"Mike" wrote in message
...

I Googled for info on sealing draughts in non-tongue_and_groove and
mostly
found the usual papier mache and solid wood fillets solutions.

I'm wondering if breathable roofing membrane directly under the boards
might
be a better solution

Yes, but to a diffrent problem. The papier mache and solid wood
fillets solutions provide some insulation but primarily are there to
stop things falling down the gap

Anna
~~ Anna Kettle, Suffolk, England
|""""| ~ Lime plaster repairs
/ ^^ \ // Freehand modelling in lime: overmantels, pargeting etc
|____| www.kettlenet.co.uk 01359 230642