Sockets in thick PIR backed plasterboard

[DJCW]

I'm drylining a solid brick wall with 25mm batons and 62.5mm Kingspan K118 plasterboard, and I need to bring the sockets forward from the wall to the plasterboard.

The set up needs to meet Welsh BC standards, which it does with these specs, but I need to work out whether I can just put plastic socket boxes into the plasterboard and move the sockets forward myself, or whether I need an electrician to do it. I've read mixed things online about how to do this, where the wires should run, etc.

Is it ok to have the wire coming up from below through a channel in the insulation where it meets the plasterboard, and embed the socket boxes from the front? This avoids making holes through the back of the PIR an messing with the vapour barrier. Or should the wires pass through the void behind and then to the back of the boxes through a hole?

Couple of photos attached for info

Thanks!
Dave

 

[ericmark]

The problem is not what the regs say, but what your LABC inspectors says. There are in appendix 3 a list of different methods, for example I do not see a problem either method, the standard ring final needs the cable to be able to take 20 amp, so this chart lays out current carrying capacity, so 2.5 mm methods 100 or 102 would be OK, but not method 101 or 103.

 

[Murdochcat]

In this case you are fortunate that you can see the cable coming up from below. I suspect to allow the sockets to come "forward" they will need to be lowered slightly to avoid needing to lengthen the cables from the floor

As for the BCO I would say ask them for their advice before you do anything

 

[martygturner]

If you have space in the CU you could just break the ring and have two 20amp radials fed from two mcb/rcbo, conduit was used in the insulation as per reference 7.

Its the option that was taken on a extension we had done on a welsh property that was formed out of insulated form work, it was more of a faf to get the insulation up to standard so that it could have roof lights and a bifold than it was to just break the ring.

 

[DJCW]

Thanks everyone - v helpful. I'll ask the BCO.