Frame Securing Devices

In-hive frame spacers are the parts that keep frames at the correct spacing inside the hive and stop them sliding during transport: self-spacing (Hoffmann) side bars, spacer ends, castellated (notched) runners, metal frame runners and transport wedges all belong to this group. Correct spacing means straight comb and easy inspections; wrong spacing brings brace comb, crushed bees and broken frames.

Why does frame spacing matter so much?

Bees build comb leaving enough space between two combs to work on both faces. When frames are set at a spacing that matches this natural measurement, the combs come out straight and parallel.

• Spacing too narrow: Combs become thin, bees are crushed and frames get glued together with propolis.
• Spacing too wide: The bees build extra comb (brace comb, burr comb) in the gap; the frames become joined together and can no longer be removed one by one.
• Sliding frames: If frames slide during transport or inspection, the spacing is lost, bees are crushed and the queen may be harmed.

In the brood box the common centre-to-centre frame spacing is about 35 mm (35 mm in the Langstroth system, slightly wider in some European systems). In the honey super, when drawn comb is used, the spacing can be deliberately widened.

What types of frame spacer are there?

Hoffmann-type (self-spacing) frame

The upper third of the side bars is widened; when the frames are pushed together, these wide sections touch and the spacing forms automatically. Usually one edge is made pointed and the other flat; this reduces the contact area and cuts down propolis build-up.

• Widely used in many hive systems; no extra parts are needed.
• During inspections the frames can be slid along as a block.
• The contact surfaces thicken with propolis over time and the spacing opens up. They should be scraped once a season.

Spacer ends and spacing nails

Plastic or metal ends slipped onto the lugs of straight-sided frames, or spacing nails driven into the side bar. The width of the end determines the spacing; ends of different widths can give separate spacings for the brood box and the super.

Castellated (notched) runners

Metal strips with regular notches, fitted in the frame rebate on the front and back walls of the hive. Each frame lug sits in a notch; the number of frames and the spacing are fixed. They are preferred especially in the honey super, to give wide spacing with fewer frames. The drawback is that the frames cannot be slid to one side; inspection is done by lifting frame after frame.

Metal frame runner

A thin metal angle strip nailed to the edge of the frame rebate. The frame lugs rest on this runner instead of on wood; propolis sticking is reduced, the frames slide easily and the wooden rebate does not wear. It gives the best results when used with self-spacing frames.

Dummy board and transport wedges

A flat board placed next to the last frame in the hive (dummy board, follower board) holds the block of frames together and is the first thing removed during an inspection, making room for the frames. In migratory beekeeping, a wedge is pushed in behind this board, or a cross batten is nailed over the frames, to stop the frames sliding.

Spacing differences between the brood box and the super

How are frame spacers used?

1. Placement: Hang the frames in the hive and push them to one side to form a block; with Hoffmann frames, the side bars must touch each other fully.
2. Side gap: Centre the gap between the block and the hive wall, or fill it with a dummy board; there should be no gap larger than a bee space between the wall and the last frame.
3. Inspection: First remove the dummy board or the outermost frame; then lift the frames one at a time by sliding them into the gap. This lets you work without crushing bees.
4. Closing up: When the inspection is over, push the frames firmly back together; if the spacing is left open, the bees build brace comb.
5. Before moving: Push the frames tight, put a wedge behind the dummy board or fit a securing batten, and fasten the boxes together with straps or locks.

Maintenance and cleaning

• Scrape propolis off the side bar contact surfaces and frame rebates with a hive tool at least once a season.
• Set aside cracked frames and frames with broken lugs; a broken lug can make a frame fall during transport.
• Check metal runners for rust; re-fix a runner that has come loose.
• Replace broken plastic spacer ends; do not mix ends of different widths in the same hive.

Common mistakes

• Leaving a frame out of the brood box and widening the spacing: brace comb and an irregular brood area.
• Leaving frames loose after an inspection.
• Using frames from different systems in the same hive; Hoffmann and straight-sided frames do not hold spacing together.
• Not securing frames before moving; frames that slide on the road crush bees and can kill the queen.
• Not noticing that thick propolis has opened up the spacing.