Expansive clay is the #1 geological cause of foundation damage in America — and your county's exposure is measurable. We computed shrink-swell risk for 2381 counties from USDA soil survey data, and paired it with real repair cost ranges.
Foundation problems get more expensive the longer they wait. Get an assessment and repair quotes from independent local pros.
Get repair quotes →| State | Avg high-risk soil | Counties mapped |
|---|---|---|
| Lousiana | 46% | 1 |
| Kansas | 45% | 105 |
| Missouri | 37% | 113 |
| South Dakota | 35% | 57 |
| Texas | 33% | 204 |
| Louisiana | 32% | 63 |
| California | 29% | 19 |
| Oklahoma | 26% | 77 |
| Illinois | 25% | 102 |
| Iowa | 24% | 99 |
| Montana | 23% | 26 |
| Arkansas | 22% | 66 |
| Wyoming | 21% | 4 |
| North Dakota | 21% | 53 |
| Colorado | 20% | 16 |
USDA's SSURGO soil survey measures linear extensibility — how much each soil shrinks and swells with moisture. We aggregate those measurements across every mapped soil component in a county, weighted by area, to score county-level foundation risk. Then each county page pairs its risk tier with method-level repair costs so you can sanity-check any bid you get.
Risk metrics are computed from USDA SSURGO soil survey data (linear extensibility of soil components, area-weighted by county). Soil varies lot to lot — this is county-scale context, not a substitute for a site-specific geotechnical or structural assessment.