bakers,
sorry late to this thread...........about moisture boards~ my experience, i do not use them. i wouldn't advise anyone living in the most northern climates to use moisture boards, fiber board, 'buildrite' whatever the stuff is called. you can purchase this stuff from any big box store. these boards do hold moisture. what happens is the boards do absorb moisture. it gets full of moisture. so, during freezing, thawing cycles, the boards at some point can't hold any more moisture and rains down on the bees all at once in a thaw. from my own experience it's detrimental. i have lost hives in the past during severe winters to find a moisture board soaked/frozen in moisture and found dead wet bees below it on the bottom board, large cluster, and bees clustered and frozen on honey frames beneath a frozen and soaked moisture board. (these were healthy bees and healthy hives) i went to using the 2" foam board, the pink stuff. haven't lost a hive since using this stuff. i quit using moisture boards.
i do have a bottom entrance and top entrance. i just think moisture boards are not a good choice in extreme winters or for more northern climates.
it may work for you? not sure?