should you install a earth rod if running a feed to a shed which is built on timber frame and is all timber , no metal parts and will have no services ie gas or water in it so no need for bonding only a supply for a light and a couple of sockets or can you use a pme earth from fuseboard if the shed supply is run in 6mm armoured from the outside of the house ( inside house 6mm t+e to fuseboard ) protected by 32amp rcbo will be installing a 2 way board with rcd main switch in shed approx 25 meters away