Knox County, TN Shrink-Swell Risk

What Knox County, TN's soil means for a foundation

Low

USDA's SSURGO data puts Knox County, TN's soil at "Low" shrink-swell potential, an area-weighted linear extensibility of 2.86% across 52.6% 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 Knox County, TN 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 Knox County will actually do.

Report cost vs. repair cost

With Knox County, TN 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 Knox County, TN compares

Nationally, Knox County, TN is the 1,295-most-constrained of 3,085 rated counties for shrink-swell soil. Within Tennessee alone it ranks 17 of 95. The county spans 508 square miles, home to 506,748 people.

Before you act on this

Orleans Parish, LA carries this site's most-constrained reading. Tishomingo County, MS and Craighead County, AR 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 Tennessee

Every county in Tennessee is on this site, including Polk County, TN and Williamson County, TN. The full underlying dataset is downloadable directly, one row per county.