A device for continuous supply of grouting into joints between longitudinal concrete elements, which are disposed chiefly horizontally next to each other to form, e.g., floors in building constructions. The device comprises a rhombic hopper adapted for displacement along the joint, wherein at least two side walls form an accumulating plow for leading the grouting in towards a vertical plane through the joint. The side walls of the hopper are latitudinally displaceable with respect to each other, and are held with an adjustable force against the surface of the concrete elements. The hopper is arranged below a discharge end of a container, the discharge end having a damper, which is operated by an actuator coupled to a level sensor in the hopper.