Supplemental bonding in bathroom (again- sorry!)

[GarethK]

Hi,

First post so go easy!

Having just fitted a new bathroom suite incl new piping in a bathroom where there was previously no supplemental earth bonding I've been advised to add some.

There are no electrical supplies falling inside the bathroom 'zones' - the only power is a light and pull cord switch which are above and outside zone 3.

All of the piping is copper, with compresion fittings. The bath and sink taps are connected using braided flexibles. I believe that there is an argument that no extra bonding is required since all piping is in copper and is subsequently connected to the main earth bonding outside of the bathroom, however have also read otherwise and it seemed that to install the bonding was to err on the side of caution.

Since the only electrical circuit is the lighting which falls outside of the zones, is it sufficient to connect all exposed pipework to each other, and NOT subsequently to any CPCs as there are none within the bathroom / zones?

Thanks in advance!

 

[nozspark]

Firstly as your lighting is outside the zones then you are right, it does not need bonding.
Secondly, if you can proove that the hot/cold and heating pipes are bonded (by measurement) then you do not need to bond them seperately. You need to test for this with an ohm meter and the reading should be below 0.05 ohms. If not then you need to run a 4mm supplimentary bond between hot, cold and heating as said previously.

 

[Norv]

I've got a similar setup to you with a combi boiler in the airing cupboard outside the bathroom. I took a 4mm cable from the bathroom light via the loft, down to the combi pipes & then cross bonded them all.

 

[Lectrician]

You can't mesure to prove continuity - the bonding must be done in close proximity to the room - by measuring, you could be reading a H to C a good distance away.

If all you pipework is copper, and lecky outside the zones, then all that is required is a link from H to C anywhere accessible in the bathroom.

 

[GarethK]

Thanks for all replies - very helpful!

Cheers