Merrimack County, NH Shrink-Swell Risk

Shrink-swell potential in Merrimack County, NH

Low

Soil across 97.4% of Merrimack County, NH comes back "Low" in USDA's shrink-swell data, averaging 1.02% 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 this number does and doesn't tell you

This is a countywide, area-weighted figure across every soil survey map unit in Merrimack County, NH - never a reading for one specific parcel. The real answer for one lot is still a site-specific geotechnical report, running about $1,000-$5,000 (typically near $2,700).

Merrimack County: the real numbers

Merrimack County's soil reading points toward standard foundation practice as the likely outcome, not the exception. 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.

Merrimack County's rank among New Hampshire counties

Among the 3,085 rated counties on this site, Merrimack County, NH ranks 2,884 most-constrained nationally, and 3 of 10 within New Hampshire. The county spans 933 square miles, home to 157,869 people.

For contrast

Orleans Parish, LA carries this site's most-constrained reading. Grundy County, TN and Alamance County, NC 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

Elsewhere in New Hampshire

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