The Natural Philosopher wrote:
adder1969 wrote:
On Feb 1, 10:28 am, The Natural Philosopher wrote:

I'm assuming a DPM is the same speak as a vapour barrier? I'm loath to
do this as it would entail lifting ALL the insulation (Pink Panther +
original).....
No need to lift the original.

Just put a seal between it and the other..

The original will stay warm enough not to condense..

If there's condensation already between the old and the new how will
putting an impervious sheet inbetween solve the problem?

Ther isn't. There is condensation IN the new.

Yebbut if it's being caused by moist air entering the loft from the
house (your suggestion) then any new moist air coming up from below will
be stopped by the new vapour barrier and soak the old insulation
instead...

David