Bonding - plastic pipes - outside toilet

[mouk]

I am having a full re-wire.

I have all copper pipework inside the house.

I understand I need an earth connection to the water and gas mains. All of my circuits will have RCD so I udnerstand the copper pipes don't need to be earthed.

I also have an outside shed which as 3 rooms - one of which is a toilet. I want to get lights and sockets to the shed.

The main SWA cable from the house to the shed enters the toielt and so the electrician has said we will need to earth it.

He is talking about extending the (yet to be fitted) earth wire fro mthe house ot the toilet. Whilst this is possible (as my patio has not gone down yet) - it will cause additional work like digging the outside floor up again and so on.

Now in the toilet the copper pipe comes out of the floor and feeds the toielt cistern and an 'outside tap' (which is inside the toilet).

If I was to cut the copper pipe at ground level and replace it with plastic would this remove the need for earthing? There woudl be next to no chance of anyone being able to touch copper in the toielt them as it would be in a very inaccessaible location in the corner than no one would ever need to get near.

The shed is fed by the blue water pipe and then coverts to copper somewhere underground - so there is no direct copper link back to the main house.

Whether plastic piep can be used in outside toilets is a question for another forum I suppose.

 

[EFLImpudence]

I understand I need an earth connection to the water and gas mains. All of my circuits will have RCD so I udnerstand the copper pipes don't need to be earthed.

It is not earthing but bonding.
Supplementary bonding is not usually necessary with RCDs but main bonding is.
It is not clear about which you are talking.

The main SWA cable from the house to the shed enters the toielt and so the electrician has said we will need to earth it.

The swa, yes.

He is talking about extending the (yet to be fitted) earth wire fro mthe house ot the toilet. Whilst this is possible (as my patio has not gone down yet) - it will cause additional work like digging the outside floor up again and so on.

I don't understand.
Is that where the water supply enters the premises?

If I was to cut the copper pipe at ground level and replace it with plastic would this remove the need for earthing? There woudl be next to no chance of anyone being able to touch copper in the toielt them as it would be in a very inaccessaible location in the corner than no one would ever need to get near.

It would - but as above.

The shed is fed by the blue water pipe and then coverts to copper somewhere underground - so there is no direct copper link back to the main house.

Ok.

Whether plastic piep can be used in outside toilets is a question for another forum I suppose.

Not really. You can use plastic if you want.



I think more specific information is required.

 

[mouk]

Electrician mentioned that a connection will need to be made to the water mains and gas mains - I believe that an earth cable will be used - if this is main bonding then that is fine as it will be done.

I think what I am talking about is supplementary bonding.

Supplementary bonding is not required in the house because I have RCDs (?).

-----
The water enters the house from a blue pipe - it goes into the kitchen

Another blue pipe enters the shed directly.

Obviously these 2 blue pipes are one pipe udnerground but split when they get near my property.

As I understand he is suggesting bonding the main stop cock - and then taking the wire outside to the copper pipes in the toielt - so essentially 1 single wire going to the stopcock and outside toilet - this makes sense as they are inlien with eachother - the gas is in a different place.

The alternative as I understand it is that we put in an earth rod - which will cause all sorts of hassles.

 

[EFLImpudence]

Electrician mentioned that a connection will need to be made to the water mains and gas mains - I believe that an earth cable will be used - if this is main bonding then that is fine as it will be done.

Yes, that is main bonding (same type of cable).
It must be connected to metal pipes where they enter the premises back to the Main Earthing Terminal.

I think what I am talking about is supplementary bonding.

Supplementary bonding is only required in Bathrooms and similar - not toilets.
It probably is not required there if all circuits have RCD protection - plus a couple of other things which you will likely have anyway.

Supplementary bonding is not required in the house because I have RCDs (?).

Most probably correct.

-----

The water enters the house from a blue pipe - it goes into the kitchen

If that were all then even main bonding would not be required.
However, if the copper pipe goes into the ground and emerges somewhere else then the main bonding would be required but it may be possible to connect it somewhere more convenient.

Another blue pipe enters the shed directly.

