A spacer that gives extra height in a hive
In beekeeping terms an "Eke" is simply a spacer that goes between, over or under hive parts to create extra space for a number of reasons. Ekes are very versatile and quite interesting bits of kit.
Unless they are used for a specific purpose, such as under a super to temporarily turn it into a brood box, the height of an eke doesn't have to be accurate. There is no standard size and an eke was never included in the British Standards for beehives (BS1300).
An eke is usually used on a temporary basis only. It needs to be reasonably well made and strong, but it can be made out of scraps of wood, as many are. Rough sawn timber is good enough, but if you have prepared available, then use it. There is no need to use preservative, as in general an eke is only in use a short time, so not exposed to the elements very much. They are usually placed where there is little damp, so rotting isn't a problem. If you want to use preservative, as you do on your other hive parts, then do so, no harm will be done.
The design is very much up to the beekeeper, but the "standard" eke is usually four boards nailed or screwed together using butt joints, but you can use fancier ones if you wish. The height of the eke is the same as the width of the boards. It is fairly important the overall dimensions are the same as the boxes. The thickness of the boards is not fussy, but is best if fairly close to the thickness of the boxes, normally 18-22mm. For obvious reasons the boards need to be cut square in both directions.
If an eke is needed to extend a super to temporarily take brood frames the depth is quite critical, needing to be the difference between the depths of the frames. For a short lugged hive four boards are adequate, providing bee space is maintained, but for long lugged hives, the ends should be made out of thicker material or fabricated to give the same effect.
An extensive search in beekeeping suppliers websites and catalogues in December 2015 showed that not all supplied ekes. Those that did were usually for a purpose, such as increasing the depth of a shallow box to a deep.
Although an eke is very useful, many beekeepers improvise with an empty box. As the auctioneer of the West Sussex BKA auction I know that ekes usually fetch quite a high price, even if made from quite rough timber, so their value is appreciated.
In writing the above I have assumed the beekeeper uses wooden hives. For poly hives some manufacturers are able to supply poly ekes, but wooden ones can be used.
There are many uses for an eke, including:-