Knox County, IL Shrink-Swell Risk

Knox County's SSURGO shrink-swell reading

Moderate

In Knox County, IL, 78.1% of the surveyed soil carries a "Moderate" shrink-swell rating, 3.85% linear extensibility on average. That's a middle reading: not the sharp swings that crack a foundation outright, but enough that grading and drainage are worth getting right.

Before you rely on this for one address

Knox 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 Knox County will actually do.

Budgeting for Knox County, IL

Knox 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.

How Knox County, IL compares

Among the 3,085 rated counties on this site, Knox County, IL ranks 646 most-constrained nationally, and 39 of 101 within Illinois. Knox County covers 716 square miles and counts 48,716 residents.

See how another county compares

Orleans Parish, LA carries this site's most-constrained reading. Rawlins County, KS and Sanders County, MT 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 Illinois

Every county in Illinois is on this site, including Kendall County, IL and Boone County, IL. The full underlying dataset is downloadable directly, one row per county.