Field Guide to Beekeeping
Assembling Wooden Supers
The Langstroth hive is simple in design. It is based on the use of one-to-three, roughly cube-shaped boxes, or supers, that form the core of the hive and to which additional supers can be added as the bee colony grows (Figure 1). Most beekeepers use hives made of wood. Of course, other options are available for hive construction materials, including plastic and Styrofoam; yet, wood remains the most popular construction material out of which hives are made.
The life expectancy of a physical hive (not the bees, or colony, within, but the hive structure in which they live) is correlated with how well the supers, lids, bottom boards, and frames are assembled. Thus, it behooves beekeepers to invest time and energy in assembling hive components right the first time. In this article, I will share with you some pointers to remember when assembling wooden supers. I will follow this article with a step-by-step pictorial guide to assembling supers.
Water: a wooden super’s worst enemy
Wooden supers eventually rot and decay, a process brought on by the equipment’s exposure to water and microorganisms. Wooden supers are in a race that inevitably leads to their loss of use and functionality. Beekeepers cannot stop the ultimate demise of their supers, but they can do a lot to slow it by focusing on a few key issues that will limit water’s ability to age and destroy the super.
1) Use rot-resistant wood. Not all wood is created equal. Pine is a popular wood used in super construction. It generally is light, cheap, and easy to work. I also have seen supers made of spruce, cedar, etc. Some wood, especially old-growth cypress, has rot-resistant qualities while other woods rot at the first sign of moisture. No wood is fully immune to the impact of water and the microorganisms that moisture promotes, but using rot-resistant wood such as cypress certainly helps prolong the life of the super. Rot-resistant wood can be hard to find or expensive. Yet, beekeepers should consider using rot-resistant wood for super construction purposes, given that it will help prolong the life of the equipment. There are a few beekeeping equipment supply companies that specialize in the production of cypress and other rot-resistant woodenware.
2) Be picky about super joints. In carpentry lingo, a joint is where two pieces of wood meet. The Langstroth super has four joints, the corners. The joints form a seam, or crack, that runs the entire length of area where the two pieces of wood touch. The joints are the most water-vulnerable parts of a super. Consequently, you should take care to use joints that minimize the length of the seam and the overall end grain exposed as both make the super vulnerable to water damage. Take a look at the joints of the two deep supers shown in Figures 2 and 3. Both figures include a super having a “box” joint, where two sides of the super interlock much like fingers in a clasped hand. Box joints are slightly different from “dovetail” joints where the interlocking fingers are tapered. Both figures also include a super having a type of “rabbet” joint which is where one side of the super fits snuggly into a special grove cut into the adjoining side of the super (the special groove can be seen in Figure 4). The end result of a rabbet joint is a joining of the two sides at a simple, straight line, or seam, that is present only on one side of the super. On the other hand, a super with box joint has a seam that zigzags down both faces of the interlocking sides. I have never done the math, but there is easily two-to-three times more surface area to protect on a box joint than there is on a rabbet joint.
Another disadvantage to using a box joint is the amount of end grain that is exposed to the elements. Wood is milled from trees that originally grew in such a way that channels were produced throughout the wood as tree rings were added annually. These channels run up and down through the wood (the tree), and allow the tree to transport nutrients throughout its structure. These growth patterns form the “grain” of the wood. Wood, typically, is cut “with the grain,” a process that makes the wood stronger. Consider the common 2×4 for example. A 2×4, before it is cut out of the tree, would run up and down the tree, with the tree’s grain. Once hewn from the tree, the 2×4 is strong because it was cut out in a pattern consistent with the growth pattern of the tree. The four long faces of a 2×4 are the most water-resistant parts of the wood, since they run with the grain, making it difficult for water to be absorbed into the wood. On the other hand, the ends of the 2×4 are spongy, being the end of the grain, or the “end grain”. The two ends of the 2×4 are more vulnerable to water damage than are the faces of the board. This is why the ends tend to rot first when exposed to the elements.
Similarly, joints on a wooden super contain some end grain, just due to the nature of the way the sides of the supers were milled at the saw mill. Have another look at the joints represented in Figures 2 and 3. You will notice that there is minimal end grain exposed in the rabbet joint relative to that exposed in the box joint. Correspondingly, the rabbet joint is easier to protect and slower to rot.
3) Take extra care to protect the joints. This is done easily after the super is assembled by applying a ...