Supplementary bonding in my bathroom

22 Jan 2007
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United Kingdom
Can somebody help me please? I've taken the panels off my bathroom walls and found that there is no supplementary bonding on the cold & hot water feeds to shower, sink, bath or toilet! I understand from previous questions placed on the forum that this has to be done in 4mm single core but i'm a bit puzzled over where I need to pick the earth up from! My first question is... do I have to run this 4mm cable back to the earth block on the consumer unit or can I run it to the earth terminal in my shower unit which is fed by 10mm twin & earth? Second question... can this be extened to the hot water tank in the airing cupborad next to the bathroom or does this need to be seperated? At present the earth block only supplies bonding to the kitchen sink & incoming water pipe from the mains supply.
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Supplementary bonding is just that - supplementary to the main equipotential bonding - MEB's go back to the earthing terminal, whereas supp does not. All it does is connect metalwork within the bathroom to each other & to the cpc's of any circuits supplying equipment in the bathroom.

So, connect your 4mm² conductor to the H&C pipes, any metal waste or soil pipes, metal baths or shower trays, CH pipes & rads, and cpc's of showers, lighting circuits, immersion heaters etc.

All connections must be unbroken or or on lugs and be accessible. If they are not accessible, you must solder them. Include the pipework in the AC if not already connected, and the IH circuit too.

The kitchen sink is no longer required to be bonded under the 16th Edition.

You should have 10mm² to the water pipe, on the consumer's side of the 'cock within 600mm, but also another on the gas pipe, either within 600mm of the meter before branch pipework on the installation pipe, or where the pipe enters the property. Again, this must be accessible.

Where does the earth cable for your installation originate from?
Sorry to be a bit thick but what do you mean by cpc's? The main earth cable originates from the an earth block on the side of the electricity boards incoming supply
Cpc's is earth wire in a cable.

Does the main earth come from the cable sheath?

Or from the side of the cut-out?
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Looking at the main fuse it would appear to be connected to the incoming neutral wire if that makes any sense!

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