Expansion tape is a non-absorbent expansion tape made of foamed polyethylene. It is used to construct flexible edge expansion joints in floor screeds bonded to the substrate. It is also used in rooms for the construction of flexible intermediate expansion joints, running through the entire cross-section of the screed, both when making self-leveling screeds and in heated floors. Thanks to its flexibility, it eliminates the harmful effects of thermal expansion and swelling of the materials used, and thermally and acoustically insulates contacting structural elements.