Steel capping

[Yukster]

I've seen an old thread about electric cable steel caping. I also had a quick look around the tinternet and I can find galvanised steel or PVC capping which people suggest in the old thread. I'm thinking it'll be safer to use a something stronger that a masonary drill can't penetrate at least not easily. Any suggestions?

 

[EFLImpudence]

I'm thinking it'll be safer to use a stronger cappinf that a masonary drill can't penetrate.

There is no such thing. That is not its purpose.

Capping merely holds the cable in place and protects it while plastering.
Plastic will do.

 

[Yukster]

I'm thinking it'll be safer to use a stronger cappinf that a masonary drill can't penetrate.

There is no such thing. That is not its purpose.

Capping merely holds the cable in place and protects it while plastering.
Plastic will do.

Gotaya. Is there another way of protecting electric cables (chased into the brickwork and plastered) from mechanical damage, e.g. drilling?

 

[Risteard]

I'm thinking it'll be safer to use a stronger cappinf that a masonary drill can't penetrate.

There is no such thing. That is not its purpose.

Capping merely holds the cable in place and protects it while plastering.
Plastic will do.

Gotaya. Is there another way of protecting electric cables (chased into the brickwork and plastered) from mechanical damage, e.g. drilling?

Earthed metallic conduit - although steel conduit again will not prevent it being drilled through, but the fact that it is earthed will mitigate the danger of this.

 

[JohnW2]

Gotaya. Is there another way of protecting electric cables (chased into the brickwork and plastered) from mechanical damage, e.g. drilling?

Earthed metallic conduit - although steel conduit again will not prevent it being drilled through, but the fact that it is earthed will mitigate the danger of this.

Particularly if one uses a traditional masonry drill bit (rather than a 'combination' bit), steel conduit usually will prevent cables being damaged, since it will usually become immediately obvious when the drill bit hits metal, before any appreciable damage is done - and only an idiot will then continue trying to drill!

... but, of course, there are a good few idiots around

Kind Regards, John

 

[Risteard]

Particularly if one uses a traditional masonry drill bit (rather than a 'combination' bit), steel conduit usually will prevent cables being damaged, since it will usually become immediately obvious when the drill bit hits metal, before any appreciable damage is done - and only an idiot will then continue trying to drill!

I worked with one in a school canteen which was being rewired. However he managed to do just that (drill through a buried steel conduit below a double socket-outlet and continue drilling) which was going into a floorbox which then had to be rewired. That existing underfloor conduit was really tight too even with Yellow 77.

 

[Taylortwocities]

Is there another way of protecting electric cables (chased into the brickwork and plastered) from mechanical damage, e.g. drilling?

It should not be necessary if you install the cables in the recognised "safe zones"
//www.diynot.com/wiki/Electrics:walls
Mind you, idiots do not know about these, either!

 

[ericmark]

The statement in the regulations

a cable concealed in a wall or partition the internal construction of which includes metallic part, other than metallic fixings such as nails, screws and the like.

means that using metal in the wall opens up further problems, in that metal can transfer the fault to another location. So if capping is metal really it should be earthed, but capping was never designed to be earthed making it hard to ensure earthing is good enough or testing latter to see if the earth is still present you would need a non plastered over section left bare for testing.

Conduit or Ali-tube cable can be tested at their ends but capping is in the main not fitted in a way allowing testing. The capping is to protect the cables while the plaster is doing his work. Once plastered it has no more use. Using plastic makes it hard for the plasterer as it flexes the oval plastic conduit flexes less so is better. The metal conduit does however dissipate heat and it seems is used to cover other services in the wall, as a result it is still made. I have questioned using metal covering over plastic central heating pipes as it does mean the wall contains metal, however it is very unlikely to become a conductor transferring a fault to a new location.

Had the wall not contained metal in the Emma Shaw case then likely the outcome would have been very different.

I really can't see how we can use metal capping with twin and earth any more and with Ali-tube we don't need it anyway.

 

[JohnW2]

It should not be necessary if you install the cables in the recognised "safe zones" ... Mind you, idiots do not know about these, either!

That, of course, is the problem. Those undertaking electrical work may (should) know about and respect the "safe zones" but they are very often not the people who subsequently do the drilling. "Safe zones" obviously achieve nothing if those 'non-electrical' tradesmen and DIYers don't know about and/or think about those safe zones! I wonder to what extent there is teaching about (or even mention of) electrical safe zones in relation to non-electrical trades and DIY?

Kind Regards, John

 

[JohnW2]

I really can't see how we can use metal capping with twin and earth any more and with Ali-tube we don't need it anyway.

You write about it often, but I wonder how often (if at all) you, or others here, have actually seen ali-tube cable used in a domestic environment.

Kind Regards, John

 

[ericmark]

I really can't see how we can use metal capping with twin and earth any more and with Ali-tube we don't need it anyway.

You write about it often, but I wonder how often (if at all) you, or others here, have actually seen ali-tube cable used in a domestic environment.

Kind Regards, John

I would agree it is too expensive and where I have seen it used it has been exposed anyway. Be it Ali-tube or SWA all I am saying there are methods which do allow hidden cables without RCD protection, but in real terms as you say they are not used. Only Ali-tube cable I have used oddly was not to BS 8436 anyway. Personally I was surprised that braided cable was not in the permitted list.

 

[JohnW2]

I would agree it is too expensive and where I have seen it used it has been exposed anyway. Be it Ali-tube or SWA all I am saying there are methods which do allow hidden cables without RCD protection, but in real terms as you say they are not used. Only Ali-tube cable I have used oddly was not to BS 8436 anyway. Personally I was surprised that braided cable was not in the permitted list.

Admittedly my experience is very limited, but I have never knowingly seen or handled ali-tube cable, and I don't think I've ever seen it listed by the major electrical wholesalers, anyway, so I presumably would have to 'ask' if I ever wanted any. How expensive is it in comparison with SWA?

Kind Regards, John

 

[ban-all-sheds]

Enough to make being seated when comparing the price a wise precaution.

.

 

[ban-all-sheds]

Particularly if one uses a traditional masonry drill bit (rather than a 'combination' bit), steel conduit usually will prevent cables being damaged, since it will usually become immediately obvious when the drill bit hits metal, before any appreciable damage is done

And hitting the conduit off-centre (good odds) is likely to deflect the bit anyway.

 

[ban-all-sheds]

Is there another way of protecting electric cables (chased into the brickwork and plastered) from mechanical damage, e.g. drilling?

Fundamental Q - why do you want to or feel you need to?