CC Miller, an accomplished beekeeper and author, invented the slatted rack in the early 1900′s after he noticed that the bee’s general well being seemed to improve when given extra space under the brood chamber. Originally, he built 2 inch deep bottom boards to create this space but quickly found that the bees would build honeycomb in it. Consequently, the slatted rack was conceived. It created a false bottom board, preventing the construction of extra comb, without compromising Miller’s idea of extra space.
The same outside dimensions of a 10 or 8 frame beehive are used to construct the slatted rack except it is only 2 inches deep. A solid piece of wood in the front portion of the rack reduces drafts at the entrance. Slats, about the same width as a frame, compose the false bottom board. These slats are closer to one side than the other so that they are as close to the frames as possible. The beekeeper places the component in between the bottom board and the bottom hive body. The solid piece is the front and should face the entrance. The top, which is the side the slats are closest to, should face up towards the bottom of the hive body. When using this with a screened bottom board for varroa, remember that the slats need to be parallel with the frames and equal in number. If they run crosswise or you have 10 slats and 9 frames the mites won’t fall through your screen. However, used properly this tool can be a great benefit.

Photo courtesy of Linda Tillman
The extra space produced by the slatted rack is said to keep a beehive warmer in the winter and cooler in the summer by creating dead air space. The dead air space works like insulation in a thermos which separates the inside temperature from the outside temperature. Thus, the outside temps have less of an effect on the inside temps and your bees (or coffee) will stay warm (or cool) longer and with less effort. Then, the honeybees have all that energy saved for something more important, like making honey!
The added space also gives the bees an extra place to congregate so, when things get crowded in the summer, they have less of a tendency to swarm. It distributes the population and the heat in the hive more evenly which also reduces swarming tendencies. The slatted rack improves ventilation as well by giving the bees more space to do their fanning when it’s hot and reducing drafts when it’s cold. Lifting the bottom bars away from the light at the entrance and the drafty bottom board also seems to encourage the queen to lay to the bottom of the frames which, in turn, increases the brood chamber. Increasing the brood chamber would increase the number of bees and the strength of your beehive as well.
Other than the fact that it is only one more piece of equipment to have to buy, or make, and manage; it seems like a great addition to a beehive for any small scale beekeeper. Wouldn’t you be happy to have a large, protected front porch? Well, that’s basically what this does for your bees and I think it makes them happy, too.
Here are some drawings to help you visualize what it should look like as well as dimensions to help you build one. The dimensions are for a standard langstroth 10 frame hive so you’ll have to adjust for whatever hive style your using. The basics are that it should be the same size as the hive and each slat should be placed under a frame. This prevents buildup on the rack and allows mites to fall through a screened bottom board. The unit goes between the floor and the brood chamber.
Dimensions

Exploded View
The exploded view will give you an idea of what materials you’ll need to build it. You can use brad nails, screws, whatever your fastener of choice for putting everything together.

Give it a try and let us know how it worked for you…






where can I find plans to make the slatted rack? Thanks
I was not aware of this item. It sounds beneficial and I would like to build one, but I cannot decipher from your article enough info to build one. I cannot get a mental picture of what it would look like. Do you have a photo of one that you could share?
Thanks,
Vince
I’ll make a drawing and post it this week. There’s a drawing at beesource but it has the slats running in the wrong direction. You want the slats running in the same direction as the frames.
So the screen board goes below this. Why dont the bees build comb in this?
Hi Therese, yes it goes between the floor and the brood box. There isn’t enough open space between the slats to interest the bees in building comb. You might get a little burr comb here and there but it won’t be too bad.
Great article, are these available for purchase if we do not want to build one?
Hi Brian, most of the major suppliers have them. Here’s a couple of links:
Brushy Mountain
Betterbee