The OP also mentioned lightning concerns here
http://www.talk.electricianforum.co.uk/topic/22821-do-i-need-to-earth-my-wood-burng-hot-tub/?p=314290
http://www.talk.electricianforum.co.uk/topic/22821-do-i-need-to-earth-my-wood-burng-hot-tub/?p=314290
