Duct Sealing in Moraga - Tested First, Written Price Second

Fast, Reliable Duct Sealing Across Moraga

Duct sealing in Moraga typically costs $1,200 – $2,800 for a whole-home system and takes one to two days, depending on whether your home has the original 1960s – 1980s rigid metal ductwork common to this area or a newer multi-zone setup. We’re the Moraga crew that shows up inside the window, prices the job in writing before touching anything, and seals it by the book under our 365-Day Done Right Promise. Dispatch and scheduling are coordinated from our San Francisco Bay Area office, and our technicians serve Moraga neighborhoods including Sanders Ranch, Rheem Valley, and the Canyon Road corridor. Call (361) 326-5060 for a free estimate.

Call (361) 326-5060

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

We’ve been sealing ducts in Moraga since long enough to know the difference between a ranch on Rheem Boulevard and a hillside custom off Canyon Road. Our background-checked, uniformed technicians arrive when we said they would, and they leave the site clean. That’s The Garrison Standard, and it’s written down, not implied.

Our 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 when your return register is dumping ash onto the floor after a Diablo wind event.

Every job gets a written price before work starts. The number does not move at the door. If the seal fails within a year, we come back and make it right at no charge, including a free second visit. That’s the 365-Day Done Right Promise, backed in writing on every job.

We know Moraga’s terrain. Homes on steep slopes draw heavy spring oak pollen and summer wildfire ash deep into ductwork, a combination almost nonexistent in flatter neighboring towns. Our Duct Sealing team maps leaks to this specific climate and geology, not to a generic checklist.

Duct Sealing Services in Moraga

Duct Sealing Services in Moraga focus on closing the gaps, cracks, and failed joints that let conditioned air escape and outdoor debris enter your HVAC system. For most Moraga homeowners with 1960s – 1980s ranch or split-level construction, the problem isn’t the duct runs themselves but the joint collars and boot connections that have worked loose from decades of seismic settling on canyon slopes. A typical whole-home duct sealing job in Moraga runs $1,200 – $2,800, with simpler single-zone ranch homes at the lower end and complex hillside custom homes with multi-zone systems at the upper end.

Joint Collar and Boot Sealing

Our tech ran a camera inspection through a 1972 split-level off Sanders Ranch Road where the homeowners had watched ash sift onto the return registers after the last Diablo wind event; every trunk joint collar in the original rigid metal supply and return ducts was weeping, pulling that fine ash straight past the air handler. We sealed the collars and boots with mastic and mesh, wrapped the exposed runs in the unconditioned crawlspace, and rebalanced the registers. The return-air plenum ash load dropped off completely on the follow-up visit. This is the work most Moraga homes need, and it’s the work many crews skip because crawling a slope-side crawlspace is harder than walking an attic.

Aerosol Duct Sealing for Hard-to-Reach Systems

Newer hillside custom homes in Moraga often have ductwork routed through soffits, chases, and sealed wall cavities that you cannot reach with mastic and a brush. For these, we use pressurized aerosol sealant that finds and plugs leaks from the inside. The process takes longer and costs more, but it’s the only way to seal what you cannot see or touch. We always pre-test with a duct blaster to measure leakage in CFM, then post-test to prove the seal held.

Duct Insulation in Moraga

Duct Insulation in Moraga addresses the unconditioned crawlspaces and attics where original rigid metal ducts run exposed, bleeding heating and cooling into spaces that do not need it. Moraga’s hot, dry summers and cool winter nights mean your system works harder here than in milder coastal zones, and uninsulated ducts in a 140-degree attic or a damp crawlspace under a slope-side home waste 20 – 30% of the air you paid to condition. A typical duct insulation job in Moraga runs $800 – $1,800, depending on linear footage, accessibility, and whether we are insulating existing sealed ducts or wrapping new work.

Crawlspace and Attic Wrap

Most Moraga ranch homes have duct runs in one or both of these spaces. We use formaldehyde-free fiberglass wrap with a reinforced vapor barrier, secured with mechanical fasteners, not tape that degrades in heat. For homes on steep lots where crawlspaces stay damp year-round, we add a closed-cell spray-foam jacket at boot connections to prevent condensation and mold.

Multi-Zone Insulation for Custom Homes

Hillside custom builds off Canyon Road and upper Rheem Valley often have ductwork split across three or four zones with exposed flex runs in garage ceiling chases. We insulate each run individually, seal the chase penetrations with fire-rated foam, and label every zone at the air handler so future service crews know what they are looking at. It takes longer. It costs more. It is the only way to do it right.

Trusted Brands We Service in Moraga

We stock parts and materials from Aprilaire, Abatement Technologies, and Guardsman, plus we run Rotobrush rotary systems for pre-sealing mechanical cleaning when ducts are loaded with debris. For Moraga customers, this means we do not wait on a parts run to Walnut Creek or special-order filtration media from a warehouse two counties away. If your system needs a specific boot size, a particular gauge of mastic mesh, or an Aprilaire media upgrade after sealing, we likely have it on the van. Fast turnaround matters when Diablo wind season is forecast and your return plenum is already weeping ash.

Common Duct Sealing Problems We See in Moraga Homes

• Sealing only attic runs while crawlspace joints leak. Many crews seal what they can reach from a ladder and call it done. On Moraga’s slope-side ranch homes, the worst leaks are often beneath the house where seismic settling has cracked boot connections. Spring oak pollen still gets pulled straight through the air handler.
• Tape or aerosol over crumbling mastic. Decades-old mastic on original rigid metal ducts has cracked from thermal cycling and ground movement. Slapping tape on top traps moisture and fails within a season. We scrape to bare metal and rebuild the seal properly.
• Ignoring shared dryer vent stacks in multifamily buildings. Moraga has denser pockets of townhomes and small apartment buildings where one unsealed lint pathway reintroduces fine debris into return-air plenums. Duct sealing that does not address the shared stack is incomplete.
• Flex-duct assumptions on rigid metal systems. Crews trained on Lafayette’s newer flex-duct stock look for crushed or disconnected runs. Moraga’s original metal trunks fail at collars and boots, not in the straight sections. The leak map is different, and the fix is different too.

Pricing for Duct Sealing in Moraga, CA

We Also Serve Cities Near Moraga

Our crews work throughout Lamorinda and the central Contra Costa corridor, including Duct Sealing in Moraga and surrounding Orinda, Walnut Creek, Lafayette, and Alamo. Each community has its own duct stock and failure pattern; we adjust the approach to the house, not the zip code.

FAQs About Duct Sealing in Moraga