Whole-home duct cleaning
Dryer vent cleaning
Camera inspection
Sanitizing & deodorizingWhole-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 Granada Hills
Duct sealing in Granada Hills typically costs $450 – $1,400 for a whole-system job on the single-family homes that dominate the area, and most work is completed in one visit. That’s the honest range, written before anyone touches your ductwork. If you’re seeing gray silt on registers within weeks of a cleaning, hearing a whistle when Santa Ana winds push against the house, or noticing some rooms never reach the temperature on the thermostat, the seams and takeoffs in your ducts are leaking. Call (661) 523-0295 and we’ll camera-inspect the system, show you exactly where the bypasses are, and put a written price in front of you before any work starts.
Why Hollis Air Duct Santa Clarita Is Granada Hills’s Preferred Duct Sealing Company
Granada Hills homeowners call us because we treat post-storm and post-wind duct work as a documentation job as much as a sealing job. When a balcony drain backs up on Rinaldi Street or a Santa Ana event drops a fresh layer of mountain dust into your attic, the question isn’t just “can you fix it” but “can you show me and my insurer what actually happened.” We do both. Our camera inspections run through every trunk, branch, and takeoff, and the footage goes to you with the written estimate. When we seal a Duct Sealing job, we seal every longitudinal seam, snap-lock join, and takeoff collar with mastic plus mesh, not tape. Then we run a negative pressure test and give you before and after airflow numbers.
You’ll get background-checked, uniformed technicians who arrive inside the quoted window. The price is written before work begins and does not move at the door. And every job is covered in writing by the 365-Day Done Right Promise: if the work fails within a year, we return and make it right at no charge, including a free second visit. Roy Castellanos runs our crew, and he expects the kind of squared-away work Granada Hills homeowners assumed they couldn’t find anymore.
Styles & brands we work with
Duct Repair in Granada Hills
Duct Repair in Granada Hills usually means one of two things: patching or replacing sections of sheet metal trunk and branch lines that have separated, rusted, or been crushed, or cutting out and replacing duct runs that water has compromised. Homes here were largely built between the 1950s and 1970s, and a lot of that original sheet metal is still in service. Seams open with age. Hangers sag in attic heat. And once a seam opens even a quarter inch, Santa Ana winds turn the duct system into a powder funnel.
What We Find in Older Sheet Metal Systems
Most Granada Hills homes have central HVAC with sheet metal ducts wrapped in fiberglass insulation. After five or six decades of thermal expansion, the longitudinal seams along the trunk line develop pinhole gaps. The tell is a thin gray line of dust along the seam, visible only when the plenum is opened or the camera goes in. We repair these with mastic and fiberglass mesh, not foil tape. Mastic cures to a hard shell that moves with the metal through summer heat cycles; tape dries and peels within two seasons.
When Repair Becomes Replacement
Water changes the math completely. If a roof or balcony drain backed up into a return chase, the fiberglass liner inside the duct wicks water outward from the breach. That liner delaminates, sheds fibers into the airstream, and becomes a mold substrate. There is no honest way to “seal” a waterlogged fiberglass liner back into service. We cut out the saturated sections, replace with R-8 flex matched to the original sizing, and seal every joint. The camera footage and a written materials list go to you for the insurance file.
Air Duct Sealing in Granada Hills
Air Duct Sealing in Granada Hills is the process of closing every seam, joint, takeoff, and plenum connection in the duct system so that conditioned air moves from the blower to the registers without leaking through gaps. On a typical 1960s ranch here, we measure 25 – 35% airflow loss before sealing. That means for every dollar you spend cooling the house in a Granada Hills summer, a third of it is cooling the attic void. Sealing brings that number down into single digits, which shows up as better register velocity in the far bedrooms and a blower that actually cycles off on hot afternoons.
Return Chase Sealing and Negative Pressure Bypass
The return side of an older Granada Hills system is where mountain dust does its worst work. Unsealed return air chases draw from the attic space around them. That attic air in summer can be 140 degrees, carrying decomposed granite and wildfire ash that the filter never sees because the bypass happens after the filter slot. The result is a supply air temperature climb that trips the high-limit switch on old blower motors. Homeowners get told the blower is failing. What’s actually happening is a negative-pressure bypass pulling hot, ash-laden air into the return. We seal the return chase with mastic on every accessible seam, install an access panel if needed, and then re-test supply air temperature with the system running.
Insurer-Grade Documentation
If water intrusion is part of the equation, the estimate we write includes something most outfits skip: a written condition report with camera stills, a measured moisture reading from the liner at the breach, and a line-item of every section we’re cutting out versus sealing. Insurers accept or deny based on documentation, not narrative. We give you a file that shows the before condition, the exact materials used, and the after airflow test numbers. That’s the difference between a denied claim and a paid one on Granada Hills storm damage.
Trusted Brands We Service in Granada Hills
We work on systems built around American Standard, Carrier, Rheem, Lennox, Day & Night, and Payne, which covers the bulk of what was installed in Granada Hills tract homes from the 1950s onward. Because our trucks carry common parts locally, we don’t have to order and return a second day for most repairs. We stock mastic, mesh, R-8 flex, takeoff collars, and plenum fittings sized to the sheet metal and duct board we see in Granada Hills attics. The equipment we use for sealing and testing comes from Guardsman and Abatement Technologies, the same tools commercial HVAC crews spec. When the job involves sealing an entire system, we use Aprilaire filtration guidance to explain what happens to air quality once the leaks are closed and the filter is no longer being bypassed.
