Decayed scaffolding is a game-generated block that looks just like regular scaffolding, only more rusty and broken. When mined, decayed scaffolding turns into scrap metal in inventory.
How to Obtain
This item was only available for a short time from a chest of plenty in one of the competition worlds during the Crashed Competition. When the competition was over, the chest was removed, and decayed scaffolding can no longer be obtained into inventory, except by trading with other players for it. You cannot use a hatchet on regular scaffolding to create decayed scaffolding.
How to Use
Players who happened to obtain this block can place it like any other block. Note, however, that once you place it, you cannot mine it back into inventory, as it will always return iron scrap metal.