Hive Floors

The hive floor (bottom board, floor board) is the part at the very bottom of a framed hive that carries the entrance and separates the hive from the ground. Ventilation, moisture drainage, varroa monitoring and winter safety are largely managed from the floor. A well-chosen and well-maintained floor is the place that tells you the most about a colony without opening the hive.

What does a hive floor do?

The floor is the part most beekeepers think about least; yet because it is the "ground" of the hive, almost every problem leaves a trace here. Its main functions are:

• Load bearing: The entire weight of the brood and honey boxes rests on the floor; a floor that warps or rots upsets the balance of the whole hive.
• Entrance: In standard framed hives the entrance is formed by the gap between the floor and the brood box. The entrance reducer and mouse guard are also fitted here.
• Ventilation and moisture drainage: Condensation inside the hive and the moisture bees evaporate trickle downwards; a good floor sends this water outside.
• Observation and measurement: Fallen mites, wax debris, dead bees and traces of pests collect on the floor.
• Insulation and protection: It keeps the hive away from ground moisture, reptiles, ants and rodents.

What types of hive floor are there?

Solid (closed) floor

A floor made of solid board without openings. It is the traditional type and is still common in Türkiye.

• It blocks the wind and reduces heat loss from below in winter.
• Condensation can pool on the floor; unless it is tilted, the wood rots quickly.
• Fallen mites mix with the bees; mite counts cannot be done.
• Wax debris and dead bees build up, creating a favourable environment for wax moth.

Open mesh (screened) floor

The central part of the floor is a stainless or galvanised wire mesh fine enough that bees cannot pass but mites can fall through (a common mesh size is about 3 mm). Today it is the most popular type for new hives.

• It improves ventilation and reduces moisture build-up; it relieves the colony in summer heat.
• Mites that the bees drop naturally cannot climb back up; however, this effect is small, and it is not varroa control on its own.
• When a sliding drawer (tray) is fitted underneath, mite drop can be counted.
• Being able to close it with the tray in winter and early spring is an advantage in cold and windy areas.

Special floors

• Deep (high-rimmed) floor: Leaves a space below; it creates an air buffer beneath the winter cluster and makes room for feeding or in-hive management.
• Migratory floor: Locks together with the boxes during transport; the entrance can be closed completely and ventilated through mesh.
• Double-entrance or divided floor: Provides two separate entrances when two colonies (e.g. a split or a nuc) are kept in the same hive.
• Plastic and polystyrene floors: Light, rot-proof and easy to wash; however, they should be of a quality that will not deform in the sun and must be secured against the wind.

Why is the tray so valuable?

The tray fitted under a mesh floor is not only for counting mites; it is like the hive's "diary". A white or light-coloured tray is used with a sticky sheet smeared with a thin layer of oil or petroleum jelly.

• Mite drop: The tray is left in for a few days and the number of fallen mites is divided by the number of days. What matters is not a single count but the trend from week to week; it is also used to check effectiveness after a treatment.
• Lines of wax debris: The strips where capping debris lies show which seams between the frames the bees are densely occupying; in winter the width and position of the cluster can be seen without opening the hive.
• Chalkbrood mummies, dead bees, wax moth larvae: Signs of disease and pests may be seen here first.
• Pollen debris: Its colour gives a clue as to which plants pollen came from that week.

How should a hive floor be positioned?

Tilt

The hive should be tilted slightly downwards at the front. That way, water leaking through the roof or condensing inside runs out through the entrance. In a hive tilted backwards, water collects at the back wall; in winter this water wets the area around the cluster and makes combs go mouldy. Bees always build comb vertically according to gravity; if the hive leans sideways, the comb spills out of the plane of the frame and sticks to the neighbouring frame, and the frames can no longer be removed easily.

Height above the ground

The floor should not be placed directly on the soil. A floor raised on a hive stand, concrete blocks, stones or wooden runners:

1. cuts off moisture and dew rising from the ground,
2. slows down rotting of the wood,
3. makes it harder for frogs, lizards, ants and rodents to reach the entrance,
4. also protects the beekeeper's back; you can inspect the hive without bending.

In grassy areas the vegetation in front of the entrance should be cut regularly; tall grass blocks the entrance and holds moisture.

Seasonal adjustment of the floor and entrance

Whether to leave a mesh floor open in winter depends on the climate. Some studies in temperate regions have reported that an open floor does not significantly worsen wintering; in harsh continental climates and exposed, windy apiaries, fitting the tray is a common and sensible practice.

How do you maintain and clean a hive floor?

The floor is the dirtiest part of the hive and the part most exposed to moisture. On the first warm days of spring, the dead bees, wax and mould accumulated over winter should be cleaned away.

1. Prepare a spare floor: Place a clean, dry floor next to the hive.
2. Carefully lift the hive body and move it onto the new floor; take the old floor away. This is much faster than scraping at the hive and disturbs the bees less.
3. Scrape the old floor with the hive tool and throw the debris in the bin, not in the apiary (it may carry disease agents and moth eggs).
4. Dry the wooden floor; if necessary, disinfect it by lightly scorching the surface with a blowtorch. On a mesh floor, clean the mesh with a stiff brush.
5. Replace a floor that is rotten, warped or has a torn mesh rather than repairing it.

In winter, dead bees can pile up behind the entrance and block it. On a mild day in midwinter, reaching inside the entrance with a thin stick and pulling out the dead bees, without opening the hive, prevents this blockage.

Common mistakes with hive floors

• Placing the floor directly on the soil: It invites moisture, rot and pests.
• A hive tilted backwards: Condensation stays inside; this is one of the silent causes of winter losses.
• Closing the entrance completely in winter: Bees cannot make cleansing flights and moisture cannot escape. Reduce it, but do not close it.
• Forgetting the monitoring tray inside for months: It becomes a nest for wax moth and mould.
• Thinking a mesh floor is a "varroa treatment": It is a tool for monitoring mite drop; control requires a separate, planned treatment.
• Mismatched size: A floor from another hive type overhangs the body or leaves gaps; robber bees and moths get in through these gaps.

What to look for when choosing a hive floor?

• Size compatibility: It must match your hive type exactly (e.g. Langstroth, Dadant); the body should sit on the floor without gaps.
• Material: For wood, knot-free, seasoned timber; for the mesh, stainless or well-galvanised wire.
• Tray: A light-coloured tray that slides easily, fits fully, and can be removed and washed.
• Entrance adjustment: A flat, sturdy front edge to which a reducer and mouse guard can be fitted.
• If you are a migratory beekeeper: Compatibility with transport locks, and an entrance that can be closed completely and ventilated.