San Francisco County, CA Shrink-Swell Risk
San Francisco County's SSURGO shrink-swell reading
Moderate
In San Francisco County, CA, 48.4% of the surveyed soil carries a "Moderate" shrink-swell rating, 3.25% linear extensibility on average. A real but modest amount of movement - standard foundations usually hold up, but drainage and moisture control around the foundation still matter more than on low-risk soil.
Before you rely on this for one address
San Francisco County's reading is an average across the whole county, not a promise about any one lot inside it. A site-specific soil report, usually $1,000-$5,000, is what an engineer would actually pull before designing a foundation on a lot in San Francisco County.
Budgeting for San Francisco County, CA
San Francisco County's soil reading points toward standard foundation practice as the likely outcome, not the exception. A geotechnical report runs $1,000-$5,000, typically around $2,700. Foundation repair, if a specific lot turns out to differ from the county average, runs $5,000-$15,000.
San Francisco County's rank among California counties
Among the 3,085 rated counties on this site, San Francisco County, CA ranks 1,013 most-constrained nationally, and 18 of 58 within California. San Francisco County, CA is 47 square miles with a population of 827,526.
For contrast
Orleans Parish, LA carries this site's most-constrained reading. Marinette County, WI and Angelina County, TX are worth a look for comparison.
How this reading is built, and its real limits · Moisture management: the cheap fix that works on any soil
Elsewhere in California
Every county in California is on this site, including Nevada County, CA and Kern County, CA. The full underlying dataset is downloadable directly, one row per county.