DIY loft insulation

loulou41

When doing diy loft insulation do you put electrtic cables under or over insualtion, I was told it does not matter but am still concerned. Also what are the tell tales of condensation in the loft, do I need to go in the loft periodicaly in winter and check? Thanks

googler

Our electrics go under, around and on top of the insulation in various places - the house is around 15 years old, so it's been that way since new.

penrhyn

The advise is to lay electrical cables over the insulation. The idea is that this keeps them cool and avoids a build up of heat that may cause a problem.

However in most circumstances this is impractical due to not having any slack in the cables to achieve this.

Especially when you have laid 100mm between the rafters with the top up layer of 170 laid at right angles over the top.

I'd like to know myself if there really is any hazard.

egyptiangirl

I too have the same question so won't start a new thread. Anyone know?! Thanks

Piggo_2

Ours are all laid over the insulation although this has been awkward when we've tried adding more insulation in.

muckybutt

Ideally cables should be laid over the top of any fibre / wool insulation.

However DO NOT place cables anywhere near polystyrene insulation.

27col

An ideal arrangement would be to have the cables above the insulation. However, this is often not practical due to the tightness of the clipped cables. It is normal for the cables in the loft to be feeding only a few lights, and nowadays these are likely also to be low wattage. Therefore, generally, the cables do not get hot from the electrical loading and the fact that they are not in free air is not going to be a problem. If you have a heavily loaded shower cable in the loft then that is a different matter and precautions should be taken to keep the cable from being covered by thick layers of insulation.