leave.
Metal Duct Repair
Lomita’s post-WWII homes often have original galvanized metal ductwork with decades of accumulated port-traffic soot and moisture damage, making mastic sealant or full metal duct repair more effective than simply replacing flex sections. The metal itself is usually sound. It’s the seams, takeoff boots, and floor register connections that corrode or separate. We cut out damaged sections, fabricate replacements from matching gauge metal, and seal all joints with mastic. Metal duct repair in Lomita typically costs $380-$620. On a recent job near PCH and Western Avenue, we found a 1950s metal trunk line with corroded takeoff boots sealed only with duct tape that had failed. We cut out the damaged sections, applied mastic sealant to all joints, and wrapped the repaired runs with new insulation to prevent future condensation.
Flex Duct Repair and Replacement
Original flex duct insulation in Lomita’s unconditioned attics collapses or separates at joints, allowing conditioned air to leak into the attic and drawing in soot-laden attic air. We see this constantly in homes off Lomita Boulevard and near the 90717 zip code boundary. When the inner liner tears or the insulation blanket compresses, the duct has to be replaced, not patched. Flex duct replacement runs $240-$420 per run in Lomita, with most homes needing two to four runs. We use insulated flex rated for attic installation and support it properly so it doesn’t sag and create new low spots where moisture collects.
Duct Insulation
Adding insulation to repaired ducts in Lomita is worth doing. The marine layer pushes moist air into attic ductwork overnight, and bare or degraded insulation lets that condensation reach the duct surface. Moisture from marine layer combined with port particulates accelerates corrosion in metal ducts, especially at seams and around floor registers nearest the truck corridors. We wrap repaired metal runs with R-6 or R-8 insulation and seal the vapor barrier with foil tape. Duct insulation work in Lomita typically adds $180-$340 to a repair job, depending on linear footage. For homeowners near PCH and Western Avenue, where the soot load is heaviest, this extra layer also helps prevent particulate infiltration through seams that aren’t perfectly sealed.
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 Lomita
We carry professional-grade equipment and materials from Nikro, Honeywell, and Abatement Technologies, the same brands serious HVAC contractors specify for commercial jobs. For Lomita repairs, we stock mastic sealant, foil tape, insulated flex duct, and metal fittings in our service vehicles so we’re not making supply runs while your system is open. That means most Lomita jobs are completed in a single visit. If we encounter something unusual, like a custom-sized galvanized fitting from a 1950s installation, we’ll fabricate it on site or source it within 24 hours.
Common Duct Repair & Sealing Problems We See in Lomita Homes
- Collapsed or separated flex duct insulation. Original flex duct in Lomita’s post-war homes has reached the end of its service life. The insulation blanket compresses, the inner liner tears at joints, and conditioned air leaks into the attic while attic air gets drawn into the system. We replace these runs with new insulated flex, properly supported.
- Corroded metal duct seams and takeoff boots. Moisture from the marine layer combined with fine port particulates accelerates corrosion in galvanized metal ducts. Technicians scoping ducts in homes nearest to PCH and Western Avenue consistently find black soot-like deposits on duct interiors that homes even a mile farther north rarely show, a pattern specific to Lomita’s location on the port-traffic belt.
- Failed duct tape repairs from previous contractors. Previous repairs using only duct tape (not mastic or foil tape) fail within a year due to temperature swings and moisture, leaving leaks that undermine IAQ improvements. We remove the old tape, clean the metal, and apply mastic for a permanent seal.
- Undersized or uninsulated return air pathways. Many Lomita homes were built with wall cavities or joist bays used as return ducts, unlined and unsealed. These draw attic air, dust, and port particulates directly into the system. We can retrofit proper return ductwork where this is found.
Pricing for Duct Repair & Sealing in Lomita, CA
| Service | Typical Range in Lomita |
|---|---|
| Mastic sealant application (standard system) | $320-$480 |
| Metal duct repair (per section) | $380-$620 |
| Flex duct replacement (per run) | $240-$420 |
| Duct insulation wrap (per run) | $180-$340 |
| Full system evaluation with camera inspection | $89-$150 (credited toward repair) |
These are the numbers we give Lomita homeowners before we start. No bait coupons, no price changes at the door. The final cost depends on what we find when we scope your system, which is why we start with a camera inspection. Homes with original 1950s metal ductwork typically need more extensive sealing work than homes with newer flex systems. Homes near PCH and Western Avenue often show heavier particulate loading that requires additional cleaning before sealing. We explain what we found, show you the camera footage, and give you a written price before any repair begins. Call (844) 685-6342 for a free estimate.
We Also Serve Cities Near Lomita
Our service area covers the full South Bay. We regularly perform Duct Repair & Sealing in Lomita and neighboring communities including Torrance, San Pedro, West Carson, and Manhattan Beach. The same technicians, the same equipment, and the same upfront pricing apply across every city we serve.
Serving Lomita, CA - Our Local Coverage Area
We’re based in the Lomita 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 Lomita
If your home has original galvanized ductwork and you’ve never had it professionally sealed with mastic, it should be evaluated now. Most of this metal in Lomita is sixty to seventy years old, and the combination of port soot and marine-layer moisture has likely compromised every joint and seam. Call (844) 685-6342 to schedule a camera inspection, and we’ll show you exactly what condition your system is in.
Yes, in most cases. The galvanized metal itself is often structurally sound. Mastic sealant bonds permanently to clean metal and remains flexible through decades of thermal expansion. We apply it to every joint, seam, and takeoff boot, then pressure-test to verify. If a section is too corroded to seal, we’ll cut it out and fabricate a replacement. Call (844) 685-6342 for an exact assessment, estimates are free.
Duct tape was never designed for this application, and in Lomita’s attics it fails predictably. Temperature swings between hot days and cool marine-layer nights cause the adhesive to degrade, and attic moisture finishes the job. Previous repairs using only duct tape (not mastic or foil tape) fail within a year due to temperature swings and moisture, leaving leaks that undermine IAQ improvements. Mastic sealant is the permanent solution. Call (844) 685-6342 and we’ll remove the old tape and do it right.
Yes, sealing is a critical part of the solution. The black deposits we find in Lomita ducts nearest to PCH and Western Avenue are fine carbon-based particulates from port traffic and drayage trucks. Leaky return ducts draw attic air directly into your system, and if your attic has infiltration from outside, those particulates circulate through your home. Sealing the duct system stops this bypass, and when combined with proper filtration, reduces the soot load significantly. Call (844) 685-6342 for a camera inspection and we’ll show you the source.
Yes, especially for metal duct runs in unconditioned attics. The marine layer keeps Lomita’s attic humidity elevated through much of the year, and bare or degraded insulation lets condensation form on the duct surface. That moisture accelerates corrosion and can support mold growth. We wrap repaired runs with new R-6 or R-8 insulation as standard practice. The added cost is modest compared to repeating the repair in five years. Call (844) 685-6342 for pricing on your specific system.
Ready to get your Lomita home’s ductwork sealed right? Call (844) 685-6342 for a free estimate. We’ll send a background-checked, uniformed technician with a camera, show you what’s happening inside your ducts, and give you one honest price before any work begins. Our 90-Day Done Right Promise means we stand behind it, no paperwork, no arguing.
Written by Ray Castillo, Owner at Bellows Air Duct & Vent Co., serving Lomita since 1984.