Sumter County, SC Shrink-Swell Risk

What Sumter County, SC's soil means for a foundation

Low

USDA's SSURGO data puts Sumter County, SC's soil at "Low" shrink-swell potential, an area-weighted linear extensibility of 1.36% across 98.8% of the county's surveyed land. That's the easiest starting point on this site's scale - a standard foundation is the reasonable default here, though any one lot can still differ.

This is a county figure, not a lot figure

USDA's survey covers the whole of Sumter County, SC at once, not any single address. A local geotechnical report, typically $1,000-$5,000 (around $2,700 typical), is the only way to know what one lot in Sumter County will actually do.

Report cost vs. repair cost

With Sumter County, SC 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 Sumter County, SC compares

Nationally, Sumter County, SC is the 2,650-most-constrained of 3,085 rated counties for shrink-swell soil. Within South Carolina alone it ranks 41 of 46. Sumter County, SC is 665 square miles with a population of 104,776.

For contrast

Orleans Parish, LA carries this site's most-constrained reading. Madison County, NE and Jackson County, KY 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 South Carolina

Every county in South Carolina is on this site, including Lee County, SC and Hampton County, SC. The full underlying dataset is downloadable directly, one row per county.