Hugo Nebula abuse@localhost wrote:
On Fri, 15 Dec 2006 15:37:34 GMT, a particular chimpanzee named
"Simon" randomly hit the keyboard and produced:

What is the easiest way to improve loft insulation, where the loft has been
converted to a room.

Is there a simpler way than removing the plasterboard, inserting rockwool
insulation, and reboarding?

Aside from the fact that you shouldn't remove the plasterboard, insert
Rockwool and reboard. You need to maintain a ventilation space above
the insulation of 50mm; Rockwool between the rafters is a relatively
poor insulator; and most illegally converted lofts will have had the
plasterboard fixed directly under the 3" or 4" rafters, meaning that
you probably only have enough space for 25mm-50mm insulation between.

The best way to improve the insulation is to take off all the
plasterboard from the walls, take up the floor, remove any stairs, fit
a loft hatch, and then put about 300mm Rockwool between the ceiling
joists. This will also have the advantage of removing a death trap.

With a suitable escape window, and fire alarms, I don't really see an
issue.

If it was me, I'd be looking at 25mm airgap, 50-75mm fiberglass against
the rafters, and lots of ventilation at the ridge and bottom - 10mm gap
or so.
Then 25mm kingspan under that, properly taped up to make a vapour
barrier.

If I was being cheap, 100-120mm of fiberglass, with slices of 50mm kingspan
along the joists, to extend them out, reduce their heat leaks, and
provide extra space for cheap fiberglass, then plasterboard,
again with a proper vapour barrier.