Duct Sealing in Norwalk - Leakage Measured, Then Priced in Writing

Fast, Reliable Duct Sealing Across Norwalk

Duct sealing in Norwalk usually costs between $450 and $1,400 for a typical single-family home, depending on how much of the ductwork you can actually reach. The work seals leaks at joints, takeoff collars, and small holes so the air your furnace or AC produces actually reaches the rooms it’s meant to heat or cool. Our crews work in Norwalk neighborhoods every week, from the older tracts near Norwalk Boulevard to the homes tucked along the I-5 and I-605 corridors. If you suspect your ducts are leaking, call (562) 548-7365 for a straight answer and a written price before anything gets touched.

Call (562) 548-7365

Why Hollis Air Duct Long Beach Is Norwalk’s Preferred Duct Sealing Company

We show up when we say we will. That’s the whole arrangement. You get a written price before work starts, and that number does not move once our technicians step inside your Norwalk home. The crews are background-checked and uniformed, so you know exactly who is walking through your door. Roy Castellanos runs our team with one rule: price it in writing, do it by the book, leave the site clean. When a Norwalk homeowner calls about weak airflow in a back bedroom or a furnace that runs constantly, we send someone who has actually opened the ducts in these 1950s and 1960s slab homes and knows what’s under there.

Our Duct Sealing crews have worked in Cerritos, Santa Fe Springs, Artesia, and Bellflower, but Norwalk’s housing stock is its own animal. The slab foundations put duct runs under concrete, which means a crushed or separated duct hides where you can’t see it until airflow drops. We bring camera inspection equipment to every Norwalk job because guessing is not diagnostics.

Duct Insulation in Norwalk

Duct Insulation in Norwalk matters more than most homeowners realize, especially in attics that hit 130 degrees during a summer afternoon and on exposed metal trunks that sweat during cool, humid mornings. Uninsulated or under-insulated ductwork loses conditioned air to the attic before it ever reaches the register. In Norwalk’s Mediterranean climate, the bigger issue is condensation: when cold air moves through a bare metal duct on a humid morning, moisture forms on the outside and eventually rusts the metal or drips onto ceiling drywall.

Typical duct insulation work on accessible attic runs in Norwalk runs $300 to $900, depending on the linear footage and whether we’re wrapping existing metal duct with R-6 or R-8 insulation or replacing crushed flex. We stock insulation material sized for the common 6-inch and 8-inch runs found in Norwalk’s tract homes, so we’re not running back and forth to a supply house.

Metal Trunk Wraps

Many Norwalk homes from the 1950s and 1960s have rectangular sheet-metal trunk lines in the attic or crawlspace. These trunks sweat. We clean the metal, seal the seams, and wrap the trunk with R-6 insulation, then tape all joints with UL 181-rated foil tape. This keeps the air cold where it belongs and stops the drip stains on ceilings.

Flex Duct Replacement in Attics

Flex duct that’s been up there for 30 years is often torn, sagging, or crushed under boxes of holiday decorations. When the insulation value is gone, wrapping it again doesn’t make sense. We remove the old flex and run new R-6 or R-8 flex, connected with proper takeoff collars and sealed with mastic. A typical Norwalk attic with four or five branch runs costs $500 to $1,100 to re-run and seal properly.

HVAC Duct Sealing in Norwalk

HVAC Duct Sealing in Norwalk addresses the leaks that form at every seam, collar, and connection point in your duct system. In a 60-year-old Norwalk home, those leaks can add up to losing 20 to 30 percent of the air your system produces. The blower works, the furnace burns fuel, but the air goes into the attic, the crawlspace, or under the slab instead of into the rooms where you’re sitting.

A typical whole-house duct sealing job in Norwalk costs $450 to $1,400. We use UL 181-rated mastic, not hardware-store tape, because mastic actually bonds to the metal and flex and stays put through years of heating and cooling cycles. Sealing includes all accessible supply and return seams, takeoff collars, and the plenum connection at the furnace or air handler.

Camera Inspection Before Any Sealing

Before we apply mastic to a Norwalk home’s ductwork, we run a camera through the accessible runs. In slab homes, we’re looking for crushed sections under the concrete, separated branch runs, and corrosion holes near the slab edge. You can’t seal what you can’t see, and sealing a duct system with a crushed run just pressurizes the problem.

Mastic and Foil-Wrapped Seams

The actual sealing work involves brushing mastic onto every accessible seam, wiping it into the joint, and where the duct is exposed to attic heat, wrapping the sealed seam with UL 181 foil tape as a mechanical reinforcement. This combination survives Santa Ana season. Tape alone bakes off. Mastic alone can crack if the duct flexes. Together, they hold.

Trusted Brands We Service in Norwalk

We work on systems built around Honeywell filtration setups, Aprilaire media cabinets, and equipment from Abatement Technologies and Guardsman. These are the brands we carry seals, collars, and replacement components for, which means a Norwalk homeowner with an Aprilaire filter housing on a 1990s-era HVAC system doesn’t wait a week for a part. We also stock the mastic, foil tape, and insulation products that meet code for this area. When a job requires a specific Honeywell bypass damper or an Aprilaire media cabinet gasket, we either have it on the truck or can get it the same week. No mystery sourcing, no universal parts that almost fit.

Common Duct Sealing Problems We See in Norwalk Homes

• Crushed runs under slab foundations. Norwalk’s 1950s and 1960s tract homes often route ducts under concrete. When the ground shifts or original uninsulated metal corrodes, sections collapse. Sealing the rest of the system won’t fix a duct that is physically flattened. Camera inspection finds these before we waste your money on mastic.
• Separated branch runs at takeoff collars. The original sheet-metal collars where branch ducts connect to the trunk line loosen over decades of heating and cooling. The branch duct simply falls away or gaps open at the joint. Rooms served by those branches go from comfortable to stagnant. We reconnect and seal these at every accessible location.
• Hardpan dust baked onto duct interiors. Along the I-5 and I-605 corridors, fine particulate matter settles inside ducts and then cooks onto the metal during Norwalk’s hot summers. This hardpan layer acts like sandpaper on sealant films. If we seal over it, the mastic delaminates within months. Source removal with agitation comes first, then sealing.
• Corrosion holes near slab edges. Metal ducts that have been in contact with slab moisture for 60 years develop pinholes and larger rust-through spots, particularly near the exterior walls. When we seal the accessible system and the blower ramps up, those weak spots blow out. Our inspection catches them before we apply sealant, and we patch or replace those sections.

Pricing for Duct Sealing in Norwalk, CA

We Also Serve Cities Near Norwalk

Our crews cover Norwalk and the surrounding communities. If you’re in Cerritos, Santa Fe Springs, Artesia, or Bellflower, the same team, the same written pricing, and the same 365-Day Done Right Promise applies. Call (562) 548-7365 and we’ll schedule a time that works, including evenings and weekends when our scheduling allows.

FAQs About Duct Sealing in Norwalk