Fast, Reliable Duct Repair & Sealing Across Clovis
Duct repair and sealing in Clovis typically costs $180–$650 depending on whether you’re addressing isolated seam gaps or full flex-duct replacement, and most Clovis jobs are completed in a single visit. If your HVAC system is blowing dust through ceiling registers, cycling longer than it should, or struggling to maintain temperature in 100°F summer heat, separated duct seams or failed insulation in your attic are the likely culprits. We’re Landmark Air Duct Cleaning Service California, and our Duct Repair & Sealing team serves Clovis homeowners directly from our Bell base — Richard Anderson personally leads every job, and we’re familiar with the specific failure patterns that Clovis’s valley climate and housing stock produce. Call (833) 958-5022 for a free estimate.

Why Landmark Air Duct Cleaning Service California Is Clovis’s Preferred Duct Repair & Sealing Company
Richard Anderson shows up — not a crew you’ve never met. That’s the difference Clovis homeowners notice when they’ve dealt with franchise dispatchers or subcontractors who change out every season.
Our 4.9-star average across 364+ verified reviews reflects 14 years focused on one trade: cleaner air, cleaner ducts. Clovis customers specifically mention the difference it makes when the same technician who diagnosed the problem seals every joint personally. We’re not generalists who added ductwork as an afterthought.
Response time to Clovis runs same-day to next-day for most repair calls, with emergency sealing available when attic heat has caused sudden seam separation and your system is drawing in 150°F attic air. We know the local landscape — from 1970s tract homes near downtown to newer subdivisions off Harlan Ranch — and we carry mastic, flex-duct, and insulation materials sized for both eras.
Professional Rotobrush and Nikro systems — not a shop vac and a sales pitch. That’s what 364+ homeowners, 4.9 stars, represents: consistency you can verify.
Our Duct Repair & Sealing Services in Clovis
Duct Sealing with Mastic Sealant
Mastic sealant is our primary repair method for Clovis homes because it outperforms tape in extreme attic conditions. In Clovis’s unconditioned attics — where summer temperatures routinely exceed 150°F — foil tape adhesives degrade within 2–3 years, while properly applied mastic maintains its bond through thousands of heat cycles. We apply mastic by hand to every plenum joint, collar connection, and longitudinal seam, then verify seal integrity with pressure testing. For homes in the 93612 ZIP near downtown, where original 1980s flex-duct meets the air handler, mastic sealing often restores 15–25% of lost system efficiency without replacing intact duct runs.
Flex Duct Repair
Flex duct fails differently in Clovis than elsewhere in California. The combination of 150°F+ attic temperatures and agricultural dust from surrounding orchards causes duct seams in 1970s–1990s homes to gap rapidly, allowing attic particulates to be drawn into the system — a problem far less common in coastal California cities with milder attics and less airborne farm debris. We responded to a home in the 93612 ZIP near downtown Clovis where the original 1980s flex-duct had multiple gaping seams at the air handler plenum. The homeowner called because dust was literally puffing out of ceiling registers. We sealed every joint with mastic and replaced the damaged flex runs, restoring system integrity. For partial failures, we splice in new flex sections; for collapsed or rodent-damaged runs, we replace full lengths with R-8 insulated flex rated for Clovis attic extremes.
Metal Duct Repair
Older Clovis homes — particularly pre-1990 builds in the 93611 and 93612 areas — sometimes feature galvanized metal trunk lines with spot-welded seams. These corrode where tule fog moisture enters attic intakes during December through February, and they rattle apart from thermal expansion after decades of 100°F+ summer cycling. Richard Anderson repairs metal duct by cutting out corroded sections, fabricating replacement plenums on-site, and sealing with mastic rather than relying on failing original gaskets. When metal duct is too far gone, we’ll advise honestly on retrofit versus repair.
Duct Insulation Replacement
Duct insulation breakdown in unconditioned attics during 100°F+ summers causes condensation and microbial growth — a hidden problem until your energy bill spikes or musty air starts circulating. In Clovis, the thermal assault is relentless: attic insulation on flex duct compresses, tears, or simply bakes off its vapor barrier over 10–15 years. We strip failed insulation, treat any microbial growth with Abatement Technologies products, and re-wrap with fresh R-8 insulation sealed at every seam. For homes in southeast Clovis’s 93619 ZIP — Loma Vista, Harlan Ranch corridor — newer ductwork often needs early insulation attention because construction dust and agricultural conversion debris accelerate degradation.

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 Clovis
We stock parts and materials from Honeywell, Aprilaire, and Abatement Technologies for Clovis jobs, which means faster turnaround without waiting for Fresno distributor runs. Honeywell media air cleaners and Aprilaire humidifier components integrate directly with duct repairs when we’re sealing plenum connections. For homes dealing with the valley’s dense particulate load — agricultural dust, wildfire smoke, tule fog residue — Abatement Technologies HEPA filtration and antimicrobial treatments address what sealing alone won’t fix. We carry these materials on our service vehicles, so most Clovis repairs don’t require a return trip.
Common Duct Repair & Sealing Problems We See in Clovis Homes
- Seam separation in attic flex-duct from extreme heat cycling. Clovis attics exceed 150°F regularly from May through October. Original flex-duct from the 1980s and 1990s was never engineered for this thermal assault — the inner liner cracks, the insulation sags, and the vapor barrier splits at every joint. We find this in nearly every pre-2000 home we inspect in the 93611 and 93612 ZIP codes.
- Orchard dust clogging return air pathways in newer 93619 subdivisions. In the 93619 ZIP, new subdivisions were built directly on subdivided farmland; when neighboring parcels are still actively tilled or orchards are shaken for harvest, technicians regularly find tan, chalky orchard-dust accumulation in ducts of homes that are only 5–8 years old — something homeowners don’t expect and that sets Clovis apart from Fresno’s older, more urban core neighborhoods. This dust packs into return plenums, reducing airflow and increasing static pressure until the blower motor strains.
