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.
Fast, Reliable Duct Sealing Across Brentwood
Duct sealing in Brentwood typically runs $450 – $1,200 for a whole-house system, and most jobs take a half-day to complete with the full scope priced in writing before we start. We’re the Duct Sealing team at Hollis Air Duct Cleaning, and we serve Brentwood from our San Francisco Bay Area dispatch office. Our crews know the tract neighborhoods here, from Deer Ridge to Shadow Lakes to the streets off Balfour Road. We’ve been doing this since 2004, and we’ve learned that a duct call in Brentwood is rarely just about cleaning. The clay soils under these slab foundations shift, the attic hits 130°F in July, and the flex-duct joints pull apart. We show up in uniform, run a camera first, and give you a written price before any work starts. Call (361) 326-5060 for a free estimate.
Why Hollis Air Duct Cleaning Is Brentwood’s Preferred Duct Sealing Company
We’ve built our reputation in Brentwood by treating duct sealing as a repair discipline, not an upsell. Homeowners here have seen the bait-and-switch: a $99 coupon that becomes an $800 invoice once the van is in the driveway. We don’t work that way. The price is written down before we touch anything, and it doesn’t move at the door.
Our technicians are background-checked and uniformed, and they operate under The Garrison Standard. That means arriving inside the quoted window, pricing in writing, completing the job by the book, and leaving the site clean. No exceptions.
Every repair we make is backed by our 365-Day Done Right Promise. If the seal fails, the joint separates, or the repair doesn’t hold, we come back and make it right at no charge, including a free second visit. That’s written on every job, not implied.
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 morning to schedule.
Duct Insulation in Brentwood
Duct Insulation in Brentwood is usually a companion job to sealing, not a standalone service, because the same attic conditions that destroy seals also degrade insulation. We install wrap insulation on flex-duct runs that have lost their R-value to compression, rodent damage, or years of 130°F attic heat. A typical duct insulation job in Brentwood runs $300 – $800 depending on linear footage and accessibility, always priced as one flat rate per system before we start.
When Insulation Beats Replacement
Some crews default to replacing every run. We don’t. If the flex duct itself is intact but the insulation jacket is compressed or torn, we can re-wrap with formaldehyde-free fiberglass or foil-faced bubble wrap, depending on the chase configuration. This saves Brentwood homeowners the cost of full duct replacement when the underlying airway is sound.
Attic Heat and R-Value Loss
Brentwood attics regularly exceed 130°F from June through September. Standard R-6 flex duct insulation degrades to an effective R-3 or lower within a decade in that environment. We measure surface temperatures with infrared guns and photograph the readings so you see what we see.
HVAC Duct Sealing in Brentwood
HVAC Duct Sealing in Brentwood is fundamentally about reconnecting ductwork that has physically separated, not just painting over old seams with mastic. The expansive Delta clay under these slab-on-grade homes shrinks during the dry-season groundwater drawdown, and that foundation movement pulls apart flex-duct joints at the plenum and boot collars. A typical HVAC duct sealing job in Brentwood runs $450 – $1,200 for a full system, with simpler single-zone repairs at the lower end and multi-story homes with extensive separation at the higher end.
Camera Inspection Before Sealing
We run a borescope camera through every accessible run before we quote. This lets us show you exactly where joints have separated versus where seals have simply aged out. Sealing over a disconnected joint hides the problem; reconnecting it fixes it. We don’t guess, and we don’t ask you to trust us blindly.
Mastic, Mesh, and Mechanical Reconnection
For separated collars, we reconnect with mechanical fasteners first, then seal with water-based mastic and fiberglass mesh. For intact seams that have aged out, we remove failed foil tape and reseal with mastic rated for the temperature swings Brentwood attics see. The work is photographed before and after, and you get the images.
Trusted Brands We Service in Brentwood
We carry professional-grade equipment and materials from Nikro, Honeywell, Aprilaire, and Abatement Technologies. Our Nikro negative-air machines handle source removal on heavily contaminated systems. For filtration upgrades after sealing, we stock Honeywell and Aprilaire media cabinets and electronic air cleaners. We keep common boot collars, flex-duct connectors, and mastic compounds on our vans so Brentwood jobs don’t wait on parts runs. Most repairs are completed in a single visit.
