Fast, Reliable Duct Repair & Sealing Across North Hills
Duct repair and sealing in North Hills typically runs $350–$1,200 depending on system size, duct type, and how many breach points need to be addressed — and most jobs are completed in a single visit. If you’re in the 91343 or 91393 ZIP code and your rooms aren’t cooling evenly, your electric bills have climbed without explanation, or you’re getting a musty or smoky smell from your registers, that’s a duct system telling you something. Call (424) 219-7459 for a free estimate — Brandon Flores and our Duct Repair & Sealing team know exactly what to look for in North Hills homes, and we’re typically on-site within 24–48 hours.
Why Certified Air Duct Specialists North Hollywood Is North Hills’s Preferred Duct Repair & Sealing Company
We’ve been doing this specialized work for 19 years, and a meaningful share of that experience has been inside North Hills homes — the 1950s–1970s tract builds along Reseda Boulevard, the post-quake retrofits in Devonshire Highlands, the Carey Ranch Estates homes that look updated from the street but still have original or 1990s-era ductwork underneath the drywall. That familiarity matters. We’re not arriving cold and guessing — we’ve seen the failure patterns that repeat in this specific housing stock, and we know where to look first.
Brandon Flores — owner and lead technician — personally handles your job. Not a subcontractor, not a crew dispatched from a call center. When you book with us, the most experienced person we have shows up on your driveway. That’s been our model for 19 years, and it’s why 613 verified customers have left an average rating of 4.9 stars. Volume and rating together tell the story: these aren’t cherry-picked testimonials, they’re consistent, repeatable results across hundreds of real jobs in the San Fernando Valley.
North Hills is a fast drive from our Valley Village base — typically under 30 minutes, even accounting for Golden State Freeway traffic. We schedule same-week service for most non-emergency jobs and can often get on-site faster than that in urgent situations. If the cooling season is bearing down and you’re already losing airflow to back bedrooms, that timeline matters.
Our Duct Repair & Sealing Services in North Hills
Flex Duct Repair
This is the service North Hills homes need more than almost any other Valley city right now — and the reason is specific and documented. The post-quake rebuild wave of 1994–1996 put a generation of flex duct into homes across the 91343 ZIP code simultaneously. That flex duct is now approximately 30 years old. Flex duct has a functional lifespan of 25–30 years under normal conditions; under the San Fernando Valley’s sustained inland heat, it ages faster. We’re finding collapsed branch joints, disconnected inner liners, and perforated outer jackets in home after home along Reseda Boulevard and the surrounding tract neighborhoods. A typical flex duct repair in North Hills runs $180–$450 per run, depending on length and access difficulty.
Mastic Sealant Application
Duct tape — the silver foil kind installers used in the 1990s — doesn’t last. It dries, cracks, and peels under repeated thermal cycling, and a Valley summer gives a duct system dozens of those cycles every week. We seal every breach and connection point with professional-grade mastic sealant, which bonds permanently and doesn’t degrade the way tape does. In North Hills homes in Devonshire Country Estates and along the northern foothill rim, mastic sealing is especially important after fire seasons: ash particulate infiltrates duct interiors and accelerates seal degradation at connection points, creating leak patterns that worsen year over year if left unaddressed. Mastic sealing for a full system in North Hills typically runs $300–$700.
Metal Duct Repair
Older North Hills homes — particularly those built in the 1950s and 1960s with original sheet metal trunk systems — sometimes have ductwork that has held up structurally but developed gaps at seams, crimped sections from previous renovation work, or damaged takeoffs where flex branches connect to the main trunk. We repair rather than replace where the metal is structurally sound, using proper sheet metal techniques and mastic sealing at every seam. Metal duct repair in North Hills generally runs $200–$600 depending on the scope, and is often significantly less expensive than replacing sections that can be rehabilitated. We use Nikro inspection equipment to map the full system before any cutting or patching begins.
Duct Insulation
Duct insulation in a San Fernando Valley attic takes a beating. Summer attic temperatures in North Hills regularly exceed 140°F, and insulation that was installed in the 1970s or during the post-quake retrofits of the mid-1990s is often compressed, moisture-damaged, or simply absent in sections that were disturbed during construction. Bare or under-insulated duct in a 140°F attic is transferring heat directly into your conditioned air before it ever reaches the register. We re-insulate using current R-value standards appropriate for the inland basin climate, and the efficiency gains are measurable — most North Hills homeowners see a real difference in cooling costs by the following billing cycle. Duct insulation jobs in North Hills typically run $400–$900 for a standard single-story tract home.
