Abstract: The invention relates to a casting device for applying a foaming reaction mixture, to at least a partial width of a cover layer, wherein the casting device comprises: a supply connection for feeding in the reaction mixture; at least one exit slit extending in a transverse direction for the exiting of the reaction mixture; two slit plates arranged opposite one another, wherein a slit space extends between the slit plates in a vertical direction above the exit slit. A supply channel connected to the supply connection is formed between the slit plates, which closes off the slit space above the exit slit in the vertical direction The supply channel has a channel cross-section, the main dimension of which is larger that the width of the slit space. The reaction mixture can be introduced into the slit space to distribute the reaction mixture over the length of the supply channel.