✓ When it comes to clays and their influence on building foundations, floors, walls, and pavements, expansive means expensive, particularly if the problem is not taken into account during construction.
✓ Three approaches are to replace the clay with something better, try and live with it, or treat it with lime so it becomes nonexpansive. Living with expansive clay means controlling the access to water, and using structural slab-on-grade foundations that can bridge between high spots, or deep foundations to support grade beams and structural floors.
✓ Basement walls can be protected by cutting the soil out at an angle so pushing is directed upward instead of flat against the wall.
✓ Repairs can involve in-situ lime stabilization, and the use of jacks to let down high places.