Abstract: The invention relates to an installation for zinc coating one or both sides of continuous steel strip. In order to retain short change-over times when changing from one process to the other, the invention proposes to flange-mount in readily releasably manner a housing (2a, 2b), with guide rolls (3a, 3b) mounted therein, on the duct (5) leading from the furnace to the zinc bath and to design this housing so that it can be interchanged with a support for the guide roll (10) during two-sided zinc coating, making use of the mounting at the duct (5).