Attic insulation in Gilroy CA - sealed first, then covered evenly out to the edges
Hot upstairs rooms or a big summer power bill? We fix what's wrong in the attic first, then insulate it evenly.
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Does my attic need more insulation, and what goes into the job?
Attic insulation in Gilroy usually means blowing loose cellulose or fiberglass through a hose across your attic floor so the ceiling slows heat better, and it helps most in older homes that have little or nothing up there now.
Maybe the upstairs bakes every afternoon, the room over the garage never warms up, or you just bought an older place and found a few flat inches of old fluff, and that's usually when people call us at Thermal Gilroy Spray Foam Insulation. The price mostly turns on how big the attic is, how much is already there, how many gaps need sealing and whether anything has to be fixed first. The schedule turns on those same repairs, because nothing new goes down until they're done. I'll put all of it in a written plan once I've been up there and seen your attic for myself.
How we do attic insulation, start to finish
First I go over the whole attic, because insulation laid over a leak or a wiring problem just hides it, and anything that needs fixing gets sorted out before new material goes down. Then our installers do the air sealing, which means closing the openings through the attic floor where pipes, wires, lights and the hatch come through, so the new layer isn't fighting a draft. That includes solid blocking over open soffits, metal collars around hot flue pipes and covers over recessed lights that aren't rated to be buried. Next they set baffles, guards near the roof edge that keep the eave vents open so the attic can still breathe and insulation can't spill into the eaves. Last, they blow in the loose fill as evenly as they can, all the way out to the top plate where the attic meets your outside walls, since thin edges are where most attics come up short.
Most attics we see get blown-in insulation, and I'll be honest that sealing the gaps and topping up loose fill usually beats foam on value. The exception is when your ductwork runs through the attic, because foam costs more but seals the air while it insulates, and that's worth talking through. If the attic is only part of the problem, say you've also got drafty rooms or cold floors, we can look at home insulation for the whole house on the same visit.
Attic insulation in Gilroy and the license it calls for
In California, the state licensing board counts installing any insulation for temperature or sound control as insulation contracting, so your attic is a job for a licensed contractor, and it's fair to ask whoever climbs your ladder to show you theirs. The California Energy Commission's newest building energy standards also took effect on January 1, 2026.
Around Gilroy we climb into plenty of older homes with a thin, settled layer, attics where the edges over the outside walls were left bare, and hot rooms over garages. We see the same mix on jobs in Morgan Hill and down in Hollister, and we work the cities around Gilroy, north into Santa Clara County and south toward Salinas and Watsonville. If your city isn't on our list, call and ask.
- Call (669) 205-6284
- Mon–Fri: 6 AM–11 PM, Sat–Sun: 7 AM–11 PM
- Gilroy, CA 95020
What happens after you call us about your attic?
Call or send the form
I answer the phone myself, or I call you back to set a time to come out. I'll ask how old the house is, which rooms bother you and whether you've seen any roof leaks, so I show up knowing what to look for.
I look over your attic
I go up, check how many inches are already there and note anything that has to be fixed first. Then I walk you through a written plan that shows the order of the work and what it will cost, so the price isn't a guess.
Our installers work in order
Repairs come first, then sealing, then baffles, then the blown insulation, and I check in while the job is going. Clearing stored boxes out of the attic beforehand helps the crew get everything level.
We walk the finished job
Before we pack up, I go over the attic with you and show you the sealed spots and the depth out at the edges. You'll know exactly what went in before we leave.
Why Gilroy homeowners call Thermal Gilroy Spray Foam Insulation for attic insulation
The owner writes your estimate
I'm the one who comes out, looks at the attic and writes the plan, and I check in while our installers work. You talk to the same person from the first look to the final walk-through.
Started in Gilroy in 2021
I spent years scheduling crews and learned insulation working beside the installers on the jobs I booked, then started this business here in 2021. That's where I learned to keep a job in the right order, so nothing gets covered up that should have been fixed.
Licensed and insured for attic work
We're licensed and insured, so the state license your attic job calls for is covered before anyone goes up the ladder. Our work is backed by our satisfaction guarantee.
On an attic, the order of the work matters most, so request your estimate and we'll start by finding out what yours needs first.
Request an estimateGet a written plan for your attic insulation
I reply within one business day to set up a free on-site look at your attic, and afterward you get a written plan with no pressure to book. Nothing goes on the schedule until you say so.
- Licensed and insured.
- Phone
- (669) 205-6284
- Location
- Gilroy, CA 95020
- Hours
- Mon–Fri: 6 AM–11 PM, Sat–Sun: 7 AM–11 PM
Questions about attic insulation in Gilroy
How much does attic insulation cost around Gilroy?
Attic insulation in the San Jose area usually runs about $1,800 to $6,000 per job. Where yours lands depends on the attic's size, how much is already up there and whether anything has to be fixed or sealed first. Your written estimate spells that out for your house.
What needs to be fixed in my attic before new insulation goes in?
A leaking roof, live knob and tube wiring, which is old wiring run on porcelain knobs, vermiculite insulation and bath fans that vent into the attic all need repair before new insulation goes down. Vermiculite can contain asbestos, so if we spot anything that looks like it, we plan for it to be handled before going any further.
How long does blown-in cellulose insulation last?
Properly installed cellulose can work well for decades, according to the cellulose makers' trade group, and it helps with sound and fire protection too. That long life depends on a careful install, which is why we seal first and keep the depth even.
What paperwork should I get after attic insulation is installed in Gilroy?
Ask for a written record that shows the insulation type, the area covered and its R-value, which tells you how well it slows heat, along with the installed and settled thickness and the number of bags. A federal weatherization checklist calls for a record like that, and when we finish, you get a written record from us of what went in and how much.
How do I prepare my attic before insulation is installed?
Move stored boxes, decorations and old furniture out of the attic before the crew arrives, so the insulation can lie level and touch the attic floor everywhere. It also gives our installers room to reach the gaps that need sealing.
How do I find air leaks in an attic that already has insulation?
In an attic that already has insulation, a do-it-yourself search usually won't turn up the small leaks buried under it. That's a fair thing to ask any contractor about, and our installers check and seal around the spots where pipes, wires and lights come through before anything new goes on top.
Other work that goes with your attic
Blown-in insulation
Loose fill blown through a hose is the quickest way to top up an attic floor that's settled thin over the years.
Home insulation
When the walls, floors or crawl space are letting heat through too, we can plan the whole house at once.
Book a look at your attic
Call (669) 205-6284 or use the form, and if you can, tell us the house's age and any roof leak, old wiring or vermiculite you've noticed so I come ready.
Request an estimateCall (669) 205-6284