Common Duct Sealing Problems We See in Brentwood Homes
- Foundation-shifted separations at plenum and boot joints. The expansive clay soils under Brentwood’s post-tension slabs shrink dramatically during the dry season, and that movement physically pulls apart flex-duct connections. We find this in Deer Ridge, Shadow Lakes, and throughout the 1990s-2000s tract neighborhoods.
- Heat-degraded foil tape and mastic in 130°F attics. Cheap tape fails in two to three summers in Brentwood’s climate. We remove the residue and reseal with high-temperature mastic rated for the actual conditions your attic sees.
- Rodent damage to flex duct and insulation during wet winters. When Delta rains push rodents indoors, they chew through attic duct runs and reopen sealed pathways. We repair the damage, seal the entry points we can access, and photograph the compromised runs.
- Disconnected returns pulling attic air into the system. A separated return duct in a Brentwood attic doesn’t just leak conditioned air out; it pulls 130°F dust-laden attic air directly into your air handler. We test static pressure before and after repair to verify the fix.
Pricing for Duct Sealing in Brentwood, CA
A typical whole-house duct sealing in Brentwood runs $450 – $1,200. Single-zone repairs or partial reconnection of separated joints start around $450. Full-system sealing on a two-story home with multiple separated boots and degraded mastic throughout runs toward $1,200. Duct insulation adds $300 – $800 depending on linear footage.
What moves the price: accessibility of attic chases, extent of separation versus simple seal degradation, whether rodent damage requires section replacement, and whether we find disconnected returns that need reconnection, not just sealing. We price by the system, not by the vent. No per-vent pricing, no teaser coupons, no invoice that balloons once we’re inside.
Every estimate is free. We inspect with a camera, show you what we found, and give you a written price before any work starts. Call (361) 326-5060 to schedule.
We Also Serve Cities Near Brentwood
Our crews regularly work in Oakley, Discovery Bay, Antioch, and Clayton. The same expansive clay soil conditions, attic heat issues, and tract housing stock extend across eastern Contra Costa County. If you’re in Brentwood or any of these neighboring communities, we run the same process: camera inspection, written price, photographed results, 365-Day Done Right Promise.
Serving Brentwood, CA - Our Local Coverage Area
We’re based in the Brentwood 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 Brentwood
Yes, probably. The dominant housing stock in Brentwood is 1990s-2020s tract construction with flex-duct runs in the attic, and those systems are now 15-25 years old. Foundation movement from expansive clay soils, combined with years of attic heat cycling, means joints have likely separated or seals have degraded even if your ducts were never touched. We run a camera inspection to confirm before we quote. Call (361) 326-5060 for a free estimate.
Every 10-15 years under normal conditions, but Brentwood’s conditions aren’t normal. The combination of foundation movement and 130°F attic heat means many homes need resealing or reconnection at 7-10 years. We don’t recommend sealing on a schedule; we recommend a camera inspection if your energy bills are climbing, rooms aren’t heating or cooling evenly, or your system runs constantly. Call (361) 326-5060 and we’ll look before we quote.
Yes. We photograph every repair with a borescope camera: the separated joint before reconnection, the reconnected and sealed joint after, and any insulation we added. You get these images as part of the job documentation. No “trust us, we fixed it.” Visual proof, in your own ducts, with your own eyes. Call (361) 326-5060 to schedule.
Yes. In Brentwood’s hot, dry summers, a disconnected return duct pulls 130°F attic air and Delta dust directly into your living space. Sealing and reconnecting those runs improves indoor air quality and reduces the load on your air handler, which extends equipment life. The energy savings matter, but the air you’re actually breathing matters more. Call (361) 326-5060 for an inspection.
We don’t promise same-day dispatch. Duct sealing is a scheduled repair that requires camera inspection, written pricing, and typically a half-day of work. We answer phones live 24/7 and schedule as quickly as our calendar allows, usually within a few days. The job is done right, not done rushed. Call (361) 326-5060 to book.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Brentwood and the San Francisco Bay Area since 2004.




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