Insulation Company in Napa, CA
Woolsey Attic Insulation is the insulation company Napa homeowners call when their attic turns into an oven in July and a freezer in January. Napa’s older housing stock and extreme daily temperature swings mean insulation here isn’t a luxury upgrade, it’s the difference between a home that holds its temperature and one that fights you every season. We install and service attic insulation and spray foam insulation, with a written price before any work begins and a 365-day guarantee on every job. Call us at (325) 240-5411 and a live person answers, day or night.
Why Napa Homes Are Different
Napa Valley’s diurnal temperature swings are among the most aggressive in the Bay Area. Summer afternoons routinely pass 100°F while marine fog pushing up from San Pablo Bay keeps mornings in the 50s. Attic temperatures spike past 140°F by mid-afternoon. Then winter nights drop into the mid-30s with radiative frost across the valley floor. The same house that bakes in July genuinely freezes in January, which means under-insulated attics and walls cost Napa homeowners disproportionately more than they do in flat-coast cities like San Francisco or consistently hot places like Sacramento.
The housing stock compounds the problem. Downtown Napa is built heavily on pre-1950s Victorians, Craftsman homes, and Spanish Revival properties, most of which were originally constructed with minimal or no wall cavity insulation. The 2014 South Napa earthquake forced structural retrofitting and gut renovations on many older properties, and those renovations exposed something ugly: decades of cosmetic updates hiding wall cavities with zero original insulation. In the Westside and Fuller Park neighborhoods, many balloon-frame homes from the 1910s through 1930s were patched for earthquake damage without full gut rehabs. The wall sheathing got repaired, but the cavities were never blown in. Infrared scanning on those blocks routinely reveals entire exterior walls with no insulation at all, even when the house looks fully updated from the street.
Post-WWII ranch homes spread across the valley floor have their own issues: thin batt insulation in attics that settled or compressed over 60 years, and uninsulated rim joists letting air pour in. Napa isn’t a mild-coast climate, and homes here weren’t built for the temperature range they actually experience.
Our Main Napa Services
The two services Napa homeowners call us about most are attic insulation and spray foam insulation. Each has its own detailed Napa page, but here’s a quick look at what makes each job different in this valley.
Attic Insulation in Napa
Napa attics take a beating. That 140°F afternoon spike radiates straight down through ceilings into living spaces, and winter’s cold air sits in the attic all night, pulling heat out of the house. We remove old, settled insulation where needed, air-seal the gaps that Napa’s older homes are full of, and blow in fresh material at the correct R-value for the valley’s temperature range. The 2014 earthquake retrofits left many attic bypasses open, gaps around chimneys, recessed lights, and plumbing chases that still leak conditioned air. We close them. Learn what a Napa attic job involves on our Attic Insulation in Napa page.

Spray Foam Insulation in Napa
Spray foam, a two-part liquid that expands on contact and seals gaps airtight, is the strongest answer for Napa’s balloon-frame homes and the earthquake-patched wall cavities that never got insulated. Closed-cell foam adds structural strength, which matters in a valley that shook hard in 2014. Open-cell foam handles sound and air sealing for interior walls and roof decks. Napa’s temperature swings mean conventional fiberglass leaves small gaps that add up, and spray foam eliminates those gaps entirely. See what’s involved, including which foam type fits which Napa home, on our Spray Foam Insulation in Napa page.

What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Brands We Service in Napa
We install and work on insulation from Johns Manville, Rockwool, and CertainTeed, among others. Parts and materials are sourced locally where available, and common installation runs typically happen within days of quote approval, weather permitting. See our brands for the full list of what we carry and why we choose them.
