Building Screened Bottom Boards
I am going to try some screened bottom boards on a couple hives this year to see how the bees respond to an open bottom. Besides ventilation and moisture differences studies suggest that some percentage of varroa will fall through the screen and potentialy not make it back into the hive. "Sticky" boards can be used under the screen to observe mite falls.
Using a 10' long 1x8 and #8 mesh (1/8" x 1/8") screen, I was able to build three screened bottom boards without much effort.
From the 1x8, I cut three 21" long sections, and three 14-3/4" long sections. The table saw was set to rip at 2" wide. Two 2" wide pieces were cut from each of the 21" section. Three 2" wide pieces where cut from each of the 14-3/4" sections. These will be used for the frame of the bottom board, and the layout can be seen in a picture attached to this post.
The table saw was set to rip at 3/4" wide. Two 3/4" wide pieces were cut from each of the remaining 21" section. The remaining wood from the 14-3/4" is already about 3/4" x 3/4", and may not need to be cut. These pieces are used as spacers to hold the hive body above the board, and to attach the screen with.
I used 1-1/2" staples and glue to assemble the frames. The screen edge closest to the entrance was stapled down with 1/2" staples. The edges and back of the screen are sandwiched through the spacers and secured to the frame with 1-1/2" staples. (I chose to stain the spacers and frame separately prior to stapling the screen on.)
Dedicated to Dick McDonald... Requiescat in pace