Mkay, so that challenges my thoughts about wrapping and/or insulating my hives over here in Cali. I remember earlier this year Bakersdozen commented that she thought that maybe the 1/2 inch rigid foam board that I had my hive wrapped with, may have been too much insulation for upper Cali. We did get up to 7 below zero for a couple of weeks this last winter. I can't remember for sure, but her thoughts were something like maybe as the weather started to warm in February, it may have over warmed the hive which amped the queen up too early, in addition to winter patties started in late January. Hense 10 swarms from March 26th for about 5 weeks.
That whole event of feeding the winter patties and the 10 swarms left me very befuddled, still am. Soooo, maybe the tar paper would be better?