Retrofit insulation in Gilroy CA - a house that stays comfortable upstairs
Hot rooms upstairs, drafty halls or a thin attic in an older house? We add what's missing, in the right order, so it actually works.
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Is it worth adding insulation to an older Gilroy house?
Retrofit insulation in Gilroy, CA means adding insulation to a house that's already built and doesn't have enough, usually in the attic first and then inside the closed walls, so your rooms hold their temperature and the drafts ease off.
Most calls start with the room over the garage that bakes all summer, cold floors in winter or a power bill that keeps creeping up. The price moves with how many inches are already up there, whether old material has to come out first, how many gaps need sealing and whether the walls are part of the plan. The schedule mostly turns on what has to be fixed before anything goes in, like a leak or old wiring, and your own figure comes from the written plan I walk you through at the estimate.
How we handle retrofit insulation, step by step
When you're weighing several upgrades, I'll usually point you to the attic first and then talk about the walls, and any signs of moisture or old wiring move to the very front of the plan, because insulation laid over a problem just hides it. In the attic, I check what's there now, and soaked insulation or material full of droppings doesn't get buried under a fresh layer, since the problem would stay. Next we do the air sealing, closing the gaps around can lights, pipes and the attic hatch so the new insulation isn't fighting a draft. Then we blow in loose fill through a hose, keeping it full at the edges where it's easy to run thin, and keeping the eave vents clear so the attic can still breathe.
If your ductwork runs through the attic, spray foam insulation on the underside of the roof can be the better call, because foam seals air while it insulates, though it costs more. For most houses, sealing the gaps and topping up the loose fill is the better value, and our attic insulation work is where most retrofits begin.
What shapes retrofit insulation in Gilroy
California's Energy Code doesn't only cover new houses. It sets efficiency requirements for changes to existing homes too, and some of its standards for insulating materials depend on the climate zone a house sits in, so we choose materials for your house with the state's rules in mind.
Around Gilroy we see plenty of older houses with a thin layer in the attic and nothing in the walls, and with long, hot summers the upstairs bedrooms are usually the first complaint. We're based in Gilroy and work in the cities around it, and we run into the same houses on jobs in San Martin and Morgan Hill, where we handle them the same way, attic first.
- 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 retrofit insulation in Gilroy?
Call or send the form
You call and I answer, or I get back to you to set up a time. I'll ask about the house first, like how old it is and which rooms bother you.
I look at the house
I come out to see the attic, walls or crawl space and note anything that needs fixing first. You get a written plan that puts the work in order, and I walk you through each part.
Our installers do the work
Stored boxes come out of the attic before we start so the insulation can lie level on the attic floor. Our installers then follow the plan in order, with sealing done before any new insulation goes in.
We go over the finished job
I walk through the finished work with you before we pack up. You'll see the depth, the edges and the vents for yourself.
Why Gilroy homeowners call Thermal Gilroy Spray Foam Insulation for retrofit work
The owner writes your estimate
I come out myself to look at the house and write the estimate, and I check in while our installers do the work. You deal with the same person from the first call to the final walk-through.
Jobs planned in order since 2021
Before I started this business in 2021, I spent years lining up crews and jobs for a busy company. That's why your plan spells out what happens first, second and third, so nobody's left guessing.
Licensed, insured and clear on payment rules
We're licensed and insured. California's Contractors State License Board licenses contractors here, and it says a down payment can't be more than $1,000 or 10 percent of the contract price, whichever is less, which is worth knowing whoever you hire.
A retrofit only holds up when the fixes come before the insulation, so the first step is a look at your attic. Send us your details or call (669) 205-6284 to set that up.
Request an estimateGet a written retrofit plan for your attic and walls
We reply within 1 business day, and I'll set up a free on-site estimate where I look at your attic, walls or crawl space and note anything that needs fixing first. You get a written plan to keep, with no pressure to book.
- 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 retrofit insulation in Gilroy
Should I insulate my attic or my walls first in Gilroy?
Start with the attic in most houses. Sealing air leaks and adding insulation between the attic and the house is usually one of the most cost-effective things you can do for comfort, so it's the best first spend. We look at the walls once we know where the attic stands.
How do I insulate walls without tearing out the drywall?
Walls are usually filled with the dense-pack method, packing loose fill tight into each space between the framing through small holes cut from outside or inside. The walls stay closed apart from those small access holes. Any moisture in the siding, the sheathing under it, the door and window framing or the inside wall has to be found and repaired first, so tell me about any stains or soft spots you've noticed.
How much does attic insulation cost in the Gilroy area?
Attic insulation in the San Jose area usually costs about $1,800 to $6,000 per job. That's the going rate around here, not our quote, and where your house lands depends on its size, what's up there now and how much sealing or cleanup comes first. Your own figure comes from the estimate.
What should I do if my attic has vermiculite insulation?
Leave it undisturbed and assume it may contain asbestos, which is what the EPA advises for vermiculite. If I find it at the estimate, we plan the job so it stays in place and your family isn't exposed to it.
Does blown-in insulation settle in the walls over time?
It can, when blown fiberglass or cellulose isn't installed at the density it's meant for. It settles and leaves open space at the top of the wall, and the insulation does less. That's why we pay close attention to how full each cavity gets.
Do I need to replace knob and tube wiring before insulating my attic?
If that old wiring is still live, it has to be replaced or properly boxed before insulation goes in, according to a national attic checklist. That electrical work goes ahead of us on the plan. The same checklist calls for a combustion safety test, a check that a natural-draft furnace or water heater vents its exhaust outside instead of spilling it into the house, when your home has one.
Other work that often goes with it
Spray foam insulation
Worth a look when ducts run through a hot attic and you want air sealing and insulation in one layer.
Attic insulation
The place most retrofits start, with gaps sealed and loose fill topped up across the whole attic floor.
Book a look at your attic and walls
If you peek into the attic and note any water stains on the walls before you call, we can cover more on that first visit.
Request an estimateCall (669) 205-6284