The present invention relates to a method for producing a two-dimensional panel (1) for floor coverings, wall and ceiling coverings, preferably for moisture-prone rooms, comprising the following steps: milling one upper longitudinal groove (6) into a base panel, starting from its useful side (5), the longitudinal groove (6) is filled with an elastic water-repellent plastics or sealing mass (9); and after hardening of the plastics or sealing mass (9), at least one lower longitudinal groove (11) is milled, starting from its rear side (10), the depth of which groove reaching as far as to the sealing mass (9) or into the sealing mass of one of the upper longitudinal grooves (6), thus forming an elastic expansion joint (12) of the panel (1). A further method comprises the following steps: one edge groove (8) each is milled into the base panel, starting from its useful side (5), in the region close to the longitudinal sides (7); the edge grooves (8) are filled with an elastic, water-repellent plastics or sealing mass (9); and after hardening of the plastics or sealing mass (9), a groove (13) as well as a tongue (14) are milled for a groove-and-tongue connection, wherein each of the outer lateral flanks (15) of the sealing mass (9) is milled.