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 Gilroy
We’re the Duct Sealing team at Hollis Air Duct Cleaning, and we handle a lot of calls from Gilroy homeowners who’ve had enough of rooms that won’t heat or cool evenly, utility bills that climb every summer, and dust that keeps coming back no matter how often they clean. Our crews dispatch from the San Francisco Bay Area office and serve Gilroy directly, so we understand the specific problems this city’s older housing stock and agricultural surroundings create for ductwork. If you’re dealing with crushed runs behind walls, gaps pulling in field dust, or sealant that’s failed after years of expansion and contraction, we’ll diagnose it, price it in writing, and fix it under our 365-Day Done Right Promise. Call (361) 326-5060 for a free estimate.
Why Hollis Air Duct Cleaning Is Gilroy’s Preferred Duct Sealing Company
We’ve been part of the Garrison Partners family since 2004, and our Gilroy customers tell us the same thing: they called us because they were tired of technicians who showed up late, priced jobs on the back of an envelope, or disappeared when something went wrong. Our technicians are background-checked and uniformed, and they arrive inside the quoted window. The price is written down before any work starts, and it does not move at the door.
Our 365-Day Done Right Promise means if a seal fails or a repair doesn’t hold within a full year, we come back and make it right at no charge, including a free second visit. That’s not a verbal assurance, it’s written on every job. Gilroy’s mix of downtown bungalows and suburban tract homes requires different approaches for different eras of construction, and our crews carry the equipment to handle both. Phones are answered by a live person 24 hours a day, 7 days a week.
Duct Insulation in Gilroy
Duct Insulation in Gilroy addresses a problem many homeowners don’t discover until they’ve already paid for sealing that didn’t solve the temperature swings. Insulation wraps around ductwork to maintain the temperature of conditioned air as it travels through unconditioned spaces like attics and crawl spaces. In Gilroy, where summer temperatures regularly exceed 100°F and attics can reach 140°F or higher, uninsulated ducts lose significant cooling capacity before air ever reaches the vent. A typical duct insulation job in Gilroy runs $800 – $1,800 depending on linear footage, accessibility, and whether we’re working with rigid galvanized or flexible duct.
When Insulation Matters More Than Sealing
We see this often in 1970s – 1990s tract homes near Eagle Ridge and the neighborhoods along Leavesley Road. The ducts are sealed adequately but the homeowner still has hot rooms in summer. The issue is thermal loss through thin duct walls, not air leakage. We wrap with formaldehyde-free insulation and secure with mechanical fasteners, not tape that’ll peel in Gilroy’s heat cycle.
Combining Sealing and Insulation
In older downtown bungalows with original galvanized runs through unconditioned crawl spaces, we typically recommend both services. Seal the joints first to stop air loss, then insulate to stop thermal loss. Doing both together avoids the cost of a second crawl-space entry and gives the homeowner one written price for the complete fix.
HVAC Duct Sealing in Gilroy
HVAC Duct Sealing in Gilroy is the process of closing gaps, cracks, and disconnected joints in your home’s forced-air distribution system. We use duct sealing mastic, a thick, fiber-reinforced compound that remains flexible after curing, along with mesh reinforcement at stress points. For accessible joints in basements, attics, and crawl spaces, we apply mastic by hand and brush. For leaks hidden behind walls or in soffits, we may use aerosol-based sealant injection systems that travel through the ductwork itself. A typical residential HVAC duct sealing job in Gilroy runs $1,200 – $2,400 for whole-system work on a single HVAC unit, with smaller partial repairs starting around $450.
Mastic vs. Tape in Gilroy’s Climate
Adhesive-backed foil tape fails here. We’ve peeled failed tape off ducts in homes near Old Gilroy and along First Street where summer expansion and winter contraction opened gaps the tape couldn’t bridge. Mastic flexes with the metal. It costs more in labor than slapping on tape, but it lasts.
Camera Verification After Sealing
We run a borescope camera through sealed sections to confirm the mastic covered the gap completely and that no debris is trapped at the joint. In Gilroy, where clay-ag dust can prevent proper bonding, this step isn’t optional for us. The camera shows the homeowner what we found and what we fixed.
Trusted Brands We Service in Gilroy
Our equipment roster includes Nikro negative-air machines for source removal before sealing, Honeywell and Aprilaire filtration components, and Abatement Technologies containment tools. We stock common duct sealing supplies and replacement fittings for systems found in Gilroy’s housing stock, from older galvanized steel to modern flex duct. This means we’re not ordering parts and making you wait. For a typical sealing job, we arrive with mastic, mesh, mechanical fasteners, and the camera equipment to verify the work. If your system needs a filtration upgrade after sealing, we carry Honeywell and Aprilaire media filters sized for residential units common in the 95020 zip code area.
