> I am using personally the new AIR BUBBLE MATERIAL <snip> > I think this is a GREAT MATERIAL. It is extremely light and easy to handle. > It is clean. It does not absorb humidity. It is easily installed in the > fall and easily removed in the spring. I suspect that it could be re-used > for many many years. It takes very little storage space. At the actual > price of Astro Foil the cost of one four pack wrap is only 16$ can. (plus > the cost of the styrofoam). Next year I plan to use a double thickness of > Astro Foil as a top (no styrofoam). I wonder if you are using upper entrances and, if so, of which type. I have been switching from using an inner cover with a slit of about 3/4 square inch area to a one inch auger hole below the hand-hold on the belief that it allows more heat to remain on the top bars. Experimentally, we have seen no advantage in survival or spring condition, but it also allows us to wrap with the telescoping summer lid on the hive - which is a huge labour saving - and I am planning to ultimately go to telescoping lids with R5 insulation built in for year round use. This is one of the reasons that I have been wondering how much insulation is required on top. I found that 1" styrofoam all around a double hive out here allowed for survival, however I did not repeat the experiments often enough and on a large enough scale to assure myself that I would commit my whole outfit to it. My father used that method for years on his hives in the Muskoka region of Ontario, and on hives he kept at Sudbury as well. Sudbury has winters that fairly closely resemble ours here, but Muskoka is considerably warmer and winter is shorter there. In those years, Muskoka had a lot of snow too. What works in one region may not work a few hundred miles north, and I am also acutely aware that winters vary in severity to the extent that one year's wintering success is virtually meaningless. A number of years results are crucial to ensuring that a method will not leave one virtually without bees some (rogue) year. Some years, no wrapping is needed, but another year that seems similar - in terms of human comfort - may well wipe out all hives that are not well insulated. Fall hive condition has a large effect on the need for insulation too. With a hive of live bees being worth $60 Cdn in the spring plus equipment, a saving of material and labour for wrapping is a small consideration - if the savings result in any additional loss of bees or condition - IMHO. One thing I am wondering also is: if there is any indication that more or less insulation affects the mite load in the spring? It willl be interesting to see how this new material proves itself and how well it lasts. BTW, Jean-Pierre,(or anyone else) have you heard any talk of beekeepers getting together to ski the BC Rockies this winter? Regards Allen W. Allen Dick, Beekeeper VE6CFK RR#1, Swalwell, Alberta Canada T0M 1Y0 Internet:[log in to unmask] Honey. Bees, Art, & Futures <http://www.cuug.ab.ca:8001/~dicka>