Whole-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.
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AfterFast, Reliable Duct Sealing Across Walnut
Duct sealing in Walnut typically runs $450 – $1,200 for a whole-home job, with most two-story tract homes falling in the $650 – $900 range. We’re usually in and out in a single day, and you’ll know the exact price before we touch anything.
We’ve been working in Walnut long enough to know the pattern. The 1980s and 1990s two-story homes in Walnut Valley, Timberline, Snow Creek, and Creekside were built with flexible ductwork in attics and between-floor chases. That flex duct is now 25 to 35 years old. It sags. It disconnects at takeoffs. It gets crushed during routine HVAC service or when someone stores holiday decorations a little too close. The result is conditioned air bleeding into your attic, dust getting pulled in from outside, and your blower motor working harder than it should. Our Duct Sealing team sees it weekly. We dispatch from our Los Angeles office and serve Walnut with local crews who know these homes.
If your upstairs rooms never cool properly, or your energy bills have climbed without explanation, the ducts are the first place to look. Call us at (361) 326-5060. We’ll show up in the window we promised, price the job in writing, and seal it by the book.
Why Hollis Air Duct Cleaning Is Walnut’s Preferred Duct Sealing Company
We’ve built our reputation in Walnut on showing up when we said we would and leaving the site clean. That’s The Garrison Standard, and it’s how every Hollis location operates.
Our technicians are background-checked and uniformed. You know who’s walking into your home before they arrive. The price is written down before any work starts, and it does not move at the door. Every duct sealing job carries our 365-Day Done Right Promise: if the work fails within a year, we come back and make it right at no charge, including a free second visit.
Phones are answered by a live person, 24 hours a day, seven days a week. No voicemail loops. No callback queues. No waiting until Monday when your upstairs bedroom is 85 degrees.
We know Walnut’s housing stock. The Mediterranean and contemporary two-story tract houses built from the late 1970s through the 1990s have specific failure modes we’ve documented across hundreds of jobs. When we arrive at a home on Amar Road or near Suzanne Park, we’re not guessing. We’re working from experience with that exact construction era and duct configuration.
Duct Repair in Walnut
Duct Repair in Walnut usually means fixing the original flex duct runs in attics and second-floor chases that have developed tears, crushed sections, or loose joints over 25 to 35 years of use. A typical repair job runs $300 – $700 depending on how many runs need attention and whether we can access them through existing openings or need to create new ones.
Crushed and Kinked Runs
Second-floor chase runs in Walnut homes get compressed during routine HVAC filter changes, coil cleanings, or when homeowners use attic or closet space for storage. A kinked duct doesn’t move air. It creates back pressure that strains your blower motor and can trip safety limits. We open the chase, reshape or replace the damaged section, and test airflow at the register before we close up.
Disconnected Takeoffs
The connection between your main trunk line and the flex duct serving a room is called a takeoff. In Walnut’s older homes, these connections loosen as tape adhesive dries out and metal supports corrode or sag. Conditioned air dumps into your attic instead of your bedroom. We reconnect with mechanical fasteners and seal with mastic, not just tape.
Air Duct Sealing in Walnut
Air Duct Sealing in Walnut addresses the gaps, joints, and seams where your duct system leaks air into unconditioned spaces like attics, crawl spaces, and wall cavities. For a typical two-story Walnut home with attic ductwork, sealing runs $650 – $900; larger homes or systems with extensive damage can reach $1,200. The work pays for itself in most cases through reduced energy use and improved comfort within two to four years.
Mastic and Foil Tape Application
We seal joints with duct mastic, a thick, fiber-reinforced compound that remains flexible after curing, backed with foil tape at high-stress points. Unlike duct tape, which dries and fails, mastic lasts the life of the duct. We apply it to every accessible joint in your attic and at the air handler connection.
Pressure Testing After Sealing
After we seal, we run a pressure test to verify the improvement. We measure static pressure and compare it to pre-sealing readings. You see the numbers. If the system doesn’t meet our standard, we find the leak and fix it before we leave. That’s The Garrison Standard.
