Cables buried in concrete floor

[DJM]

It's looking likely that the most practical route that I will have to take for the ring is across a concrete floor. There is a relatively short section which is where I would take it and run parallel to the walls. It will need to take 2 off 2.5 T+E cables, and wouild be concreted over then tiled, so no real access afterward, so can you tell me

1) Is there a minimum depth I need to burry the cables,
2) do I need to use steel conduit, or can I just use capping.
3) do I need to cover with protective markings
4) any reason not to do this

thanks

 

[plugwash]

You should really use steel conduit, there is likely to be little if any indication of where the cables are and anything capable of breaking up solid floor will go straight through

I also reccomend using singles rather than T&E, making sure the conduit has plenty of free space and keeping bends to a minimum. If any cable damage does happen you will need to be able to pull in replacements.

 

[DJM]

Thanks for the reply.

This will form part of a ring, and the distance travelled is not much wider than a door under concrete (less than 2m).

I had been considering using http://www.tlc-direct.co.uk/Products/CO25slash3.html

There will be no bends in the run so if cable replacement necessary should be fairly straightforward, but I guess I could use 2 separate conduits, one for each T+E in the ring to make it eaisier still.

What depth should I bury them?

 

[Adam_151]

There will be no bends in the run

Whats going to happen at the ends then?

 

[DJM]

house is a mixture of suspended wood floors and solid concrete. All bends will be under the supsended parts and so easily accessable.

Damaged cables could probably be pulled through from there if I had to.

 

[DJM]

Just to add, Other routes are just as complicated and would add at least 20m to ring.

I was going to put it 50mm into floor is that enough?

 

[BS3036]

Not trying to hijack the thread - it may be relevant. I want to do something similar, though floor hasn't yet been screeded. Wouldn't the steel conduit need to be earthed? I can't see how to do this in an easy way.