Common Duct Sealing Problems We See in Gilroy Homes
- Crushed supply runs in downtown bungalows. Original galvanized ducts from the 1920s – 1940s were often installed with minimal clearance behind walls. We’ve found flattened sections in homes off Monterey Street and along Fifth Street where settling or renovation compressed the metal, creating restriction points that feel like “no airflow” to the homeowner.
- Clay-ag dust preventing sealant bond. Gilroy’s expansive clay soils and nearby open farmland mean return ducts pull in a fine, gritty clay-ag dust mix that binds to galvanized steel. This abrasive debris can degrade duct sealant over time, so we perform camera inspection to verify the seal holds against this specific soil-duct interaction.
- Failed foil tape from thermal cycling. Summer temperatures over 100°F expand duct metal; cool, damp winters contract it. Adhesive-backed tape peels, gaps open, and conditioned air escapes into attics and crawl spaces. We remove failed tape entirely before applying mastic.
- Pinhole leaks in flex duct from pest and vibration damage. Suburban homes built from the 1970s through 2000s often have flex duct runs that develop small leaks where rodents have accessed crawl spaces or where vibration has worn holes at support points. Standard visual inspection misses these; we use pressure testing and camera work to locate them.
Pricing for Duct Sealing in Gilroy, CA
Whole-system HVAC duct sealing in Gilroy typically runs $1,200 – $2,400 for a single-system home, with partial repairs or single-zone sealing starting at $450. Duct insulation, when needed, adds $800 – $1,800 depending on linear footage and attic or crawl-space accessibility. What moves the price: how much of the system is accessible (crawl space vs. finished basement), whether we need to remove failed tape and debris before sealing, and if camera inspection reveals hidden damage requiring additional repair. We give one flat price per system, agreed in writing before work starts. No per-vent pricing, no add-ons at the door. Call (361) 326-5060 for a free estimate, we’ll inspect your system and give you the exact number.
We Also Serve Cities Near Gilroy
Our crews work throughout the southern Santa Clara County area, including Duct Sealing in Gilroy and the surrounding communities of San Martin, Morgan Hill, Los Gatos, and Campbell. Each area has different housing stock and different duct problems, and we adjust our approach accordingly.
Serving Gilroy, CA - Our Local Coverage Area
We’re based in the Gilroy 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 Gilroy
Original galvanized steel ducts in Gilroy’s downtown bungalows and early tract homes have endured decades of thermal expansion, clay-ag dust abrasion, and occasional pest intrusion that modern flex duct hasn’t. The metal fatigues at seams, old sealant degrades, and the cumulative effect is more leakage than you’d see in a 2010s build. We typically recommend inspection every 5 – 7 years for pre-1980 systems. Call (361) 326-5060 to schedule a look.
The fine particulate from surrounding garlic and produce fields settles in ductwork and combines with clay soils tracked in from nearby open land, creating a gritty, organic debris mix that prevents sealant from bonding properly. We always perform source removal cleaning with agitation tools before sealing, then verify with camera inspection that the seal holds against this specific debris type. Call (361) 326-5060 if you suspect dust is compromising your ducts.
Duct sealing alone won’t eliminate odors that have already permeated duct walls, but it stops the ongoing infiltration of harvest-season particulate that carries those odors into your home. For existing odor issues, we combine sealing with deodorizing treatment during a full duct cleaning. The sealing then prevents re-intrusion. This combination is particularly effective for homes near the agricultural perimeter. Call (361) 326-5060 to discuss your situation.
Uneven temperatures room-to-room, dust accumulation at registers that returns quickly after cleaning, utility bills that spike in summer without rate changes, and whistling or rushing sounds from ductwork all point to leakage. In Gilroy specifically, homeowners near open fields may notice agricultural odors indoors during harvest months. If you’re seeing two or more of these signs, call (361) 326-5060 for a free inspection.
Duct cleaning removes debris, dust, and buildup from inside the ductwork using negative-air machines and rotary brush systems. Duct sealing closes the physical gaps and leaks that allowed that debris to enter and conditioned air to escape. We typically clean before we seal, because sealant won’t bond to dusty surfaces. The two services solve different problems and complement each other. Call (361) 326-5060 and we’ll tell you which your home needs, or if it needs both.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Gilroy and the greater Bay Area since 2004.