My nan has had a problem with tripping of her TT supply whole cu protected by 30ma RCD. Found problem about 6 cables from outside all plugged into a home made box with a socket strip inside it. Got damp. Told my nan dodgy as hell but wont listen!. But i was curious about the earth rod which is located under the stairs which is about 6 metres away form the CU just wondered is that normal to have an earth rod placed inside the house. I know that all the electrics were done by a sparky 15 years ago by the local authority before my Nan purchased the house.