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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After
Before
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Before
AfterFast, Reliable Duct Sealing Across Walnut Creek
Duct sealing in Walnut Creek typically runs $800 – $2,400 for a whole-home system, with most ranch homes falling in the $1,200 – $1,800 range depending on whether the original 1960s ductwork needs partial replacement or just joint sealing. We’re the Walnut Creek crew from Hollis Air Duct Cleaning, and we know this city’s housing stock: the 1970s ranches off Ygnacio Valley Road, the downtown condos with shared chases, the hillside homes catching Diablo wind smoke every fire season. Our technicians are background-checked, uniformed, and carry the same Rotobrush and Nikro equipment commercial crews use. Calls go to a live person, 24 hours a day, and we quote in writing before touching anything. If you’re smelling smoke when the AC kicks on or your upstairs rooms never cool down, call (361) 326-5060.
Why Hollis Air Duct Cleaning Is Walnut Creek’s Preferred Duct Sealing Company
We’ve been working in Walnut Creek long enough to know which neighborhoods have original flex duct, which downtown buildings share vertical chases between units, and why a standard duct cleaning doesn’t stop smoke odor from coming back. Our crew serves the full Walnut Creek area from our San Francisco Bay Area dispatch office, with scheduling that respects the parking restrictions and access rules common to downtown condos and apartment stacks.
Our customers in Walnut Creek come back because we do what we said we’d do. The Garrison Standard means arriving inside the quoted window, pricing in writing before any work starts, and leaving the site clean. Every job carries the 365-Day Done Right Promise: if the seal fails or the smoke odor returns within a year, we come back and make it right at no charge, including a free second visit. No negotiation, no runaround.
Our technicians are accountable. Background-checked, uniformed, and trained on The Garrison Code. You know who’s walking into your home before they arrive. That’s not a slogan; it’s how we operate on every job in Walnut Creek, from the ranch homes near Larkey Park to the condo buildings along North Main Street.
Duct Sealing Services in Walnut Creek
Duct Sealing Services in Walnut Creek address a problem most homeowners don’t know they have: conditioned air leaking into attics, crawl spaces, and wall cavities through gaps at joints, seams, and connections. In a typical Walnut Creek ranch home with original 1960s ductwork, we regularly measure 25 – 35% air loss before sealing. That means your AC works harder, your upstairs rooms stay hot, and your energy bill climbs every summer when temperatures hit 100°F and stay there.
Our Duct Sealing process starts with a pressure test to locate leaks, followed by mechanical sealing of joints using mastic compound and specialized tape rated for HVAC systems. For homes with flex duct runs that have degraded at connections, we replace damaged sections and seal the new joints properly. A typical whole-home sealing job in Walnut Creek runs $1,200 – $1,800 for a single-story ranch, $1,800 – $2,400 for larger two-story homes or those needing significant duct repair. We quote the full price in writing before starting.
Smoke-Odor Sealing and Plenum Inspection
After Diablo wind events, standard duct cleaning often misses the real problem. Fine ash settles in the return plenum, and leaky joints pull it back through the air handler every cycle. We check the return plenum for smoke odor before opening any registers, then seal the leaks that let it recirculate. This specialized service adds $200 – $400 to a standard sealing job but solves the problem cleaning alone cannot.
Shared-Chase Sealing for Condos and Apartments
In downtown Walnut Creek buildings with shared duct chases, smoke and odors migrate between units through gaps in common vertical runs. Sealing only your unit’s supply and return ducts leaves these pathways open. We inspect common chases where accessible and coordinate with building management when needed to address cross-unit leakage.
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.
Duct Insulation in Walnut Creek
Duct Insulation in Walnut Creek matters because uninsulated or poorly insulated ductwork in attics and crawl spaces loses temperature fast. When it’s 100°F outside and your attic hits 140°F, a supply duct with thin or degraded insulation is dumping cooled air into a furnace before it reaches your bedroom. In Walnut Creek’s climate, this isn’t a comfort issue; it’s an efficiency killer that shows up on your PG&E bill every summer.
We install foil-faced fiberglass duct insulation or closed-cell foam wrap depending on the application, with R-values appropriate for California Title 24 requirements. For original 1960s ranch homes with uninsulated metal duct, we often combine sealing and insulation in one pass. Typical insulation work in Walnut Creek runs $600 – $1,500 for a whole-home system, with smaller partial jobs starting around $400. We quote exact scope and price before starting.
