Insulation in Sunnyvale - Free Estimate, Written Price Up Front
We provide fast, reliable, and affordable insulation services across Sunnyvale to keep your home safe and running. Licensed, insured, and trusted by local homeowners.
Work is performed by our local vetted partner.
At Walt's Insulation, we specialize in fast, reliable, and affordable insulation services for homeowners and businesses.
About Us
Our Simple 3-Step Process
Request Service or Call Us
Call us or send a quick message. Tell us about your insulation project and we'll set up a free on-site visit.
Inspection & Free Estimate
We inspect and measure, then give you a clear written estimate with no hidden fees.
Scheduled & Done Right
A licensed local partner does the work on the date in your quote.
Don't let a insulation problem slow you down. Contact Walt's Insulation today and our experts will take it from the first call to the finished job.
Call (669) 215-4805
What Our Customers Are Saying
"Walt came out himself, stuck his head in the attic, and told me I had about four inches where I needed fourteen. No sales pitch, just the number and what it would cost to fix it. Crew was here two days later."
"Radiant barrier and new insulation in one visit. Walt explained what the foil actually does and what it does not, which nobody else bothered to. Electric bill in July was the lowest it has been in this house."
"The house had rats in the attic insulation and a smell we could not place. Walt's crew pulled all of it, sealed the gaps where they were getting in, sanitized, and put in new blown-in. He sent photos of the sealed openings so I could see it done."
"Spray foam in the garage ceiling under the bonus room. That room used to be unusable in summer. Walt talked me out of foaming the whole attic because it did not need it, which saved me a couple thousand and I trust him more for it."
Areas We Proudly Serve
Serving Sunnyvale, CA - Our Local Coverage Area
We serve Sunnyvale and nearby communities. Use the map below to see the area we cover. If you're nearby, we can almost certainly help.
Request Your Free Estimate
Prefer to talk now? Call us directly and we will set up your free estimate. No obligation, no sales pitch.
Call or Text(669) 215-4805Request A Free Quote
Insulation Service Across the Sunnyvale Area
We Are the Sunnyvale Team for Walt's.
Walt Brenner sticks his own head in the attic before he quotes anything, and tells you the depth you have and the depth you need in inches, not adjectives. He has talked more customers out of spray foam than into it. The written price is the price, the crew's van has his name on it, and he still answers the phone himself - including when somebody texts him a moisture reading from a crawl space he did six years ago.
Same training, same parts, same pricing practice, and the same Done Right Promise - delivered by people who live here.
Visit Walt's →Part of the Locally Family.
Locally is a family of home-service brands held to one written standard, and Walt's is the insulation company in it. One promise stands behind every trade, in every town.
Expert Insulation Repair and Installation Services
Every job on this list is handled by trained, background-checked technicians working to one national standard, priced upfront from a free estimate.
Attic Insulation
Air-seal the attic floor first, then blow or lay insulation to the code depth for your climate zone. The depth ruler gets photographed before the hatch closes.
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Free Insulation Estimates
A technician measures what you have, tells you the depth you need in inches, and prices the whole job in writing before a bag is opened.
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Crawl Space Encapsulation & Vapor Barrier
A sealed liner up the foundation walls, taped seams, sealed vents and a dehumidifier sized for the space. Cold floors and musty air stop at the source.
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Spray Foam Insulation
Open- or closed-cell foam on rim joists, roof decks and garage ceilings. The one insulation that air-seals and insulates in a single pass.
Learn More →Materials That Hold the Line for Decades
Insulation is only as good as the material and the prep underneath it. Here is what we put into an attic, a crawl space or a wall, and what the cheap bid puts in instead.
Blown-In Insulation
Loose-fill is most of what goes into an attic. The material and the depth it is blown to decide whether the attic holds R-38 in ten years or has settled to half of it.
We blow dense, borate-treated cellulose or premium fiberglass to the full code depth with a depth marker in every bay, over an air-sealed floor. Cellulose settles less than 15% and the borate keeps insects and mold out.
A cheap bid blows the thinnest bag count that reads "insulated" from the hatch, over a floor nobody sealed. It settles a third within a few winters, and the gaps around every can light and top plate keep leaking conditioned air.
Spray Foam
Closed-cell and open-cell foam are different products for different places. Applying the wrong one, or applying it thin, is the most expensive mistake in the trade.
We use closed-cell foam where moisture and structure matter: rim joists, roof decks, crawl walls: sprayed in passes to the rated thickness, and open-cell only where its vapor-open behavior is the right call.
A cheap bid sprays one thin pass of whatever is handy, leaves voids behind wiring and plumbing, and puts open-cell against a roof deck where it can trap moisture in the sheathing.
Radiant Barrier
In a hot-climate attic the radiant barrier is what keeps the roof deck from cooking the insulation below it. The foil grade and how it is hung decide whether it works.
We staple perforated, tear-resistant reflective foil to the underside of the rafters with an air gap on the shiny side, so radiant heat bounces before it reaches the attic floor and moisture can still escape.
A cheap bid lays a thin foil-faced bubble wrap flat on top of the insulation, where dust kills its reflectivity in a season and it traps moisture against the batts.
Crawl Space Vapor Barrier
The liner is the crawl space job. Thickness, seam treatment and how far it climbs the wall decide whether the moisture reading drops or the liner is a puddle in two years.
We lay 12- to 20-mil reinforced polyethylene, overlap every seam by a foot and tape it, run it up the foundation wall and mechanically fasten it, then seal the vents so the space can dry.
A cheap bid rolls out 6-mil builder plastic, leaves the seams loose and stops at the footing. Ground moisture wicks around every edge and the plastic tears the first time anyone crawls on it.
Air Sealing
Insulation slows heat; only air sealing stops the air that carries it. The sealing products used on the attic floor are the difference between a comfortable house and an insulated leaky one.
We foam every top plate, plumbing and wiring penetration, fit fire-rated covers over recessed lights and gasket the attic hatch before any insulation goes down: the blower-door number proves it.
A cheap bid skips sealing entirely, or squirts a little foam where it is visible from the hatch, then buries the open can lights and gaps under new insulation where they leak for good.