About ShrinkSwellCheck
Why this exists
Expansive clay damages roughly one in four US homes and, by the American Society of Civil Engineers' own estimate, costs property owners more per year than earthquakes, floods, hurricanes and tornadoes combined - yet most homeowners only learn their soil is the expansive kind after a wall has already cracked. ShrinkSwellCheck reports what USDA already knows: the dominant soil's linear extensibility, the lab measurement behind shrink-swell risk, for every county, before that crack happens or right after it does.
What goes into the number
Every figure traces to USDA's Soil Survey Geographic (SSURGO) database, specifically chorizon.lep_r (linear extensibility percent), depth-weighted across the top 100cm of each county's major soil components and area-weighted by mapunit acreage. Nothing here is re-normalized or estimated - the data-quality guide documents exactly how the reading is built and where it runs out. The full table is available on the data page, one row per county.
Written by
The county pages on ShrinkSwellCheck are written with AI tools working from USDA's Soil Data Access tables, not reported by a named journalist. Each page's figures are cross-referenced against USDA's published tables before publication, and the site is maintained by its publisher.
Who runs this
ShrinkSwellCheck is an independently run site. It is not affiliated with the USDA, any state or county building department, or any foundation-repair contractor. Where a page includes a sponsored or affiliate link, that is disclosed on the page itself and in the privacy policy.
Corrections
If a county's numbers look wrong, report it through the contact page - corrections are checked against USDA's source tables directly, not against another site's copy of them.