Fast, Reliable Duct Repair & Sealing Across San Bernardino
Most duct repair calls we take from San Bernardino are from folks who’ve lived in the same house since the Reagan administration. They don’t want a sales pitch. They want someone who knows why the vents are blowing tan grit every October, and whether the original 1965 ductwork is worth saving or if it’s time to start over. We’re Bellows Air Duct & Vent Co., and we’ve been driving out to San Bernardino from our Los Angeles base since 1984. Our Duct Repair & Sealing team can usually be on your doorstep in San Bernardino within a few hours of your call, and most repairs are finished in a single visit. If your ducts are leaking, rattling, or pushing desert dust into your living room, call us at (855) 401-6006 for a free estimate with upfront pricing.
Why Bellows Air Duct & Vent Co. of California Is San Bernardino’s Preferred Duct Repair & Sealing Company
We’ve built our reputation in San Bernardino one repair at a time, mostly by word of mouth from homeowners in the 92404 and 92407 zip codes who’ve watched us pull apart their original ductwork and explain exactly what failed and why. Roger Castañeda has led this company since its founding, and our 90-Day Done Right Promise is stamped on every job we do in San Bernardino: if it’s not right, we come back at no charge, no paperwork, no arguing.
Our technicians are background-checked, uniformed, and equipped with camera inspection systems so you see the before and after with your own eyes. Calls are answered by a live person 24 hours a day, not an app or a voicemail tree. We don’t bait you with a low coupon and then change the price at the door. The number we give you on the phone is the number on the invoice. That’s been our policy for 42 years, and it’s not changing.
Our Duct Repair & Sealing Services in San Bernardino
Duct Sealing with Mastic Sealant
San Bernardino’s original 1950s-1970s tract homes commonly feature duct board or sheet-metal ducts with Duro Dyne or hard-cast mastic joints that fail after 50+ years. When those joints crack, they don’t just leak conditioned air; they release decades of trapped fine particulate from wildfire smoke and desert silica directly into your living spaces, especially during Santa Ana wind events. We seal with professional-grade mastic sealant rated for attic temperatures that regularly exceed 140°F in San Bernardino summers. A typical mastic sealing job for a 1,200-1,800 square foot home in San Bernardino runs $340-$580.

Metal Duct Repair
Legacy galvanized sheet-metal ductwork in San Bernardino’s older neighborhoods has a specific failure pattern we see constantly. Sheet-metal saddle taps sheer off during Santa Ana wind pressure surges, creating massive air leaks that bypass your filter entirely and pull unfiltered Mojave silt straight into your HVAC equipment. That abrasive tan grit destroys blower motors and coats evaporator coils. We repair or replace metal trunk lines, restore proper saddle tap connections, and reinforce weak points. Metal duct repair in San Bernardino typically costs $280-$620 depending on accessibility and extent of damage.

Flex Duct Repair and Replacement
The 1970s additions common in San Bernardino’s post-military boom housing stock were often plumbed with undersized flex-duct runs that collapse under the combined weight of dust accumulation and attic heat exceeding 150°F. Patching a collapsed flex duct is usually throwing good money after bad. We replace with properly sized, insulated flex duct rated for the thermal load. Expect $180-$340 per run for replacement, or $120-$220 for repair if the damage is localized and the duct is properly sized.

Duct Insulation
Uninsulated or degraded duct insulation in San Bernardino attics is costing you more than almost anywhere else in California. With summer temperatures pushing 105°F for months straight, attic ductwork without R-6 wrap or better is essentially trying to cool your house with a radiator. We wrap trunk lines and replace degraded insulation with foil-faced fiberglass or closed-cell foam appropriate for your system. Duct insulation work in San Bernardino generally runs $420-$780 for a typical single-system home.

