San Juan County, WA Shrink-Swell Risk
San Juan County's SSURGO shrink-swell reading
Low
In San Juan County, WA, 90.4% of the surveyed soil carries a "Low" shrink-swell rating, 1.88% linear extensibility on average. That's as favorable a county-level reading as this dataset produces - standard foundation practice, pending one lot's own geotechnical report.
Before you rely on this for one address
San Juan County's reading is an average across the whole county, not a promise about any one lot inside it. A local geotechnical report, typically $1,000-$5,000 (around $2,700 typical), is the only way to know what one lot in San Juan County will actually do.
Budgeting for San Juan County, WA
San Juan 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 Juan County's rank among Washington counties
Among the 3,085 rated counties on this site, San Juan County, WA ranks 2,097 most-constrained nationally, and 17 of 39 within Washington. San Juan County covers 174 square miles and counts 18,668 residents.
Before you act on this
Orleans Parish, LA carries this site's most-constrained reading. Rockingham County, NH and Anderson 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 Washington
Every county in Washington is on this site, including Jefferson County, WA and Stevens County, WA. The full underlying dataset is downloadable directly, one row per county.