Philadelphia County, PA Shrink-Swell Risk

What Philadelphia County, PA's soil means for a foundation

Low

USDA's SSURGO data puts Philadelphia County, PA's soil at "Low" shrink-swell potential, an area-weighted linear extensibility of 1.77% across 86% of the county's surveyed land. 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.

This is a county figure, not a lot figure

USDA's survey covers the whole of Philadelphia County, PA at once, not any single address. A local geotechnical report, typically $1,000-$5,000 (around $2,700 typical), is the only way to know what one lot in Philadelphia County will actually do.

Report cost vs. repair cost

With Philadelphia County, PA 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, Philadelphia County, PA is the 2,191-most-constrained of 3,085 rated counties for shrink-swell soil. Within Pennsylvania alone it ranks 15 of 67. The county spans 134 square miles, home to 1,573,916 people.

See how another county compares

Orleans Parish, LA carries this site's most-constrained reading. Moore County, NC and Grant 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

More of Pennsylvania

Every county in Pennsylvania is on this site, including Butler County, PA and Bradford County, PA. The full underlying dataset is downloadable directly, one row per county.