On 18 Jun 2004 15:42:44 +0100, a particular chimpanzee named John
Richer randomly hit the keyboard and produced:

I have a loft that I want to insulate better, but also use as storage
space - so I don't want to lay deep insulation roll loosely on top.

The best insulation is currently Celotex (Kingspan is equivalent).
It's almost twice as effective as mineral wool. 100mm of mineral wool
isn't particularly effective, and you should be looking for at least
200mm thick, or 100mm Celotex between the joists.

When you start getting to these thicknesses of insulation, the heat
loss through the joists starts to become significant and you get
better 'value for money' out of your insulation if you can cover your
joists.
--
Hugo Nebula
"The fact that no-one wants a piece of this
shows just how far you've strayed from the pack"