Street creep is a phenomenon that occurs as a result of nature’s uncontrollable effect on concrete slabs and joints. Both gravity and thermal (changes in temperature) expansion and contraction cause streets to literally move or slide toward surrounding homes. This movement causes pressure and cracking to the foundation of the homes it affects. Contractors place expansion joints in exterior concrete slabs to control movements caused by thermal activity. This is typically done by placing a buffer made of wood, rubber, or other material in between two slabs of concrete. The joints will shrink and expand as the concrete moves, absorbing the force before it damages the foundation. Eventually, these joints become filled with sand, gravel, and other debris and pressure is displaced from street, to driveway, to garage floor, and eventually to your home’s foundation walls.