How San Antonio Clay Soil Damages Foundations

Much of San Antonio — especially the East Side, South Side and nearby suburbs like Schertz and Converse — sits on expansive clay. These soils can swell significantly when wet and shrink and crack when dry.

A typical San Antonio year brings long stretches of heat and drought, broken by intense storms. During drought, the soil along the foundation perimeter dries and pulls away. When storms return, it swells unevenly. That repeated flexing is what breaks slabs and pushes pier-and-beam supports out of place.

North of Loop 1604, in areas like Stone Oak, the challenge is different: shallow limestone and graded fill. Homes there settle when fill compresses on the downhill side of a lot.

The best protection is consistent moisture and good drainage. Grading soil away from the house, discharging gutters well away from the slab, and using a soaker hose during drought all help. See our foundation drainage correction service for details.