What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
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 San Bernardino
We carry parts and materials from Honeywell, Aprilaire, and Nikro on every San Bernardino service truck, which means most repairs don’t require a second trip. Honeywell zone dampers and Aprilaire media air cleaners integrate directly with legacy ductwork configurations common in San Bernardino’s older housing stock. Our Nikro HEPA vacuums and contact cleaning equipment handle the heavy particulate loads we pull from San Bernardino systems without clogging or losing suction. If your system uses a specific component we don’t stock, we’ll tell you before we start and give you an exact timeline for parts arrival. No surprises on the bill.
Common Duct Repair & Sealing Problems We See in San Bernardino Homes
- Original duct board joints disintegrating from age and moisture. The 1950s-1970s tract homes that dominate San Bernardino’s affordable housing market were built with duct board joints sealed with hard-cast mastic that turns brittle after five decades. When those joints fail, they release decades of accumulated wildfire ash and desert silica into rooms, especially in 92404 and 92407 foothill homes where Santa Ana winds pressurize the attic space.
- Sheet-metal saddle taps sheering off during wind pressure surges. Santa Ana events blasting through Cajon Pass create pressure differentials that stress legacy duct connections. We’ve found saddle taps completely separated from trunk lines, pulling unfiltered attic air and Mojave silt directly into the HVAC stream.
- Undersized flex-duct runs collapsing under dust and heat load. The 1970s additions common near Cal State San Bernardino and along Base Line were often retrofitted with flex duct too small for the airflow demand. After fifty years of dust accumulation and thermal degradation, these runs collapse entirely and require full replacement.
- Insulation degradation from extreme attic temperatures. San Bernardino attics regularly exceed 140°F in summer, degrading fiberglass insulation and vapor barriers faster than in coastal climates. Exposed ductwork becomes a heat source instead of a distribution system, driving cooling costs up and system runtime into the red.
Pricing for Duct Repair & Sealing in San Bernardino, CA
Here’s what honest duct repair pricing looks like in San Bernardino’s market. These ranges reflect our actual invoices from the last twelve months across the 92401, 92402, 92403, and 92404 zip codes:
| Service | Typical Range in San Bernardino |
|---|---|
| Mastic sealant application (whole system) | $340 - $580 |
| Metal duct repair (per section/trunk) | $280 - $620 |
| Flex duct repair (localized patch) | $120 - $220 |
| Flex duct replacement (per run) | $180 - $340 |
| Duct insulation (R-6 wrap, typical home) | $420 - $780 |
| Camera inspection with full report | $89 - $149 |
What moves you toward the higher end: multiple attic access points, extensive contamination requiring pre-cleaning, or hard-to-reach ductwork in tight eave spaces. What keeps you toward the lower end: straightforward access, localized damage, and systems that have been maintained within the last decade. We disclose your exact price before we lift a single tool. Our standing $50 Off Any Repair Over $250 applies to most jobs on this list, and we offer a permanent 5% Senior and Veteran discount. Call (855) 401-6006 for your free estimate.
We Also Serve Cities Near San Bernardino
Our service area extends throughout the San Bernardino Valley and surrounding foothill communities. We regularly run calls in San Bernardino proper as well as Muscoy, Highland, Loma Linda, and Rialto. Same response standards apply: live person on the phone, background-checked technician at your door, camera-verified results, and the 90-Day Done Right Promise in writing.
Serving San Bernardino, CA - Our Local Coverage Area
We’re based in the San Bernardino 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 San Bernardino
That tan grit is desert silica blown through Cajon Pass during Santa Ana conditions, entering your attic through soffit vents and penetrating cracked duct joints. Your original 1960s ductwork likely has deteriorated mastic seals or separated saddle taps that bypass your air filter entirely. We see this constantly in north-side and foothill-adjacent zip codes like 92404 and 92407. Call (855) 401-6006 and we’ll camera-inspect your system to locate every leak point.
Repair is viable if the metal is structurally sound and leaks are limited to accessible joints and connections. Replacement makes sense when the trunk line is rusted through, extensively contaminated with baked-on silt, or undersized for your current HVAC load. We sealed a 1965 ranch-style home on N Sierra Way in the 92407 foothills where original galvanized duct joints had cracked, spewing tan desert silt into every room. Our crew applied mastic sealant and wrapped the main trunk with R-6 insulation, cutting summer cooling costs by 22% per the homeowner’s follow-up. We’ll give you a straight assessment with camera evidence so you can decide. Free estimates at (855) 401-6006.
Given San Bernardino’s unique contamination load from wildfire smoke, desert silica, and ozone-trapping valley geography, we recommend inspection every 3-5 years for homes with original ductwork, and every 5-7 years for systems that have been previously sealed or replaced. If you notice increased dust, uneven cooling, or spikes in your summer electric bill, call sooner. Our $89 Seasonal Tune-Up includes a basic leak check. Call (855) 401-6006 to schedule.
Yes, if it’s the right product. We use fiber-reinforced, water-based mastic rated for continuous exposure to 200°F, which exceeds even the worst San Bernardino attic conditions. The cheap brush-on products sold at hardware stores dry out and crack within two summers. Our mastic remains flexible and maintains its seal through temperature cycles that would destroy lesser materials. A proper mastic sealing job in San Bernardino typically lasts 15-20 years. Call (855) 401-6006 for an exact quote - estimates are free.
Undersized flex-duct common in 1970s San Bernardino additions was never designed for the airflow demand of modern HVAC equipment, and fifty years of dust accumulation adds weight that the original wire helix can’t support. Attic heat exceeding 140°F degrades the plastic vapor barrier, weakening the structure further. Patching doesn’t solve the underlying sizing problem. We replace with properly engineered flex duct or rigid metal where appropriate, sized to your system’s CFM requirements. Replacement runs $180-$340 per run in San Bernardino. Call (855) 401-6006 for a free assessment.
Ready to stop losing conditioned air to your attic and breathing decades of accumulated desert dust? Call Bellows Air Duct & Vent Co. at (855) 401-6006 for a free estimate on duct repair and sealing in San Bernardino. We’ll show you exactly what’s failing, fix it right, and stand behind it for 90 days in writing. That’s the square deal we’ve offered for 42 years.
Written by Roger Castañeda, Owner at Bellows Air Duct & Vent Co., serving San Bernardino since 1984.