Safe zone for cable

[Jupiter01]

I want to install a new double socket half way up the wall to serve my wall hanging TV.
There is a double socket in the bottom left corner of this wall. I think this is on a Ring but I will test for continuity before proceeding with this. I would like to spur from here. The wall is dot-and-dabbed with plasterboard and I would run cables in he void behind the plasterboard.

I think there are two options:
- take a cable diagonally from this socket to the new socket (middle of the wall)
- take a cable horizontally to the middle of the wall and then turn vertically to go up to the location of this new socket.

As far as I am aware, neither are allowed as they defy the safe cable route practice.

Perhaps I need "something" where the cable goes from horizontal to vertical as that would indicate the presence of cables. This isn't ideal as I was planning to wallpaper the wall and minimize any surface objects.

Can you please advise on how this should be handled. Also, when running cables behind plasterboard, the line of the cables will never be completely straight as the cables may be swerving above/below dabs in the plasterboard. I assume this is acceptable?

 

[DetlefSchmitz]

Horizontally then vertically from existing socket is ok.

 

[Jupiter01]

Horizontally then vertically from existing socket is ok.

Can I please check that this is okay even when there is no socket/accessory at the junction where we go from horizontal to vertical?
Also, is the slight variation in the direction of the cables allowed as would be the case in a dot and dabbed wall?

 

[DetlefSchmitz]

There doesn't need to be an accessory at the change of direction. The cable must remain within the width of the accessory.

 

[Murdochcat]

Safe zones are horizontally and vertically from any accessory AND within 150 mm of a corner or the ceiling

 

[JohnW2]

There doesn't need to be an accessory at the change of direction. The cable must remain within the width of the accessory.

That is strictly true but it amuses me a little when I see fuss being made abut slight deviations from that, given that one rarely knows exactly the position/route of cables 'wallowing about' in a cavity wall

Kind Regards, John

 

[DetlefSchmitz]

it amuses me a little when I see fuss being made abut slight deviations from that

Well there's the rules that you have to tell people, and there's what you do with them when you implement them.
It's as well to know what you should do.

 

[sparkwright]

That is strictly true but it amuses me a little when I see fuss being made abut slight deviations from that, given that one rarely knows exactly the position/route of cables 'wallowing about' in a cavity wall

Kind Regards, John

Not sure what you mean.

If by cavity wall you mean studwork, where the cable is less than 50mm from the surface, the zones still apply - so not sure how this would be different.

 

[pcaouolte]

In this case the OP is proposing to shove the new cable behind some existing dot and dab fixed plasterboard and hope that it will form a nice L shape where it changes direction from vertical to horizontal. It should also magically float in a perfectly horizontal position behind the plasterboard without any fixings. We all (including the OP) know that isn't going to happen.

 

[sparkwright]

when running cables behind plasterboard, the line of the cables will never be completely straight as the cables may be swerving above/below dabs in the plasterboard. I assume this is acceptable?

No.

If the cable falls out of line from being within the prescribed cable zones because there is dot of plasterboard adhesive in the way, this is not acceptable.

You would have to make some slots of notches in the plasterboard for the cable to ensure the cable is within the zones.

 

[JohnW2]

Not sure what you mean. If by cavity wall you mean studwork, where the cable is less than 50mm from the surface, the zones still apply - so not sure how this would be different.

Yes, I'm talking about a stud wall, or similar.

As you say, the rules are the same as for any buried cable, but it's implementing/obeying them that is the problem. Unless the cable is unusually 'taught' (in my experience, there are almost always 'flopping about', with a fair degree of slack), whilst one can ascertain that the two ends of the cable are within a 'safe' zone, but cannot be at all sure that the cable between those two ends remains within that zone.

Kind Regards, John

 

[JohnW2]

Well there's the rules that you have to tell people, and there's what you do with them when you implement them. ... It's as well to know what you should do.

I don't disagree with that, but I also think one has to be aware of, and 'accept', that in some situations one simply will not know for certain that the entire length of the cable will be within the zone within which it should be.

One would hope that anyone taking a drill, chisel, saw hammer and nails or whatever to the wall would take this into account, and assume that it is quite possible that there could be a cable wihin at least an inch or three on either side of a prescribed 'safe zone' (a 'dangersous zone' for them!) - but I wouldn't put money on everyone thinking that way!

Kind Regards, John

 

[sparkwright]

Yes, there will always be a small element of uncertainty if the cable is, or stays, within the cable zone.

Often, if someone decides to clip the cable down the stud, this will nearly always mean the cable can't be in-line with the plasterboard box. I try to avoid clipping them, for the reason, but I will fit a clip somewhere near where the box will go - and yank the cable from the clip before cutting the box in.

One solution to all this may be to fit the boxes on noggins before boarding, and possibly use rigid 20mm plastic round conduit, held in place by the timber.

 

[DetlefSchmitz]

To avoid discussing the wrong problem, the wall in question is dot and dab. Now, John, carry on with re-writing the wiring regulations.

 

[Murdochcat]

Now, John, carry on with re-writing the wiring regulations.

the regs need to be given to the plain English society for review and edit