Wiring Concerns

[tflda29]

Hello all,

I recently had problems with an overheating shower switch where the cable had started to melt....thanks to all who replied.

Whilst waiting for Wimpey electrician (new house) to come round i had a look in the loft to see if the cable had melted right back or not......I noticed that all the wiring in the loft is under about a foot of insulation!!!!

I thought this was not meant to be like that and that cables were meant to be clipped away from and not covered in the insulation....

Anyone have any ideas on this.... House was built a year ago and is in Scotland....not sure if there are different laws or not and when they came out.

Thanks
Trevor

 

[davy_owen_88]

Every effort should be made to prevent cables being covered with insulation, but it is often the case that insulation is put in last and the installers don't understand the dangers involved when they insulate the cables.

Cables that must be covered in insulation have far lower current carrying capacities (as low as 50%) so for a given load the cables needed are far bigger. If you can pull the cables out of the insulation and clip them somewhere where they can not become covered in the future then do so, if not the cable will need to be replaced with something more substantial.

 

[tflda29]

thanks for prompt reply.

Do you think this is something that should have been done in a new house, i know the insulation goes in last but should there not be a final check to make sure everything is ok?

Just concerned as we have had a wiring problem already in a fairly new house and if things are not the way they should be i would want the builder to sort it.

thanks
Trevor

 

[JohnD]

It should not be done but often is.

Have a look at the cables.

Lighting cables are so lightly loaded that it is not generally a problem.

However, the cable for an Immersion Heater or an Electric Shower is loaded nearer its capacity and can get hot which shortens its life. If you have any of these under insulation, have a look at how they are run. Ideally they should be clipped to timbers and not surrounded by insulation. However, if they are clipped to the timber and either in contact with the plaster on the bottom, or exposed to the air at the top, they can still lose heat. We have a report somewhere on various positioning of cables and insulation.

With luck you will have enough slack to take out the clips and re-staple the cables outside the insulation.

 

[DESL]

With luck you will have enough slack to take out the clips and re-staple the cables outside the insulation.

Shouldn't have to do that on a new house the bl**dy designer of the installation should have got his sums right in the first place. Assuming shower was fitted by house builder.

 

[JohnD]

should

Couldn't agree more