THE FOLLOWING HAS BEEN UPDATED SINCE ORIGINALLY POSTED.
I made another bottom board from scrap wood I found in my shed, just like the first one, but this time I cut a big hole in the bottom and stapled a screen over the hole. Hence, the world’s cheapest, ugliest screened bottom board:
The screen is not the standard 1/8th screen. It’s just some old mosquito and insect screening (photo), which is fine for a mite-free province like Newfoundland. I stapled Masonite to the back and front of the screen to cover the sharp bits. The plywood is cheap, but strong enough to get through the rest of the summer. Humidity in the hive is not a good thing. I’ll see if the screened bottom board makes a difference after I install it on one of our hives in a few days. And here’s what the underside looks like:
That’s some fancy pants carpentry going on.
August 22/11: This is just a prototype made from scrap lumber and other materials I happened to have around. It ain’t pretty, but it’s working beautifully so far. Stay tuned for further updates on the design. I just figured out a cheap and easy way to transform it into a dual solid & screened bottom board, a.k.a. a summer & winter bottom board.
Jan. 20/15: Don’t lay this flat-bottom bottom board on a pallet or anything kind of flat surface support, if that makes sense. The wood can easily become moist, and you don’t want moisture if the hive. You want the hive off the ground, but preferably with something that makes minimal contact with the bottom board so the air can flow underneath.