What is Burr Comb and How to Control it?

​If you have ever opened up a hive for inspection only to find some sticky wax comb in places that you didn’t expect, then you have already experienced burr comb. Burr comb is also known as brace comb or sometimes bridge comb.

So what is Burr Comb? Burr comb is wax comb which bees have built in unwanted places and at odd angles inside the hive. When bees build comb they leave a bee space of about  ⅜” (1 cm) as a passageway. Bees will do their best to fill any space greater than this bee space with comb. This burr comb is considered a nuisance for beekeepers because it bonds hive parts together and can make frame inspection difficult.

Unwanted beeswax can make a beekeepers life more complicated. In an ideal world, honey bees would build nice neat frames of comb, and nothing else. But given a chance, bees will bridge any gaps they deem useful with wax comb.

So what can a beekeeper do to prevent burr comb, and what should you do when it (inevitably) appears?

Why do Bees Build Burr Comb?

Bees build comb in any available space they consider useful. This isn’t a problem for bees, but it can be annoying for beekeepers who need to access frames and manage hives with ease. Any superfluous beeswax that a beekeeper finds in unwanted places usually gets removed. So the bees have spent time and energy building comb that you don’t want, you spend time removing it, and the bees waste more time cleaning up behind you.

Not the most efficient situation.

​But bees are in fact very efficient in their use of space. They like to build their nests in cavities and as the colony grows they fill up all the room they have. The only space they don’t fill with comb is the space they need to circulate around the colony taking care of bee business or just hanging out with other bees. This space is known as bee space and it was first discovered in the mid-1800’s.

Bee space is considered to be a distance not less than ¼” (6mm) and not bigger than ⅜” (10mm). Anything smaller and bees plug the gaps with propolis (bee glue) to keep their hive airtight. Anything bigger and you get burr comb.

The beekeeper Lorenzo Langstroth incorporated the discovery of bee space into his hive design to help control the comb building habits of honey bees. The Langstroth hive was one of the first of its kind to take into account bee space and provide easily removable frames, which is good for bees and makes hive management simpler.

The Langstroth hive and all other contemporary hives are designed with this bee space dimension in mind. So in theory bees only build comb on the frames and not anywhere else. The objective is to have easily removed and accessible frames of honeycomb and to limit the production of extra comb in other areas of the hive.

However, In the real world, things are not so simple.

For example, if you don’t install the inner cover of your hive properly, you can end up with a space greater than ⅜” and bees will grab the opportunity to bridge it with comb. Or maybe you’ve combined two hive boxes which were not built by the same manufacturer and the dimensions are slightly different. This might produce additional space below the frames. Yes… You guessed it… bees will fill up the gap for you (This can be particularly annoying when comb extends below the hive box, you can’t even set it down during inspections without causing damage!). Alternatively, if you don’t space your frames correctly, you can end up with a bridge of comb between two frames, which makes removing the frame complicated.

These are just a few examples, but once you find beeswax in undesirable places you need to get rid of it.

How to Remove Burr Comb

When you find burr comb it’s generally recommended that you remove it. Most hive tools have a beveled end for scraping which is ideal for lifting off the unwanted comb. When you remove it, do so gently. If there are bees on the surface they will soon get out of the way. Once it’s detached, encourage the bees to leave the surface by shaking gently or with a bee brush.

You can always use your bee smoker to incite your bees to “get outta town”!

​Don’t discard the burr comb. It’s a shame to waste such a valuable product! Just remove it and save it for use later. Keep some kind of beeswax container near your hive so you can collect the wax during your inspections. A plastic pail with a lid is ideal. Alternatively, some beekeepers leave the burr comb on top of the frames inside an empty hive box so that bees can recover any nectar and wax.

Whatever you do don’t just discard surplus comb near the hives. This can attract predators such as ants or larger animals like skunks or even bears depending on where you live. It may even encourage robbing.

How to Control Burr Comb

If you do find superfluous wax anywhere in a hive then try to understand the reason for it being there. There is often a problem with the spacing between different hive parts. Try to locate the problem area and if possible reduce the space inside the hive in that spot so that the remaining space is not less than ⅜” (10mm).

Here are a few examples of how to avoid burr comb…

Make sure you have your frames arranged so that they are tight up against each other and evenly spread out across the hive box. Frames are designed with bee space in mind. Doing this will leave only the amount of room needed for bees to pass between the frames. The remaining gap should be too small for building comb and too big to fill with propolis. This is especially important if you’re starting a new colony. If the spacing is wrong then bees will start building comb as they please. You don’t want bees building across the frames rather than along the frames. If left uncontrolled it can lead to more problems.

If one of the frames has badly built comb you can try to get bees to modify their building behavior by moving the frame away from the center and placing it next to another “good” frame. Use a long-bladed knife to slice off any unwanted wax so the honeycomb fits.

In the spring when you finish feeding bees during the cold months, try to remove any feeding shims you put on the hive as early as possible. The extra space provided by these top feeders can be taken as an opportunity to build comb. It’s just a shame to let bees waste time building so much wax that ends up getting taken away, especially if it contains brood.

On a Langstroth hive, some people use a slatted rack underneath the brood box (this is said to improve airflow in the summer and prevent chilling in the winter). Be careful to install slatted racks the right way round. The slots should run in the same direction as your frames. Also, slatted racks have a shallow and deep side. The shallow side must face upwards or you will create extra space which can get filled with burr comb.

What to do with Burr Comb

Once you’ve collected all that lovely beeswax there are a number of things you can do with it. Beeswax is an amazing natural substance that you can use for making all kinds of products such as candles, lip balm, body lotions, soaps, or just plain beeswax polish.

You’ll probably want to wait until you have enough of it to make it worthwhile melting down for making beeswax products. In the meantime, you can store it in plastic wrapping or putting it in freezer bags and keeping it in a cool place.

Before you can use beeswax for making products you need to clean it up. It will probably be full of honey and nectar which will dissolve easily if washed out in water. If you’re keeping the cleaned wax for later make sure you store it in a freezer. Otherwise the added moisture will make the beeswax ferment.

Burr comb isn’t an uncommon occurrence so don’t be surprised if you find some. Simply try to remedy the situation that gave rise to the unwanted comb building.