 concrete and that can cause cracks also the soil underneath the foundation or beneath column supports may have shrunk due to moisture loss or if you have too much moisture around the house the soil under the foundation can weaken and some soils also are expansive and very sensitive the amount of moisture so lots of reasons the idea is and what you really have to do is keep your eyes out in the formation cracks and track them over time it's one of the ways you know how serious it is