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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AfterFast, Reliable Duct Sealing Across Concord
Duct sealing in Concord typically costs $350 – $850 for a whole-house seal on mid-century homes, and most jobs are completed in a single visit. If you’re tired of hot bedrooms, dusty air, or utility bills that climb every summer, the problem is usually leaks at the plenum, crushed flex runs, or tape that’s turned to powder in your attic.
We serve Concord from our San Francisco Bay Area dispatch office, with crews running daily routes through Sun Terrace, Concord Park, and the neighborhoods off Treat Boulevard and Clayton Road. We know the 1960s ranch with original flex duct, the two-story tract off Oak Grove Road, and the newer infill near the Concord BART station. Each needs a different approach, and we price it in writing before we touch anything. Call (361) 326-5060 for a free estimate.
Why Hollis Air Duct Cleaning Is Concord’s Preferred Duct Sealing Company
We’ve been part of the Garrison Partners family since 2004, and our Duct Sealing in Concord crews have worked in enough Sun Terrace attics to know what the original builders left behind. Our technicians are background-checked, uniformed, and expected to operate by The Garrison Code: arrive inside the quoted window, price in writing, complete the job by the book, and leave the site clean.
Every repair we make carries our 365-Day Done Right Promise. If the seal fails within a year, we return and make it right at no charge, including a free second visit. No negotiation, no runaround. The price you approve in writing before we start is the price on the invoice. We’ve found that Concord homeowners who’ve been burned by bait-and-switch pricing elsewhere appreciate that discipline.
Phones are answered by a live person 24 hours a day, 7 days a week. No voicemail loops, no callback queues, no waiting until Monday to schedule.
HVAC Duct Sealing in Concord
HVAC Duct Sealing in Concord means finding every leak in your forced-air system and closing it with the right material for the joint, the temperature, and the local conditions. In most Concord homes we work on, the real problem isn’t a single big hole. It’s dozens of small leaks at the plenum, at register boots, and where original foil tape has dried and lifted in attic heat that regularly exceeds 140°F during Diablo wind events.
We start with a camera inspection and static-pressure test to map the damage. Then we seal metal joints with mastic, replace failed flex runs, and rebalance the system so every room gets designed airflow. A typical whole-house seal in Concord runs $350 – $850 depending on accessibility and how much of the original ductwork needs attention.
Sealing at the Plenum and Air Handler
The plenum is the sheet-metal box that sits on top of your furnace or air handler. In Concord’s older homes, this joint was often sealed with tape that turns brittle after a decade in attic heat. We clean the galvanized surface, apply mastic, and mechanically secure the connection so it survives the next hot season.
Register Boot and Trunk Line Seals
Leaks where the duct meets the ceiling register are common in homes with settling framing. We seal these with mastic or replace the boot if it’s crushed or corroded. This is often the fix for rooms that never cool properly despite a new HVAC unit.
Duct Repair in Concord
Duct Repair in Concord addresses the physical damage we find inside systems that cleaning alone won’t fix. Crushed flex runs, rodent-chewed jackets, and disconnected collars are standard findings in Sun Terrace and Concord Park homes built during the 1960s and 1970s. We don’t patch over this damage. We remove the failed section, install new flex or rigid duct, seal every joint with mastic, and test static pressure before we leave.
Repair costs in Concord typically run $200 – $600 per damaged run, with whole-system replacements reaching $1,200 – $2,500 when the original flex duct has reached end of life. We photograph everything we find and show you before we quote.
Flex Duct Replacement
When the inner liner is crushed or the insulation jacket is saturated with rodent waste, sealing the joints is pointless. We pull the failed run and install new R-8 flex duct with mechanical supports that prevent the sagging that caused the original failure.
Static Pressure Rebalancing
After repairs, we measure static pressure across the system and adjust dampers to deliver designed airflow to every room. In Concord’s two-story tracts, this often means correcting the original builder’s assumption that upstairs and downstairs should share a single zone.
