Franklin County, IA Shrink-Swell Risk

Shrink-swell potential in Franklin County, IA

Moderate

Soil across 52% of Franklin County, IA comes back "Moderate" in USDA's shrink-swell data, averaging 3.12% linear extensibility. That's a middle reading: not the sharp swings that crack a foundation outright, but enough that grading and drainage are worth getting right.

What this number does and doesn't tell you

This is a countywide, area-weighted figure across every soil survey map unit in Franklin County, IA - 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).

Franklin County: the real numbers

Franklin 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.

How Franklin County, IA compares

Among the 3,085 rated counties on this site, Franklin County, IA ranks 1,103 most-constrained nationally, and 79 of 99 within Iowa. Franklin County, IA is 582 square miles with a population of 10,024.

See how another county compares

Orleans Parish, LA carries this site's most-constrained reading. Valencia County, NM and Warren County, NY 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 Iowa

Every county in Iowa is on this site, including Humboldt County, IA and Allamakee County, IA. The full underlying dataset is downloadable directly, one row per county.