Horse racing fences in the Grand National are made of Sitka or Norway spruce, which is brought down from the Lake District, and it is weaved into a plastic birch structure which provides flexibility should a runner make a mistake at the jump.
The old Grand National fences used to be constructed from natural thorn hedges and were known as ‘thorn fences’. But for the health and safety of the runners and riders, they designed the newer jumps to provide more flexibility.
With the exception of a water jump, all steeplechase fences must be a minimum of 4′ 6” in height.