John Rumm wrote:
NT wrote:
On Jul 15, 3:20 pm, Rad wrote:
On 15 July, 08:47, Tim S wrote:



OK, stupid time.
Accidently bought 6 sheets of ordinary 9.5mm PB in 3x6' sheets. Need
to use
vapour barrier PB for the ceilings on some bay window ceilings which
will
be insulated with celotex above. I don't even think the use of vapour
barrier PB is that critical as there's a huge void over half the bay
ceiling as the pitched roof meets the lead flat roof of the bay, but
vapour
barrier was suggested.
Any harm in using normal PB together with a vapour barrier or either
plastic
or perhaps even bacofoil (turkey sized) stuck on the back of the board.
Seems a pointless waste to dump the board as I can't use it elsewhere.
Cheers
Tim
Tim
There is a BG wall board "paint on" vapour barrier - ? wall board top
coat or the like
any oil based paint will do
chris

I assume a coat of oil based paint is significantly less effective
than foil though, and less effective than plastic film. May be good
enough though.

You can get paint on DPC products if you want. Used before laying
screeds etc.


Probably not as effective on a porous surface though. IIRC paraffin wax
is the vital ingredient in water resistant PB