Duct Sealing in Lafayette - Tested First, Written Price Second

Fast, Reliable Duct Sealing Across Lafayette

Duct sealing in Lafayette, CA typically costs $650 – $1,800 for a whole-home seal, with most jobs completed in a single visit. If your energy bills keep climbing or certain rooms never reach temperature, the problem is usually air leaking into your attic or crawlspace rather than your HVAC unit failing.

Call (361) 326-5060

We’ve been sending crews to Lafayette from our San Francisco Bay Area dispatch office for years. We know the difference between a hillside ranch off Happy Valley Road and a storybook cottage near the downtown corridor. That local knowledge matters because Lafayette’s housing stock isn’t like Berkeley’s flats or Walnut Creek’s newer tracts. The ductwork here was almost always retrofitted into homes built decades before central air existed, which means our Duct Sealing team spends more time hunting through unconditioned attics and tight crawlspaces than we do working on accessible basement systems.

Our phones are answered by a live person 24 hours a day, 7 days a week. Call (361) 326-5060 to schedule a free estimate. We’ll arrive inside the quoted window, price the job in writing before any work starts, and leave your site clean.

Why Hollis Air Duct Cleaning Is Lafayette’s Preferred Duct Sealing Company

Hollis Air Duct Cleaning has been part of the Garrison Partners family since 2004. Our track record predates most competitors you’ll find in Contra Costa County, and our 365-Day Done Right Promise is backed in writing on every Lafayette job. If the seal fails within a year, we return and make it right at no charge, including a free second visit.

Our technicians are background-checked and uniformed. You know who’s walking into your home before they arrive. We don’t send day laborers or subcontractors. Every crew member operates under The Garrison Standard: arrive inside the window, price in writing, complete the job by the book, leave the site clean.

We serve Lafayette specifically, not as an afterthought on a regional route. Our crews understand that the oak canopy around Reliez Valley Road means different debris loading than the exposed hillside properties off Upper Happy Valley Road. That local specificity shows up in how we prep the job, what we inspect first, and what we warn you about before we start.

Our equipment roster includes Rotobrush rotary brush systems, Nikro negative-air machines, and professional-grade sealing materials. These are the same tools commercial crews use, not hardware-store gear. We explain what each piece does and why we’re using it on your particular Lafayette home.

Duct Sealing Services in Lafayette

Duct Sealing Services in Lafayette address the reality that most local homes were never designed for central HVAC. The ductwork was added later, often by installers working in cramped, unconditioned spaces with long flex runs that sag, kink, and leak at every collar. Our job is to find those leaks, seal them properly, and restore the pressure balance your system was supposed to maintain.

A typical whole-home duct sealing in Lafayette runs $650 – $1,200 for accessible systems, with complex retrofits in tight attics or crawlspaces reaching $1,400 – $1,800. We give you a written price before any work starts. That price does not move at the door.

You’ll know you need duct sealing when rooms stay stubbornly hot or cold, your energy bills spike without explanation, or you smell attic dust when the system kicks on. In Lafayette’s older core, we regularly find handyman-era junction boxes bleeding directly into living spaces.

Leak Detection and Pressure Testing

We start every Lafayette job with a pressure test to quantify how much air you’re losing. Our techs use calibrated manometers to measure static pressure at the air handler and compare it against supply and return readings. A significant drop means leaks somewhere in the system. We follow that with a camera inspection through accessible runs to pinpoint the worst offenders before we open any walls or disturb insulation.

Mastic and Mechanical Sealing

We don’t rely on foil tape alone. For Lafayette’s retrofitted systems, we apply duct mastic, a thick, fiber-reinforced sealant that remains flexible through temperature swings, then reinforce critical joints with mechanical fasteners. This matters because Lafayette’s mild winters mean your ductwork cycles hot-cold repeatedly, and tape alone will gap open within a season.

Duct Insulation in Lafayette

Duct Insulation in Lafayette protects the air you’ve already paid to condition. In this city’s climate, with hot, dry summers and mild winters, uninsulated ducts in attics can lose 20 – 30% of their thermal energy before the air reaches your vents. That’s money bleeding into uninhabited space.

Typical duct insulation in Lafayette costs $800 – $1,500 for a standard retrofit system, with larger hillside homes or extensive crawlspace runs reaching $1,800 – $2,400. We price by the system, not by the linear foot, so you know the total before we start.

Lafayette’s older homes are the worst offenders. The original installers ran flex duct through attics that hit 140°F in July and drop to 40°F in January. Without insulation, your system works overtime for diminishing returns.

Fiberglass Wrap and Reflective Barrier

We use professional-grade fiberglass insulation with vapor barrier jacketing, rated for the temperature swings Lafayette attics experience. On exposed trunk lines, we add reflective radiant barrier where it makes sense. We don’t sell you more than your system needs. The goal is to stop the loss, not to pad the invoice.

Crawlspace and Attic Specific Solutions

Lafayette’s storybook cottages often have partial basements or dirt-floored crawlspaces beneath the original footprint, with later additions sitting on slab or raised foundation. That patchwork construction means duct runs cross multiple environments. We inspect every transition and insulate accordingly, because a sealed but uninsulated duct in a damp crawlspace will condense, grow mold, and fail again.

Trusted Brands We Service in Lafayette

Our Lafayette crews carry professional-grade equipment from Rotobrush, Nikro, and Abatement Technologies. We stock sealing mastics, mechanical fasteners, and insulation materials from Honeywell, Aprilaire, and Guardsman product lines. This means fast turnaround on most Lafayette jobs. We don’t wait on parts shipments from out of state. If your system needs a specific collar size or plenum adapter for a retrofit installation, we likely have it on the van. If we don’t, our Bay Area supply relationships get it next day, not next week.

Common Duct Sealing Problems We See in Lafayette Homes

• Retrofit flex runs sagging and pulling apart at collars. Lafayette’s 1920s – 1950s homes were never built for ductwork, so installers ran long flex runs through attics and crawlspaces. Gravity, vibration, and thermal cycling cause these runs to sag, kink, and separate at the connection points. Seam tape fails within a season, and the leaks return worse than before.
• Rodent nesting and acorn debris in exterior intakes. The hillside oak canopy around Lafayette means our technicians routinely clear rodent nests, acorns, and leaf debris from exterior intake screens in late fall. This debris starves the system, raises static pressure, and forces leaks at weaker joints elsewhere in the ductwork.
• Poorly cured mastic and tape seals from intermittent winter use. Lafayette’s mild winters keep HVAC use intermittent rather than constant. Mastic and foil-tape seals need sustained temperature to cure properly. When ducts cycle hot-cold repeatedly without long run times, the seals never fully set, and gaps open at flex connectors by spring.
• DIY and handyman retrofits bleeding into living spaces. In Lafayette’s older pedestrian-friendly core, we regularly find hidden attic duct junctions leaking directly into living spaces after amateur retrofits. The homeowner smells attic dust every time the system runs, and the energy bills climb because the system is pressurizing uninhabited space instead of conditioned rooms.

Pricing for Duct Sealing in Lafayette, CA

We Also Serve Cities Near Lafayette

Our crews regularly work in Walnut Creek, Orinda, Moraga, and Pleasant Hill. Each city has its own housing stock quirks and ductwork challenges, but the same Garrison Standard applies: written price, written guarantee, background-checked uniformed technicians, and a 365-Day Done Right Promise on every job. If you’re near the Lafayette border in any of these communities, we can typically schedule you on the same routing day.

FAQs About Duct Sealing in Lafayette