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 Woodside
We dispatch to Woodside from our San Francisco Bay Area scheduling office, and crews are usually on-site within one to two business days of your call. If you live off Kings Mountain Road or down near the Canada Road corridor, you’ve probably noticed how your upstairs guest wing never quite reaches the temperature your thermostat promises. That’s not your imagination. In a town where custom estate homes hide forty-foot duct runs through redwood-shaded crawlspaces, leaking ducts are less a maintenance issue and more a design feature of the local housing stock.
Call us at (361) 326-5060 for a free estimate. We’ll seal your ductwork by the book, price it in writing before we start, and back it with our 365-Day Done Right Promise.
Why Hollis Air Duct Cleaning Is Woodside’s Preferred Duct Sealing Company
We’ve been serving the San Francisco Bay Area since 2004 as part of the Garrison Partners family, and Woodside’s particular mix of historic estates and modern builds has taught us what generic duct crews miss. Our technicians know to look for acorn caches near Huddart Park properties, and they understand why a 1920s stone manor off Mountain Home Road needs a different sealing approach than a glass-and-steel new build near the Portola Valley border.
Our Duct Sealing in Woodside crews arrive uniformed, background-checked, and equipped with professional-grade mastic and aerosol sealant tools from Nikro and Abatement Technologies. The price we write down before any work starts is the price you pay. No per-vent add-ons, no surprise charges once we’re in your crawlspace. If the seal fails within a year, we come back and make it right at no charge, including a free second visit. That’s not a slogan. It’s written on every job sheet.
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.
Air Duct Sealing in Woodside
Air Duct Sealing in Woodside addresses the pressurized leaks that waste heated and cooled air before it ever reaches your living spaces. Most Woodside homes lose 20 to 30 percent of conditioned air through gaps at joint connections, seams around air handlers, and penetrations where ductwork passes through unconditioned attics or crawlspaces. Our crew pressurizes the system, identifies leakage points with a smoke pencil or digital manometer, then seals them with mastic compound or aerosolized sealant depending on access and duct material.
A typical whole-house duct sealing job in Woodside runs $1,200 to $2,800. Smaller partial systems or single-zone repairs can start around $650. What moves the needle: how many linear feet of duct we’re accessing, whether we need to enter a tight crawlspace beneath a historic foundation, and if we’re also cleaning debris from oak pollen or rodent activity before we seal.
Multi-Zone System Sealing
Many Woodside estates were built with four, five, or six independent HVAC zones, each with its own air handler and duct network. We seal zone by zone, testing static pressure before and after so you can see the improvement in writing. This matters especially in guest houses and pool houses where duct runs are longest and leakage percentages tend to be highest.
Crawlspace and Attic Access Work
Our technicians carry low-profile equipment specifically for the tight clearances common beneath Woodside’s older homes. If your ductwork runs through an unconditioned attic above a vaulted ceiling, we’ll seal those trunk lines without tearing out drywall. The Garrison Code requires us to leave every access point clean and secure.
Duct Sealing Services in Woodside
Duct Sealing Services in Woodside cover more than slapping tape on a loose joint. We start with a full-system pressure test to establish your baseline leakage rate, then map the duct network to find where conditioned air is escaping into your attic, crawlspace, or wall cavities. In Woodside’s climate, that escaped air carries moisture in winter and dust in summer, both of which degrade indoor air quality and force your HVAC equipment to run longer cycles.
Our Duct Sealing team uses mastic compound for accessible seams and joints, plus aerosol sealant for the pinhole leaks that tape and standard caulking miss. For homes near open space preserves where rodents have breached duct walls, we may recommend section replacement before sealing. A typical repair-and-seal combination in Woodside runs $1,800 to $3,400 depending on linear footage and access difficulty.
Pre-Sealing Inspection and Testing
Every job begins with a written inspection report. We photograph your duct condition, measure airflow at each register, and document leakage rates with a digital manometer. You get this report before we quote any sealing work. No hidden findings, no price shifts after we’re inside your system.

Post-Sealing Verification
After sealing, we re-test under the same conditions and show you the before-and-after numbers. Most Woodside homes see a 15 to 25 percent improvement in delivered airflow at the registers. That translates to shorter run times, more even temperatures between rooms, and lower utility bills.

