Steel capping

[JohnW2]

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

Indeed so.

Kind Regards, John

 

[ban-all-sheds]

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

Capping does not count as internal metallic construction - that regulation refers to this sort of WOTD:

How could capping transfer a fault to another location?

 

[JohnW2]

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?

Perhaps because of the existence of the aforementioned 'idiots' and other people who haven't even heard of electrical safe zones? It's all very well to suggest that they shouldn't exist - but they do!

Kind Regards, John

 

[flameport]

How expensive is it in comparison with SWA?

50% more, based on
armoured cable 3 core: http://www.screwfix.com/p/p/66142
earthshield 3 core: http://www.screwfix.com/p/p/21793

Compared to T&E, 3-4x as much, adding £100s to a typical rewire for no reason at all.

 

[JohnW2]

How expensive is it in comparison with SWA?

50% more, based on .... Compared to T&E, 3-4x as much, adding £100s to a typical rewire for no reason at all.

Indeed. Thanks. I must confess that I hadn't noticed that Screwfix sold it - maybe I hadn't been looking in the right places!

Kind Regards, John

 

[ban-all-sheds]

ebay bargain

 

[PBC_1966]

"Safe zones" obviously achieve nothing if those 'non-electrical' tradesmen and DIYers don't know about and/or think about those safe zones!

Even if everyone who has worked on the house wiring has scrupulously followed the zone rules since they were introduced, if the house is more than a few years old there's a good chance there are cables outside of those zones anyway, put there long before the whole prescribed-zones concept was introduced.

 

[JohnW2]

Even if everyone who has worked on the house wiring has scrupulously followed the zone rules since they were introduced, if the house is more than a few years old there's a good chance there are cables outside of those zones anyway, put there long before the whole prescribed-zones concept was introduced.

That's true. Under any circumstances, one can only conclude that hidden cables are less likely within 'safe zones' than outside them - since, even if the wiring were done after the concept of 'safe zones' came into being, it would clearly be foolish to assume that this 'guaranteed' that there could not be any cables within those zones.

Kind Regards, John

 

[ericmark]

Capping does not count as internal metallic construction - that regulation refers to this sort of WOTD:

How could capping transfer a fault to another location?

It may be the person writing the regulation was thinking about what is in your picture, however since it states "other than metallic fixings such as nails, screws and the like." it seems to indicate any item over that size is included. Capping is around 2" wide, but the line wire is less than 0.1" wide so if the line wire is hit then it makes any other penetration far more likely to hit a live bit of metal.

 

[theprinceofdarkness]

Working on an old cottage, when knocking of the plaster in one room, came across buried capping with a masonary pin through the centre of it. When it was removed, it had sheared the earth conductor (2.5mm T&E) and shorted to the live. So I still have the cable sample with a nail hole in it and smoke marks. .
Frank

 

[ban-all-sheds]

It may be the person writing the regulation was thinking about what is in your picture, however since it states "other than metallic fixings such as nails, screws and the like." it seems to indicate any item over that size is included.

I think the key word is "construction". i.e. what is the wall constructed of, built using etc.

Capping is not part of the construction of the wall.

 

[Iggifer]

How expensive is it in comparison with SWA?

50% more, based on
armoured cable 3 core: http://www.screwfix.com/p/p/66142
earthshield 3 core: http://www.screwfix.com/p/p/21793

Compared to T&E, 3-4x as much, adding £100s to a typical rewire for no reason at all.

But...the colours are wrong, and you MUST not oversleeve

 

[Taylortwocities]

Working on an old cottage, when knocking of the plaster in one room, came across buried capping with a masonary pin through the centre of it. When it was removed, it had sheared the earth conductor (2.5mm T&E) and shorted to the live. So I still have the cable sample with a nail hole in it and smoke marks. .

Almost the same thing here. This was a screw holding a kitchen cabinet that had been there for quite a few years. Lighting circuit was still working.