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 San Martin
San Martin homeowners know the feeling: one room never cools down in July, the utility bill climbs every summer, and there’s a faint whistling from the crawlspace whenever the AC kicks on. That’s air escaping through gaps in your ductwork, and in San Martin’s climate, it costs you every single month the system runs. We’re Hollis Air Duct Cleaning, part of the Garrison Partners family, and our crews handle Duct Sealing calls throughout the valley, from the rural spreads along Llagas Road to the newer tracts near San Martin Avenue. Dispatch runs from our Bay Area office, but technicians live and work this corridor daily. If your ducts are leaking conditioned air into your attic or crawlspace, call (361) 326-5060. We’ll give you a written price before any work starts, and every repair carries our 365-Day Done Right Promise.
Why Hollis Air Duct Cleaning Is San Martin’s Preferred Duct Sealing Company
We’ve been in business since 2004, and the Garrison Standard we operate under was built for customers who’ve been burned by the home service industry before. That means written prices, background-checked uniformed technicians, and a full year of coverage on every repair. Our Duct Sealing in San Martin crew knows the local housing stock: the 1960s ranch homes off Monterey Road with original sheet-metal ducts, the 1990s subdivisions near Fitzgerald Avenue with flex duct that’s started to sag, and the new estate builds along the foothills where builders sometimes skip the final sealing phase.
Phones get answered by a live person 24 hours a day, 7 days a week. No voicemail loops, no “leave a message and we’ll call back Monday.” When you schedule a window, we arrive inside it. The technician who shows up is the technician whose background check you can verify. And the price we write down before touching anything is the price you pay. 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 in writing on every job.
Duct Repair in San Martin
Duct Repair in San Martin covers everything from patching separated flex-duct runs to replacing corroded sheet-metal sections and rebuilding plenum connections that have shaken loose after decades of valley heat cycles. Most San Martin homeowners need it when they notice hot spots in specific rooms, hear rattling from the walls, or see insulation drooping in the attic. A typical duct repair in San Martin runs $280 – $620 depending on accessibility and material. Older ranch homes off Llagas Road often need section replacement where agricultural dust has accelerated corrosion, while newer homes near San Martin Avenue may only need reconnection of builder-grade seams that failed prematurely.
Separated Seams and Joint Failure
The constant vibration of HVAC systems in San Martin’s long cooling season loosens tape and mastic at duct joints. We open the seam, clean the mating surfaces, and reseal with professional-grade mastic rated for the temperature swings these attics see. For sheet-metal connections, we add mechanical fasteners so the repair outlasts the original installation.
Crushed or Collapsed Flex Duct
Flex duct in crawlspaces gets damaged by pests, storage activity, or simple gravity over time. Our crew replaces the damaged run with new insulated flex, supported every four feet to prevent sagging, and sealed with nylon straps and mastic at both ends. We use the same Nikro negative-air equipment on repair jobs that we use on full cleanings, so no construction debris enters your living space.
Air Duct Sealing in San Martin
Air Duct Sealing in San Martin is the precision work of closing every gap, joint, and penetration point where conditioned air escapes before reaching your rooms. We seal with mastic compound and fiberglass mesh, not duct tape, because tape dries and fails within a few years in the heat of a San Martin attic. Most homeowners need sealing when rooms won’t balance, dust blows from registers, or energy bills spike during the May-through-October cooling season. A whole-system seal in San Martin typically runs $1,400 – $2,800 for an average single-family home, with larger ranch properties or multi-zone estates running higher based on total linear footage.
Mastic Sealing of Supply and Return Plenums
The plenum, where your air handler connects to the duct trunk, is the highest-pressure point in the system and often the leakiest. We coat every seam and penetration with two layers of mastic, reinforced with mesh at stress points. In San Martin’s older homes, we frequently find original plenums with no sealant at all, just raw sheet-metal edges leaking 15 – 20% of total airflow.
Register Boot and Penetration Sealing
Where ducts pass through drywall or flooring, gaps around the boot assembly pull attic air into your living space. We seal the boot-to-drywall joint with low-VOC caulk and the boot-to-duct connection with mastic, then verify with a smoke pencil that no leakage remains. This matters especially in San Martin’s agricultural zone, where unsealed boots draw in field dust and pollen directly behind your walls.
