Cable behind plasterboard

[JDR]

In removing extremely well attached tiles I have also stripped the plaster from the wall in my understairs WC. In doing this a cable running horizontally along the wall has been exposed. This was previously covered by a thin metal cover/conduit and buried in the old plaster.

The cable is for now secured to the bare brick wall with cable clips.

To redoecorate I intend to dot and dab plasterboard over.

The question is - what to do with the cable?

Is is acceptable to simply board over so that the cable is in the small gap between the plasterboard and wall or should I add additional protection to the cable - i.e. plastic trunking/conduit

 

[luminaire]

It can just be boarded over, as they don't require protection from the plasterer's trowel.

 

[Lectrician]

But it does sound like it is not in a designated "safe" zone.

Does it run horizontally to or from an accessory with in the room?

Once you have boarded, how would you know where the cable was? You go putting up your mirror or bog roll holder.......

 

[pbar]

But it does sound like it is not in a designated "safe" zone.

Does it run horizontally to or from an accessory with in the room?

Once you have boarded, how would you know where the cable was? You go putting up your mirror or bog roll holder.......

Take pictures of the cable runs before you plasterboard for future reference.

 

[GaryMo]

Take pictures of the cable runs before you plasterboard for future reference.

Or abide by current BS7671 regulations, assuming the cable is run out of a designated wiring zone. You have one of two options:

Sink to a depth greater than 50mm or run the cable within an earthed metallic conduit.

 

[JDR]

Thanks for the replies.

On the point about 'safe zones' and sticking a drill through at a later date...

I will obviously know where the cable runs since I will be the one to cover it over - so to me that will be 'safe' - unlike the location of other cables in the house. I would hope that the next person along would check first - but will attach a label by the CU in the adjacent cupboard just to be sure.

What is a safe zone? - when it comes to putting anything into a wall - drill, nail or anything else I would never assume it is 'safe' - I always check first with the cable locator, checking it first around a light switch or socket where I know for certain there will be a cable to see if it is working properly.

I know in theory that cables should run in a certain direction from a fixture, but would rather not have my final thought being - "the electrician hasn't followed the proper standards with this cooker cable route!" - so I don't assume anything to be a safe zone.

 

[securespark]

You go putting up your bog roll holder.......

Lec, you are uncouth. Do you mean "lavatory tissue dispenser"?

 

[pbar]

Thanks for the replies.

On the point about 'safe zones' and sticking a drill through at a later date...

I will obviously know where the cable runs since I will be the one to cover it over - so to me that will be 'safe' - unlike the location of other cables in the house. I would hope that the next person along would check first - but will attach a label by the CU in the adjacent cupboard just to be sure.

What is a safe zone? - when it comes to putting anything into a wall - drill, nail or anything else I would never assume it is 'safe' - I always check first with the cable locator, checking it first around a light switch or socket where I know for certain there will be a cable to see if it is working properly.

I know in theory that cables should run in a certain direction from a fixture, but would rather not have my final thought being - "the electrician hasn't followed the proper standards with this cooker cable route!" - so I don't assume anything to be a safe zone.

A safe zone isn't to your discretion and it isn't up to you to decide what is safe and what isn't, it is regulation, and that's the end of it. 'To you it will be safe' simply will not do. For example a home owner cannot run a cable to his cooker up his living room wall, diagonally to his hallway, over the ceiling to his boiler room then down across several twist and turns to his kitchen wall, diagonally down to his cooker, then plaster it all over, on the thoughts that he did it, he knows where it is, he'll leave a label for someone else. Years go by, people forget. A label disappears. House has new owners. Doting Dad puts a picture up of his kids in the living room, BANG, goodnight...forever.
You asked the question my friend, and got the answer, it's not arguable.
There are safe zones for a reason. The experienced/knowledgeable electricians on here will be able to advise further should you request it.

 

[JDR]

pbar - I am not arguing the regulation or the point of them or using my discretion as to what is or isn't a safe zone - merely stating the fact that I personally do not consider anywhere to be safe before doing anything - I don't know where the so safe zones are defined as and if I did I still wouldn't take a drill to the wall with out checking even if it was in a "safe zone" - people do not always follow the regulations do they?

The cable was in place before moved in - so I have not actually put it there. If I had not taken the tiles off which damaged the patchy plaster underneath I might never have know it was there and as such would not have been able to pass on its location to the next person in the house - so I don't really get the point you are making. As it happens the screws for the loo roll holder put in by the previous owners were about 10mm from the cable - whether by luck or good judgement who knows.

So now I am aware of the run of the cable are you suggesting I need to have it moved it if it is not in a 'safe zone' because I know it is there? Rather than ensuring it is adequately protected in its present position as in my original question?

The location is as follows. Understairs cupboard has been split in two - the larger side is the WC, the smaller part is a cupboard containing the electric and gas meters etc. The cable runs horizontal along the outer wall at about 600mm from floor level, about the same height as the CU in the adjacent cupboard, it runs a few cm below the WC window cill and then onwards through the wall in to the kitchen from there I do not know where it goes or what it serves.

 

[Lectrician]

Pbar goes from saying take a photo to do it properly! Now which way would you go Pbar

To comply to the regs you can't just assume someone will use a wire locator - and I would never rely on one of those anyway.

If there is no accessory in the horizontal or vertical plane of this cable on the wall then you are contravening the regs, unless you bury it deeper than 50mm, in which case it maywell then be out of a zone on the reverse of the wall! And a horizontal chase 50mm deep is not good for the structure of the wall.

You could use earthed conduit, SWA, MI etc.

Sounds like you want to board it anyway and are trying to justify this - you cant.


stick a 16mm metal box on the wall, and a blank plate on the front - run the cable through this so it is horizontally planed to the cable - leave a note inside if you so wish. This is your easiest get out.

 

[Pensdown]

ummm, I wonder what he would write on the note Anyone got any tips?

 

[ColJack]

metal capping is fine if you earth it.. just use some of that and plaster over it..

 

[Lectrician]

metal capping is fine if you earth it.. just use some of that and plaster over it..

Yuk.

 

[ColJack]

why yuk?

use screws and plugs to secure it to the wall, and put a ring crimped earth lead under one screw and run the lead to the nearest earth ( usually the socket or switch box.. )

 

[RF Lighting]

Metal capping is NOT sufficient protection to allow a cable to be run outside of the prescribed safe zones, wether it is earthed or not.

BS7671 calls for the cable to be completely surrounded with earthed metal.