Charleston County, SC Shrink-Swell Risk

Charleston County's SSURGO shrink-swell reading

Low

In Charleston County, SC, 97.3% of the surveyed soil carries a "Low" shrink-swell rating, 1.55% 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

Charleston 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 Charleston County will actually do.

Budgeting for Charleston County, SC

Charleston 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.

Where this sits nationally

Among the 3,085 rated counties on this site, Charleston County, SC ranks 2,439 most-constrained nationally, and 34 of 46 within South Carolina. The county spans 918 square miles, home to 431,001 people.

For contrast

Orleans Parish, LA carries this site's most-constrained reading. Cassia County, ID and Miami County, KS 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 South Carolina

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