So likely does not need bonding in the shed.

Obviously these 2 blue pipes are one pipe udnerground but split when they get near my property.

Yes.

As I understand he is suggesting bonding the main stop cock - and then taking the wire outside to the copper pipes in the toielt - so essentially 1 single wire going to the stopcock and outside toilet - this makes sense as they are inlien with eachother - the gas is in a different place.

It is difficult to say not knowing the layout but -
from what you say it does not need bonding at the stopcock (because of plastic supply) - but connecting it there (or somewhere more convenient) back to the M.E.T. may be sufficient to also ensure the toilet pipe is connected effectively.

Measurements can be taken to determine this.

The alternative as I understand it is that we put in an earth rod - which will cause all sorts of hassles.

Quite.

 

[OwainDIYer]

How far is the shed from the house? What size of SWA are you using?

Is the pipe going into the shed copper or plastic? If it's plastic you don't need to bond.

 

[mouk]

Maybe the attached pic helps

BLUE mains water pipe goes to the garden where it splits to toielt and house stopcock

Both stopcocks are brass and then have copper pipe

My house currently has no plastic pipe and the shed has no plastic pipework

The SWA is 6mm

The pci does not show all the standard 15mm and 22mm copper pipework.

 

[JohnW2]

BLUE mains water pipe goes to the garden where it splits to toielt and house stopcock ... Both stopcocks are brass and then have copper pipe ... My house currently has no plastic pipe and the shed has no plastic pipework

If no metal pipe enters either house or shed from outside (i.e. underground), then there is no need for any bonding - indeed, there would be nothing to bond. Metal pipework wholly within the house, or wholly within the shed, does not need main bonding (but may possibly need 'supplementary bonding' within a bathroom).

Kind Regards, John

 

[mouk]

OK thanks

Well my water is blue pipe and my gas is yellow plastic pipe - both of these were put in fairly recently - last 20 years I think

Is supplementary bonding required because pipes used to be metal?

I will raise it with my electrician as he may have assuemd its all metal.

 

[Taylortwocities]

I stand to be corrected here but

In most cases blue pipe coming into a property will be the water service and will be PVC, so no bonding necessary.
For gas, the pipe is yellow, but I believe that the pipe is always metal but with a yellow plastic serve on the outside. So bonding is always necessary. Can anyone confirm my belief?

 

[JohnW2]

I stand to be corrected here but ... In most cases blue pipe coming into a property will be the water service and will be PVC, so no bonding necessary. For gas, the pipe is yellow, but I believe that the pipe is always metal but with a yellow plastic serve on the outside. So bonding is always necessary. Can anyone confirm my belief?

Yes, I think so. My understanding is that it is not permitted for any gas pipework (including the incoming service) within a domestic property (possibly/probably wider than that) to be plastic - so, as you say, if it appears to be yellow plastic, there will (should!!) be metal underneath the covering.

Kind Regards, John

 

[JohnW2]

Is supplementary bonding required because pipes used to be metal?

No. Supplementary bonding is no longer ever required anywhere other than in bathrooms, and if the bathroom circuits are RCD-protected, supplementary bonding will not usually be required even there.

Kind Regards, John

 

[ban-all-sheds]

If no metal pipe enters either house or shed from outside (i.e. underground), then there is no need for any bonding - indeed, there would be nothing to bond. Metal pipework wholly within the house, or wholly within the shed, does not need main bonding (but may possibly need 'supplementary bonding' within a bathroom).

If no metal pipe enters either house or shed from outside (i.e. underground), would copper pipes in a bathroom be e-c-ps?

 

[JohnW2]

If no metal pipe enters either house or shed from outside (i.e. underground), would copper pipes in a bathroom be e-c-ps?

Very probably not - although bernard might start talking about 'damp walls', and EFLI about the need to test to be sure.

Given that BS7671 appears to require main bonding of pipework downstream of an 'insulating section', I'm hesitant to say anything (based on engineering, physics and logic!) about what the regs believe (despite their definition) constitutes an extraneous-c-p!

Kind Regards, John