Flooring material including floor boards (1) with an essentially square, rectangular or rhomboidal shape. The floor boards (1) are provided with edges (2), a horizontal lower side (5) and a horizontal decorative upper surface (3). The floor boards (1) are provided lower joining lips (10) at two adjacent edges (2) while the two remaining edges (2) are provided with upper joining lips (20). The lower joining lips (10) are provided essentially vertical lower lip surfaces 911) arranged parallel to the closest edge (2). The lower surfaces (11) are intended to interact with mainly vertical upper lip surfaces (21) arranged on the upper joining lips (20). Two joined adjacent floor boards (1) are hereby locked together in a horizontal direction. The joining lips (10 and 20 respectively) are furthermore provided with one or more heels (31) intended to snap join with recesses (32) adapted thereto which, by being provided with essentially horizontal locking surfaces, limits vertical movement between two joined adjacent floor boards (1).