Fast, Reliable Duct Repair & Sealing Across Burlingame
We’re Bellows Air Duct & Vent Co., and we’ve been driving up the Peninsula to fix ductwork in Burlingame since 1984. Most days we can get a truck to your door in Burlingame within the hour, whether you’re off El Camino Real, up in the hills near Skyline Boulevard, or in the flat neighborhoods around Burlingame Avenue. Our Duct Repair & Sealing team knows the particular headaches of Burlingame homes: the 1920s Craftsman with original sheet-metal trunks, the Tudor Revival that got new flex runs during the FAA sound-insulation program, the Spanish Colonial where decades of Bay moisture have turned unsealed joints into mold nurseries. If your system is blowing dust, smelling musty, or running your PG&E bill higher every month, call (844) 685-6342. We’ll show you exactly what’s wrong with a camera, tell you the full price before we touch a tool, and back the work with our 90-Day Done Right Promise in writing.
Why Bellows Air Duct & Vent Co. Is Burlingame’s Preferred Duct Repair & Sealing Company
We’ve built our name in Burlingame on showing up when we say and leaving the job done right. Homeowners here don’t want a coupon that balloons at the door, and we don’t operate that way. Our 90-Day Done Right Promise means if something isn’t right, we come back and make it right. No forms to fill out, no arguments.
Our technicians are background-checked, uniformed, and equipped with Rotobrush and Nikro professional-grade gear. Every job gets a camera inspection before and after, so you see what we see, not just take our word for it. And when you call (844) 685-6342, a live person answers, 24 hours a day, not a voicemail tree.
We know Burlingame’s housing stock intimately. The 94010 and 94011 ZIP codes are filled with homes built between the 1920s and 1940s, many with original or partially-updated duct systems that have accumulated the Peninsula’s damp particulate matter for generations. We’ve worked on Floribunda Avenue in Easton Addition, on streets in Burlingame Park, and throughout the neighborhoods where the FAA’s Residential Sound Insulation Program left behind mixed-age systems that need specialized attention. That local knowledge saves time and prevents callbacks.
Our Duct Repair & Sealing Services in Burlingame
Duct Sealing
Leaky ducts can waste 20 to 30 percent of your heated and cooled air before it ever reaches your rooms. In Burlingame, the problem is often worse than inland cities because our coastal humidity swells and degrades older sealants faster. We pressure-test your system, locate every leak with a smoke pencil or blower-door assist, and seal with mastic or foil-backed tape rated for marine-climate exposure. A typical whole-system duct sealing in Burlingame runs $1,200-$2,400 depending on accessibility and the condition of existing joints.
Flex Duct Repair
Flex duct is common in attic retrofits and additions throughout Burlingame, including many of the FAA sound-insulation upgrades from the 2010s. But flex gets pinched against old rafters, kinked around trusses, or crushed by storage boxes. Restricted airflow creates low-pressure zones where condensation pools, especially in our persistently humid microclimate. We replace damaged sections with properly supported new flex, seal all connections with mastic, and verify airflow with a manometer. Single-section flex duct repair in Burlingame typically costs $280-$550.
Metal Duct Repair
Burlingame’s pre-war homes are full of original galvanized steel trunk lines that have carried air for 80 to 100 years. The metal itself often holds up, but the seams, takeoff collars, and register boots corrode or separate. We’ve resealed original 1940s trunks in Easton Addition homes, patched rusted sections with matching gauge steel, and reattached collars that were pulling away from decades of vibration. Metal duct repair in Burlingame generally ranges from $350 for a localized seam seal to $900 for extensive trunk-line restoration with multiple access cuts.
Duct Insulation
When your ducts run through an unconditioned attic or crawl space, uninsulated or degraded insulation means you’re paying to heat or cool the air around the ducts, not the air inside them. Burlingame’s marine layer keeps those spaces cool and damp year-round, amplifying the energy loss. We wrap repaired or sealed ducts with formaldehyde-free fiberglass insulation or closed-cell foam where appropriate, sealed with vapor-barrier jacketing. Duct insulation in Burlingame typically runs $4-$8 per linear foot, with most whole-attic jobs falling between $800 and $1,800.
Mastic Sealant Application
For Burlingame’s humid conditions, we prefer mastic over foil tape for most permanent seals. Mastic is a thick, fiber-reinforced paste that brushes onto joints and hardens into a flexible, waterproof bond. It won’t peel like tape can when condensation forms. We apply it to every metal-to-metal and metal-to-flex junction after cleaning the surface, then verify with a pressure test. Mastic sealing as a standalone service for accessible ductwork in Burlingame costs $180-$340 for a typical system.
What happens when you call
- 1
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 Burlingame
We carry parts and materials from the brands that serious HVAC contractors specify: Rotobrush for mechanical agitation and HEPA vacuuming, Nikro for negative-air and containment equipment, and Abatement Technologies for filtration and remediation supplies. We don’t show up hoping we have what your job needs. Our trucks are stocked for Burlingame’s common repair scenarios, from replacing corroded sheet-metal fittings to sealing modern flex connections. That means most repairs are completed in a single visit, not stretched across multiple appointments while parts get ordered.
Common Duct Repair & Sealing Problems We See in Burlingame Homes
- Mold colonization at retrofit junctions. In Burlingame’s flat Easton Addition and Burlingame Park neighborhoods, directly under SFO approach paths, ductwork from FAA sound-insulation retrofits routinely meets decades-old original trunk lines. The hidden gaps at these junction points collect particulate and condensation, creating ideal conditions for mold growth in our persistently humid microclimate.
