On Sep 16, 3:31*pm, geraldthehamster wrote:
That's probably true. Having said that, in an ideal world one would
have a vapour barrier underneath the insulation, to stop warm moist
air rising into the loft space from the house.

Often wondered, would Dulux Plaster Seal (interior) do sufficiently -
either on top of the ceiling or underneath where it is bare? There are
various other sealing products available, which can then be painted.