I am laying wet underfloor heating in a mill conversion. Upstairs the pipes
are laid on 30mm celotex between the joists. There is then an infill of
dry(damp)mix around the pipes up to the top of the joists. 20mm T&G oak is
then due to be laid on top of that. I was wondering whether the efficiency
of heat transfer would be improved by some sort of heat transfer paste
between the drymix and the oak. Not seen it discussed before but it is done
on a different scale for microprocessor heat sinks. The only product I have
seen in a quick look is a silicon paste by uponor.

Anyone know of any other products and whether it is worth the effort?
I thought just putting pva down might help?

Regards
Bruce