Bathroom bonding Q - light and shaver socket

[iwest]

I have just moved into a house and have had a good look around at the bathroom bonding. All the pipes (bath, basin, central heating) are all nicely bonded together, as are the pipes in the airing cupboard which also houses a whole house pump.

However..... I notice the bathroom light ( a proper zone 2 one) and the shaver socket (a new looking MK one) do not have their earths bonded to the pipework. Now looking around this would be very difficult without lots of chasing/drilling (there is a flat roof above with no access), the difficulty may be why it was not done in the firstplace!

Now in the loft space about 5 feet away from the bathroom light is a lighting junction box with all the lighting connections, and this J/B feeds the bathroom light as well as (via a 3A FCU) the shaver socket. Would it be sensible to run a 4mm earth cable from the J/B earth in the loft, through the airing cupboard, under the floor to the bathroom pipe bonds in an attempt to get an equipotential, or is this pointless as it would rely on the earth cable in the 1.5mm T+E cables to the shaver/light rather than how it should have been done... Or shall I just leave it as is?

Also, should the whole house pump in the airing cupboard have a 4mm earth lead from the switched FCU (which comes from the ring main) to the copper pipes in the airing cupboard?

many thanks

 

[JohnD]

You do not have to supplementary-bond each individual fittings (shaver point, light fitting etc) to the pipes. You have to bond the CPC (earth wire) of each circuit that enters the bathroom to all the metal services that enter the bathroom.

So if the two outlets are both fed from the lighting circuit, you can run your 4mm G&Y to the nearest convenient point. This is usually a light switch or fitting above the ceiling. If one of them comes from the sockets circuit you have to bond to that as well. You should bond to the CH pump and the immersion heater earth as well when these come off different circuits.

The bonding can be done immediately outside the bathroom, e.g. in an adjacent airing cupboard, provided you have copper pipes with a continuous metal (soldered connections of any joints). You can treat these copper pipes as part of the supplementary bonding so you do not need to run wires in parallel to bonded copper pipes.

If you have a lot of wires to gather together it can be useful to have an earth block. this is best done in the airing cupboard as they are rather unsightly.

 

[jj4091]

I may be wrong but I think that the bonding of the bathroom fittings is a relatively new regulation, which may explain why it was not done originally & as far as I am aware the regs are not retrospective so I do not think you HAVE to do anything unless you are doing other works or if it is for your own peace of mind.

 

[iwest]

Yes that makes sense, the bonding appears to be in order for when it was done (5 yrs ago?). I will improve when I next do some more major work/decoration

thanks