can I run cables horizontally 2-3 inches below the ceiling

[baxtec1]

can I run cables horizontally 2-3 inches below the ceiling in kitchen and then vertically to sockets etc or do they have to go horizontally above the ceiling through the joists?

 

[PrenticeBoyofDerry]

It sounds like you can, are talking surface mounted or buried cables.
There are permitted safe zones for buried cable and that cable does have to conform to the requirements of RCD protection, as do any newly installed socket outlets.

//www.diynot.com/wiki/Electrics:walls

 

[baxtec1]

The cables will be buried and at the fuse box I'm pretty certain they are on a RCD circuit. I was thinking of covering the cables in the wall in some plastic cover which they are currently covered by, is this ok?

 

[PrenticeBoyofDerry]

The plastic or metal capping can be fitted, but it is not a requirement or considered as mechanical protection. It mainly holds the cable in place and protects from any potential trowel damage caused when plastering/filling over.

Alternatively you can chase in deep enough so trowel will not damage and cable clip.

There are also regulations on chase depths, you can not exceed 1/6th of the thickness of the leaf/skin of wall on horizontal chases and 1/3rd on the vertical chase. (note: this is the single skin only, so do not calculate the total of any double skin cavity walls)

Link to building regs on chase depth
http://www.waveney.gov.uk/site/scripts/documents_info.php?documentID=258&categoryID=811&pageNumber=5

 

[PrenticeBoyofDerry]

You must confirm that RCD protection is present and I would personally want assurances that the RCD is functioning correct (this will require special test equipment and a competent person testing and understanding results).

One way to confirm the RCD is on the circuit to be altered/extended, would be to press the test button on the RCD,RCCB,RCBO, then check that the circuit to be worked on has power loss.