Moisture Control

Newspaper filling the space within the formic shim above the inner cover to absorb moisture.

In some locations in the United States moisture can kill honey bee colonies over the winter months. This moisture is caused by the condensation of the water vapor as it rises from the cluster and cools at the interface between the warmer and colder air. This interface is usually at the inner cover in most hives. Bees can be killed by moisture if it builds on the inner cover and rains down onto the bees when clustered. The bees can tolerate the cold but not when they are wet. Many beekeepers will place an empty hive body above the inner cover for added protection against the cold. Some beekeepers will place different substrates within the space above the inner cover to soak up the humidity. I have heard some using compressed cardboard or even hay. There are many different materials to choose from and I use newspaper since it is fairly cheap. I crumble the newspaper into balls and place them in an empty hive body above the inner cover as shown below. You can see I put an open sheet over the top; it is easier to use as an indicator if the paper is wet when you pick this sheet up. In the picture above I used a formic acid shim instead of a hive body to place newspaper into. The newspaper can become saturated quick depending on the weather. It is important to remove and replace the newspaper once a week to prevent mold. If you are using screen bottom boards, you may need to change the newspaper more or less frequently.

Newspaper filling the space within a medium hive body above the inner cover to absorb moisture.

Written By: Rob Snyder

Rob Snyder has written 66 post in this blog.

I currently work out of the Butte County Cooperative Extension in Oroville, CA as a Crop Protection Agent. I received my B.S. in biology from Delaware Valley College, PA. There I attained a majority of my entomological knowledge from Dr. Chris Tipping and Dr. Robert Berthold. After graduation, I was an apiary inspector for 2 years at the Department of Agriculture in Pennsylvania. In my third year there, I still inspected some colonies but I mainly focused on The Pennsylvania Native Bee Survey (PANBS) where I pinned, labeled, entered data and identified native bees to genus species. Leo Donavall assisted me in learning the basics on positive Identifications of the native bees. Around the same time I began working on coordinating kit construction and distribution for the APHIS National Honey Bee Survey. I was also fortunate to conduct many of these surveys with fellow co-worker Mike Andree and Nathan Rice of USDA/ARS throughout California. All of these experiences have led me to where I am today, working to assist beekeepers in maintaining genetic diverse colonies resistant to parasites while reducing the use of chemical treatments in colonies. The BIP Diagnostic Lab at the University of MD is in an integral part of this process by generating reports in which we can track change and report to beekeepers vital information in a timely manner which may influence their treatment decisions.


17 Responses to “Moisture Control”

  1. john bailey

    have had real problems w/moisture in past. some of my hives are in very low spots. in bee culture mag ,i fount a product called a top hat advertized,and bought 10 of them. it actually has a metal dome in top that condenses the moisture ,which runs into a small gutter on either side,and is piped out of the hive. have used it for the last 2 years w/very good results. this may be too expensive for large operations but is perfect for the small operator.

  2. Mary Colebeck

    We live in Tennessee and we just started with a swarm. we Have them all decked out in a hive. we are seeding them with a pollen syrup feeder w/ liner. I know I can’t use it all winter bur I want to know if once the feeder is taken away do I need to put our vented super on the top under the outer metal cover. We do have a vented screened bottom board. Do I use both or only 1? which one is best?

  3. Rob Snyder

    You can use both, The top entrance is key to let moisture escape. It is best to use some sort of screening to keep pest out though. If you add an extra hive body under the top cover it is best to use place a inner cover below that hive body, this creates and insulated space. In that space (the one pictured above) if you dont put news paper in, the moisture will build up on your telescoping cover and eventually mold. This is why I started adding newspaper, its easy and cheap. There are a plethora of materials you can use. There are also many different ways to manage moisture, the key is to look at the hive every now and then to see whats going on. It is also good to lift the hive from the bottom to check food stores. If its light you may want to feed sugar candy or fondent.