Horizontal top-bar hive

Although guidebooks for use in Africa often give precise dimensions for the Kenyan hive, and encourage beekeepers to keep their equipment of uniform and thus interchangeable sizes, one of the main selling points of the KTBH among proponents from English speaking countries is the fact that it can be made to practically any size and shape, as long as the top bars have an appropriate width.

The angle of the sloped sides is most commonly recommended to be 30 degrees. The width of the top bars is the sum of comb thickness and one measure of beespace. This helps ensure that bees build exactly one comb per top bar. Most top-bar hive plans freely available on the internet show hives of roughly 1 meter long and between 30 cm and 50 cm wide and high.

In English speaking countries, the top-bar hive is usually mounted on a set of legs that lift the hive to a height that is comfortable for beekeepers. In African countries, the height of the hive is often also determined by the type of animal the hive is meant to be protected from.

Top Bars

A top-bar hive has bars from which the honey bees attach and hang wax comb, an array of hexagonal (six sided) cells.

A beekeeper can make top bars from any plain wood. The top bars are usually 1¼ inches to 1⅜ inches (32–35 mm) wide, depending on local conditions and the type of bee to be housed. Combs can be handled individually. The depth of the bar and the length of the bar can be whatever the beekeeper wants, but usually between 17" and 20". The depth of the top bar hive should be 12" or less. If deeper, the weight of the comb filled with honey tends to cause it to fall off the bar into the bottom of the hive. The bees will lose access to this during the winter cluster in the hanging combs, thus increasing their likelihood of starving.

It is important to give the bees a clear starting point to build comb on each top bar. Some TBH beekeepers fashion their top bars with a V-shaped bottom to guide the comb building. Alternatively, some use a table saw to cut two closely spaced slots along the long axis of each new top bar. Either type of guide, wax line or grooves, gives bees a place to hold on to with their hooked feet. This allows a substantial "drape" of bees to form, which is the beginning of comb building.

Entrance

Top hives have entrances that are a small slot or a number of holes of an inch in diameter or thereabouts, which more closely mimics what honey bees prefer in nest cavities.[9]

The brood nest will be established nearest the entrance. If the entrance is at the narrow end of the hive, the honey storage will be deep in the hive beyond the brood nest combs. Typically inspections will then begin with either the beginning of the brood nest at the front, or with the end of the honey storage at the rear. If the entrance is placed in the center of the long wall, the brood nest will be at the center, and the honey storage will be on either side. As it is not possible to safely remove a bar from the middle of the occupied combs, due to possible side attachments, this means the inspection can begin on either side of the honey storage and there are fewer before the brood nest is reached.

The entrance should not be placed high on the hive as this will allow the escape of winter heat (but see [10]) for an alternative perspective).

The bees will be able to keep a top bar hive cool enough with only three holes of 1 inch diameter. They do so by both lining up to fan cool air into the hive and exhaust warm air, and by evaporation[11] – essentially air-conditioning the hive. It is possible to have too small of an entrance, such as a 4-inch slot of only 3/8 or 1/2 inch, and this did result in combs falling from the bars in the heat. It also resulted in much traffic back up at the entrance.

It is suggested that bees in a Kenyan hive will have much less tendency to adhere comb to the sides of the hive. Once adhered comb is freed from the side (leaving a beespace) the bees tend to not rejoin the comb, so this is not a significant problem for either hive. It is important in either type that end access or some free space without comb is available so adhered comb may be freed.

The initial costs and equipment requirements are typically much less than other hive designs. Scrap wood can often be used to build a good hive, and top bars are easy to make out of scrap timber. Horizontal hives do not require the beekeeper to lift super boxes; all usual checks and manipulation can be done while lifting only one comb at a time and with minimal bending. In areas where large land animals (such as ratels and bears) present a threat to beehives, single-box hives may be suspended out of reach. Elsewhere, they are commonly raised to a level that allows the beekeeper to inspect and manipulate them in comfort. Since no seasonal storage of honey collection boxes ("supers") is needed, nor is a centrifugal extractor commonly used, the equipment budget and storage space requirements are greatly reduced. Time and money may not need to be spent wiring foundation into frames.

