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 Fairfax
Duct sealing in Fairfax, CA typically costs $450 – $1,200 for a whole-home system, and most jobs are completed in a single visit with the price written down before we start. We’re the Duct Sealing crew that serves Fairfax from our San Francisco Bay Area office, dispatching teams who know the steep, winding roads of the Ross Valley and the quirks of the housing stock here. Whether you’re in a 1950s rancher off Sir Francis Drake Boulevard or a hillside custom home above Cascade Drive, we’ve sealed ducts in your kind of attic, crawlspace, or chase. Call (361) 326-5060 for a free estimate.
Why Hollis Air Duct Cleaning Is Fairfax’s Preferred Duct Sealing Company
Fairfax homeowners know the difference between a crew that understands local conditions and one that’s guessing. We’ve worked in the tight, unconditioned crawlspaces beneath homes in the Fairfax flats, where winter rains from the Ross Valley push moisture against duct seams, and we’ve navigated the steep hillside attics off Deer Park Avenue where flex duct runs sag and pull apart at the connections.
Our technicians are background-checked, uniformed, and expected to arrive inside the quoted window, price the job in writing before touching anything, and leave the site clean. That’s The Garrison Standard, and it’s how every Hollis location operates, including ours serving Fairfax. The 365-Day Done Right Promise backs every duct sealing job in writing: if the seal fails within a year, we return and make it right at no charge, including a free second visit.
Calls 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.
Duct Repair in Fairfax
Duct Repair in Fairfax addresses the cracked, corroded, or disconnected runs that waste heated and cooled air in homes throughout the Ross Valley. Most Fairfax homes built between the 1920s and 1970s still have original rigid metal ductwork with aged seams and failing tape, while newer hillside remodels often mix flex and rigid runs that pull apart where they join. A typical duct repair in Fairfax runs $280 – $650 depending on accessibility and the extent of the damage.
Smoke-Damaged Duct Connections
After major wildfire smoke events, we find metal seams that have expanded and contracted enough to loosen the original sealant, especially in homes near the wildland-urban interface above Cascade Drive. We cut out the failed section, fabricate a replacement, and seal it with mastic rated for the temperature swings these attics see.
Crawlspace Moisture Repairs
Heavy winter rains in the Fairfax flats push water into crawlspaces along Sir Francis Drake Boulevard and the neighborhoods near the creek. We replace rusted metal or water-damaged flex duct and elevate new runs on proper supports to keep them out of seasonal pooling.
Air Duct Sealing in Fairfax
Air Duct Sealing in Fairfax closes the gaps, cracks, and disconnected joints that leak conditioned air into attics, crawlspaces, and wall cavities before it ever reaches your rooms. In a town where wildfire smoke and redwood pollen already stress HVAC systems, unsealed ducts pull those contaminants in through return leaks and waste 20 – 30% of your heating and cooling energy. A typical whole-home air duct sealing job in Fairfax runs $450 – $1,200, with larger hillside homes or complex multi-zone systems toward the upper end.
Mastic Sealing for Older Metal Duct
The original rigid duct in Fairfax’s postwar ranchers was sealed with fabric tape that dries and fails over decades. We brush on water-based duct mastic, a thick sealant that remains flexible and fills gaps up to 1/8 inch, then reinforce high-pressure joints with mesh and a second coat.
Aeroseal for Inaccessible Runs
Some Fairfax hillside homes have ductwork buried in finished soffits or tight framing that we can’t reach by hand. We pressurize the system and inject sealant particles that automatically bond to leak edges, sealing from the inside without cutting into walls or ceilings.
Trusted Brands We Service in Fairfax
We seal and repair systems using professional-grade equipment and materials, including mastic and sealants from Abatement Technologies and filtration components from Aprilaire and Guardsman. Our crews carry Rotobrush rotary brush systems for pre-sealing cleaning when smoke residue or pollen buildup would prevent a proper seal. We stock common duct diameters and sealing supplies for Fairfax’s predominant 1950s – 1970s systems, so most repairs don’t wait on parts. If your system uses specialized components from a hillside custom build, we’ll source them fast and give you a written timeline before we start.
Common Duct Sealing Problems We See in Fairfax Homes
- Wildfire smoke residue breaking original tape seals. The fine ash and char particles that pour down the Ross Valley canyons coat duct walls and degrade adhesive seals, especially in older homes near the open space boundaries. We clean with HEPA-filtered rotary brushes before resealing so the mastic bonds properly.
- Original 1950s – 1970s metal duct with failing fabric tape at every joint. These systems were never meant to last 60-plus years, and the tape crumbles to dust in hot attics. We remove the old tape entirely and apply fresh mastic for a seal that flexes with temperature swings.
- Hillside remodels with unsupported flex duct sagging between connections. Flex duct that dips collects condensation and pulls apart at the collars. We add proper supports and replace damaged sections, then seal with engineered clamps and mastic.
- Crawlspace moisture corroding metal seams in flats neighborhoods. Seasonal flooding along the creek corridor rusts through low-hanging duct and destroys seals. We elevate, replace, and seal with moisture-resistant materials rated for damp environments.
Pricing for Duct Sealing in Fairfax, CA
Whole-home duct sealing in Fairfax typically runs $450 – $1,200. A small bungalow with accessible attic ductwork and straightforward metal seams falls at the lower end. Larger hillside homes with multiple zones, buried flex runs, or smoke-damaged systems requiring pre-cleaning run higher. Duct repair for isolated damage costs $280 – $650 per section.
What moves the price: accessibility (tight crawlspace versus walkable attic), the condition of existing seals (tape failure versus full corrosion), whether we need to clean smoke residue before sealing, and the linear footage of duct involved. We do not price per vent or per linear foot at the door. We inspect, write one flat price for the complete system, and you approve it before we start. Estimates are free. Call (361) 326-5060.
We Also Serve Cities Near Fairfax
Our crews work throughout central Marin County, including Air Duct Cleaning in Fairfax and neighboring Dryer Vent Cleaning in Fairfax, plus San Anselmo, Kentfield, San Rafael, and Larkspur. Same written pricing, same 365-Day Done Right Promise, same live-answer phones.
Serving Fairfax, CA - Our Local Coverage Area
We’re based in the Fairfax 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 Fairfax
Whole-home duct sealing in Fairfax costs $450 – $1,200, with most single-family homes falling between $550 and $850. The exact price depends on your home’s duct layout, accessibility, and whether smoke residue or moisture damage requires pre-cleaning or repair before we seal. Call (361) 326-5060 for a free written estimate.
Most Fairfax duct sealing jobs are completed in 3 – 6 hours for a typical single-system home. Older ranchers with accessible attics often finish faster; hillside homes with multiple zones or buried duct runs take longer. We give you a written time estimate with the price before we start.
Yes, we seal ducts throughout Fairfax, from the flats near downtown and the creek corridor to the hillside homes off Deer Park Avenue, Cascade Drive, and the upper reaches toward the open space preserve. Our crews are familiar with the access challenges of steep driveways, tight crawlspaces, and unconditioned attics throughout town.
Fairfax pricing is comparable to San Anselmo and San Rafael, though hillside homes with complex access can run slightly higher than flats neighborhoods in any of these towns. The bigger cost driver is your specific duct condition, not your zip code. We use the same written pricing structure across our Marin County service area.
If any sealed joint fails, leaks, or separates within 365 days of our work, we return and repair it at no charge, including a free second visit. This is backed in writing on every job, not a verbal assurance. The Promise covers our labor and materials; it does not cover new damage from unrelated causes like flooding, pest intrusion, or structural shifts.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Fairfax and central Marin County.