> By insulating, (I should have made clear) I mean more than wrapping with
> roofing felt, which has much less than R-1 insulation value.  I meant to
> ask, has anyone had experience wintering colonies in R-4 to R-16
insulation
> of some kind?

Beware of OVER-insulating!  The results may be like keeping your bees in a
cooler.  There are occasional opportunities for cleansing flights that come
in very short windows.  A small window of a few hours of opportune cleansing
filght could possible be missed if a hive is SO insulated that the bees
inside are also shielded from the warmth of a later winter day.  The benefit
of tar paper is not its R-value, its benefits come from shielding from
drafty windss and it's black color which warms quickly as the sun gets
higher in the sky as winter wanes.

Aaron Morris - I think, therefore I bee!