What types of soil conditions can affect a home's foundation?

The impact of soil conditions on a home's foundation is critical for assessing stability and longevity. Expansive clay is particularly known for its ability to swell when wet and shrink when dry, which can lead to significant changes in volume and pressure on a foundation. Sandy soil, while generally allowing for good drainage, can also cause issues if it is poorly compacted; it can shift and settle over time, leading to foundation movement. Poorly drained soils hold water, increasing hydrostatic pressure against foundation walls, which can also lead to structural damage.

Other soil types, while they may play a role in certain contexts, do not have the same level of direct impact on foundation stability as expansive clay and poorly drained soils do. Silty soils can retain moisture but do not exhibit the same expansive properties, while sandy soils, depending on drainage and compaction, might not exert enough pressure to be significantly harmful. Therefore, the combination of expansive clay, sandy soil, and poorly drained soils clearly outlines the key types that can create problematic conditions for a foundation.