Earth Bonding

There are different types of bonding. In a room containing a bath or shower, you need to bond together all the exposed conductive parts which stand any chance of becoming live due to a fault, such as all the pipes entering the room (unless they are plastic), metal baths, etc. You need to connect this bonding to the earths of all the electrical appliances and electrical circuits present in the room, but no separate direct connection is required to the main earth block. IIRC (and I don't have the regs on me to check), you only need 4mm² cable for this, or 2.5mm² if the cable is protected, but your 6mm² will be fine (except it may be hard to get into some earth terminals).

The other type of earthing you need is service bonding, i.e. bonding together all your incoming services; water, gas, oil. This is done with 10mm² cable, and connected back to the main earth block.

There are some other things too such as bonding exposed metal building framework, lighning conductors, etc, but they are rarely relevant in a house.

Do you know what type of earthing your electrical installation is? See

IIRC (and I don't have the regs on me to check), you

Your memory serves you well Andrew (as usual). They are indeed the correct sizes according to the OSG.

Mick, have a look at

Adam