I've been too busy to keep up on the list emails, but finally caught  
up today...
Years ago, when I kept bees on a rooftop, we had pieces of 2"  
blueboard covered with a thin layer of concrete up there to walk on -  
presumably to protect the roof surface. One winter, I took a broken  
piece (a little bigger than the outer cover) and put it right on top  
of the outer cover - with the concrete layer, it was heavy enough to  
hold down the whole lid. I think it worked well for insulation, and  
kept doing it until I moved the bees to a different location. This  
might work for those who are thinking of replacing the cover with  
just blueboard. I've never seen this stuff in a hardware or building  
supply store, but I haven't really looked.

Now in a colder place, I've taken to wrapping the hives for the first  
time (black felt/tar roofing paper, about $20 for a huge roll), and  
I've put 1.5" blueboard between the outer and inner cover. I also  
generally put 4 little sticks in the corners of top of the top box,  
between the hivebody and the inner cover to allow it to vent  
moisture... or not - some hives have an entrance at the top - wither  
an Imrie shim or a bore hole in the top box.

Kurt

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