ZeitGeist wrote:
On Wed, 07 Jan 2009 20:29:29 +0000, The Natural Philosopher
wrote:

The void should be ventilated to teh outside world. it is advisable to
put a vapour barrier between the joists and the flooring above the
insulation.

Do you mean that the vapour barrier should run underneath the floor
over the joists and insulation? i.e. directly beneath the
floorboards?

yes.

What I would do is to lift the floor, nail battens to the joists to
support the insulation, at the right height to bring the celotex panels
flush with the joist tops, and then tape over the joists and panels with
celortex foil tape.

And lay the barrier over that before putting the floorboards back
down?

yes.

I should have mentioned I can access the void and could work from
below without lifting the floorboards.

Ah. In which case take a chance, and simply slap the insulation up and
between with a dab of no more nails?

And use some mastic to _utterly_ seal any gaps. Its not as good as
overall vapour barrier, but should be good enough.



TIA