"George" wrote in message
...
some wrote:
It is best to lay a vapour barrier on the loft floor above the
plasterboard.
This is poly sheet. This will prevent water vapour entering and
condensing
in the loft. Also seal up any pipe and wire holes in the loft.


but shouldnt the vapuor barrier be at the warm side,
which is underneath the insulation?

Yep.

and why are you insulating the floor
if the loft is to be used for computering,
shouldnt the insulation go above the room?

Yep. Insulate the roof. Have Rockwool insulation in the floor to reduce
sound.