Standard Dimensions
A bottom board needs to match the width of your boxes and extend forward to form a landing area. Commonly quoted sizes are below. Exact measurements differ by manufacturer.
| Hive | Typical width | Typical length | Typical thickness |
|---|---|---|---|
| 10-frame | about 16 1/4 in (41 cm) | about 21 to 22 in (53 to 56 cm) | about 2 to 2 9/16 in with rails |
| 8-frame | about 13 3/4 to 14 in (35 cm) | about 21 to 22 in | about 2 to 2 9/16 in |
| 5-frame nuc | smaller, varies by maker | varies | varies |
Compare these with your own boxes (see the bee hive size guide) rather than relying on a table alone.
Parts of a Bottom Board
Most boards have a flat floor, side rails that set the entrance height, and a rear rail. Many are reversible: one side has a shallow entrance of around 3/8 in, and the other a deeper one of about 3/4 in. Turning the board changes the entrance height. For width adjustments see hive entrance size. For the other pieces of the hive, see parts of a bee hive.
Solid vs Screened
Solid boards are simple, durable and hold heat better in cold weather. They tend to be cheaper.
Screened boards have a mesh floor, giving more ventilation and letting debris and mites fall through. Many include a removable tray (often called a sticky board) so you can monitor mite drop.
The effect of screened floors on mite control appears modest, so do not rely on them as a treatment. Their ventilation can help in hot climates, while some beekeepers close them with a tray or insert in winter.
How to Choose
- Hot, humid climates often suit screened boards.
- Cold climates often suit solid boards, or screened with a tray inserted for winter.
- If you want to monitor mite drops, a screened board with a tray is convenient.
- Beginners can use either; consistency across hives matters more.
Should You Paint a Bottom Board?
Many beekeepers paint exterior surfaces of wooden equipment with exterior latex paint to protect against weather, and let it dry and air out before use. Avoid painting the inside surfaces or the screen. Bottom boards sit close to the ground and damp, so a stand helps. Follow the paint label.
Matching Your Boxes
The width must match your hive bodies, and 8- and 10-frame boards are not interchangeable. If you build your own, measure the boxes you actually have and keep the box edge flush with the board, without gaps. Weight on the board matters too; see hive weight. Costs are usually modest compared with the rest of the setup, as covered in what a hive costs.
FAQ
What are the dimensions of a bee hive frame? Deep frames are roughly 9 1/8 in tall with a 19 in top bar, mediums about 6 1/4 in tall and shallows about 5 3/8 in tall.