Running cables in stud wall insulation

[regsmyth]

I am insulating the external walls of the bungalow, fitting double thickness 45mm celotex into the studwork.
There are a couple of sockets on the wall.
The combined thickness gives about 85mm, the studs are 95mm.
The cables come from the loft, through the top of the stud wall and down to the sockets.

Is it ok to run the cables down the inside face of the inner sheet of celotex, ie immediately behind the plasterboard? (Where they will be vulnerable to indiscriminate picture hangers).

Or is it better to notch out a vertical channel and position the cable between the sheets?

Any advice welcome thanks.

 

[chivers67]

It's ok to do that as long as it's in a safe zone, if you are concerned you could always put some capping over it to give it a degree of mechanical protection.

How big if any is the gap between the celotex and plasterboard?

just another point has the circuit got RCD protection at all just in case someone didn't realise it was there without using a pipe/cable tester ?