plastic or metal cable sheathing?

[ban-all-sheds]

Everyone is entitled to my opinion.

 

[Robgers]

Everyone is entitled to my opinion.

A classic

 

[sparkwright]

Ignore the conduit, if you look closely to the bottom left you will see the remains of some old metal capping, or sheathing as three people like to call it.

No requirement to use capping or similar protection but possibly considered better practice.

Metal or plastic, capping or oval/round conduit.

 

[xr4x4]

Ignored

Awesome.... So I can blot him out aswell...!

 

[1john]

I cannot see the need for capping, especially metal, I would imagine it is quite possible to nail through the capping and through the line or neutral of a flat T&E without so much as catching the CPC, quite likely leaving a live sheet of steel in the wall. If any, I would use plastic if there are concerns of cable damage by a plasterer, although why on earth they would want to damage a tool which takes for ever to wear in to be "just right" is beyond me. Steel conduit is very effective and can be reliably earthed at the accerrory boxes unlike capping and also satisfies the requirements of the regs and provides a higher level of protection against penetration, although i suspect a drill would go straight through it without the operative being any wiser until its too late. Drawbacks are that is is very heavy, time consuming and labor intersive to install with specialist tools required, therefore IMO pvc conduit is the best bet wether it be oval or round, obviously the round conduit is better suited to deeper boxes which will more than likely need rebating into the substrate to allow for coverage of render . backing plaster and finish plaster.

 

[Adam_151]

Steel conduit is very effective and can be reliably earthed at the accerrory boxes unlike capping and also satisfies the requirements of the regs and provides a higher level of protection against penetration, although i suspect a drill would go straight through it without the operative being any wiser until its too late..

You won't put a masonary bit through metallic conduit without knowing about it, it'll make a horrible noise and start to shake the plaster off the wall first...

 

[1john]

even an SDS in a cement rendered wall which has been setting for the past 25 years??

 

[ban-all-sheds]

i suspect a drill would go straight through it without the operative being any wiser until its too late.

I suspect not.

Unless you're using a really powerful SDS drill, I think that a masonry bit will slow down and start to make a different sort of noise when it hits steel conduit. Plus, as it's probably surrounded by plaster it's going to slide off to one side unless you hit it bang in the centre and at a perfect 90°.

Drawbacks are that is is very heavy, time consuming and labor intersive to install with specialist tools required,

Satisfying though.

therefore IMO pvc conduit is the best bet wether it be oval or round, obviously the round conduit is better suited to deeper boxes

Why "obviously"?

 

[1john]

Because with a 25mm deep box the gland sits flush with the front of the box and the saddles keep it in line with the box meaning little skim over top and likelyhood of cracking. Agreed, pulling, setting and threading conduit is satisfying work it does take up alot of time.

 

[ban-all-sheds]

Ah - I see.

I was trying to make sense of it the other way around, i.e. I thought you were saying that if you had a deep box round conduit was better than oval for it.

BTW - these MK Masterseal conduit adapters are great for taking oval conduit into a box.