See the difference
Before
After
Before
After
Before
AfterCommon Duct Sealing Problems We See in Granada Hills Homes
- Pinhole leaks at original sheet metal seams. The 1950s – 70s tin-lock seams in Granada Hills trunk lines loosen with every summer heat cycle. Once they open, Santa Ana wind events push fine dust through the gaps and coat registers within weeks of a cleaning. Mastic sealing closes these permanently.
- Water-saturated fiberglass duct liner. Winter storms back up roof drains and balcony scuppers, soaking the return chase. The liner wicks water away from the visible breach, so homeowners see white fibers at the registers but can’t find the source. We camera-inspect the full run and cut out every saturated section.
- Unsealed return chases pulling attic air. Homes near the Santa Susana Mountains run hot in summer. An unsealed return draw pulls 140-degree attic air into the system, raising supply temps and tripping the high-limit switch on old blowers. It’s misread as a failing motor when it’s actually a bypass.
- Mountain dust infiltration through supply leaks. Decomposed granite and wildfire ash from the northern ridgeline settle in attics. Supply runs with open takeoffs pull that dust in under pressure. Homeowners on the north side of Granada Hills see gray silt on supply registers even with a clean filter.
Pricing for Duct Sealing in Granada Hills, CA
Whole-system duct sealing in Granada Hills runs $450 – $1,400 on a single-family home, depending on system size, attic access, and how much repair work is needed before sealing starts. Sealing a single room’s supply run with accessible seams typically lands $200 – $450. Water-damage repair that requires cutting out saturated duct sections and replacing with R-8 flex adds $300 – $800 per section depending on length and chase access. We don’t price per vent, and we don’t write a low teaser number that changes once the technician is in your attic. The written estimate we give before work starts is the price. Call (661) 523-0295 for a free estimate. We’ll put the whole number on paper and you can look at it for as long as you need.
We Also Serve Cities Near Granada Hills
Our trucks serve the neighborhoods that border Granada Hills, including Mission Hills, San Fernando, Northridge, and Sylmar. If you’re on the north Valley rim and dealing with dust or post-storm duct damage, we can get a crew to you. See the full scope of our Granada Hills duct sealing work and coverage area, or call (661) 523-0295 to schedule an inspection.
Serving Granada Hills, CA - Our Local Coverage Area
We’re based in the Granada 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 Granada Hills
That gray silt is mountain dust bypassing the filter through leaks in the supply runs, and it is almost always a sealing issue. A new filter does nothing if the air is entering the ducts after the filter slot. On Granada Hills homes near the northern ridge, the dust accumulates in attics during wind events, then gets pulled into open takeoffs and seam gaps under supply pressure. Cleaning removes what’s already in there; sealing is what stops the next event from coating the registers again. Call (661) 523-0295 and we’ll camera-inspect the supply side to find every bypass before writing the estimate.
We decide by measuring moisture in the duct liner and inspecting the metal for rust-through, not by guessing. If the liner is dry and the sheet metal is sound, sealing is the honest fix. If the fiberglass liner has wicked water more than a few inches from the breach, or if the metal shows mineral crust and delamination, that section gets cut out and replaced. The deciding factor in Granada Hills is that water sits in attic chases for weeks after a winter storm, and fiberglass liner doesn’t dry out once saturated. Our camera stills and moisture readings go into the written estimate so you and your insurer don’t have to take anyone’s word for it.
Yes. The return air chase in most Granada Hills ranch and traditional homes is accessible either from the attic side or through the return grille opening, and we seal it from the accessible side with mastic on every seam, joint, and plenum connection. Some homes have chases that run through a wall cavity, and those are the exception: if the cavity is built from gypsum board with no metal liner, sealing requires either an access panel or replacement with a dedicated return duct. We’ll camera the chase first, show you what’s there, and only recommend opening a wall if it is genuinely the only way to seal the system properly. The written estimate covers the access method before we start.
That’s a classic negative-pressure bypass on the return side, and it gets worse after cleaning because the filter sees less restriction, so more airflow comes from wherever the return leaks instead of from the conditioned space. In Granada Hills summer heat, the attic air pulled into an unsealed return chase can be 140 degrees. That heated return air raises the supply air temperature, the blower runs hotter, and the high-limit switch trips. In winter the same attic air is cooler, so the symptom disappears. Sealing the return chase fixes it. If you’re hearing a blower shut down on hot afternoons, call (661) 523-0295 for a return-side inspection before anyone sells you a new motor.
A repair estimate an insurer will actually accept includes dated camera stills of the water damage, a moisture reading from the duct liner at the breach, a written description of the source of the intrusion, a line-item list of every section being removed versus sealed, and a materials list showing what the replacement duct is. It also helps to include the after photo of the completed repair and a note on the test method used to verify the fix. We write estimates in Granada Hills for homeowners filing storm claims specifically to include these items. When we sealed a 1960s ranch on Rinaldi Street after a clogged balcony drain soaked the return chase, the insurer accepted the estimate on first submission because the file included camera footage of the liner wicking water six feet in, the mineral crust at the seams, and the airflow loss number before and after. That documentation is the difference between a paid claim and a denied one. Call (661) 523-0295 for an estimate written to insurer standards.
Written by Roy Castellanos, Owner at Hollis Air Duct Santa Clarita, serving Granada Hills with written pricing and the 365-Day Done Right Promise.