Embedding cables out of CU

[vargen]

Capping doesn't provide sufficient mechanical protection for you to run cables outside the zones and less than 50mm deep anyway...

If mechanical protection is required (burying outside the zones) and galvanised steel conduit is used, does it need to be earthed, or is that only for a full run of conduit from box to box?

I ask because I want to mount light switches and a thermostat in the end of a brick wall (as distinct from the faces of the wall) in my hallway, which doesn't form part of a corner (it's just the continuation of a wall in my living room past the l/r door). I was planning to use capping for the runs of cable within the zones and then go into conduit for the remainder of the runs which are outside the zones into the back boxes.

 

[Taylortwocities]

If you use steel conduit as the means of protecting cables (eg outside zone/ less than 50mm deep) then the steel conduit must be earthed.

 

[ban-all-sheds]

I was planning to use capping for the runs of cable within the zones

Why do you want to use capping?

and then go into conduit for the remainder of the runs which are outside the zones into the back boxes.

Are you not able to run the cables vertically or horizontally to the accessories?

 

[vargen]

There's a reinforced concrete joist supported by the end wall, which I think it might be inadvisable to cut into. Running outside the zones in conduit just seemed a safer alternative. This is also the shortest route to run the tails from underfloor heating to the stat, which would otherwise need a joint and extension (unless I drill through the joist).

I'm very tempted to think it's safe enough to shallow chase the joist for the lighting circuit and go vertically down the wall to the switches (through the stat box) and back up to the lamps, but since I was going to use conduit for the heating I thought I may as well do the lighting the same way.

I have no experience of using steel conduit and would much prefer to avoid it!

 

[vargen]

Forgot this part:-

I was planning to use capping for the runs of cable within the zones

Why do you want to use capping?

The brickwork is to be rendered or hardwalled, so I need to protect the cables, I assume.

 

[ban-all-sheds]

Probably not a bad idea - depends how gung-ho your plasterer is with his trowel edge...

PVC conduit instead of capping would make any future changes easier.

 

[vargen]

If PVC won't degenerate under sand/cement render or hardwall, I'll use that instead.

Thanks for your help. Much appreciated.

 

[Taylortwocities]

Its fine under cement/plaster.

Just so long as the cables are in the safe zones, per the above.