Trusted Brands We Service in Concord
Our Duct Sealing crews carry professional-grade equipment from Rotobrush and Nikro, plus filtration and sealing products from Honeywell, Aprilaire, and Abatement Technologies. We stock mastic, foil tape rated for high-temperature attics, and replacement flex duct in common diameters so most Concord jobs don’t wait on parts. For newer homes with Honeywell or Aprilaire whole-house filtration, we verify that our sealing work doesn’t compromise the pressure balance those systems depend on.
Common Duct Sealing Problems We See in Concord Homes
- Brittle foil tape on original flex duct. In Concord’s Sun Terrace and Concord Park tracts, builders ran foil-tape-wrapped flex duct through attics that hit 140°F+ in a Diablo-wind summer, so the tape dries, lifts, and lets roof rats pull the insulation open at connections – a failure pattern you rarely see in the BART-corridor infill where ducts are sealed and conditioned.
- Crushed runs behind furnace platforms. The original installers in 1960s Concord homes often routed flex duct across unfinished framing with minimal support. Decades of vibration and attic traffic compress the inner liner until airflow drops to a trickle.
- DIY patches that fail within a season. Homeowners in the Concord Park area sometimes try sealing metal trunk joints with hardware-store foil tape, but the galvanized surface wasn’t cleaned of dust first, so the adhesive never bonds and the leak returns at the next Diablo wind event.
- Rodent damage in unsealed attics. Roof rats in Sun Terrace and Concord Park chew through the flex jacket, stash acorns inside, and crush the inner liner. A sealed joint is useless if the run itself is compromised, so we always scope before we seal.
Pricing for Duct Sealing in Concord, CA
Whole-house duct sealing in Concord typically runs $350 – $850 for homes with accessible attics and standard residential systems. Duct repair, when we need to replace crushed or rodent-damaged runs, adds $200 – $600 per section. Full system replacement on a 1,500-square-foot home with original flex duct reaches $1,200 – $2,500.
What moves the price: attic accessibility (tight trusses add labor), how many runs need replacement versus sealing only, and whether we need to rebalance dampers or add return-air capacity. We give you one flat price per system, agreed in writing before work starts. No per-vent pricing, no add-ons at the door. We photograph before and after so you see what was done. Call (361) 326-5060 for a free estimate.
We Also Serve Cities Near Concord
Our crews run regular routes to Pleasant Hill, Walnut Creek, Lafayette, and Martinez. The same written pricing, same 365-Day Done Right Promise, same background-checked uniformed technicians apply in every city we serve.
Serving Concord, CA - Our Local Coverage Area
We’re based in the Concord 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 Concord
It depends on what the camera shows. If the inner liner is intact and only the tape has failed, we clean the joints and seal with mastic for $350 – $600. If the flex is crushed, sagging, or rodent-damaged, replacement is the only lasting fix, and we’ll show you the photos before we quote. Call (361) 326-5060 to schedule a scope.
Cleaning removes dust and debris; sealing fixes the leaks that let attic air and dust back in. If you’ve had your ducts cleaned but rooms are still dusty or uneven in temperature, the problem is leaks, not dirt. We test static pressure to tell the difference and quote accordingly. Call (361) 326-5060 for a free assessment.
Generally no. The infill townhomes and condos near the BART station use sealed, conditioned duct systems with register gaskets as the typical failure point. We see these for minor gasket replacement at $150 – $300, not the extensive tape and mastic work that 1960s tracts require. Call (361) 326-5060 and we’ll tell you which category your home falls into.
We power down the system, remove old tape and degraded sealant, clean the galvanized metal surface with a wire brush and solvent, apply mastic with a reinforced mesh on large joints, and mechanically secure the connection. Then we test static pressure to confirm the seal holds under operating load. A typical plenum seal runs $200 – $400. Call (361) 326-5060 for an exact quote.
Yes, significantly. Concord’s hot, dry summers and Diablo winds drive fine dust and pollen into leaky duct systems. Sealing the supply side prevents attic air from entering your living space, which is often the real source of persistent dust despite regular cleaning. Most Concord customers notice cleaner surfaces and fewer allergy symptoms within two weeks. Call (361) 326-5060 to discuss your symptoms and schedule a test.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Concord and the San Francisco Bay Area since 2004.