Duct Sealing in San Ramon - Tested First, Written Price Second

Fast, Reliable Duct Sealing Across San Ramon

Duct sealing in San Ramon typically costs $1,200 – $2,800 for a whole-home system, with most jobs completed in a single visit after a written estimate. We’re the San Ramon crew from Hollis Air Duct Cleaning, and we’ve been sealing ducts in the valley long enough to know the difference between a Gale Ranch attic flex-duct job and a rural property off Bollinger Canyon Road where wildfire ash has been leaking in for three fire seasons. Our technicians dispatch from the San Francisco Bay Area office and carry mastic, foil tape, and aerosol sealant rated for the temperature swings these hills throw at ductwork. Call (361) 326-5060 and we’ll put a flat price in writing before any sealant touches your system.

Call (361) 326-5060

Why Hollis Air Duct Cleaning Is San Ramon’s Preferred Duct Sealing Company

We’ve sealed ducts in San Ramon’s master-planned communities and in rural parcels backing to Las Trampas Ridge, so we know which homes need mastic reapplied every five years and which ones need the whole plenum rebuilt. Our Duct Sealing team works under The Garrison Standard: arrive inside the quoted window, price in writing before work starts, leave the site clean. Every job carries our 365-Day Done Right Promise – if the seal fails or the dust returns within a year, we come back at no charge, including a free second visit.

Our technicians are background-checked and uniformed, and you’ll know who’s arriving before they pull in. Phones are answered by a live person 24 hours a day, 7 days a week – no voicemail loops, no callback queues. We’ve built our reputation in San Ramon on operational specifics, not adjectives. Show up. Price it. Seal it. Stand behind it.

Duct Insulation in San Ramon

Duct Insulation in San Ramon runs $800 – $1,800 for a typical single-system home, with larger multi-zone setups in Windemere or Gale Ranch reaching the upper end. The job involves wrapping supply and return trunk lines in conditioned or unconditioned spaces with fiberglass duct wrap or foil-faced insulation, then sealing the seams to prevent condensation and thermal loss. In San Ramon’s climate, where attic temperatures hit 140°F in August and drop to the 40s during winter rains, uninsulated flex ducts in vented attics bleed conditioned air year-round. We see this most in 1990s-built homes where original insulation has compressed or torn at hanger points.

When Attic Ducts Lose Their Wrap

Compressed or displaced insulation on flex duct runs is common in San Ramon homes where HVAC contractors used wire hangers too tight to the duct. We remove the old wrap, inspect the inner liner for leaks, seal any gaps with mastic, then reinstall with proper support spacing so the insulation stays put.

Condensation and Mold Risk

During San Ramon’s wet winters, cold supply air in uninsulated metal trunks creates condensation that drips into ceiling cavities. We insulate and seal simultaneously, using vapor-barrier-facing products that meet California Title 24 requirements for duct systems in unconditioned spaces.

HVAC Duct Sealing in San Ramon

HVAC Duct Sealing in San Ramon costs $1,200 – $2,800 for whole-system work using mastic, foil tape, and mechanical fasteners on accessible joints, with aerosol-based duct sealing running $2,500 – $4,000 for homes where ducts are buried in walls or sealed cavities. The job targets leaks at the air handler plenum, trunk-line connections, flex-duct collars, and register boots – anywhere conditioned air escapes before reaching your rooms. In San Ramon’s tightly sealed, energy-efficient homes built from the 1980s through the 2000s, even 15% duct leakage can pressurize walls and pull garage fumes or attic dust into living space. We seal to reduce that infiltration and restore design airflow.

Aerosol Sealing for Inaccessible Ducts

When ducts run through San Ramon’s insulated wall cavities or buried chases, we use aerosol sealant technology that pressurizes the system and seals leaks from the inside. The process takes 4 – 6 hours and delivers measurable results – we verify with a manometer before and after.

Multi-Zone System Complications

Homes in Gale Ranch and Windemere with zone dampers and bypass ducts have more failure points than single-zone systems. We test static pressure across each zone, seal damper frames and bypass connections, then balance the system so every zone gets its design CFM.

Trusted Brands We Service in San Ramon

We stock parts and sealants from Honeywell, Aprilaire, and Abatement Technologies for San Ramon jobs – no waiting on a Bay Area supply house to open Monday morning. Honeywell zone panels and Aprilaire media air cleaners integrate directly with the duct systems we seal, and Abatement Technologies HEPA filtration equipment lets us clean before we seal on ash-heavy rural properties. Our vans carry Rotobrush rotary brush systems and Nikro negative-air machines for source removal when sealing alone won’t solve the problem. If your San Ramon home has a specific filtration setup or zone controller, tell us when you call and we’ll match the technician to the job.

Common Duct Sealing Problems We See in San Ramon Homes

• Wildfire ash infiltration in rural west-side properties. Because San Ramon’s Las Trampas Ridge foothills sit downwind of Diablo-wind corridors, duct systems in west-side rural properties accumulate fine wildfire ash that behaves more like a sealing problem than a cleaning problem – ash infiltrates via negative pressure leaks and gets pulled through the air handler, so sealing is often the first fix.
• Mastic cracks at flex-duct collars in attic temperature swings. Flexible duct runs in unconditioned attics of Gale Ranch and Windemere homes expand and contract with San Ramon’s hot-dry to mild-wet swing, cracking mastic at the air handler collar and register boots.
• Overlooked outbuilding systems on rural parcels. Outbuilding and detached-shop systems on rural parcels are often overlooked during main-house service, so their blower motor and return ducts stay leaky and overloaded with wood-smoke particulate.
• Dust and pollen loading from unpaved approaches. Ash and dust from unpaved road approaches and open ridge land clog return ducts and defeat seals before they cure, so sealing alone fails without source removal and HEPA filtration first.

Pricing for Duct Sealing in San Ramon, CA

We Also Serve Cities Near San Ramon

Our crews work throughout the San Ramon Valley and surrounding communities, including Dublin, Danville, Hayward, and Pleasanton. Each job follows The Garrison Standard: written price, written guarantee, 365-Day Done Right Promise. If you’re in a nearby city and your ducts are leaking conditioned air into your attic or pulling wildfire ash inside, we’ll put the same flat-price estimate in writing.

FAQs About Duct Sealing in San Ramon