Double Screen Board Pros & Cons

Double Screen Boards are a great tool for beekeepers. The double screen board consists of a board the size of a super. I make mine out of 3/4 plywood or Advantech, and drill the holes using a 3 inch hole saw on a large drill. The holes are covered top and bottom with #8 hardware cloth. A 3/4″ rim is placed on the upper side to create proper bee space for hive bodies placed on top of it.

The double screen board functions as a bottom board that can be placed on top of another hive. It’s a piece of equipment that covers some corner case beekeeping tasks.

Double Screen Board Common Uses:

1. Splitting a hive
2. Starting a small nucleus colony
3. Increasing odds of virgin queen mating success

The key to the double screen board is obviously the double screen. Because the bees on top of the board and underneath the board cannot touch each other, they cannot share Queen Mandibular Pheromone, the primary pheromone that tells the hive they’re queenright.

The second key is the hole or holes in the board itself. These holes allow heat to rise from the lower colony and be transmitted to the upper colony.

These two factors are very important as they allow you use the board in several ways.

Double Screen Board Use Cases:

Split a hive that has swarm cells.

In the video above I witnessed a swarm issue from a colony and then used the double screen board to split the colony, leaving swarm cells in the upper nuc and in the lower nuc.

The purpose was to give me better odds of returning at least one mated queen at a time of year when dragonfly and bird populations are high and pose a high predation risk to virgin queens out on mating flights.

If both queens returned, then I successfully split the colony into two hives. If only one mated queen returned, I could pull the double screen board out and newspaper combine the upper and lower nucs into one hive.

Since the foragers in both nucs are oriented to the same location, this recombine is extremely easy to do.

Use Rising Heat To Boost Splits

Heat rising from the lower colony allows the upper colony to survive with a smaller cluster than it would be able to otherwise. This is important, especially as it can allow you to make smaller splits earlier in the spring.

This heat also allows those nucs to build up faster than they could otherwise. The queen can lay a bigger pattern, and the nurse bees can tend more brood because they have an artificial heat source.

Normally the workers would constrain the queens laying pattern and cannibalize any eggs that they could keep warm with cluster generated heat. But because they nuc on top is warmed by the stronger colony below, they can tend and rear more brood earlier in the year.

Double Screen Board Cons

Like any tool, there are good and bad things about double screen boards. The most inconvenient one for me is that to inspect or feed the colony on bottom, you have to remove the entire nuc on top. This gets to be a lot of lifting.

Also, when the time comes to move the nucleus colony on top they need to be reoriented in another yard. If you move the nuc on top to a hive stand in the same yard, then all the foragers will return to where the hive used to be, not where it is.

A third, and more important consideration is heat dependence. A small nuc on top of a larger colony benefits from the heat rising from below, and the queen is free to expand the broodnest because of that resource. The hive now becomes dependent on that heat source.

If you move the nuc too early, especially when cold nights prevail, then the bees will cluster and brood will be left outside the cluster. This results in chilled brood, potential for chalk brood, colony stress, and opens the door for disease.

So if you’re splitting with a double screen board early in the year, wait until your nuc is populous and strong before stripping off.