I think it would be a great insulator, but… if it starts to leak water, it will get inside the hive and promote mold growth. Also with this I doubt any condensation or water could evaporate through the top, leaving humidity in the hive, back to mold. In Virginia, ants love to live in planters, and they would already be drawn to the smell of honey. During the winter, not much grows, so I would assume you would replace it with the previous roof you had? I would like to see if anyone else has this and what their responses are. I think some lavender and other kinds of small plants would be good up there. Also the weight would hold it down in winds.