Screened Bottom with Slatted Rack
These plans are not for the typical SBB (Screened Bottom Board), as the typical SBB is also a bottom entrance. This SB is not intrinsically designed as a bottom entrance, though with the addition of one of my entrance rims placed between it and the first super, an entrance can be that easily added.
Last year, to overcome toad predation/depopulation I decided to eliminate bottom entrances. I tried various ways to accomplish this. Creating a quick and easy screened bottom board was fairly simple using cheap 1"x2" furring strips:
But even in our hot Summer weather the bees seemed to avoid raising brood near the SBB, sometimes they avoided even using most of the bottom super. Earlier, when I was still using conventional bottom boards, I noticed the bees would frequently avoid using comb near the entrance, especially for brood. To reduce this aversion to the comb near the entrance I had been using slatted racks. So I decided to try them with my entrance-free SBBs, but I was never completely satisfied with the design of the typical "Miller" type slatted rack. Since I was creating my own equipment, I decided to try a variation of the usual slatted rack. Considering that slatted racks are used to give the bees an area to cluster, away from the brood nest, and to enhance the bees ability to moderate their internal nest environment, slatted racks help do this in several ways. So I tried the typical design next to my modified design and compared them together, the results were encouraging. I tried several hives with just SBBs, no slatted racks; SBBs, typical slatted racks; and SBBs, redesigned slatted racks. The bees did well on all configurations. The differences I noticed appeared during the Winter and early Spring (January - March). The colonies that utilized their bottom super most completely, stayed strong without intervention, and built up more quickly were those that were using the SBBs with the redesigned slatted racks. Here is an image of the drop-in slatted rack:
A web page with SketchUp plan files is here: SBB/Slatted Rack plans
The slatted racks are made with nominal "1 by" wood, which is actually 3/4" thick. Many different widths would work nearly the same, the runner/spacers can be changed in width (the plans call for 3/4", but 3/8" works well too, and uses less material) and I only use two runners to further conserve materials, but more could be used without problems. Using a 1x6, I cut it to 18" in length, then 1/2" in from one end I cut 1/4" wide dadoes and space them 3/8" apart until I reach the other end. Next, using my bandsaw I cut these into the runner/spacer strips (widths may vary to suit your preference). Then using 1 by lumber, cut to 12" lengths, I set the bandsaw to cut 1/4" width and cut the slats needed to complete the slatted rack. Placing the runners parallel and on a flat surface at the preferred spacing I then put a drop of glue in each spacer groove and drop in the slats, finally I align the slats, square with the runners, I then place a heavy board to keep the slats firmly in place until the glue sets.
Last edited by Joseph Clemens; 03-14-2008 at 06:18 PM.
As I was putting this post together, and after having assembled a half dozen slatted racks using the plans in this post, I thought of a different way to make a screened bottom with slatted rack built-in.
Here's what I came up with:Image of SB+SR
Link to zipped SketchUp plans: SketchUp plans of SB+SR
I picked up setup for two hives this last week (new beekeeper). The bee folks set me up with a SBB for each. When I went for the Slotted Rack(s), they said they weren't necessary with a SBB.
Of course, having read my head off lately, remember reading that it provides even ventilation, place to congregrate, decrease in cool drafts, etc.
I should have just purchased the two SBB's, but still in learner mode here.