I am a first year beekeeper with 20 hives. I've tried solid wood bottom boards, a fancy Jonz bottom board and now have all of our hives on PVC screened bottom boards. I am noticing a problem with our bees not wanting to use the bottom brood box after a second box is added on top. We just split one hive that was preparing to swarm and found the bottom box mostly empty. I suspect this is because the bees don't like the screen bottom, I have read about this on the forum.
I assumed that I needed the screen bottoms because it is so hot here in Florida and our hives are in full sun for most of the day. Am I wrong?
I'd prefer to stay away from the middle of the road option that use a tray to capture pests like the Freeman or Jonz style ones. When I have areas that the bees can't patrol they rapidly fill up with giant ants.
I run between 20 and 30 hives on the Florida/Alabama line. I use screened bottom boards, but I would not have any issue using solids either. I prefer screened because I like to monitor mite drop counts after OAV. Also, it just seems like it would be a little bit cooler for them on these 100F+ days we get down here. But that is probably helping my feelings more than theirs. They would be fine either way. Also, bees naturally work their way up in their hives. You can reverse the boxes if you would like, but that is not necessary.
Don't sweat the bottom boards. It is unimportant. They would do fine with solids, they would do fine with no bottom board and they will do fine with the screened bottom boards you have on them now. Just make sure they are queenright going into winter and that you have treated for mites and have them under control. Good luck.
Keep this in mind.
An average deep frame has aprox 4500 cells per side so thats 9000 per frame and 90,000 per 10 frame box.
The average Queen lays between 1500 and 2000 eggs per day so at 2000 eggs per day for 21 days(time from egg to adult),the maximum number of cells in use would be
42,000,less than half the number of cells in a 10 frame deep.
Honey bees will find the most efficient use of a cavity to make their home.Obviously they have found that the upper deep in your location with an open screen is the best place to raise brood.