Sparks wrote:
NT:

Poor Bert, you took my reply seriously- and that of many other
contributors here. There is no requirement or reason to earth a
kitchen
sink.

I thought from my description you'd realise it was not serious.

FWIW I didn't see any indication of you joking!

A little :-) may have helped a bit!

I thought the idea of digging up the floor under every sink to put in
earth rods, connecting them with 16mm2, and the evident implied
illegality of a sink anywhere but on the ground floor would make it all
obvious. As usual I was wrong.

NT