Burr comb, bridge comb, and brace comb are all terms used to describe comb that is built in places that are reasonable to the bees but annoying to the beekeeper. Wherever honey bees find excess space in the hive—a space greater than about 3/8” (1 cm) wide—they will attempt to build comb.
It is a problem for the beekeeper because it glues things together and makes removing the frames very difficult. Many beekeepers make a habit of scraping away any burr comb when they see it and, if possible, correct the situation that gave the bees the extra space.
How to reduce burr comb
One way to reduce burr comb in the hive is to space the frames as evenly as possible across the width of the hive boxes. If you are using 10-frame equipment, for example, just equalize all the slots between the frames. This prevents having an over-sized space somewhere in the box that the bees will see as an opportunity. Another common place to see burr comb is below the inner cover, especially when it is installed incorrectly—with the rim facing down instead of up. And if you install a slatted rack upside down, the bees will fill in the area below the lowest set of frames.
If you find burr comb, just scrape it away with your hive tool after assuring that the queen is not on it. If you find a new piece of burr comb down in the brood area, hold it up to the light: you may be able to see eggs or larvae inside. Don’t leave the scrapings lying around the apiary, especially if they contain honey, because they may attract animal or insect pests that can become a nuisance. If you are thinking of making candles or some other beeswax product, just collect the burr comb for later use.
Honey Bee Suite