A surface element designed to be assembled together with similar surface elements to form a unit of a plurality of joined surface elements; said surface elements comprising a core, a decorative upper surface and edges for joining, including a first and a second edges allowing joining by rotational movement, and a third and a fourth edge allowing joining by vertical movement, wherein two adjacent edges of the surface element at the same time, and concurrently with said rotational movement, is joined with a surface element adjacent to the first edge and a surface element adjacent to the third or fourth edge.