An expansion joint is a structural gap, intentionally introduced in buildings or other structures, designed to allow the free movement of individual parts of the structure. It is used to compensate for movements caused by changes in temperature, humidity, loads or soil settlement. Expansion joints are necessary in large constructions, where the lack of flexibility of construction materials could lead to cracks or damage. Apart from technical functions, expansion joints can also play an aesthetic role, being a decorative element of the façade. They can have many forms, depending on the design and aesthetic needs. We distinguish, among others, vertical, horizontal, roof and foundation expansion joints.