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 North Hills
We work with equipment from Honeywell, Aprilaire, Abatement Technologies, and Guardsman across North Hills homes — brands that show up in the HVAC and air quality systems installed during the post-quake rebuild era as well as in more recent upgrades. Our Rotobrush and Nikro professional systems handle both inspection and remediation, which means we’re not outsourcing the diagnostic step to a different crew or a different visit. If your North Hills home has equipment from any of these manufacturers, we can inspect, clean, repair, and seal around it without creating additional coordination delays.
Common Duct Repair & Sealing Problems We See in North Hills Homes
- Collapsed flex duct at branch joints (post-quake vintage, circa 1994–1996): The synchronized aging of post-Northridge earthquake ductwork across the 91343 ZIP code means entire rooms losing conditioned airflow at once. We see this pattern repeatedly in tract homes between Reseda Boulevard and the Golden State Freeway — it’s not a random failure, it’s a predictable end-of-life event for a specific installation generation.
- Ash and fine particulate coating duct interiors after fire season: Homes in Devonshire Highlands and Devonshire Country Estates, positioned closest to the Santa Susana Mountains corridor, accumulate visible ash residue inside duct interiors after each fall fire season. This residue doesn’t just circulate into living spaces — it accelerates liner degradation and causes seal failure at connection points faster than flat-valley addresses a mile south on Reseda or Victory Boulevard.
- Cracked and peeled duct tape seals from Valley heat cycling: The San Fernando Valley’s inland basin heat — routinely exceeding 100°F from May through October — puts HVAC systems in North Hills under nearly continuous load for six months. That thermal cycling destroys 1990s-era foil tape seals methodically. By the time a homeowner notices uneven cooling, the system is often leaking conditioned air at multiple points simultaneously.
- Degraded or missing duct insulation in attics: Many North Hills tract homes still have original or early-retrofit insulation on their duct systems — compressed fiberglass wrap that has been through 30-plus Valley summers and one major earthquake. Degraded insulation doesn’t just reduce efficiency; it allows condensation to form on duct surfaces in the shoulder seasons, which accelerates mold growth inside the duct liner and compounds the indoor air quality problem.
The 1994 Northridge Earthquake and North Hills’s Once-in-a-Generation Duct Problem
This is the local context no generic duct company is going to walk you through, but it’s the most important thing to understand if you own a home in North Hills. The epicenter of the 1994 Northridge earthquake was just a few miles from the 91343 ZIP code. The seismic damage across North Hills was severe enough that a large share of the housing stock had ductwork repaired or fully replaced in the 1994–1996 window, all at roughly the same time. That post-quake generation of flex duct is now approximately 30 years old — right at or past its design lifespan — and it’s failing across the ZIP code in a concentrated, synchronized wave. Neighboring Valley cities like Van Nuys or Reseda that escaped comparable earthquake damage don’t have this dynamic. Their duct failures are distributed across installation decades. In North Hills, the failures are clustering.
We were called to a 1960s tract home in Devonshire Highlands where the homeowner had noticed a sharp spike in summer cooling bills and a persistent musty smell that got worse after the previous fall’s Santa Susana corridor fire season. When we pulled the access panels, we found post-quake flex duct installed circa 1995 that had collapsed at three branch joints and was coated in visible ash residue at every upstream register. Using Nikro inspection equipment to map the full system, we sealed every breach with mastic sealant, replaced the failed flex runs, and re-insulated the main trunk before the next 100°F heat wave hit Reseda Boulevard and Victory Boulevard — restoring airflow to rooms that had been starved of conditioned air for at least two summers. That’s not a dramatic outlier. That’s a representative North Hills job in 2024 and 2025.
The question for North Hills homeowners isn’t whether post-quake ductwork needs attention — it’s whether what’s in place can be repaired and sealed, or whether it’s deteriorated past the point where repair is the right investment. Brandon Flores makes that call after a full system inspection, not before. We don’t walk in recommending full replacement; we walk in with Nikro inspection equipment and show you what we found.
Pricing for Duct Repair & Sealing in North Hills, CA
Here’s what North Hills homeowners are actually paying for these services, based on the types of homes and systems we work on in the 91343 and 91393 ZIP codes:
- Flex duct repair (per run): $180–$450
- Mastic sealant application (full system): $300–$700
- Metal duct repair: $200–$600
- Duct insulation (standard single-story tract home): $400–$900
- Full duct repair and sealing package (combined scope): $650–$1,800
What pushes a job toward the higher end: limited attic access, heavy ash or debris accumulation in the duct interior requiring remediation before sealing, multiple collapsed flex runs, or a system that hasn’t been inspected since the post-quake install. Jobs on the lower end tend to be single-zone repairs with good access. We give you a firm estimate before any work begins — no open-ended quotes. Call (424) 219-7459 and we’ll tell you exactly what we’re looking at after the inspection.
