Gary,
 
I'm using only plastic hives. Boxes too and it works fine.
But it's not the same plastic material. In northern Europe it's quite
common to use styrofoam hives. The walls are 40 mm thick and
gives enough insulation to take bees through winter so no
other wrapping is needed. They are also very light and saves the
beekeepers back. Minimum 90 grams per litre density make them
hard enough to stand normal handling.
 
Moisture in winter is no big problem when there is a large ventilation
hole in the bottom board. No ventilation is provided in the top of
the hive.
 
http://www.algonet.se/~beeman/biodling/hive.htm
 
--
Regards
 
P-O Gustafsson, Sweden
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