One of the driveways on our property has a wooden bridge going over a creek. The deck is composed of three inch thick hemlock planks. Some of the planks are rotting, and it's time to replace them, but we don't want to have to do this every few years. We'd like to replace the wood with metal. My wife has checked out diamond plate, which is do-able but expensive. Does anyone have any other ideas? The bridge is roughly 18 feet long by 18 feet wide.

Thanks!!