Copper sheathing, iron reinforcement, and corrosion

When did builders begin using iron or iron-reinforced framing, and was it practical?

Iron reinforcement grew alongside copper sheathing, but the metals caused serious corrosion when paired directly, so builders used insulating wood layers and retained much timber structure for a long time.

Greater use of iron reinforcement coincided with the adoption of copper sheathing. Iron and copper in close contact created rapid corrosion, so later iron-hulled vessels intended for foreign service could be wood-sheathed before being coppered, insulating the metals from one another. Earlier builders used iron selectively for guns, fittings, and repairs while retaining wood for much of the structure. Cost and ease of replacement reinforced that preference.