Shrink-Swell Potential

Shrink-swell potential measures how much a soil's volume changes as it gets wet and dries out. High shrink-swell soils — usually Vertisols and other clay-rich soils — can expand by 30% or more when saturated and crack deeply when dry.

This matters enormously for building. High shrink-swell soils can crack foundations, buckle roads, and damage underground pipes as the ground literally moves beneath them. Homes on these soils need specially engineered foundations (pier-and-beam, post-tensioned slabs) that add significant cost.

For gardening, high shrink-swell soils are fertile but difficult to work. They're sticky and unworkable when wet, and brick-hard when dry. Adding organic matter and mulch helps moderate the extremes.

Look up your address to see the specific soil conditions at your property, or browse the full glossary for more terms.