Log Cabin - Internal wiring

[Peter Watson]

Further to an earlier post about getting power to a log cabin, now a question about the internal wiring...

The cabin I'll be building is constructed of 45mm internal and external walls with a 70mm cavity. The cavity will have foil backed insulation board inserted.

Not being a fan of surface wiring I'd like to recess the sockets, probably by cutting a suitable hall in the inner wall and fixing a dry lining box with a couple of screws through the sides (as the wood is too thick for the normal clamp arrangement).

Question - Is it OK to just fit T&E in the cavity before fitting the insulation? Is there a potential issue with the non-bonded foil backed insulation in this scenario? I'll have the choice of where to fit the garage style CU so the wiring could run round the top and down or round the base of the wall and up - The latter would mean the cable is less likely to be accidentally damaged by a future owner, though there will need to be a vertical run for the light switch of course!

A similar cabin is shown going up here:

the wiring is show around 1:25 in...

TIA

Peter

[Tabby]

I'd use ordinary backboxes, not dry liners

NT

[John Rumm]

You don't want the cables buried in insulation if possible - they are better off in contact with one of the inner surfaces of the timber. This could mean surface wiring the inside of the outer leaf for example, or fixing the wiring on top of the inner surface of the insulation prior to fitting the inner skin.

This assumes the insulation is PIR foam boards or similar and not something that will react with the PVC such as polystyrene.

You could run round at socket height without going up or down - depends a little on the nature of use and where you want your sockets.

[Peter Watson]

Any particular reason?

Thanks,

Peter

[Peter Watson]

I'm hoping to clip to the cavity side of the inner leaf - My concern was whether I need any extra mechanical protection for the cable...

The boards are PIR I believe - Quest Therm?

Most sockets at low level but probably a couple at around 800-900mm to be above a desk plus a light switch so most wiring can be at low level.

[Tabby]

one is fully suitable, one isnt. I cant imagine why you'd use drylines.

NT

[John Rumm]

As long as you have 30mA trip RCD protection for the cables then no.

[ARWadsworth]

It would better job.