Cant find the water earth bonding....but it's there??

warwicktate

Hi,

As per the title, during an EICR, the electrician couldn't find the water earth bonding on/near the stop-tap, so marked this as a code FI, and the report was marked as Unsatisfactory. He quoted the additional cost of finding it. I agreed, and a few days later he popped back. After much huffing and puffing, he still couldn't find it, however he performed a long lead continuity test, which confirmed the earth bond was verified, as the result was 0.02, which is Satisfactory. (This was within a minor electrical installation works certificate).

I have recently had a new kitchen fitted, and as there was a fair bit of electrical work, I want to repeat the EICR. The electrician that did the work (who just so happens to be my BIL, a newly qualified electrician) has said that if the bonding can't be found, his boss (who will be doing the EICR) will once again give it an Unsatisfactory. And he will then proceed to bash a load of holes to install a new earth bonding line from the consumer unit to the stop-tap (see image). So, my intention is to find the damn thing myself. And, looking at the picture underneath, where would the best/most logical place be to start looking? I hope to pull up as few floorboards as possible. Bit of context, the house is approx. 100 years old, terraced, and I believe it has a suspended floor. My guess would be the bonding is between the front door and the CU (consumer unit) where the water comes into the property. Any other guesses? (The stop-tap is in the kitchen, marked ST). 


Many thanks 

fenwick458

it might not be there....
this test that your electrician did does not confirm that there is earth bonding, it just confirmed that there is a low resistance between the 2 points. (stop tap and main incoming earth)

stator

My house has an earth bonding upstairs near the bathroom. Part of the house was rewired, the easiest place to put the bonding was where the cold water mains pipe goes upstairs towards the bathroom, it's actually under the floorboard in my bedroom, next to the bathroom.   When the kitchen was redone a few years later, they put in an earth bonding there too, so now I have two.

Ectophile

Have you checked what your incoming water pipe is made of?  If it's plastic, then the bonding is pointless anyway.

Risteard

There isn't actually any such thing as "Earth bonding". It is main protective bonding you are referring to. Earthing and bonding serve different purposes.

tacpot12

Assuming the water supply pipe is conductive (it' s worth checking this as Ectophile suggested), then bonding will be needed to the water supply pipe, and it is supposed to be visible and close to the stop tap. With care, a bonding cable can be installed so that it remains hidden and unnecessary damage and making-good avoided.

If you want to trace the cable, you should start at the CU, and check that you can identify that there is a bonding cable for the water supply. The main earth terminal will have a cable going into the CU, and may have cables to the supply head, any gas pipe and any water pipe that come into the property. If you can trace the cables to the CU, gas, and supply head and have a cable you can't trace, you have at least confirmed that there might be bond to the water pipe already installed. Trace this cable as far as you can. 

Stud detectors often have a voltage and/or metal detection capability an if you are lucky you might be able to use this to follow the cable further. A cheap endoscope camera can be useful to look inside walls to see if a cable that has entered a wall or floor continues is the same direction is was travelling in, or makes a change of direction. You can also buy the sort of cable finder tone generator that your electrician will use quite cheaply on eBay. They won't be as good as a quality brand, but they may be sufficient.

Knowing or mapping where the cold water feed into the house goes will also help you find it. If the bond exists it will be attached to a cold water pipe. The metal detector function of a stud finder would be the way to trace the pipework.

warwicktate

Many thanks for your comments.

So, it looks like I'll just have to start at the front of the house, and work backwards pulling up floorboards and trying to track the water pipe. I'm really hoping the bonding (if its actually there) will be close to the front door, but I'm guessing I won't be that lucky!!

I'm fairly sure its not a plastic water pipe, as I can see most of the piping in the kitchen and its all copper. I would expect it to be copper all the way through (unless previous owners did some work, but we have no knowledge of that). 

Just a question for the electricians. As I've already had a long lead continuity test and the result was 0.02, which is Satisfactory, do I still need bonding onto the water pipe if its not already there?

Risteard

If it's not present and the part is extraneous then you absolutely MUST have main protective bonding. 

warwicktate

Risteard said:

If it's not present and the part is extraneous then you absolutely MUST have main protective bonding. 

That's great, thanks for clarifying that 

FreeBear

Risteard said: If it's not present and the part is extraneous then you absolutely MUST have main protective bonding. 

To be compliant with current regulations.

FTFY

Many older installations did not require bonding, and are still perfectly safe even if they won't pass an inspection to the current standards.

warwicktate

Thanks for all your help. 

Next question. We are going to sell the house once the kitchen is sorted. Would it be a good idea to get a new EICR sorted before sale (considering my BIL can get it up to spec very cheaply), or just let the potential buyer sort all that out?