- Duct insulation breakdown causing condensation and microbial growth. When insulation’s vapor barrier fails in a 150°F attic, the temperature differential between conditioned air (55°F) and attic air creates persistent condensation. In Clovis’s humidity spikes during tule fog season, this moisture feeds microbial colonies that homeowners smell before they see. We replace insulation and treat affected plenum areas before resealing.
- Construction debris contamination in 2000s–2010s master-planned homes. The large wave of 2000s–2010s subdivisions in southeast Clovis (93619 — Loma Vista, Harlan Ranch corridor) had newer ductwork contaminated early by construction dust and proximity to freshly converted agricultural land. Drywall dust, wood particulates, and agricultural soils settle in low-velocity duct sections, eventually breaking down seals and creating abrasive wear at joints.
Pricing for Duct Repair & Sealing in Clovis, CA
| Service | Typical Range in Clovis |
|---|---|
| Mastic sealant application (partial system) | $180–$320 |
| Flex duct repair / section replacement (per run) | $220–$380 |
| Full flex duct replacement (single zone) | $450–$650 |
| Duct insulation replacement (per run) | $160–$290 |
| Metal duct fabrication and repair | $280–$520 |
What moves you within these ranges? Accessibility (tight attics take longer), extent of contamination (orchard dust cleanup adds steps), and whether we’re addressing isolated failures or system-wide degradation. Homes in 93619 with newer but compromised ductwork often land in the lower half — the materials are newer, we’re sealing and spot-repairing rather than replacing decades-old infrastructure. Original 1970s–1990s systems in 93611 and 93612 typically need more comprehensive work. We provide exact quotes after inspection — estimates are free, and Richard Anderson personally evaluates every system. Call (833) 958-5022.
We Also Serve Cities Near Clovis
Our service radius covers Fresno to the west, Old Fig Garden’s mature tree canopy and historic housing stock, Sanger’s agricultural edge communities, and Fowler’s small-town residential areas. Each presents distinct duct challenges — Fresno’s urban density and older commercial conversions, Sanger’s intensified orchard proximity, Fowler’s mix of ranch-era and newer construction — but the San Joaquin Valley’s thermal and particulate realities affect them all. If you’re in these communities and seeing dust from registers or uneven cooling, we apply the same direct assessment and owner-led repair approach.
Serving Clovis, CA — Our Local Coverage Area
We’re based in the Clovis 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 Clovis
Agricultural dust in Clovis is finer and more abrasive than typical household dust — it’s loaded with silica from tilled soil, organic matter from orchard operations, and calcium carbonate from valley minerals. This dust infiltrates through even hairline gaps in duct seams, then acts as grinding compound every time the blower cycles, widening gaps exponentially. In Clovis’s near-continuous HVAC operation from May through October, that mechanical wear happens fast. Call (833) 958-5022 if you’re seeing dust accumulation around ceiling registers — we’ll inspect seal integrity at no charge.
Construction debris and early agricultural exposure compromise seals prematurely in 93619 subdivisions. Drywall dust settles in ducts during build-out, then the vibration of HVAC startup embeds it in mastic joints; meanwhile, surrounding active farmland generates dust loads that 5–8-year-old systems weren’t designed to filter. The seals themselves may be intact but overloaded with debris, or the original builder-grade mastic may have been thinly applied. We reseal with heavier mastic application and verify with pressure testing. Call (833) 958-5022 for an assessment — estimates are free.
Yes — quality mastic is formulated for moisture exposure and outperforms tape adhesives in Clovis’s winter humidity spikes. Tule fog deposits fine moisture at air handler intakes, but mastic’s water-resistant acrylic or latex base maintains flexibility and bond where foil tape would delaminate. We specify mastic rated for wet-location HVAC application, and we inspect fog-season moisture points during every sealing job. For homes with chronic intake moisture, we’ll also recommend Aprilaire humidity control integration. Call (833) 958-5022 to discuss your specific setup.
Often yes, but with honest limits. If the ductwork is intact structurally — no collapsed runs, no rodent damage, no widespread corrosion — mastic sealing and insulation replacement can restore 20–30% efficiency and stop attic dust infiltration immediately. However, if the inner liner is crumbling or multiple runs are crushed, replacement becomes more economical than repeated repair calls. Richard Anderson evaluates 1970s–1990s systems regularly in the 93611 and 93612 ZIPs and will tell you directly when sealing is throwing good money at failing infrastructure. Call (833) 958-5022 for that straight assessment.
Failed insulation shows three clear signs: uneven cooling between rooms (the duct is losing conditioned air to the attic), condensation or water staining on duct exterior (the vapor barrier is gone), and musty or “hot attic” smell when the system runs. In Clovis, insulation breakdown accelerates dramatically after year 10 in unconditioned attics — we’ve found R-6 insulation compressed to R-2 effectiveness in 15-year-old systems. Richard Anderson checks insulation integrity as part of every duct inspection. Call (833) 958-5022 and we’ll verify whether your insulation is still protecting your system.
Ready to stop losing conditioned air to your attic and breathing valley dust through every register? Richard Anderson personally handles every duct repair and sealing assessment in Clovis — from downtown’s 1980s flex-duct systems to Harlan Ranch’s newer builds dealing with agricultural conversion debris. We’ll inspect your ductwork, show you exactly where seals have failed or insulation has degraded, and quote honest repair ranges with no pressure to add services you don’t need. Call (833) 958-5022 today for your free estimate.
Written by Richard Anderson, Owner at Landmark Air Duct Cleaning Service California, serving Clovis since 2011.