Terrebonne Parish, LA Shrink-Swell Risk

Terrebonne Parish, LA's soil, for shrink-swell risk

Very High

Terrebonne Parish, LA: USDA's soil survey rates 44.8% of the county "Very High" for shrink-swell potential (9.74% linear extensibility). That's the range most associated with real foundation cracking - stair-step cracks in mortar joints, sticking doors, gaps around window frames - and it typically needs an engineered foundation (post-tension slab, drilled piers), not a standard footing.

What Terrebonne Parish's reading doesn't cover

Two lots a mile apart in Terrebonne Parish can carry different soil, even though they share one countywide reading. A local geotechnical report, typically $1,000-$5,000 (around $2,700 typical), is the only way to know what one lot in Terrebonne Parish will actually do.

What it costs to find out, versus to ignore it

Terrebonne Parish's soil reading is exactly the case where a report before construction, or before cracks widen, pays for itself. The report ($1,000-$5,000) is what tells you whether Terrebonne Parish's county-level reading applies to your lot; the repair ($5,000-$15,000) is what it costs if you skip that and find out from the cracks instead.

How Terrebonne Parish, LA compares

Nationally, Terrebonne Parish, LA is the 33-most-constrained of 3,085 rated counties for shrink-swell soil. Within Louisiana alone it ranks 18 of 64. Terrebonne Parish covers 1,230 square miles and counts 103,864 residents.

Before you act on this

Orleans Parish, LA carries this site's most-constrained reading. Freeborn County, MN and Essex County, NY are worth a look for comparison.

How this reading is built, and its real limits · The warning signs of expansive-clay damage, explained

More of Louisiana

Every county in Louisiana is on this site, including St. Martin Parish, LA and St. Tammany Parish, LA. The full underlying dataset is downloadable directly, one row per county.