Joints are critical to the performance of concrete parking structures because they allow movement caused by temperature change, drying shrinkage, and creep. Three types of joints are commonly used in concrete parking decks. Control joints, sometimes called contraction joints, are used on parking decks to reduce random cracking. Construction joints occur at the outer edge of each pour sequence. Isolation joints relieve stresses associated with volume change forces caused by shrinkage, thermal cycling, elastic shortening, and creep. They are also used to separate the floor slab from other structural elements of the building.