Duct Sealing in Los Altos - Tested First, Written Price Second

Fast, Reliable Duct Sealing Across Los Altos

Duct sealing in Los Altos typically costs $1,200 – $2,800 for a whole-home system, and most jobs are completed in a single day. If your upstairs bedroom stays cold while the utility bill climbs, the problem is usually air leaking from joints and splices in the attic, not your furnace itself.

Call (361) 326-5060

We serve Los Altos from our San Francisco Bay Area dispatch office, with crews running scheduled appointments throughout the week. The drive to Old Los Altos, Loyola Corners, or the ranch properties along Magdalena Avenue is routine for us. We’ve worked on enough 1960s ranches with 1990s additions to know what hides above those ceilings: original galvanized trunks feeding new flex runs, DIY splices that failed years ago, and filters pulling oak pollen and road dust through gaps the homeowner never sees. Call (361) 326-5060 for a free estimate. We’ll show up in the window we promised, price the work in writing before we touch anything, and stand behind it for a full year.

Why Hollis Air Duct Cleaning Is Los Altos’s Preferred Duct Sealing Company

We’ve been in business since 2004 as part of the Garrison Partners family, and our Los Altos customers come back because the price on the page matches the price at the door. That’s not common in this trade. Our Duct Sealing team works under The Garrison Standard: arrive inside the quoted window, put the price in writing before any work starts, complete the job by the book, and leave the site clean.

Our technicians are background-checked and uniformed. You know who’s walking into your home before they arrive. Phones are answered by a live person 24 hours a day, 7 days a week. No voicemail loops, no callback queues, no waiting until Monday for a scheduling question.

The 365-Day Done Right Promise covers every job we do in Los Altos. If the seal fails, the airflow doesn’t improve, or something we touched needs correction within a year, we come back at no charge. That includes a free second visit, not a negotiation.

We know the local housing stock. Los Altos is mostly 1950s – 1970s ranch-style and Eichler-influenced homes on large lots, many extensively remodeled. That means original ductwork patched into additions, new HVAC tied into old trunks, and a lot of hidden leakage that a surface cleaning won’t fix. We don’t pretend every job is the same. We inspect, we explain what we found, and we fix what we quote.

Duct Sealing Services in Los Altos

Duct Sealing Services in Los Altos address the hidden air leaks in your forced-air system: joints where metal meets flex, collars that have separated above the ceiling, and splices that were never properly sealed when a previous owner added on. In a city of mature, high-value single-family homes where decades of remodel layers stack original 1950s-60s ductwork against new HVAC equipment, sealing is often a diagnostic and correction service, not a routine maintenance sweep. A typical whole-home duct sealing job in Los Altos runs $1,200 – $2,800, depending on system size, attic accessibility, and how many failed splices we find.

Leak Detection and Static Pressure Testing

We start with a pressure test, not a guess. Our techs use professional-grade equipment to measure how much air your system is losing before it ever reaches a register. In Los Altos homes with original galvanized trunks feeding new additions, we regularly see static pressure readings that explain why the back bedroom never heats. The numbers tell the story. We show them to you.

Mastic Sealing and Mechanical Reconnection

Tape alone fails in Los Altos attics. The dry heat and temperature swings between summer days and cool nights crack adhesive within a season. We seal joints with duct mastic, a water-based sealant that flexes and holds, then reinforce with foil tape where mechanical stress requires it. For disconnected collars and undersized runs, we reconfigure the connection properly rather than patch over a design flaw.

Duct Insulation in Los Altos

Duct Insulation in Los Altos matters because even sealed ducts lose efficiency when they run through unconditioned attic space. Los Altos has a mild, dry Mediterranean climate, so HVAC use is moderate and ducts rarely see the condensation problems of humid regions. But summer AC use in well-sealed homes can recirculate construction dust from nearby remodels, and poorly insulated flex duct in a hot attic dumps cooled air before it reaches the register. A typical duct insulation job in Los Altos runs $800 – $1,800 for partial-system work, or $1,500 – $3,200 for full replacement of degraded flex with insulated, sealed runs.

Attic Flex Replacement with Insulated R-8 Duct

Old flex duct in Los Altos attics collapses, tears, and loses its insulation jacket over time. We replace it with R-8 insulated flex or rigid duct where the run allows, sealed at every joint and supported to prevent sagging. Sagging flex creates pools of dust and pollen, and in Los Altos, that means coarse road dust and oak pollen from unpaved drive aprons and open lots.

Vapor Barrier and Rodent Protection

Los Altos’s dry climate doesn’t produce humidity damage, but attic temperatures still swing hard. We inspect insulation jackets for gaps where rodents have accessed ductwork, common in properties with open land and oak canopy. A proper vapor barrier and sealed access point protect the system after we leave.

Trusted Brands We Service in Los Altos

Our equipment roster includes Rotobrush rotary brush systems for mechanical cleaning, Nikro negative-air machines for containment and extraction, and sealing and filtration products from Abatement Technologies and Guardsman. We stock parts and materials for Los Altos jobs locally, so we’re not waiting on a warehouse shipment to finish a seal. When we find a failed component during inspection, we can usually source the replacement and complete the repair in the same visit. The tools are professional-grade, the same equipment commercial crews use, and we explain what each piece does for your specific system before we start.

Common Duct Sealing Problems We See in Los Altos Homes

• Original trunks never resized for additions. In neighborhoods like Old Los Altos and Loyola Corners, a permitted 1990s bedroom addition often left the 1962 galvanized trunk still feeding new rooms. The farthest bedroom gets almost no airflow while the air handler strains. Sealing the joints without resizing the run leaves the room still starved.
• Flex-to-metal splices taped, not mastic-sealed. Attic flex duct spliced to old rigid galvanized with tape fails within a season of Los Altos’s dry heat and temperature swings. The joint reopens, pulling unpaved-drive dust and oak pollen straight into the return stream past the filter.
• Neglected outbuilding and detached-garage systems. Large Los Altos lots often have separate HVAC for a guest house, studio, or garage conversion. These systems sit on their own filter buses, frequently ignored. Sealing the main house while leaving the outbuilding open leaves a second, unfiltered pollen source feeding the same property.
• Wood-heat properties with smoke residue in returns. Homes with fireplaces or wood stoves pull creosote-tinged smoke residue through return leaks when the system cycles. Sealing the ducts without removing the source material leaves that odor recirculating even after the joints look tight.

Pricing for Duct Sealing in Los Altos, CA

We Also Serve Cities Near Los Altos

Our crews run scheduled appointments throughout the Peninsula. We also provide Duct Sealing in Los Altos and surrounding communities including Mountain View, Stanford, Palo Alto, and Portola Valley. The same written price, same 365-Day Done Right Promise, same background-checked uniformed technicians apply in every city we serve.

FAQs About Duct Sealing in Los Altos