Anyone ever use it? I bought 3 for my hives. It is a thick black plastic with a thin layer of foam inside of that. I used velcro to keep it together and push pins around the upper entrances.
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Sorry but, the cover should be respirative. Plastic keeps moisture inside and you boxes will be rotten soon. Paint loosens first.
Hive is moist and warm and it exrecets moisture. The movement of moisture stops to the plastic. There should be a gap for air, from where moisture ventilates away.
In Finland we have a lot of houses where owner has installed "outer water cover" or "heat cover". If moisture will not escape from structure, home is soon a mould ball.
I use insulated boxes, but 30 years ago I had mere wood like you.
Here is both wooden in a carry and styryfoam on the ground.
http://bees.freesuperhost.com/yabbfiles/Attachments/Kuva_036.jpg