HG voegenreiniger concentrate removes strong pollution of the joints. Yellow or brown pollution that is left behind after cleaning is limescale. This is removed with HG professional limescale remover. For black released add HG mold-, moisture - and the smell is so pleasant.
Dilute (1:4) HG voegenreiniger concentrate with lukewarm water. Then apply with a hard broom or hand brush. Let soak, scrub well and rinse with water. Eén liter is good for 10 to 15 square meters on the wall or floor.
HG voegenreiniger concentrate is also available in a hand & plain version.