Insulation + Cables

[number49]

The loft desperately needs insulating.

I know the short answer is that cables should be on top of the insulation;

but

most of the cables don't have enough slack to get the insulation beneath them.

If any, what are the alternatives? Modding cables is not really an option at the moment.

 

[stem]

Cables may need de-rating according to their method of installation.

Here's an on line calculator.
http://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html

Most of the cables in lofts are usually for lighting and may likely still be OK. Power circuits or showers may be OK or may not. Run the information you have through the calculator and then you will have a better idea if you have a problem or not.