where to route cable

[mattysupra]

What depth do cables (240v) need to be at when under a concrete floor? And what are the zones? Like can they run across a door way where a door strip for carpet will be screwed down? Or close to the edge where gripper is pinned down?

And also are you allowed to run cable behind the door archichive where wood flooring installers cut the bottom out?

 

[Spark123]

They need to be deep enough to avoid them being damaged, will also need to be either in an earthed metal conduit or be SWA or similar.
You shouldn't install a cable behind an architrave as is isn't in a safe zone.

 

[mattysupra]

cheers for the reply, do you know what depth they should be at? And the proper safe zones for under concrete?

 

[mattysupra]

i take it there are no safe zones? Does anyone know ?

 

[RF Lighting]

There are no defined safe zones for cables enclosed in a concrete floor.

 

[mattysupra]

how about depth? How come there are no safe zones? Seems strange for how many cables get damaged by floor layers! I myself have hit a few and i must get a couple of phone calls a week of fitters who are asking my advice on where the cables should be when they hit them!

I guess it must be left down to common sense of the sparky installing not to run them where gripper and door strips are put down?

O and are you allowed to run cables behind skirting boards where fitters will be nailing beading on?

 

[RF Lighting]

Normally I would expect a minimum of 50mm deep, and an earthed metallic outer such as those mentioned by spark123.

I don't know of many cables buried in the floor which get damaged.

The favorite one for damage is alarm cables sat on top of the floor just tucked under the carpet.

It is not acceptable to run cables behind skirting boards as this is not a perscribed safe zone.

 

[mattysupra]

cheers RF, we get loads in conservatories running in front of doors. You might not get much problems repairing cables in floors as i think you will find most floor layers will repair the cable them selfs and reset the trip or fix blown fuse. Of course this is not the correct thing to do but most fitters get the blame for it and will repair rather than pay a bill for hitting a cable 20 mm under the surface or in a daft place like a doorway. Proberly floor layers that fit some of them junction boxes under the floor boards of your 'pic of the week' ! Which they should not be damaging these as all nails used should not be long enough to pass all the way through the board, and if screwing down a floorboard then its easy to check first!

As for alarm cables, you tend to blow a fuse or something in the alarm panel which is a bit out the legue for fixing for most floor layers! Plus the owner of the house tends to know they have cut through them when the alarm is ringing and your asking for the alarm code! But then again, you know yourself that these cables should NOT be running under carpet but under the floor boards.