On Sun, 23 Apr 2017 04:46:37 -0700 (PDT), wrote:

On Sunday, 23 April 2017 09:21:57 UTC+1, F Murtz wrote:


I have a strange situation in my bathroom, all the copper water pipes
are bonded to earth externally but I sometimes get a tingle to taps when
standing in the shower, (About 5 volts measured from metal round drain
to taps)
I can only assume that when the house was built(on concrete slab) the
reo steel in the concrete was not bonded to earth which is a requirement
today

You need to fix that.

Using a JCB :-)