Durham County, NC Shrink-Swell Risk

What Durham County, NC's soil means for a foundation

High

USDA's SSURGO data puts Durham County, NC's soil at "High" shrink-swell potential, an area-weighted linear extensibility of 6.82% across 45.7% of the county's surveyed land. Soil at this level can crack a standard foundation without moisture-control measures - consistent watering near the foundation, correct grading, root barriers - or added structural design.

This is a county figure, not a lot figure

USDA's survey covers the whole of Durham County, NC at once, not any single address. The real answer for one lot is still a site-specific geotechnical report, running about $1,000-$5,000 (typically near $2,700).

Report cost vs. repair cost

Given Durham County's rating, spending a few thousand now is the way to avoid spending tens of thousands later. The report ($1,000-$5,000) is what tells you whether Durham County'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 Durham County, NC compares

Nationally, Durham County, NC is the 83-most-constrained of 3,085 rated counties for shrink-swell soil. Within North Carolina alone it ranks 1 of 100. The county spans 288 square miles, home to 343,628 people.

See how another county compares

Orleans Parish, LA carries this site's most-constrained reading. Union County, SC and Victoria County, TX 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 North Carolina

Every county in North Carolina is on this site, including Edgecombe County, NC and Wilkes County, NC. The full underlying dataset is downloadable directly, one row per county.