Trusted Brands We Service in San Martin
Our trucks carry sealing and filtration products from Abatement Technologies, Guardsman, and Rotobrush, the same brands commercial HVAC contractors specify for schools and medical facilities. We don’t make you wait for a parts order from San Jose. For San Martin customers, that means most seal and repair jobs finish in one visit, not two. If your system needs a filtration upgrade alongside the sealing work, we stock Honeywell and Aprilaire media cabinets that drop into standard return plenums without duct modification. Every product gets explained in plain terms before installation, and every component carries the same 365-Day Done Right Promise as our labor.
Common Duct Sealing Problems We See in San Martin Homes
- Original 1970s sheet-metal with failed tape joints. Ranch homes near the intersection of Llagas Road and Monterey Road still run ducts that were sealed with cloth-backed tape forty years ago. The adhesive has turned to powder, and every joint leaks conditioned air into the crawlspace.
- Construction debris in new tract home ductwork. Builders in the San Martin Avenue corridor sometimes leave drywall dust, wood scraps, and even fast-food wrappers in ducts before final close-up. That grit abrades seals and creates leak paths at joints that should be tight.
- Undersized returns choked with agricultural dust. After the fall grape harvest, fine soil and chaff get drawn into return ducts on rural properties. The restriction increases static pressure and blows out seals at the air handler plenum.
- Condensation damage in winter. San Martin’s mild, damp Januarys can create moisture in poorly insulated attic ducts. Wet mastic loses adhesion, and sheet-metal connections rust through, especially on north-facing roof sections where morning fog lingers.
Pricing for Duct Sealing in San Martin, CA
We’re upfront about this because we’ve heard the stories: a low phone quote that triples once the technician is in your driveway. That doesn’t happen here. A typical spot repair on a single duct run in San Martin runs $280 – $620. Whole-system duct sealing for an average three-bedroom home runs $1,400 – $2,800. Larger ranch properties with multiple zones or long trunk lines, common in the rural spreads east of Highway 101, can run $3,200 – $4,500. What moves the price: total linear footage of ductwork, accessibility (crawlspace vs. walkable attic), material type (flex duct repairs cost less than sheet-metal replacement), and whether we find additional damage once we’re inside the system. We write the price down before any work starts, and it does not move at the door. Estimates are free. Call (361) 326-5060 to schedule.
We Also Serve Cities Near San Martin
Our crews run the full South County corridor. We handle Air Duct Cleaning in San Martin and surrounding communities, plus Dryer Vent Cleaning in San Martin for homeowners who want the full system maintained. If you’re in Morgan Hill, Gilroy, Los Gatos, or Campbell, the same scheduling line and the same Garrison Standard apply. Dispatch coordinates from our Bay Area office, but technicians serve each city locally.
Serving San Martin, CA - Our Local Coverage Area
We’re based in the San Martin 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 San Martin
Duct sealing in San Martin runs comparable to Morgan Hill and slightly less than Los Gatos, where hillside access and older custom homes drive labor time up. A typical whole-system seal in San Martin is $1,400 – $2,800, with rural properties on larger lots toward the higher end. Call (361) 326-5060 for an exact quote on your home, estimates are free.
Yes, we seal ducts from the town center near San Martin Avenue out to the vineyard properties along Llagas Road and the estate builds in the eastern foothills. Our technicians carry the equipment to handle long runs and multiple zones common on rural acreage.
Every duct sealing job is covered by our 365-Day Done Right Promise. If the seal fails within a full year, Hollis returns and makes it right at no charge, including a free second visit. That’s written on every invoice, not implied.
Signs pointing to sealing include uneven room temperatures, whistling from registers, dust blowing even after cleaning, and summer bills that climb year over year. We also handle Air Duct Cleaning in San Martin if your ducts are intact but contaminated. A technician can assess which you need during a free estimate visit.
Yes. We work in 1950s – 1970s ranch homes regularly and use low-profile access methods that don’t require cutting finished walls. Most sealing happens at the plenum, in the attic, or through existing register openings. We explain every access point before we cut anything.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving San Martin since 2004.