Trusted Brands We Service in Walnut
We carry equipment and filtration products from Aprilaire, Abatement Technologies, and Guardsman, and our rotary brush and negative-air systems come from Rotobrush and Nikro. These are the same tools commercial crews use, not hardware-store gear. For Walnut homeowners, this means we stock the parts and materials to complete most sealing jobs without ordering components and rescheduling. If your system uses Aprilaire media filters or Guardsman UV components, we can service and replace them while we’re sealing your ducts. Fast turnaround matters when your system is leaking conditioned air into your attic every day it goes unfixed.
Common Duct Sealing Problems We See in Walnut Homes
- Sagging flex duct at attic takeoffs. In Walnut Valley and Timberline homes, the original 1980s flex duct has lost tension and pulled away from trunk connections. Conditioned air pours into the attic, and return ducts pull in hot, dusty attic air instead of filtered indoor air.
- Crushed second-floor chase runs. The narrow chases between floors in these two-story tract homes don’t leave much room for error. A storage bin pushed too far, or a technician stepping wrong during HVAC service, collapses the duct and chokes airflow to upstairs rooms.
- Fine construction dust infiltration. The ongoing 57/60 freeway corridor work generates concrete and asphalt dust that Santa Ana winds push through outdoor HVAC intakes and attic vents. Leaky return ducts pull this dust into your system and redistribute it through your home.
- Loose joints at supply and return connections. Metal duct connections in original construction were often sealed with tape that has dried and failed. We find dust streaks around these joints during camera inspection, clear evidence of pressure loss and leakage.
Pricing for Duct Sealing in Walnut, CA
Whole-home duct sealing in Walnut runs $450 – $1,200, with most two-story tract homes in the $650 – $900 range. Single repairs or partial sealing start around $300. What moves the price: how many duct runs need attention, whether we can access them through existing attic openings or need to open chases, and whether we’re repairing crushed or disconnected sections in addition to sealing joints.
We do not quote per-vent pricing. We price per system, agreed in writing before work starts. One flat price. No add-ons at the door. You’ll see the number on paper before we pick up a tool.
Every sealing job includes before-and-after photos of your ductwork. You see what we found and what we fixed. Estimates are free. Call (361) 326-5060 to schedule.
We Also Serve Cities Near Walnut
Our crews work throughout the San Gabriel Valley. We regularly handle Duct Sealing in Walnut and neighboring communities including Rowland Heights, Diamond Bar, La Puente, and West Covina. The same written pricing, same 365-Day Done Right Promise, same uniformed technicians at every stop.
Serving Walnut, CA - Our Local Coverage Area
We’re based in the Walnut 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 Walnut
Cleaning removes dust and debris, but it doesn’t fix the leaks that let new dust in and waste conditioned air. Walnut’s 1980s – 1990s flex duct systems have reached the age where sagging, disconnected takeoffs, and crushed runs are the root problem. We clean first, then seal, so the system stays clean and efficient. Call (361) 326-5060 and we’ll inspect yours at no charge.
Signs include rooms that never reach the thermostat setting, unusually high summer electric bills, excess dust after windy days, and visible dust streaks around ceiling registers. We confirm leaks with camera inspection and pressure testing. If you suspect a problem, we’ll verify it before quoting any work.
We access the attic, inspect every run with a camera, mark leaks and disconnections, then seal accessible joints with mastic and foil tape. Crushed or sagging sections get reshaped or replaced. We pressure-test afterward to confirm improvement. Most Walnut two-story jobs finish in one day.
Yes, indirectly. The construction generates fine concrete and asphalt dust that Santa Ana winds carry through outdoor HVAC intakes and attic vents. If your return ducts leak, they pull this dust into your system and blow it through your home. Sealing the ducts stops the infiltration path.
Most jobs take four to eight hours for a two-story home with attic ductwork. Larger homes or those needing extensive repair of crushed or disconnected runs may take a full day. We give you a time estimate with your written price, before we start.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Walnut and the San Gabriel Valley since 2004.