Pricing for Insulation Company in Napa, CA
| Service | Typical range in Napa |
|---|---|
| Attic insulation – remove and replace (1,200 sq ft attic) | $2,400 – $4,200 |
| Attic insulation – blow-in over existing (1,200 sq ft attic) | $1,500 – $2,800 |
| Attic air sealing (attic floor, top plates, penetrations) | $600 – $1,500 |
| Spray foam – rim joist sealing (full perimeter, 1,500 sq ft home) | $1,200 – $2,600 |
| Spray foam – closed-cell attic roof deck (1,000 sq ft) | $3,700 – $6,800 |
| Spray foam – crawl space walls (1,200 sq ft footprint) | $3,200 – $5,900 |
| Spray foam – wall cavity injection (balloon-frame retrofit, priced per wall section) | $2,600 – $5,100 |
| Thermal barrier coating over spray foam (per sq ft) | $1.10 – $2.10 |
Two things push Napa prices higher than the state average: older homes with multiple layers of settled insulation that need removal before anything new goes in, and earthquake-patched wall cavities requiring careful drilling and injection rather than open-stud work. Whatever the number comes to, you get it in writing before we touch anything. The Kingswell Guarantee means the price we quote is the price you pay, no door-step adjustments, on every single job.
Neighborhoods We Serve in Napa
We work across Napa’s residential neighborhoods, from the Victorian and Craftsman blocks around downtown to the ranch-style spreads on the valley floor and the pockets of newer construction on the hillsides. Crews serve the entire city, including:
- Downtown Napa and the older Victorian and Craftsman streets around Fuller Park
- Westside, including the balloon-frame homes from the 1910s through 1930s
- Browns Valley and the ranch homes along the valley floor
- Alta Heights and the hillside properties east of downtown
- Pueblo and the neighborhoods south of Highway 221
Most Napa property visits can be scheduled within a few business days, and emergency calls, like a pest-damaged attic or a remodel inspection, get priority. We’ll give you a real arrival window before we come out, not a vague “sometime between 8 and 6.”
Service Area – Cities Near Napa
Beyond Napa itself, we serve the surrounding communities across the valley and into Solano County. You’ll find us working in Boyes Hot Springs, CA, Sonoma, CA, Fairfield, CA, and Vacaville, CA. Dispatch and scheduling coordinates from the brand’s San Francisco Bay Area office, and local crews respond across the Napa service area. Call ahead and we’ll confirm we can reach your address before you wait on a visit.
Serving Napa, CA - Our Local Coverage Area
We’re based in the Napa area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About Insulation Company in Napa
Most Napa appointments are scheduled within a few business days, and urgent calls like a ceiling leak or an open attic after a storm get priority. We give you a confirmed arrival window before we dispatch, and a live person answers the phone 24/7 at (325) 240-5411.
Most attic and spray foam insulation jobs in Napa don’t require a city permit, but some balloon-frame wall injections and whole-attic conversions can fall under building department review depending on scope. We check Napa’s current requirements before quoting and tell you exactly what applies to your project.
The Westside and Fuller Park blocks with pre-1950s balloon-frame homes are the worst off, many with no wall insulation at all even after earthquake retrofits. But the ranch homes across the valley floor are close behind with settled, compressed attic batts. If your Napa home is over 40 years old, there’s a good chance it’s under-insulated.
Ready to talk about your Napa home? Call (325) 240-5411 for a free, no-pressure estimate. We’ll give you a written price, a real arrival window, and a 365-day guarantee on every job. Led by Glenn Hartley, Woolsey Attic Insulation keeps every promise in writing.
What happens when you call
- 1A real person answersNo phone trees - talk to a local insulation pro.
- 2You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
- 3A background-checked tech heads outLicensed & insured, typically within 30-60 min.
- 4You approve before work beginsNothing starts until you say go.
What Napa Customers Say
"Insulation job was done well. Scheduling took a little longer than I'd have liked, they were booked out a couple weeks. But once they came it was quick and the house is cozier."
- Felicia Grant"The guy didn't try to sell me on foaming the whole house. He said the attic was where I'd actually feel it and left it at that. Honest, and he was right, our bills dropped."
- Angela Ruiz"Drafty old house that never felt comfortable. After the attic and some air sealing it's a different place. On time, clean, and the quote didn't change. Wish I'd done it years ago."
- Dmitri Kozlov