St. Johns County, FL Shrink-Swell Risk

St. Johns County, FL's soil, for shrink-swell risk

Low

St. Johns County, FL: USDA's soil survey rates 93.4% of the county "Low" for shrink-swell potential (1.51% linear extensibility). That's as favorable a county-level reading as this dataset produces - standard foundation practice, pending one lot's own geotechnical report.

What St. Johns County's reading doesn't cover

Two lots a mile apart in St. Johns County can carry different soil, even though they share one countywide reading. A local geotechnical report, typically $1,000-$5,000 (around $2,700 typical), is the only way to know what one lot in St. Johns County will actually do.

What it costs to find out, versus to ignore it

With St. Johns County, FL rating "Low", a geotechnical report is still worthwhile before a build, just less urgent than in a high-risk county. 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.

How St. Johns County, FL compares

Nationally, St. Johns County, FL is the 2,478-most-constrained of 3,085 rated counties for shrink-swell soil. Within Florida alone it ranks 6 of 66. The county spans 601 square miles, home to 334,928 people.

Before you act on this

Orleans Parish, LA carries this site's most-constrained reading. Tippecanoe County, IN and Glades County, FL 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

More of Florida

Every county in Florida is on this site, including Franklin County, FL and Hamilton County, FL. The full underlying dataset is downloadable directly, one row per county.