Although buildings are often constructed using flexible materials, roof and Structural expansion joints are required when plan dimensions are large. It is not possible to State exact requirements relative to distances between expansion joints because of the many Variables involved, such as ambient temperatures during construction and the expected Temperature range during the life of a building. Expansion joints are periodic breaks in the Structure of the buildings. An expansion joint is a gap in the building structure provided by an architect or engineer to allow for the movement of the building due to temperature Changes. An expansion joint is an assembly designed to safely absorb the heat-induced Expansion and contraction of various construction materials. They are commonly found between sections of slabs, bridges, and other structures.