A device for forming grooves in floor covering material such as linoleum for applying a welding wire into said groove, comprising a carrier (1) having running wheels or sliding surfaces (2), by means of which said carrier (1) can be moved over the floor covering material (3), a support (8) provided on said carrier (1) for accommodating, if required, a heating apparatus (10) and a gouge (4) arranged, as seen in the direc­tion of movement, behind said support (8), said gouge extending over a distance corresponding to the desired depth of the groove (6) beyond the lower surface of the carrier (1), which heating apparatus (10) is, in particular, a hot air apparatus with thermostatic protection.