Insulation Company in San Francisco, CA
San Francisco insulation work is different from anywhere else in the Bay Area, and it comes down to three things: old wood-frame houses, fog that doesn’t quit, and families living close together in every direction. Most of the homes we work in were built before 1940, which means lath-and-plaster walls, empty attics, and cavities that have never held insulation. Adding insulation to those homes requires a lighter touch than a modern build, and it demands attention to moisture that newer neighborhoods never think about. If you own one of those San Francisco homes, call us at (341) 247-0222 and we’ll walk you through what your attic actually needs.
Why San Francisco Homes Are Different
Walk through the Sunset or the Richmond on a foggy afternoon and you can feel the difference before you see it. The cold works its way through uninsulated plaster walls, and the marine air brings moisture with it. In San Francisco, insulation isn’t just about temperature. It’s about managing dampness so it doesn’t settle inside wall cavities and start doing quiet damage. We check for condensation where warm interior air meets a cold exterior wall, because in this city that junction is where most insulation problems begin.
The housing stock adds another layer. Two- and three-story wood-frame Victorians and Edwardians dominate whole neighborhoods, and many still have their original enclosed cavities. Drilling into those walls takes care, because the ornate plaster ceilings and period trim below the attic hatch aren’t things anyone wants cracked. We plan every blow-in job around the finishes, not through them. San Francisco also builds tight: homes sit shoulder to shoulder, which makes sound transfer between adjoining walls an everyday reality. A well-insulated attic and proper cavity fill do more up here than in a suburban cul-de-sac.
Our Main San Francisco Services
Most San Francisco homeowners call us about two things: getting insulation into an attic that has never had any, and sealing hard-to-reach spaces with spray foam. Here’s what each involves in this city.
Attic Insulation in San Francisco
Many San Francisco attics are nothing more than a crawl space under a pitched roof, with a hatch in a hallway ceiling and decades of nothing between the family below and the fog above. We blow in loose-fill insulation at a depth matched to your home’s age and exposure, and we pay close attention to the areas around recessed lights and bath fans, where air leaks are common in older framing. In the Sunset and Richmond especially, we check for moisture before we insulate, because trapping damp air in a 1920s attic creates more problems than it solves. Learn more about Attic Insulation in San Francisco.

Spray Foam Insulation in San Francisco
San Francisco homes have odd angles, enclosed cavities, and gaps around rim joists that fiberglass was never designed to seal. Spray foam excels in those spaces: it expands into the irregular openings common in pre-1940 framing, and it stops air movement in a way loose fill can’t match. Because the fog keeps things damp, we’re careful about where open-cell foam is the right call and where closed-cell is the better moisture barrier. It’s a product decision we make with you, not for you. See what’s involved on our Spray Foam Insulation in San Francisco 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 San Francisco
We install insulation from manufacturers we trust for San Francisco’s climate and housing stock, including Owens Corning, Icynene, and Demilec. That’s a short list, but it covers loose fill for old attics, open-cell foam for interior cavities, and closed-cell for damp exposure. For a closer look, see our brands.
Pricing for Insulation Company in San Francisco, CA
| Service | Typical range in San Francisco |
|---|---|
| Attic insulation – small attic | $1,800 – $3,200 |
| Attic insulation – medium attic | $2,800 – $4,700 |
| Attic insulation – large attic | $4,000 – $6,500 |
| Attic insulation – 2-story home | $3,500 – $6,000 |
| Blown-in fiberglass insulation | $1,900 – $3,400 |
| Blown-in cellulose insulation | $2,100 – $3,600 |
| Spray foam – open-cell (per sq ft) | $1.10 – $2.25 |
| Spray foam – closed-cell (per sq ft) | $2.40 – $3.85 |
| Attic air sealing | $650 – $1,500 |
| Attic insulation removal | $1,300 – $3,000 |
San Francisco pricing tends to shift based on how difficult your attic is to reach and whether older insulation needs to come out before new material goes in. Steep stair access, low clearance, and old wiring that needs to be worked around all push the number up. You’ll get your written price before any work begins, so there are no surprises on the invoice.
Neighborhoods We Serve in San Francisco
Our crews work throughout San Francisco, from the fog-heavy west side to the warmer eastern slopes. We know how different the conditions are block to block, and we plan each job for the house in front of us, not a generic ZIP code.
- Outer Sunset
- Richmond District
- Noe Valley
- Bernal Heights
- Glen Park
Most San Francisco neighborhoods can be reached same day or next morning from our Bay Area dispatch office.
Service Area – Cities Near San Francisco
While this page focuses on San Francisco, our crews also cover communities just south and across the Bay. We work regularly in San Bruno, CA, Albany, CA, Piedmont, CA, and El Cerrito, CA. If you’re in one of those cities, the same team and the same written-price promise apply.
Serving San Francisco, CA - Our Local Coverage Area
We’re based in the San Francisco 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 San Francisco
We can usually reach most San Francisco neighborhoods the same day or next morning. Because dispatch and scheduling are coordinated from our Bay Area office, a crew is never far from the city. Call us and we’ll give you a realistic arrival window, not a guess.
In most cases, adding insulation to an existing attic does not require a permit in San Francisco, but if your project involves new electrical work, venting changes, or structural modifications, a permit may come into play. We’ll tell you before we start what your specific home needs. Call (341) 247-0222 and we can talk through your street and building type.
Yes, and we plan for it. Shoe covers go on at the door, drop cloths cover the hallway floor, and we choose pet-safe insulation products where a choice exists. If a baby is napping, we keep tools quiet and work around the schedule you give us. That’s standard, not an upgrade.
For a free estimate on insulation work in San Francisco, call Thistledown Insulation at (341) 247-0222. We’ll put the price in writing before anything starts.
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 same-day.
- 4You approve before work beginsNothing starts until you say go.
What San Francisco Customers Say
"Solid attic job. A little of the old insulation dust settled near the hatch, but they came back up and vacuumed it when I pointed it out. Otherwise careful and the house is warmer."
- Cindy Vasquez"Attic insulation with a newborn in the house. The crew was quiet, laid protection on every floor they crossed, and hauled off all the old material. Left it spotless and the house is cozier already."
- Corinne Dyer"Our bedrooms were always cold. They added insulation and air sealed the attic, and were meticulous about cleanup, you'd never know they'd been in the attic. So much cozier now."
- Donna Petrie