Potts snuggle board info and then on ebay
£29 for an insulated under floor floor. That goes under the open mesh floor.
I’m not sure what this is supposed to be insulated… Any downward heat (And heat rises anyway) would be blow through with the back of the OMF being open and the hive having an entrance in.
The info says no sign of dampness in the hive – well it’s not insulating the hive to make a difference to what goes on it in.
If it was tested last year then I don’t think that was a particularly bad winter for bees – certainly not here anyway.