St. Clair County, AL Shrink-Swell Risk

St. Clair County, AL's soil, for shrink-swell risk

Low

St. Clair County, AL: USDA's soil survey rates 83.6% of the county "Low" for shrink-swell potential (2.19% linear extensibility). 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.

What St. Clair County's reading doesn't cover

Two lots a mile apart in St. Clair County can carry different soil, even though they share one countywide reading. A site-specific soil report, usually $1,000-$5,000, is what an engineer would actually pull before designing a foundation on a lot in St. Clair County.

What it costs to find out, versus to ignore it

With St. Clair County, AL 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.

St. Clair County's rank among Alabama counties

Nationally, St. Clair County, AL is the 1,811-most-constrained of 3,085 rated counties for shrink-swell soil. Within Alabama alone it ranks 22 of 67. St. Clair County covers 632 square miles and counts 96,927 residents.

Before you act on this

Orleans Parish, LA carries this site's most-constrained reading. Hardin County, OH and Madison County, NY 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 Alabama

Every county in Alabama is on this site, including Barbour County, AL and Marion County, AL. The full underlying dataset is downloadable directly, one row per county.