Expansive soils are soils that expand when water is added, and shrink when they dry out.
This continuous change in soil volume can cause homes built on this soil to move
unevenly and crack. Each year in the United States, expansive soils cause $2.3 billion in
damage to houses, other buildings, roads, pipelines, and other structures. This is more
than twice the damage from floods, hurricanes, tornadoes, and earthquakes combined.