Material should be kept as clean as possible and away from mud, grease, oil, paint, concrete, mortar and other substances to minimise cleaning costs. • In almost all cases where the Cor-Ten steel is used as a façade cladding, this is used as rainscreen system installed on a substructure or rail system typically specified in other architectural metal. Joining different metals may induce galvanic corrosion. Galvanic corrosion occurs when two metals with different electrolytic potential come into contact in the presence of an electrolyte such as water. The table below summarises the risks of pairing Cor-Ten steels with other metals commonly used in facades.