Hillsborough County, NH Shrink-Swell Risk

Hillsborough County, NH's soil, for shrink-swell risk

Low

Hillsborough County, NH: USDA's soil survey rates 97.3% of the county "Low" for shrink-swell potential (0.67% linear extensibility). Among the 3,144 counties on this site, that's the clean result: little shrink-swell movement, standard construction the likely outcome.

What Hillsborough County's reading doesn't cover

Two lots a mile apart in Hillsborough 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 Hillsborough County.

What it costs to find out, versus to ignore it

With Hillsborough County, NH 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, Hillsborough County, NH is the 3,022-most-constrained of 3,085 rated counties for shrink-swell soil. Within New Hampshire alone it ranks 10 of 10. The county spans 877 square miles, home to 430,462 people.

Before you act on this

Orleans Parish, LA carries this site's most-constrained reading. Chesterfield County, SC and Monroe County, OH 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 New Hampshire

Every county in New Hampshire is on this site, including Sullivan County, NH and Merrimack County, NH. The full underlying dataset is downloadable directly, one row per county.