District of Columbia, DC Shrink-Swell Risk

Shrink-swell potential in District of Columbia, DC

Low

Soil across 88.1% of District of Columbia, DC comes back "Low" in USDA's shrink-swell data, averaging 1.66% 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 District of Columbia, DC - never a reading for one specific parcel. 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 District of Columbia.

District of Columbia: the real numbers

District of Columbia'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.

Where this sits nationally

Among the 3,085 rated counties on this site, District of Columbia, DC ranks 2,319 most-constrained nationally, and 1 of 1 within District of Columbia. District of Columbia, DC is 61 square miles with a population of 702,250.

Before you act on this

Orleans Parish, LA carries this site's most-constrained reading. Bristol city, VA and Gregory County, SD 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 District of Columbia

Every county in District of Columbia is on this site. The full underlying dataset is downloadable directly, one row per county.