Attic Duct Insulation Replacement
Insulation on attic ductwork compresses and degrades over decades. We remove the old material, seal any newly accessible joints, and install fresh insulation with proper vapor barriers. This is standard practice on Walnut Creek ranches built before 1980, where original insulation has often fallen off entirely.
Crawl Space Duct Protection
Walnut Creek’s wet winters can put moisture into crawl spaces, degrading duct insulation from the outside in. We use moisture-resistant insulation products and check for condensation issues that could undermine the new work within a season.
Trusted Brands We Service in Walnut Creek
Our Walnut Creek crews work with professional-grade equipment from Nikro, Honeywell, and Aprilaire. The Nikro negative-air machines we use for containment during sealing jobs are the same units found in commercial remediation work. For filtration upgrades after sealing, we stock Honeywell and Aprilaire media filters in common sizes, so Walnut Creek customers don’t wait days for parts. We also carry Abatement Technologies HEPA filtration units for post-smoke sealing jobs where fine particulate control matters. Everything is specified in your written quote; nothing gets added at the door.
Common Duct Sealing Problems We See in Walnut Creek Homes
- Smoke ash trapped in return plenums after Diablo wind events. Standard cleaning scrubs the ducts but misses the plenum where fine ash settles. Leaky joints pull it back into circulation. We check the plenum first, seal the leaks, and verify with camera inspection.
- Original 1960s flex duct with unsealed joints at every connection. Walnut Creek ranch homes often have decades of vibration working joints loose. We pressure-test to find the worst leaks, then seal or replace as needed.
- Cross-unit smoke migration in downtown condos with shared chases. One unit’s duct seal failure lets smoke-laden air pass to neighbors. We inspect common runs and seal accessible penetration points.
- Upgraded HVAC on original ductwork without resizing or sealing. A new high-efficiency system pushing more air through leaky old ducts just makes the leaks worse. We match sealing scope to the actual airflow the system delivers.
Pricing for Duct Sealing in Walnut Creek, CA
Whole-home duct sealing in Walnut Creek runs $800 – $2,400, with most single-story ranch homes between $1,200 – $1,800. Two-story homes, larger square footage, or significant duct repair push toward the higher end. Smoke-odor remediation with plenum sealing adds $200 – $400. Duct insulation alone runs $600 – $1,500. We don’t quote per-vent pricing or teaser rates that balloon once we’re inside. You get one flat price per system, agreed in writing before work starts. Factors that affect your specific price: accessibility of duct runs, amount of damaged flex needing replacement, whether shared chases in condo buildings require coordination, and any insulation replacement bundled with the sealing. Call (361) 326-5060 for a free estimate with exact numbers for your home.
We Also Serve Cities Near Walnut Creek
Our crews work throughout the central Contra Costa corridor, including Duct Sealing in Walnut Creek and the surrounding communities of Lafayette, Alamo, Moraga, and Pleasant Hill. Same standards, same written pricing, same 365-Day Done Right Promise apply in every city we serve.
Serving Walnut Creek, CA - Our Local Coverage Area
We’re based in the Walnut Creek 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 Walnut Creek
Because cleaning removes loose debris but doesn’t seal the leaks that let ash recirculate from the return plenum. Fine ash from Diablo wind events settles deep in the plenum and gets pulled back through the air handler every cycle through gaps at duct joints. We seal those leaks and verify with camera inspection; call (361) 326-5060 if the odor persists after your last cleaning.
We work with your building management to schedule access to common mechanical rooms and shared chases where possible. In-unit work covers your supply and return ducts; common-area sealing requires building approval and coordination. We document everything in writing for your HOA if needed.
MERV 11 – 13 for most homes, MERV 13 or higher with added filtration if you’re in a heavy pollen zone near the oak woodlands or dealing with recurring wildfire smoke. Sealing fixes the leaks; proper filtration catches what gets through. We stock Honeywell and Aprilaire media in standard sizes and can recommend based on your specific location and system capacity.
Yes. Shared dryer vent stacks in downtown Walnut Creek condos are a separate service from HVAC duct sealing, but we handle both, including Walnut Creek Dryer Vent Cleaning. Stack sealing requires building-wide coordination and proper fire-rated materials. Call (361) 326-5060 to discuss your building’s specific setup.
Every 10 – 15 years for inspection, sooner if you notice uneven cooling, rising energy bills, or smoke odor after fire season. Original 1960s – 70s flex duct degrades faster than modern materials, and Walnut Creek’s temperature swings stress joints annually. We include a written assessment of remaining duct life with every sealing job.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Walnut Creek since 2004.