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 Agoura Hills
Duct sealing in Agoura Hills typically runs $450 – $1,200 for a whole-home seal on a standard single-family system, and most jobs are completed in a single visit after a written estimate. If your home was built in the 1970s through 1990s and you’ve never had the ductwork professionally inspected, disconnected flex runs and crushed attic lines are more common than you’d expect. Call Hollis Air Duct Cleaning at (361) 326-5060 for a free estimate with a written price before any work starts.
We’ve been working in the Santa Monica Mountains foothills long enough to know the local housing stock. Most Agoura Hills homes went up during the tract and custom-build boom of the ’70s, ’80s, and ’90s, and many still run on original flexible duct in the attic with older sheet-metal plenums. Our crews serve Agoura Hills from our Los Angeles dispatch office, and we know the difference between a routine seal job and the kind of repair these hillside systems actually need. Whether you’re off Kanan Road, near the 101 corridor, or back in the canyon neighborhoods of Old Agoura, we arrive inside the quoted window, price it in writing, and leave the site clean.
Why Hollis Air Duct Cleaning Is Agoura Hills’s Preferred Duct Sealing Company
Hollis Air Duct Cleaning has been part of the Garrison Partners family since 2004, and our Duct Sealing in Agoura Hills follows the same standard we’ve applied across Southern California: written prices, written guarantees, and technicians who show up squared away. Our 365-Day Done Right Promise means if a seal fails within a year, we return and make it right at no charge, including a free second visit. That’s not a verbal assurance. It’s on every job.
Our technicians are background-checked and uniformed, and we use professional-grade equipment from Rotobrush, Nikro, and Abatement Technologies, not hardware-store gear. Calls are answered by a live person 24 hours a day, 7 days a week. No voicemail loops. No waiting until Monday. In a market where bait-and-switch pricing is common, our price is written down before any work starts and does not move at the door.
HVAC Duct Sealing in Agoura Hills
HVAC Duct Sealing in Agoura Hills starts with understanding that this foothill community’s homes were built for a different era of energy efficiency and have spent decades expanding and contracting through hot, dry summers. The sealing work we perform targets the leaks that develop at flex-duct collars, plenum connections, and penetrations through attic framing, leaks that pull canyon dust, pollen, and post-wind ash directly into your living space. A typical whole-home seal in Agoura Hills runs $450 – $1,200 depending on system size, attic accessibility, and how many runs need reconnection or replacement.
What We Seal and Why It Fails
Original flexible duct from the 1970s – 1990s hardens and pulls loose from sheet-metal collars after years of heat cycling and dry-season contraction. The mastic or tape used originally dries to dust. We remove the failed material, reconnect the run with mechanical fasteners, then seal with new mastic and reinforcing mesh for a joint that holds. Every sealed connection gets a visual and static-pressure check before we close the attic.
How We Verify the Fix
We don’t guess. After sealing, we run a second camera pass through the ductwork and check static pressure at the air handler. If the numbers don’t improve, we find the leak we missed. Verification is part of the job, not an extra.
Duct Repair in Agoura Hills
Duct Repair in Agoura Hills often goes hand-in-hand with sealing because the same age and conditions that loosen a collar can crush a run or tear a connection at the air handler. We’ve found flex ducts pinched between roof joists and plenums, runs chewed by rodents in crawlspaces, and original fiberglass ductboard crumbling at the seams. Repair costs in Agoura Hills typically range from $280 for a single run replacement to $890 for multiple crushed lines and plenum patching, with full written pricing before we touch anything.
Crushed and Disconnected Runs
A flex run crushed against framing starves the blower motor and creates negative pressure that pulls unfiltered attic air through every gap in the system. We replace the damaged section with new insulated flex, support it properly, and seal all connections. Your MERV-rated filter can’t protect you if the duct is drawing around it.
Air Handler Connection Failures
The connection between your return plenum and the air handler is a common failure point in older Agoura Hills systems. Heat cycling and vibration loosen the seal, letting return-side dust bypass the filter entirely. We rebuild this joint with sheet-metal screws, mastic, and mesh for a permanent seal.
