Supplementary bonding in bathroom Ask questions and find answers to many subjects relating to electrics and electrical work

[iain watson]

HI all,

Completely refitting a bathroom upstairs. Have ripped out all old stuff and the floor - there is no sign at all of any pre-installed in situ bonding.

I think I might have a significant misunderstanding.............when I bond all the non-electric metallic bits, does that bonding then have to be connected back to the MET? (all my notes state that it does) - That being the case it was my intention to splice into an earth cable which comes up from the kitchen-sink water supply pipes and then goes onto the MET.

Have a feeling I'm missing something obvious here and would appreciate any guidance - however noddy it may sound.

Cheers,
Iain

[sparx]

Hi Ian,
do not connect back to main bonding!!
the idea is to keep all exposed metal parts that could become live at same potential (voltage) in the room.
If you connect to MET or other earthed wire outside, a fault on any circuit
which may lead to a voltage on the earth system rising to above 50V before tripping/blowing the mcb/fuse.
whilst in a dry place this is not considered dangerous, bringing that potential into a place where due to wet conditions your skin resistance is llowered could prove fatal.
That's why it's called 'Equi-potential bonding' rather than earth bonding.
hope that helps with a very misunderstood subject,

regards Sparx

[sparx]

I was going to ask if you are Part-P registered but see from there you currently are not.
Unfortunately what you are doing is Illegal.
I assumed you where qualified electrician confirming a detail, DIY forums cannot condone law breaking, all work in bathrooms is notifiable to LABC before starting or must be done by Registered leckie.