Closed-cell foam insulation in Gilroy CA - more insulation where roof space is tight
Upstairs too hot and no room in the roof for deep insulation? We spray dense foam that seals and insulates in one layer.
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Is closed-cell foam the right insulation for my Gilroy house?
Closed-cell foam insulation is a dense, rigid spray foam that insulates, stops air leaks and blocks moisture in one layer. In Gilroy, CA, we suggest it where there's little room to work with, like a shallow roof or a sloped ceiling.
Most folks call us because the upstairs runs hot, the room over the garage never feels right or the power bill keeps climbing, and the roof above has only a few inches of space. Foam costs more than blown-in insulation, so sealing the gaps and topping up loose fill usually wins, unless your ductwork lives up there or the roof is too shallow to hold enough fill. The price moves with how much area we're covering, how thick the foam has to go, how easy the space is to reach and whether anything needs fixing first. The schedule turns on those fixes and on the conditions inside your house, and I'll put all of it in a written plan when I come out.
How we install closed-cell foam insulation
I start by looking over the space and noting anything that needs fixing before foam goes on, because foam sprayed over a roof leak or a wiring problem just hides it. We check the temperature, the humidity and how dry the surfaces are inside your house before we pick a spray day, since foam needs the right conditions to stick and rise properly. On the day, we cover anything that shouldn't get foam and seal the gaps around wiring, pipes, light fixtures and the attic hatch. Then we spray in even passes so the edges come out as full as the middle, air the space out and clean up.
When your attic has plenty of depth, open-cell foam insulation is the lighter, softer cousin and can do the job for less. Property managers also call us about commercial insulation for offices and shops, where closed-cell foam often goes on roofs and walls that have little room to spare.
Closed-cell foam insulation in Gilroy and California's climate zones
California's energy code sets several efficiency standards, including the ones for a house's walls, roof and windows, by climate zone, and Gilroy falls in the same zone as San Jose, Palo Alto and Sunnyvale. The state's standards also have a part that covers adding insulation to an existing attic, which describes most of the calls we get. When I write your plan, I check what those standards ask for in your zone, so the thickness we spray fits the rules for your house.
Around here we see a lot of houses with low roofs, rooms over the garage and ductwork running through a hot attic, which is where closed-cell foam earns its cost. We meet the same tight roof spaces on jobs in Morgan Hill and Hollister, and we work north into Santa Clara County and south toward Salinas and Watsonville too.
- Call (669) 205-6284
- Mon–Fri: 6 AM–11 PM, Sat–Sun: 7 AM–11 PM
- Gilroy, CA 95020
What happens after you call about closed-cell foam in Gilroy?
Call or send the form
I answer the phone myself or call you back, and I'll ask how old the house is and which rooms run hot or cold. If you know the rough size of the area, tell me, because it helps me plan the visit.
I look and write the plan
I come out to look at the attic, roof, walls or crawl space and note anything that has to be fixed before foam goes on. You get a written plan, and we go over it together so you see the whole job before you decide anything.
Our installers spray in order
Once the conditions inside are right, our installers seal, spray and clean up in the order the plan lays out while you're out of the house. I check in during the job and tell you when it's time to come home.
We walk the finished job
I go over the finished job with you before we pack up. You'll see the foam, the sealed gaps and the cleanup for yourself.
Why Gilroy homeowners call Thermal Gilroy Spray Foam Insulation for closed-cell foam
The owner writes your estimate
I come out to look at the job and write the plan myself, then I check in while our installers do the work. The person who planned your job is the one who makes sure it's done that way.
Fixes first, foam second
If there's a roof leak or a wiring problem where we'd spray, we flag it and it gets dealt with before any foam goes on. Foam sprayed over a problem only hides it where nobody can see it.
In business since 2021
We're based in Gilroy, and I started this business here so I could do the work and keep each job running in the right order. Before that, I spent years scheduling crews and learned insulation working next to the installers on the jobs I booked.
Licensed and insured
We're licensed and insured, so the work in your house is covered. It's worth asking any contractor you're comparing for the same before they climb into your attic.
On a closed-cell job, the order of the work matters most, and that starts with a look at your house. Tell us about your project or call (669) 205-6284.
Request an estimateGet a written plan for closed-cell foam in your house
We reply within 1 business day, and then I come out for a free on-site look at the space you want insulated, with no pressure to book. I'll note anything that needs fixing first and walk you through your written plan.
- 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 closed-cell foam insulation in Gilroy
How much does closed-cell spray foam insulation cost near Gilroy?
Closed-cell spray foam in the San Jose area usually costs about $1 to $1.60 per board foot, which is one square foot of foam one inch thick. Your own total depends on the area, how thick the foam goes and any fixes needed first, and all of that goes in your written plan.
How long do we have to stay out of the house after spray foam insulation?
You'll be out while we spray and until the foam has cured and the house has been aired out and cleaned, which is what federal safety guidance advises. Some foam makers recommend 24 hours before anyone comes back, but it varies by product, so I'll tell you which foam we're using and what its maker says for you, the kids and the pets.
Is closed-cell or open-cell foam better for my attic?
Closed-cell is usually the better pick when the roof space is shallow, because it rates about R-6 per inch, a measure of how well it slows heat, against roughly 3.6 for typical open-cell foam. One building guide also prefers closed-cell in every climate for attics sealed off from outside air and for cathedral ceilings. If your attic has plenty of depth, open-cell may do the job for less.
Who is allowed to install spray foam insulation in California?
In California, installing insulation falls under the C-2 Insulation and Acoustical class set by the Contractors State License Board. Before you book, ask any contractor you're comparing which license they hold.
Can closed-cell foam go in a crawl space?
Yes, and one building guide says that in a crawl space nobody uses for storage, a light ignition barrier, which can be an approved paint that swells up in a fire, may be enough over the foam. In a basement, the same guide says foam has to be covered by a sturdier fire-resistant layer, so I'll ask how you use the space before we plan it.
What is the best way to seal and insulate rim joists?
Spray foam is a good way to do it, because it air-seals and insulates the rim joist, the band of framing that sits on top of the foundation, in one step. Closed-cell foam has to be at least 1.5 inches thick there to count as an air barrier.
Other insulation work we handle
Open-cell foam insulation
A softer, lighter foam that can make more sense when your attic or walls have room for a thicker layer.
Commercial insulation
For property managers who need offices, shops or other buildings insulated with the same careful planning.
Start your closed-cell foam estimate today
Have the area you want insulated and its rough size handy when you call or fill out the form, and I can plan the visit around it.
Request an estimateCall (669) 205-6284