A top bar hive can also be rapidly converted to two or even three mini hives, called a nucleus hive, by placing bee-tight dividers within the hive, and allowing access to independent entrances. This may avoid the need to purchase and store such nucleus hives.

Disadvantages include (usually) unsupported combs that cannot be spun in most honey extractors. It is not usually possible to expand the hive if additional honey storage space is required. Most horizontal hives cannot easily be lifted and carried by one person.

It is recommended that new or recycled empty bars be placed at each side of the brood chamber just before spring build-up as it is easier for the bees to make new comb than to move honey stores to make room for new brood. This will also ensure the maintenance of a well built honey barrier between the brood and higher grade stores. To prevent the buildup of old comb in the brood chamber it may be advantageous to add new bars only on the entrance side of the brood chamber just past the pollen stores. This will cause a collection of older honey in re-used comb, which may be removed and used to produce a somewhat lesser quality of honey, as it will have additional flavors from the propolis used to strengthen and protect the brood comb. Such honey may be especially appropriate for making mead and root beer, as additional flavors will predominate. The progressive removal of brood comb appears, as noted above, consistent with control of AFB. The use of follower boards to selectively control the amount of interior space available to the bees can be helpful, particularly in young hives or when dealing with newly captured swarms.

The recent introduction of sliding 'follower boards' [12] to enclose the colony within the hive body has enabled more flexible management of top bar hives and facilitated quicker inspections with minimal disturbance to the bees. (Follower boards are adjustable solid panels, which effectively reduce the size of the interior space within the hive box that is accessible to the bees.)

Natural queen exclusion occurs more frequently in top-bar hives, because the brood nest is separated from the honey section by at least a full bar of honey comb, and not just a few centimetres of honey as may be the case in a multi-storey framed hive. And the more honey is gathered, the further the brood nest becomes from newly created comb.

However, some commercial top-bar beekeepers have found that artificial queen excluders are sometimes necessary to keep the queen from laying eggs in the honey section of the hive.[13]

A top-bar hive is inspected by lifting the bars of comb individually. Some beekeepers start their inspection at any one of the bars, and can be completed over several sessions. Others start at either the front of the hive, against the wall or divider, or at the rear of the combs. This way the beekeeper can see and cut any side attachments before moving the first comb. Side attachments can be cut with a conventional hive tool; using a specially-made tool long enough to reach the bottom of the hive, but with a narrow "leg" at the bottom, is more efficient. More than one bar can be separated from the side walls at a time. The use of smoke is commonly recommended.

Inspection of the combs can be carried out with far less disturbance to the bees than is the case with multi-storey hives, since only a small amount of the hive is exposed at any one time. Some hives incorporate a viewing glass window in the side of the hive that allows for observation without opening the hive itself, since in theory the combs do not get attached to the sloping sides.

The top-bars rest freely on the hive walls without spacers, which means that the top-bars can be slid easily along the length of the hive during the inspection, without altering the sequence of the combs, and non-inspected bars need not be lifted out of the way to gain access to other bars.

As part of the "natural beekeeping" concept, some beekeepers recommend opening the brood area only once a year.[2]

The most popular method of harvesting honey from a top-bar hive is by cutting the comb from the top-bar, crushing the comb and straining the honey. This results in honey with a higher pollen content than honey that is extracted by flinging out without crushing the comb. Top-bar hive comb can be extracted by flinging motion e.g. in a hobbyist or commercial rotary extractor, but it can be problematic, because (a) if no foundation was used, the comb will break more easily during rotary movement, (b) top-bar hives combs may use irregular or non-standard sizes that do not fit into commercially available extractors, (c) if the comb is not uniformly flat, it may be difficult to uncap the cells, which is required for rotary extraction and (d) not all rotary extractors have cages or mesh to prevent loose pieces of comb from falling into the drum.

Honey can also be harvested from top-bar comb as cut comb.

Owing to the fact that crushing and straining is the most common method for honey harvesting in this type of hive, beeswax is often a by-product of top-bar hive beekeeping.