Hardboard is a thin sheet of board that comes in 4 by 8 foot sections. It comes in 3 mm or 4.5 mm (1/8 or 3/16 inch) thicknesses. Hardboard is used for many applications including walls and fascia boards. It is also used as a skateboard ramp. When using it as a skateboard ramp, it is sometimes necessary to bend the hardboard. Bending hardboard can be a time-consuming task, but with the proper instructions, it can be completed and your ramp can be built.