These soils contain clay minerals that attract and absorb water. As a result, these soils expand
when they get wet and shrink when they dry. Other names used to describe these soils include
bentonite, swelling, heaving or unstable. Builders often refer to soil movement and expansion as lateral
fill extension, slope creep or lot stretching. When these soils become wet and expand, the resulting
expanding pressure can cause uplift against concrete slabs and foundation footings, causing a wide
variety of damages to buildings and surrounding structures. Damages include: cracking and heaving of
concrete, including garage slabs, driveways, sidewalks, patios, foundations, underground parking
structures and concrete flatwork. Other damages include drywall cracks, cracked ceramic tile flooring,
heaving wood flooring, sticking doors and windows, broken water lines and gas lines.