Duct Repair & Sealing in Los Angeles, CA

Fast, Reliable Duct Repair & Sealing Across Los Angeles

Duct repair and sealing in Los Angeles typically runs $280–$750 depending on whether you’re dealing with a single flex-duct tear or a full-system mastic seal, and most jobs are completed in one visit. If you’re noticing uneven temperatures, rising energy bills, or dust that keeps returning no matter how often you clean, your ductwork is likely leaking conditioned air into attics, crawlspaces, or between walls. Call (833) 958-5022 for a free estimate — Richard Anderson personally assesses every system before we quote.

Call (833) 958-5022

We’ve worked across Los Angeles for fourteen years, from the 1920s bungalows near Vermont Square to the dense apartment stacks of Koreatown and the hillside homes above Echo Park. That range matters. A technician who’s only seen suburban tract housing won’t recognize how LA’s retrofitted ductwork fails differently than purpose-built systems. Our Duct Repair & Sealing team knows the local building stock because we’ve crawled through it — literally.

Why Landmark Air Duct Cleaning Service California Is Los Angeles’s Preferred Duct Repair & Sealing Company

Richard Anderson shows up. Not a crew you’ve never met. Across 364+ verified reviews, we’ve held a 4.9-star average because the same person who answers your call is the one testing your ducts with a manometer and applying the mastic sealant himself. Fourteen years focused on one trade: cleaner air, cleaner ducts.

Los Angeles customers specifically mention our response time in reviews — we typically schedule within 48 hours and arrive when we say we will, which matters in a city where parking alone can eat twenty minutes. We know which Koreatown buildings have alley access only, which Silver Lake hillsides require ladder sets for attic entry, and where the I-110 corridor’s particulate load concentrates in older homes’ duct returns. That local knowledge saves you a return visit.

Our equipment isn’t borrowed from a general contractor’s van. We run professional Rotobrush and Nikro systems — the same rotary brush and negative-air extraction rigs commercial restoration contractors use — plus Honeywell and Aprilaire testing hardware to verify seal integrity after the work. No shop vac and a sales pitch.

Our Duct Repair & Sealing Services in Los Angeles

Duct Sealing with Mastic Sealant

Mastic sealant is our primary repair method for Los Angeles’s aging ductwork, especially in the 1920s–1950s bungalows that dominate South LA and the corridors near Vermont and Western Avenues. These homes were retrofitted with central HVAC decades after construction, meaning flex duct was often run through attic spaces that hit 140°F or higher in summer. That heat degrades the adhesive on foil tape within three to five years, while mastic remains flexible and airtight for fifteen-plus. We brush mastic onto every joint, seam, and penetration, then test with a digital manometer to confirm zero leakage before we leave. A typical mastic sealing job in Los Angeles runs $380–$620 for a single-system home.

Flex Duct Repair

Flex duct tears are the most common call we get from Los Angeles’s older housing stock. The plastic liner inside flex duct becomes brittle in sustained attic heat, then splits where it hangs over rafters or gets compressed by insulation. We recently sealed a flex-duct labyrinth in a 1920s bungalow near Vermont Square where a leaky return in the attic — hitting 145°F — was sucking in fine tire-rubber dust from the I-110 corridor. Our crew used Rotobrush agitation and mastic sealant on every joint, then tested with a manometer to ensure zero leakage before re-insulating the entire trunk line. Flex duct repair in Los Angeles typically costs $280–$450 per damaged run, including new insulation wrap.

Metal Duct Repair

Galvanized steel ductwork in Los Angeles’s mid-century apartment buildings and commercial conversions tends to separate at seams or rust through where condensation collects. Metal repair requires cutting out damaged sections, fabricating replacement pieces, and sealing with mastic rather than tape — tape fails on metal’s thermal expansion cycle. We see this most often in the post-WWII multi-units along Koreatown’s 6th Street corridor, where rooftop package units feed metal trunk lines that have been vibrating for sixty years. Metal duct repair in Los Angeles runs $420–$750 depending on access and extent.

Duct Insulation & Air Leak Repair

Uninsulated or poorly insulated ductwork in Los Angeles attics loses 20–30% of conditioned air before it reaches your vents. We remove degraded insulation, seal all leaks first, then wrap with fresh R-6 or R-8 insulation secured with mechanical fasteners — never tape alone. This is critical in View Park-Windsor Hills and the hillside neighborhoods above Silver Lake, where long duct runs through unconditioned space create the biggest efficiency losses. Full insulation replacement with air leak repair in Los Angeles typically costs $580–$950.

Trusted Brands We Service in Los Angeles

We stock components and testing equipment from Honeywell, Aprilaire, and Abatement Technologies — brands that hold up under LA’s dry, particulate-heavy conditions. Honeywell zone dampers and Aprilaire media filters integrate directly with the systems we seal, so you’re not waiting on parts from out of state. Our Nikro negative-air machines extract debris before we seal, which matters because standard sealing over contaminated ductwork just traps the problem. Fast turnaround means most Los Angeles customers have sealed, tested, and verified ductwork within a single appointment.

Common Duct Repair & Sealing Problems We See in Los Angeles Homes

• Flex duct liner degrades faster in 140°F+ attics typical of LA’s older bungalows, leading to tears and unsealed leaks that re-contaminate the living space. The 90001–90010 ZIP codes are full of these retrofitted systems, and the damage accelerates every summer.
• Shared rooftop plenums in Koreatown apartments allow cross-contamination from a single roach-infested return to spread debris through all units — sealing only one branch is futile. In Los Angeles’s Koreatown corridor along 6th Street and Vermont Avenue, rooftop package HVAC units sharing a single plenum across 4–8 apartments mean a cockroach or rodent intrusion in one unit’s return can distribute debris and allergens building-wide through shared ductwork — a cross-contamination pattern that’s routine here but rare in single-family neighborhoods.
• High freeway PM2.5 loads settle deeper into retrofitted ductwork due to LA’s near-zero relative humidity for months at a time. Fine particulates — tire rubber dust from the I-110 and I-10 corridors, smog aerosols, wildfire ash — stay suspended and recirculating rather than clumping and settling, embedding into duct liner pores that standard sealing won’t reach without aggressive rotary brush agitation first.
• Wildfire smoke infiltration after basin fire events creates seasonal demand spikes unique to Los Angeles’s bowl topography. The San Gabriel, Santa Monica, and San Gabriel mountains trap wildfire smoke, vehicle exhaust, and industrial particulates directly into residential HVAC systems. After major fire events in the surrounding hills and canyons — recurring events in this region — duct systems throughout the basin accumulate fine ash and combustion particles even in homes miles from the fire perimeter, degrading seals and contaminating branches that were clean before the fire season.

Pricing for Duct Repair & Sealing in Los Angeles, CA

We Also Serve Cities Near Los Angeles

Our service radius covers Koreatown, Echo Park, Silver Lake, and View Park-Windsor Hills with the same direct response Richard Anderson provides in central Los Angeles. Whether you’re managing a multi-unit building off Vermont Avenue or sealing ductwork in a 1930s Spanish Colonial above Echo Park Lake, we know the access constraints and parking realities of each neighborhood.

FAQs — Duct Repair & Sealing in Los Angeles