Manufactured from extruded aluminium pieces with a bonded rubber infill, expansion joints (also known as movement joints) are used as an intentional interruption within the tile or stone surface, allowing for movement in the wall or floor. Hard flooring expands and contracts which is why it is important to us an expansion joint to prevent tiles and grout from cracking or the tiles de-bonding from the substrate. Expansion joints are designed to safely absorb any heat induced expansion and the contraction of construction materials. They also absorb vibrations allowing movement for ground settlement.