Capping

[New2Game]

Should capping always be put over cables before they are plastered over?
If using galv capping does it have to be earthed?

 

[breezer]

yes

no

 

[New2Game]

Why does galv not have to be earthed?

 

[breezer]

1) how would you?

2) because its electricaly isolated

 

[New2Game]

So if you always have to use capping, is that because the plaster can damage the insulation?
Is that why you dont need it if its boarded over with plasterboard?

 

[breezer]

not quite, its also (so i believe) so the plaster or simlar doesnt "eat" the cable

It also gives mechanical protection to the cable, but it doesn't stop a drill bit in a drill though

 

[New2Game]

So am i right in saying if its boarded over with plaster board it dosnt need capping?

 

[TopTrumper]

if its getting dot and dabbed you dont need cable protection.
Unless its the polish lads who work for same builder as me, in that case everything needs protecting, including your backboxes.

 

[RF Lighting]

For the cost of it, it is daft not to use capping, or even better, oval conduit.

It will make it far easier for repair or replacement in the future.

 

[securespark]

Cables buried directly in plaster, render and the like are not contravening regulation. Capping affords very little mechanical protection, that is not its purpose.

Its job is purely to protect the cable from the plasterer's tools.

Plus, it may be useful come the time to rewire.

 

[jj4091]

Plus, it may be useful come the time to rewire.

Thats a very big "may" Securespark

 

[securespark]

All I know is that, where it has been used in older houses for switch (and sometimes socket) drops, the capping can (99/100) be used along with the old cable to run a new one in.

 

[JohnD]

IMO the oval conduit is better for running replacement cables down, but if you're using T&E it is very tight so only useful for a straight run, where you can get at both bottom and top. Switch drops, for example, or some under-counter outlets in a kitchen after some numbskull has put a drill through them. Poking singles down is easier.


A. Numbskull

 

[joe-90]

I see it as an interesting point that under dot and dab plasterboard no cable protection is required.

The ammendment to the regs stating that cables must now be buried 50mm in the wall would be (I assume) to stop them being damaged by the ubiquitous inch-and-a-half-eight screws.

However, if you had a wall with a cable in a bit of plastic capping running down it and you covered it in plasterboard, then that wouldn't give any protection for any screw from 3/4 inch up.

Simply sticking a screwdriver into the plasterboard and through the capping into the cable would take virtually no effort.

Surely this fouls the rule that cables should be given 'physical protection'.

What do the Pro's think?

Personally I would use metal capping - but is that the rule? Or just common sense?

 

[JohnD]

Remember that when cables are run vertically (or horizontally) e.g. from a socket or a light switch, people are expected to use their eyes to observe the presence of an accessory, and deduce the presence of a cable, and to avoid drilling where it can be expected.

In this case, earthed protection or deep burying is not required.

Metal capping provides negligible protection from screws and drills.