- Debris-laden air leaks at unsealed takeoff collars. When sound-insulation contractors installed new flex runs, many takeoff collars weren’t resealed afterward. These leaks bypass your filter entirely, pulling attic dust and jet-exhaust particulates directly into your airflow and coating your evaporator coils with fine grime unique to Burlingame’s airport-adjacent environment.
- Flex-duct compression in cramped attics. Installers working around Burlingame’s original rafters often pinched new flex runs into tight spaces. The resulting kinks restrict airflow, create low-velocity zones where condensation pools, and eventually split at the stress points. We see this repeatedly in the older homes off Burlingame Avenue and near the Broadway corridor.
- Biological growth in low-velocity return sections. Unlike drier Peninsula cities to the south, Burlingame’s coastal moisture means duct contamination skews heavily toward mold and mildew rather than simple dust accumulation. Return-air ducts with poor slope or sagging flex develop standing condensation that feeds persistent mildew colonies.
Pricing for Duct Repair & Sealing in Burlingame, CA
We don’t do bait pricing. The number we give on the phone is the number on the invoice, and we disclose it before lifting a single tool. Here are the honest ranges for Duct Repair & Sealing in Burlingame:
| Service | Typical Range in Burlingame |
|---|---|
| Mastic sealant application (accessible ductwork) | $180 - $340 |
| Single-section flex duct repair/replacement | $280 - $550 |
| Metal duct repair (localized seam to trunk restoration) | $350 - $900 |
| Whole-system duct sealing | $1,200 - $2,400 |
| Duct insulation (per linear foot) | $4 - $8 |
| Full attic duct insulation job | $800 - $1,800 |
What moves you within these ranges? Accessibility (crawl space vs. walk-in attic), the extent of corrosion or mold damage, whether we need to cut access panels in finished ceilings, and how many junction points require sealing. We also honor our standing $50 Off Any Repair Over $250, and we always offer a Free Second Opinion on Any Written Estimate you’ve received elsewhere. Call (844) 685-6342 for an exact quote on your specific system - estimates are free, and there’s no obligation.
We Also Serve Cities Near Burlingame
Our trucks run regular routes throughout the mid-Peninsula. If you’re in Millbrae, San Mateo, San Bruno, or Foster City and dealing with duct leaks, moldy flex lines, or rising energy bills, we can get there. The same upfront pricing, camera verification, and 90-Day Done Right Promise apply. Call (844) 685-6342 and we’ll dispatch the nearest available technician.
Serving Burlingame, CA - Our Local Coverage Area
We’re based in the Burlingame 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 Burlingame
Look for rooms that never reach temperature, musty odors when the system runs, or visible flex duct in your attic that connects to older metal with no mastic at the joint. On a Tudor Revival home on Floribunda Avenue in Easton Addition, we found the original 1940s metal trunk line mated to a 2018 sound-insulation flex run with unsealed takeoffs. The gap was sucking in attic dust and marine-layer moisture, feeding a mildew colony that was recirculating into the master bedroom. We mastic-sealed every junction and installed a Rotobrush HEPA-vac cleaning on both the old and new sections. If your home was in the FAA program and your ducts have never been inspected since, call (844) 685-6342 for a camera inspection - we’ll show you exactly what’s there.
Active mold growth must be physically removed before sealing; encapsulating live mold traps moisture and makes the problem worse. We use mechanical brushing with HEPA vacuuming to remove biological growth, then apply an EPA-registered sanitizer before sealing with mastic. In Burlingame’s marine-layer conditions, this step is non-negotiable. Call (844) 685-6342 if you smell mildew when your system runs - we’ll inspect with a camera and tell you whether removal and sealing are needed.
Mastic outperforms foil tape in Burlingame’s humidity. Tape adhesive degradates faster when condensation forms on duct surfaces, and tape edges can peel. Mastic is a brush-applied, fiber-reinforced compound that cures into a flexible, waterproof bond rated for wet conditions. We use mastic on every permanent seal we intend to stand behind. For a pressure-tested, mastic-sealed system in Burlingame, call (844) 685-6342 for an estimate - most jobs are done in one visit.
Not necessarily. Original galvanized steel trunk lines often last 80 to 100 years; the problem is almost always at the joints, collars, and connections to newer flex runs. We evaluate the metal’s structural integrity with a camera inspection. If the trunk is sound, we repair the connection points, seal with mastic, and verify airflow. Replacement only makes sense when the metal is extensively corroded or the duct geometry is fundamentally wrong for your current system. A typical inspection and localized repair runs $350-$900 in Burlingame versus $3,000-$6,000 for full replacement. Call (844) 685-6342 and we’ll give you an honest assessment.
Proper duct repair preserves and can improve your soundproofing. The FAA program sealed building envelopes and often added interior insulation; leaky ducts create pressure imbalances that force air through cracks, undermining that tight envelope. Sealing your ductwork restores balanced pressure, reduces the load on your HVAC, and keeps conditioned air where it belongs. We work around existing sound-insulation materials and never compromise the envelope integrity. If you’re concerned about maintaining your retrofit benefits, call (844) 685-6342 - we’ll inspect and explain exactly what we touch and what we don’t.
Ready to get your Burlingame home’s ductwork sealed right? Call Bellows Air Duct & Vent Co. at (844) 685-6342 for a free estimate. We’ll camera-inspect your system, show you the exact price before we start, and back every seal with our 90-Day Done Right Promise. Most repairs are completed in a single visit by a background-checked, uniformed technician. We also honor a permanent 5% Senior and Veteran discount, and our $89 Seasonal Tune-Up can catch small problems before they turn into expensive leaks. We’ve served this area for over 42 years. We’ll be there when we say.
Written by Ray Castillo, Owner at Bellows Air Duct & Vent Co., serving Burlingame since 1984.