We Also Serve Cities Near North Hills
Our duct repair and sealing service covers the full surrounding area. If you’re in Van Nuys, Valley Glen, Encino, or Sherman Oaks, we’re regularly working in your neighborhood and can typically schedule service on the same timeline as a North Hills job. Call us directly to confirm availability for your city.
Serving North Hills, CA — Our Local Coverage Area
We’re based in the North 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 — Duct Repair & Sealing in North Hills
Not automatically — but you’re in the window where a thorough inspection is overdue. Post-quake flex duct installed in 1994–1996 is now 28–30 years old, which is at or past its reliable service life in the San Fernando Valley’s heat environment. Whether you need full replacement or targeted repair depends on what we find: systems with isolated joint failures and intact liners can often be repaired and sealed at a fraction of replacement cost. Systems with widespread liner collapse, perforated outer jackets, or heavy ash accumulation throughout generally warrant full replacement. We inspect first, give you both options with honest pricing, and let you decide. Call (424) 219-7459 for a free inspection estimate.
A burnt or acrid smell from registers after fire season in Devonshire Highlands is usually a duct problem, not just a filter problem. Homes in that northern rim of North Hills — closest to the Santa Susana corridor — pull ash and fine particulate directly into duct systems during Santa Ana wind events. A filter catches some of it; the duct interior and the liner surface catch the rest. Ash residue inside ducts doesn’t just smell — it accelerates liner degradation and can carry combustion byproducts into living areas every time the system runs. A filter swap won’t address what’s coating the interior of the duct. An inspection and cleaning, followed by mastic sealing of any breach points, will. Call (424) 219-7459 to schedule.
Same floor plan, same equipment vintage, different duct condition — that’s almost always the explanation. A duct system leaking conditioned air into an unconditioned attic forces your HVAC unit to run longer cycles to hit the thermostat setpoint, and in a Valley summer exceeding 100°F, those longer cycles add up fast on your electric bill. If your neighbors had a duct repair or sealing job done in the last five years and you haven’t, the efficiency gap between identical houses can easily produce a $60–$120 monthly billing difference in peak cooling season. We can inspect your system along Victory Boulevard or anywhere in the 91343 ZIP and quantify what you’re losing. Call (424) 219-7459.
Yes — and it’s one of the more underdiagnosed combinations we see in older North Hills homes. Degraded duct insulation allows attic heat to transfer directly into the conditioned air stream, reducing the effective cooling your system delivers. At the same time, deteriorated insulation wrap can develop moisture on its surface during the shoulder seasons, which feeds mold growth inside the duct liner. That mold circulates through every room the system serves. So you’re losing cooling efficiency and circulating biological contaminants simultaneously from the same underlying problem. Replacing the insulation and sealing the system addresses both. Jobs like this in North Hills typically run $400–$900 for the insulation work plus any associated sealing. Call (424) 219-7459 for an estimate.
The honest answer is that you can’t know without an inspection using real diagnostic equipment — and any contractor who quotes full replacement without one is overselling. Our process in Carey Ranch homes is to run a full Nikro system inspection, map every breach and failure point, and then give you a clear picture: here’s what repair costs, here’s what replacement costs, and here’s our recommendation based on the actual condition of the system. If more than 40–50% of the flex runs are collapsed or the liner integrity is compromised throughout, replacement is usually the better long-term investment. If the failures are localized — a few branch joints and deteriorated seals — repair and mastic sealing at $350–$800 is often all you need. We’ll show you what we found and let you make the call. Call (424) 219-7459 to set up the inspection.
Schedule Your North Hills Duct Repair & Sealing Inspection
If your North Hills home has post-quake ductwork from the 1990s, or you’ve noticed uneven cooling, rising electric bills, or any burnt or musty smell from your registers after fire season, the duct system is worth inspecting before the next Valley heat season arrives. Brandon Flores and our team serve North Hills, Devonshire Highlands, Carey Ranch, and the full 91343 and 91393 ZIP codes. Call (424) 219-7459 for a free estimate — we’ll tell you exactly what we find and what it costs to fix it, before any work begins.
Reviewed by Brandon Flores, Owner & Lead Technician at Certified Air Duct Specialists North Hollywood, serving North Hills and the San Fernando Valley for 19 years.
