Earth Bonding

[OxiaUK]

Hi

My dad has just bought a new house (1930s) and we are in the process of updating it all. It's previously had a dual rcd split load board fitted at some point.

We are now having some plumbing done to replace lead pipes and fit central heating.. the plumber will replace half of the lead water main pipe running under the floor and connect a new plastic one to the kitchen.

My questions are:

Now that the main water pipe is half plastic does it still require bonding?

Is it still a requirement to cross bond pipes in the bathroom and also the central heating pipes?

If both gas and water pipes need bonding do you have to run 2x 10mm earth cables or can you use 1x cable and link them together with a bonding clamp?

Any help would be great!

 

[AndyPRK]

Cross bonding no longer required.
Gas pipe should be bonded

 

[EFLImpudence]

We are now having some plumbing done to replace lead pipes and fit central heating.. the plumber will replace half of the lead water main pipe running under the floor and connect a new plastic one to the kitchen.
My questions are:
Now that the main water pipe is half plastic does it still require bonding?

I am presuming the remaining lead emerges from the ground.
If the remaining lead enters the premises then that will still require Main Bonding.

Is it still a requirement to cross bond pipes in the bathroom and also the central heating pipes?

It's called Supplementary Bonding (just means additional bonding) and is still required for Extraneous-Conductive-Parts entering the bathroom.
You cannot tell by looking at the pipes whether that is the case.
However, if ALL the circuits of the bathroom are covered by an RCD - plus a couple of other conditions are met then SB might not be required.
Central heating pipes are no different as far as the bathroom is concerned but if any of them are buried in the ground, they might require MB.

If both gas and water pipes need bonding do you have to run 2x 10mm earth cables or can you use 1x cable and link them together with a bonding clamp?

One cable linked will do.

 

[EFLImpudence]

P.S.

Any SB also includes any 'simultaneously accessible' Exposed-Conductive-Parts in the bathroom.
That is metal parts of any electrical appliances and accessories.

 

[SUNRAY]

One cable linked will do.

Is the requirement still in place that the 2 cables where linked have to be soldered or crinped together?

 

[EFLImpudence]

No. I don't think it ever was.

 

[SUNRAY]

No. I don't think it ever was.

I was always under the impression that if a bond went to say the gas then onto the water, at the gas the 2 cables had to be terminated in such a way that if the termination is undone the 2 cables do not come apart. For example both crimped into the same lug.
I've known the point to fail inspection.

 

[EFLImpudence]

There are lots of myths around.

 

[OxiaUK]

Thanks for all your replys. There will be about 1m of lead water pipe left under the floor (the total run is about 5m) and the rest will be plastic.

Would you need to supplementary bond an old cast iron bath?

 

[EFLImpudence]

Would you need to supplementary bond an old cast iron bath?

Not the bath itself (assuming it is not in contact with the ground).

Perhaps the water pipes and waste pipe if metal.

 

[OxiaUK]

Thanks, so would I be best taking a new cable to the bathroom from the CU and bond the bath pipes, sink and shower pipes?

Sorry for so many questions... just a bit confused

 

[OxiaUK]

also do I need to earth the main water pipe after the new tap?

 

[EFLImpudence]

Thanks, so would I be best taking a new cable to the bathroom from the CU and bond the bath pipes, sink and shower pipes?

Sorry for so many questions... just a bit confused

No. You just have to connect them together so there can be no (or very little) voltage difference between them when there is a fault.
You can do it in the bathroom or nearby - in airing cupboard if adjacent.

It's more complicated than you think.
It is not "Oh. there's a pipe, bond it".

also do I need to earth the main water pipe after the new tap?

Not if it is the pipe which enters the building is plastic.

 

[OxiaUK]

No. You just have to connect them together so there can be no (or very little) voltage difference between them when there is a fault.
You can do it in the bathroom or nearby - in airing cupboard if adjacent.

It's more complicated than you think.
It is not "Oh. there's a pipe, bond it".




Not if it is the pipe which enters the building is plastic.

The main water enters the house in lead for about 1m then is jointed to plastic for the remaining length.

 

[EFLImpudence]

Then you have to Main Bond the lead pipe at the point of entry to the premise (or 'where practicable').