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.
Trusted Brands We Service in Woodside
We stock sealing materials and filtration components from Honeywell, Aprilaire, and Abatement Technologies, the same brands commercial HVAC crews specify for hospitals and schools. For Woodside homeowners with existing Honeywell or Aprilaire air cleaners integrated into their duct systems, we verify that our sealing work doesn’t disrupt those connections or void manufacturer warranties. Our Nikro negative-air machines keep your home clean during the process, capturing any disturbed debris before it circulates. Parts are sourced through Bay Area distributors, so if your sealing job reveals a failed damper or disconnected flex duct that needs replacement, we’re not waiting on a two-week shipping window.
Common Duct Sealing Problems We See in Woodside Homes
- Long trunk lines in estate homes lose pressure. Custom Woodside properties often have duct runs exceeding fifty feet from air handler to distant guest wing registers. Every joint and seam along that run is a potential leak point, and cumulative leakage can drop delivered airflow by a third before air ever exits the vent.
- Historic homes use uninsulated metal duct in unconditioned spaces. Early 1900s estates near Mountain Home Road frequently have original galvanized ductwork running through dirt-floored crawlspaces. The metal corrodes at seams, tape adhesive fails in damp winter conditions, and the resulting leaks pull musty air directly into your supply.
- Wildlife breaches create secondary leakage paths. Our crews regularly find rodent entry holes chewed through flex duct near exterior penetrations, especially on properties backing up to Huddart Park or the open space preserves along Skyline Boulevard. We seal the breach, replace damaged sections, and then seal the surrounding network to restore system integrity.
- Multi-zone damper failures masquerade as duct leaks. Modern luxury builds with zone control systems sometimes present as uneven heating when the real culprit is a stuck or leaking damper. We test each zone independently before sealing, so we’re not treating a mechanical failure with sealant.
Pricing for Duct Sealing in Woodside, CA
Whole-house duct sealing in Woodside typically runs $1,200 to $2,800. Single-zone or partial-system sealing starts around $650 and ranges up to $1,500 depending on linear footage. If we’re combining sealing with Air Duct Cleaning in Woodside or Dryer Vent Cleaning in Woodside, we package those services at a reduced combined rate.
What affects your specific price: how many feet of duct we need to access and seal, whether that access requires working in a tight crawlspace or elevated attic, the condition of existing duct material (mastic adheres differently to old metal versus modern flex duct), and whether we find rodent damage or disconnected sections that need repair before sealing can be effective. We also offer dryer vent cleaning as a standalone service or bundled with duct work.
We give you one flat price per system, agreed in writing before any work starts. No per-vent pricing, no teaser coupon that balloons once the van is in your driveway. Estimates are free. Call (361) 326-5060 to schedule.
We Also Serve Cities Near Woodside
Our crews work throughout the San Francisco Bay Area and beyond. We regularly dispatch to Los Angeles, San Diego, San Jose, and San Francisco for larger estate properties and multi-system commercial jobs. Scheduling is coordinated from our Bay Area office, with local technicians assigned to minimize travel time and keep appointments inside the quoted window.
Serving Woodside, CA - Our Local Coverage Area
We’re based in the Woodside 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 Woodside
We typically schedule Woodside appointments within one to two business days, with dispatch coordinated from our San Francisco Bay Area office. Call (361) 326-5060 and we’ll find the next available slot that works with your schedule.
Yes, we serve the full Woodside area including properties off Kings Mountain Road, along Mountain Home Road, near the Canada Road corridor, and homes adjacent to Huddart Park and the Skyline Boulevard open space. Our crews carry equipment sized for both tight crawlspace access and large multi-acre estates.
We do not offer after-hours emergency dispatch for duct sealing, as this is a scheduled maintenance and repair service rather than an urgent safety issue. If you have an HVAC failure in extreme weather, call your heating and cooling contractor first. Once the mechanical issue is resolved, we can seal the ductwork to restore efficiency.
Woodside prices run roughly 10 to 20 percent above Peninsula averages due to larger homes, longer duct runs, and more complex multi-zone systems. The tradeoff is that proper sealing here often yields bigger efficiency gains because the baseline leakage in these estate properties tends to be higher than in standard suburban construction.
Every duct sealing job is backed by our 365-Day Done Right Promise in writing. If the seal fails, airflow drops, or you notice the same temperature imbalances within a year, we return and make it right at no charge, including a free second visit. The guarantee transfers if you sell the home during that period.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Woodside and the San Francisco Bay Area since 2004.




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