Insulation Company in San Francisco, CA
Thistledown Attic Insulation works in San Francisco homes where the fog, the salt air, and the age of the house decide everything about how insulation should be installed. Most San Francisco attics belong to Victorians and Edwardians built before wall insulation existed, which means we’re usually working in tight crawl spaces, around original redwood framing, and against moisture conditions that drier Bay Area cities never see. If you need insulation work done right in San Francisco, call (909) 768-6501 and you’ll get a live person, a straight answer, and a written price before anyone climbs into your attic.
Why San Francisco Homes Are Different
San Francisco’s marine fog changes the whole job. In the Outer Sunset, the Richmond, and Ingleside, the air stays damp for most of the year, even in July when the average high barely reaches 65°F. That means the insulation challenge here is not blocking summer heat. It’s holding modest indoor warmth against a cool, wet exterior while keeping moisture vapor from migrating through uninsulated walls and condensing inside the assembly. No neighboring Bay Area city faces this same combination. Oakland is warmer. Daly City’s inland pockets get sun. San Jose is a different climate entirely.
The housing stock compounds this. San Francisco’s Victorians from the 1880s to 1900s and Edwardians from 1900 to 1915 were framed with old-growth redwood and finished with horsehair plaster, and none of them had wall-cavity insulation. The 1930s-to-1950s stucco Sunset-style homes that blanket the western neighborhoods are not much better. When we open those walls, we often find original redwood shiplap sheathing with zero insulation and years of moisture staining from the fog-soaked exterior. Choosing a material without accounting for that inward vapor drive can trap moisture and quietly rot the framing that still holds up much of the city’s western housing. That is why we plan every San Francisco job around vapor control first and R-value second.
Our Main San Francisco Services
San Francisco homeowners call us about two things most often: attic insulation for the older homes that lose heat through the roof, and spray foam for the hard-to-reach wall and rim-joist cavities where batts simply will not fit.
Attic Insulation in San Francisco
Most San Francisco attics are shallow, awkward, and framed with lumber that has been there for a century or more. We lay drop cloths across your hallway, wear shoe covers from the front door to the attic hatch, and inspect what is already up there before recommending anything. In older San Francisco flats, that often means air-sealing around recessed lights and plumbing chases before adding insulation, because in a foggy climate, air leaks carry moisture, not just heat. We install Owens Corning, Johns Manville, and Knauf products matched to the existing framing and roof pitch. See Attic Insulation in San Francisco for the full breakdown of what the job involves, including typical price ranges.
Spray Foam Insulation in San Francisco
Spray foam earns its keep in San Francisco where the wall cavities are irregular, the rim joists are exposed to damp crawlspace air, and the framing is too fragile to force batts into. We install closed-cell spray foam from brands like Demilec and Icynene in San Francisco crawlspaces and rim joists, where they form an air barrier as well as an insulator. Because San Francisco’s relative humidity stays elevated year-round, we are careful about open-cell foam in wall assemblies where inward vapor drive could create condensation against the sheathing. Read Spray Foam Insulation in San Francisco for the honest rundown on when spray foam is the right call here and when another product is safer.
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 carry and install Rockwool, Owens Corning, Johns Manville, and Knauf products in San Francisco, with the right material matched to each attic and each family’s needs. Common product lines are stocked at our Bay Area dispatch office and available on a standard service schedule. Browse our brands to see the full set, including pet-safe options where a choice exists.
Pricing for Insulation Company in San Francisco, CA
These are the price ranges we typically see for insulation work in San Francisco. Your exact written price comes before any work starts, every single time.
| Service | Typical range in San Francisco |
|---|---|
| Attic air sealing + insulation (small attic, up to 800 sq ft) | $1,800 – $3,200 |
| Attic air sealing + insulation (larger attic, 1,500+ sq ft) | $3,800 – $6,500 |
| Attic insulation removal and replacement (contaminated or old) | $2,500 – $5,000 |
| Dense-pack cellulose into existing Victorians/Edwardian walls (per wall section) | $900 – $2,400 |
| Rim joist spray foam (per 20 linear feet) | $550 – $1,100 |
| Closed-cell spray foam in crawlspace ceiling (per 300 sq ft) | $2,000 – $3,800 |
| Spray foam in attic roofline (small attic) | $2,800 – $5,200 |
| Insulation removal, cleaning, and sanitary treatment of attic | $2,200 – $4,600 |
| Whole-home insulation package (attic + walls + rim joists, typical flat) | $6,000 – $12,000 |
San Francisco prices run higher than surrounding areas for two reasons: the labor to work inside century-old plaster walls without damaging them, and the extra steps required to manage moisture in a fog-driven climate. Whatever your number ends up being, it will be in writing before we touch a rafter, and it will not change unless you change the scope.
Neighborhoods We Serve in San Francisco
We work across the entire city, from the fog-heavy west side to the sunnier eastern slopes. Our crews know which neighborhoods have Sunset-style stucco, which have Edwardian row houses, and which have both on the same block. Representative areas we serve:
- Outer Sunset
- Richmond District
- Ingleside
- Noe Valley
- Bernal Heights
Most San Francisco appointments can be scheduled within a few business days, and emergency calls get a live person any hour.
Service Area – Cities Near San Francisco
While this page covers San Francisco itself, our crews also handle jobs in nearby communities. Homeowners in Daly City, CA and South San Francisco, CA often deal with the same fog belt and similar housing stock. Across the bay, Alameda, CA has its own Victorian inventory and damp marine air. And Sausalito, CA hillside homes present the same old-framing challenges we see every day in San Francisco.
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
Most San Francisco appointments run within two to four business days, and we answer every call live, 24/7. If you have an urgent issue like wet insulation after a roof leak, call (909) 768-6501 and we’ll tell you honestly when a crew can be there.
Most re-insulation and air-sealing work in San Francisco does not require a permit when the cavity is already accessible and we are not modifying structure. If your job does trigger a permit, we will tell you before the work starts and write it into your scope.
We plan around it. Our techs protect floors with drop cloths, wear shoe covers at the door, and ask before moving anything. When drilling is necessary, we do it in discrete locations and leave the job with a photo of the clean-up before the van pulls away.
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 the hour.
- 4You approve before work beginsNothing starts until you say go.
What San Francisco Customers Say
"Attic insulation with a baby in the house. The crew was quiet, clean, and protected every floor they crossed. Took away all the debris and left it tidy. Already feeling the difference in comfort."
- Omar Leon"Spray foam in the garage and new attic insulation. Considerate, calm crew that protected the floors and kept the dust down with our little ones around. Explained it all patiently."
- Hassan Qureshi"Careful and clean from start to finish. They covered the hallway, wore booties, and hauled off all the old material without leaving a speck. Respectful of the home the whole time."
- Brett Yamamoto