Miami-Dade County, FL Shrink-Swell Risk

What Miami-Dade County, FL's soil means for a foundation

Low

USDA's SSURGO data puts Miami-Dade County, FL's soil at "Low" shrink-swell potential, an area-weighted linear extensibility of 0.24% across 100% 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 Miami-Dade County, FL 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 Miami-Dade County will actually do.

Report cost vs. repair cost

With Miami-Dade County, FL 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.

Where this sits nationally

Nationally, Miami-Dade County, FL is the 3,077-most-constrained of 3,085 rated counties for shrink-swell soil. Within Florida alone it ranks 65 of 66. Miami-Dade County covers 1,900 square miles and counts 2,838,461 residents.

For contrast

Orleans Parish, LA carries this site's most-constrained reading. Bibb County, GA and Poinsett 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 Florida

Every county in Florida is on this site, including Brevard County, FL and Sumter County, FL. The full underlying dataset is downloadable directly, one row per county.