Insulation between ground and first floor. What would be the most cost effective option

[JohnD]

the heating or overheating of cables surely points to an electrical problem or the unsuitability of said cable. every loft in the country has cables buried under insulation .or buried in chased walls. ?

No, it doesn't work like that.

 

[JohnD]

The way my house had cable buried into the walls was to find out the electrician and jail him for 50 years at minimum.

No, it doesn't work like that.

 

[IT Minion]

No, it doesn't work like that.

To expand on that, cables are designed, and the ratings given for them, for chasing into walls.

That traps some heat in the wires but it's designed for. They aren't designed to be surrounded by insulation which is much much more effective at keeping the heat in.

 

[endecotp]

every loft in the country has cables buried under insulation

Most of the wires in a typical loft are for ceiling lights, which don’t take much power so overheating is unlikely to be a problem.

If you’re installing insulation you need to look out for cooker, shower and socket wires.