New Extension Sockets, Cables and insulation

[Seanie_230]

Hello All
in 2013 my kitchen extension will be fully underway. for current building regs the outer walls will need to be batterned and plasterboarded or drylined.
how does this work with the electric cables?
i know this is a really simple question but i cannot find the answers.
are the cables build into the insulation / behind the insulation next to the brickwork?
can anyone give me a heads up how they do it all?

 

[DJH]

Hmm, not too sure but I would imagine they would be chased into the wall and capped rather than cut any insulation away from the back of the plasterboard.

 

[Seanie_230]

Sorry what i meant was the walls are currently bare as its the outbuilding.
the regs state that any external walls have to be insulated so i was wondering where and how the electics are done in the situation cables do not overheat.

 

[DJH]

What is the room to be used for Seanie as if it was say a utility room or something along those lines you could use conduits surface mounted or even in conduits behind your plasterboard.

 

[Zebra]

As far as cables overheating under the insulation is concerned, that wouldn't be a problem in this instance. It's a bit more complicated than this but basically if only one side of the cable is in contact with the thermal insulation, then you don't have to recalculate your cable sizes. If you were running cables between two layers of insulation you'd be getting in trouble in terms of overheating.
As to how you fix the cables - if you were fixing battens to the wall, to which the insulation boards would be attached, then there's no need to do anything in particular with the cables, just let them run in the void in between the battens, in exactly the right place and then when you cut the hole for a dryliner backbox in the plasterboard you fish them out. If you have to go behind a batten then chase it out a bit. Obviously normal rules apply about cables having to be run in a straight line to an outlet or accessory, not diagonally or round corners. If you are "dotting and dabbing" - not sure if you can do this with foil backed insulated plasterboard as it's not my area of expertise - then you could just run them directly on the wall and cover them with capping, then you'd have to dot and dab around them, or if you were having only a very thin layer of adhesive so this would affect the boarding, then chase them in flush first in either capping or oval conduit. That's what I'd do anyway.

 

[88v8]

And when you've run the cables take some pics, so that when you want to do some job in the future that involves drilling holes in the wall, you won't drill the cables!

Ivor