Insulation Company in Sebastopol, CA
Woolsey Attic Insulation specializes in attic and spray foam insulation for Sebastopol homes, where the real work is almost always retrofit, not new construction. The town’s craftsman bungalows, Victorian-era farmhouses, and converted agricultural outbuildings were built long before insulation was standard practice, and the mild climate convinced generations of homeowners they’d never need it. They do. Morning fog off the Pacific pushes moisture into unsealed wall cavities, and the original redwood board sheathing that makes these homes so beautiful also makes insulating them a job that rewards experience. Call (325) 240-5411 for a written quote before any work starts.
Why Sebastopol Homes Are Different
Sebastopol sits in what locals call the banana belt, a marine-influenced pocket that keeps temperatures gentler than inland Sonoma County. That mildness created a problem, not a solution. Homes along Gravenstein Highway and the rural roads branching west toward Freestone and Occidental were framed with the assumption that heavy insulation was unnecessary, so the builders skipped it. Now those same houses carry the moisture load that comes with dense morning fog and persistent coastal dampness.
What we find in Sebastopol attics and walls tells the same story again and again: original redwood board-and-batten walls with zero cavity fill, crawl spaces that were never sealed against ground vapor, and fiberglass batts from the 1970s that have slumped, compressed, and quit doing their job. The older craftsman bungalows near downtown often have rubble-stone foundations and no sill sealing, which lets the fog-driven groundwater wick straight up into the floor framing. Insulation here means vapor control first, R-value second. A house that traps moisture rots from the inside, and Sebastopol’s climate doesn’t forgive sloppy assembly.
Our Main Sebastopol Services
Most Sebastopol homeowners call us for one of two things: upgrading an attic that’s barely insulated, or sealing a home with spray foam where moisture and air leakage are the real problem. Here’s what each one involves locally.
Attic Insulation in Sebastopol
Older Sebastopol homes typically have R-11 to R-19 in the attic, far below what modern comfort and energy use demand. We remove degraded material, air-seal the attic floor, and install new insulation to the proper depth for the house and the space. The marine fog makes air sealing especially important here, because warm household air leaking into a cold attic is what causes condensation, mildew, and the damp-smell complaints we hear constantly from homeowners near the Laguna de Santa Rosa. See the full breakdown on our Attic Insulation in Sebastopol page.

Spray Foam Insulation in Sebastopol
Spray foam, a two-part liquid that expands on contact and seals gaps airtight, solves the moisture problem that batt insulation can’t. In Sebastopol’s older farmhouses, we often find open wall cavities where fog-driven damp air moves freely through the redwood sheathing. Closed-cell foam creates both an air barrier and a vapor retarder in one pass, which matters when you’re insulating a wall assembly that was never designed for it. Details and pricing are on the Spray Foam Insulation in Sebastopol 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 Sebastopol
We install insulation from Johns Manville, Knauf, Rockwool, and CertainTeed, choosing the material that fits the home rather than forcing a brand to fit the job. For Sebastopol’s moisture-prone attics and walls, Rockwool’s moisture resistance and Knauf’s air-sealing batt lines come up often. Common materials and parts are stocked regionally, which keeps most project start times short. See our brands for the full list.
Pricing for Insulation Company in Sebastopol, CA
| Service | Typical range in Sebastopol |
|---|---|
| Attic insulation inspection and air-seal | $450 – $900 |
| Blown-in fiberglass attic insulation (1,000 sq ft, R-38) | $1,400 – $2,200 |
| Blown-in cellulose attic insulation (1,000 sq ft, R-38) | $1,600 – $2,600 |
| Fiberglass batt replacement over existing attic floor | $900 – $1,800 |
| Mineral wool (Rockwool) batt installation in attic | $1,900 – $3,200 |
| Spray foam air sealing – rim joists and top plates | $800 – $1,500 |
| Two-part spray foam, open-cell, full attic underside (1,000 sq ft) | $3,500 – $6,000 |
| Two-part spray foam, closed-cell, full attic underside (1,000 sq ft) | $4,500 – $7,500 |
| Closed-cell spray foam for crawl space rim joists | $700 – $1,600 |
| Whole-wall spray foam retrofit (1,200 sq ft, existing home) | $5,500 – $10,500 |
Sebastopol pricing runs slightly higher than surrounding cities because the homes are older and the access is tighter: low-pitch attics, narrow scuttle holes, and original framing that requires careful work. The Kingswell Guarantee means the written price we give you before any work starts is the price you pay, with no door-step change orders.
Neighborhoods We Serve in Sebastopol
We work throughout Sebastopol and the surrounding unincorporated areas, from the older bungalow clusters near downtown to the farmhouse lanes off Gravenstein Highway and the hillside properties east toward the Laguna. Response time for most Sebastopol jobs is within the week, and emergency moisture or insulation failures can often be scheduled faster. Give us the cross-street and we’ll give you a straight arrival window.
- Downtown Sebastopol historic district
- Gravenstein Highway corridor
- West Sebastopol near Freestone Road
- Sebastopol Hills
- Pleasant Hill area east of town
Service Area – Cities Near Sebastopol
While this page covers Sebastopol specifically, our crews also serve homeowners in the surrounding Sonoma County communities. If you’re in Santa Rosa, CA, Rohnert Park, CA, Cotati, CA, or Windsor, CA, you’ll get the same written price, the same live-answer phone line, and the same 365-day guarantee.
Serving Sebastopol, CA - Our Local Coverage Area
We’re based in the Sebastopol 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 Sebastopol
Most Sebastopol jobs are scheduled within five to seven business days. Emergency moisture problems, like a leaking roof that soaked the attic insulation, can often be seen sooner. Call (325) 240-5411 and you’ll get a real person and a real arrival window, not a voicemail.
Insulation retrofits typically don’t require a building permit in Sebastopol when the scope stays within existing cavities. If your project involves structural changes or a full wall cavity retrofit, the city may require a permit. We’ll tell you what applies to your house before we quote it.
In most cases, yes. Blown-in dense-pack cellulose or injection foam can fill open wall cavities through small access holes, preserving the original redwood board-and-batten siding. The approach depends on the sheathing and framing condition, which we assess before recommending any method.
If you’re ready to know what your Sebastopol attic or walls actually need, call (325) 240-5411 for a free estimate and a written price before anything gets touched.
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 Sebastopol 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