Cable position with rigid insulation boards- help?

[SHONCRR]

Hi,

I am involved with wiring a conversion. The building is a old stone barn. A timber frame has been built internally. Rigid Kingspan foiled backed insulation will be fitted inside the timber frame wall sections and overlaid with additional rigid insulation and plasterboard. It is been suggested that I run cabling between the stone wall and the insulation. I am concerned that damp may come through the wall and follow through my cables. Has anyone been involved in a similar project? If so any advice would be appreciated. Thanks

 

[telectrix]

firstly, is the stonework damp? secondly, make sure the cables are rated according to the installation method used as regards insulation.

 

[SHONCRR]

Hi,

Thanks for your reply. The stonework does not appear damp. It is a very old and very thick wall- made up of whinstone and sandstone. The cables are rated enough for the insulation as it is not a big load in the property- just small lounge/kitchen and 2 ensuite bed.

 

[truckster]

Keep the cables clear of the polystyrene as it can cause the pvc to become brittle as the plasticiser migrates

 

[telectrix]

might be an idea to use oval tube fixed to the stonework. protects cable from any chemical attack and makes rewiring possible.

 

[lj.l]

I done one recently and they formed a void between the rigid insulation and the plasterboard using 1" lath 35mm boxes fitted well and cabels were in free air.