Trusted Brands We Service in Agoura Hills
Our Agoura Hills crews carry parts and sealing products from Aprilaire, Abatement Technologies, and Guardsman, plus professional-grade mastics and mesh tapes rated for the temperature swings these attic systems see. We don’t run to the supply house mid-job. That means faster turnaround for you and a technician who finishes what he started. We also service systems with Honeywell and Rotobrush components, and we’re familiar with the filtration setups common in local homes, from basic 1-inch pleated filters to whole-house Aprilaire media cleaners.
Common Duct Sealing Problems We See in Agoura Hills Homes
- Disconnected flex-duct collars in 1970s – 1990s tract homes. The original zip ties or tape harden and snap, leaving a 6-inch gap blowing conditioned air into your attic and pulling canyon dust into the return. We find this in maybe half the Agoura Hills homes we open.
- Post-Santa Ana ash intrusion through failed vent fittings. After the first strong fall winds, we get calls from Old Agoura and canyon-edge neighborhoods with grey grit on supply registers. The ash isn’t coming through the filter; it’s coming around it, through unsealed duct penetrations and loose collar connections.
- Crushed flex runs pinched between roof framing and the plenum. Hillside custom builds with complex rooflines are especially prone. The restriction raises static pressure, strains the blower, and creates suction that bypasses filtration entirely.
- Torn return plenum connections at the air handler. Years of vibration and dry-season contraction separate the return from the unit, letting attic air and everything in it enter the system downstream of any filter you own.
Pricing for Duct Sealing in Agoura Hills, CA
Whole-home duct sealing in Agoura Hills typically costs $450 – $1,200 for a standard single-family system up to about 2,500 square feet. Single-run repairs or spot sealing run $280 – $550. Larger hillside homes with multiple attic zones, complex duct routing, or significant reconnection work can reach $890 – $1,400. What moves the price: how many runs need attention, whether we’re working in a tight attic or open crawlspace, and if we find crushed or rodent-damaged sections that need replacement rather than just sealing.
We do not quote per-vent teaser prices that balloon once the van is in your driveway. We inspect, we write the price, and that number doesn’t change. Before-and-after photos of your own ducts are included. Call (361) 326-5060 for a free estimate.
We Also Serve Cities Near Agoura Hills
Our Duct Sealing crews work throughout the western San Fernando Valley and Ventura County corridor, including Westlake Village, Oak Park, Calabasas, and Thousand Oaks. Same standard, same written pricing, same 365-Day Done Right Promise.
Serving Agoura Hills, CA - Our Local Coverage Area
We’re based in the Agoura Hills 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 Agoura Hills
We usually find original flex-duct runs that have pulled loose from their sheet-metal collars, hardened mastic flaking off plenum connections, and occasionally a crushed run where the duct was pinched against framing. The tape or zip ties used in that era don’t survive four decades of Agoura Hills heat cycling. Call (361) 326-5060 and we’ll camera-inspect the system to show you exactly what’s happening in your attic.
It’s almost always both, but the sealing is the root fix. The grit is coming through gaps in your ductwork, not through your filter. Cleaning removes what’s already inside; sealing stops more from entering. In Old Agoura and other canyon-edge neighborhoods, we see this pattern every fall after the first strong Santa Ana event. We recommend camera inspection to locate the entry points, then sealing with mastic and mesh.
Yes. Agoura Hills sits in the Wildland-Urban Interface, and ember-intrusion vent screening is already part of defensible-space planning for many homeowners. But screening the vents doesn’t help if your ducts are pulling ash through unsealed collar connections and plenum gaps. A properly sealed duct system is a sealed duct system, period. It reduces the path for fine particulate to enter regardless of source, whether that’s routine canyon dust or post-fire ash.
Low humidity means we don’t see the biological growth common in coastal climates, but we do see accelerated drying and hardening of flexible duct materials and mastic. The dry climate makes original seals brittle faster. Our approach uses modern mastic formulations rated for the temperature swings and low-moisture conditions of Santa Monica Mountains foothill attics, applied with reinforcing mesh for flexibility that lasts.
We start with a camera inspection of the accessible ductwork, then write a price before any work begins. We disconnect and reseat loose flex runs, replace crushed sections, seal all plenum and collar connections with mastic and mesh, and rebuild damaged air handler joints. After sealing, we run a second camera pass and check static pressure to verify the fix. The job isn’t done until the numbers improve and you’ve seen the before-and-after. Call (361) 326-5060 to schedule.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Agoura Hills since 2004 as part of the Garrison Partners family.