View Full Version : moisture problem

beeman 202
01-08-2003, 07:13 PM
A serious problem in colder climates is the accumulation of moisture in hives during winter. The warm moist vapor rising off the cluster of bees hits a very cold upper reaches of the hive. The moisture condenses and freezes, only to thaw later and drip on the cluster, killing bees. This moisture also causes problems with mold and fungus, and surely contributes to other problems such as chalkbrood and chillbrood.

I would love to here a discussion of the many solutions that beekeepers have tried in their struggles with this problem.

01-08-2003, 11:33 PM
I raise one corner of the inner cover and put in a small stick about 1/8th to 1/4 diameter to keep some ventilation moving. One might also raise the back side higher so the condensation will drain to front and down the wall to the exit. We haven't been down to ten degrees yet and it was 70 today. I always enjoy this January thaw...

01-09-2003, 05:22 AM
Try a Screen Bottom board.

Michael Bush
01-09-2003, 05:53 AM
I have an inner cover with about three times as many holes covered with hardware cloth and a medium box with vents in the side and a piece of plywood for the ventilated top. Sometimes I cut the holes in the inner cover the size of a mason jar so I can put a jar on as a feeder in the spring.

Here's some pictures of the inner cover: http://www.beesource.com/eob/althive/bush/bush6.htm

Here's a some pictures of the vent box: http://www.beesource.com/eob/althive/bush/bush3.htm

01-09-2003, 07:38 AM
I leave the standard hive entrance (3/8" high) open all year round on my hives. Most of the hives have a notch in the outer cover that will allow bees to escape through the top.

This winter I am trying a new inner cover made from plexi-glass. http://www.bee-l.com/biobeefiles/barry/barry_13.htm
I have been monitoring it since it went on in the Fall and I am surprised at what I see. Contrary to what I thought, I see virtually no moisture under the inner cover once it got cold. In the Fall (when the above photo was taken) when the temps were still mild is when I saw the moisture. I would also see the bees up under the lid gathering the moisture.

I would suggest you try a clear inner cover on your hives to see exactly what the moisture situation is in your wintering hives.


[This message has been edited by Barry (edited January 09, 2003).]

Michael Bush
01-09-2003, 08:37 AM
I don't see any holes in the plexiglass. I would have expected the standard one in the middle. How difficult was the inner cover to make with plexiglass? I like the idea all year round because I can peek inside and see the activity and general health without opening it.

01-09-2003, 09:46 AM
Hi Guys, Isn't it great to have a site like this to exchange tricks, ideas and etc. Interesting to see the different kinds of inner covers. One can always learn if we always keep an open mind. We can't possibly live long enough to make ALL the mistakes.
I thought I would tell you what I have been doing. Visited a beekeeper friend and he showed me a Syrup feeder that he has used in the past. It was made by Superbee Inc. Montrose, Co. I modifyed it to suit me. It is the shape of a hive body and 4" tall. On one end you place a board 3/8" back from the end keeping 3/8" bee space down from the top.Then you place 1/8" hdw. cloth over this area and extend the hdw. cloth out over the divider board keeping 3/8" beespace between the hdw.cloth. This provides a space for the bees to come up out of the hive, over the top of the board and down to the syrup. The advantage of this is you can refill it with disturbing the bees. Place the opening for the bees to come up at the front of the hive, that way the syrup will always drain towards the bees. The one I made will hold about 4 Gal. of syrup. Sorry I don't have a way to post a picture. Questions just E-mail me. Dale

Michael Bush
01-09-2003, 10:03 AM
I have several rigged up this way. Some came that way. I think I bought them from http://www.bee-commerce.com./ Other's I have from Brushy Mountain http://www.beeequipment.com/shop.aspcame with a float and I changed them over to what you described with very little trouble. With the hardware cloth and a minimum space, making the trip down and back to the syrup works well and I have very few dead bees. My only complaint is when you do have dead bees they are harder to clean out.

I also have feeders from http://www.beeworks.com/uspage5.asp
that sit on top of the hole in the inner cover and allow you to fill them without opening the hive or facing any bees. They hold plenty of syrup for me for spring stimulus or essential oil treatments.

Speaking of moisture, that is one complaint I have with the hive top feeders. more exposed surface of syrup means more moisture. Also the syrup or honey dries out and crystalizes if the bees don't take it quick enough.

01-09-2003, 10:28 AM
Michael -

The plexi-glass cover does not have any notches or holes in it for venting or bee escape. However, this hive consists of 3 medium brood chambers and the top chamber/super has a half circle (1") cut into it right at the front bottom edge in the middle. The reason for this is these supers use to be full depth with 1" holes drilled into them for access. When I converted everything over to mediums, it just so happened that these holes were dead center where the cut was for mediums. I left them there.

So this hive has the fully open front bottom entrance 3/8" high and this half circle opening in the top chamber facing the front, between the 2nd and 3rd box.

The cover is very easy to make. I simply cut the glass the same size as the hive body, made strips of wood 3/4" x 3/8" thick and cut them to fit around the edge of it on both sides. Drill screw holes from one side through the glass so the screw doesn't catch it and attach them together. This created a space above the top bars that is more than 3/8" but as you can see, the bees only built a couple of small pieces of burr comb. If they continue, I'll put thinner wood on the one side.

It's a nice way to monitor mites. I took some pictures yesterday of a small group of bees on the top bars as it was about 60 degrees out. I was able to spot some varroa on the bees. I will post them soon. I know Dennis Murrell can pretty well figure his mite load in the hive by counting mites this way.


01-09-2003, 10:32 AM
Hi all -

Anyone is welcome to send me pictures for posting. Either attach to email as a jpeg or send me a hard copy via snail mail. Please contact me first before sending so I am aware what is coming.


01-09-2003, 02:25 PM
Hello Everyone,

My experience with a plex inner cover indicates that excessive moisture may not be as extensive a problem as generally assumed. I would suggest that everyone monitor the moisture with a plex inner cover and the share the results.

I actually fill a boardman feeder with water and keep it in the top box my 3 story hives. The feeder is left empty on the sunny side of the hive and is filled in late winter once brood rearing begins. I filled them last week.

Once the bees learn where the water is located they will break cluster and get a drink. I have seen 4 or more inches of water disappear from the feeder in a 24 hour period. The first few times I thought the feeders were leaking and would fill them up again. They might sit for a week or 10 days with very little change, then the bees would get thirst and take a drink.

Don't expect to see lots of bees drinking the water. Usually less than a dozen, even on a warm day.

When brood rearing accelerates in late winter to early spring, the feeders will be emptied in a week or so.

I remove the feeders once the bees can fly freely without danger of being frozen while foraging for water.

Best Wishes
Knowing my bees need canteens and not umbrellas

01-09-2003, 02:45 PM
Concerning Moisture, I recently bought the hive kit from www.beeworks.com. (http://www.beeworks.com.) My moisture problem is not an issue anymore. It costs a little, but it was worth more than I paid for it. Here's the link, read the detail, I think it will be worth your time.

Hope this helps.


Michael Bush
01-09-2003, 09:43 PM
I have also bought quite a few of the mod kits from beeworks. I love them.

01-09-2003, 09:55 PM
I usually put a candy pattie on newspaper over the top bars of the brood chamber and this absorbs most of the moisture plus makes the candy easier for the bees to eat.

01-10-2003, 12:15 AM
Hi all -

I posted some recent pictures of my "plex" hive showing bees under it with mites on them. Also a couple of shots of the clusters on 3 of my hives.


01-10-2003, 12:43 AM
Thanks for the pics. Barry.
One question, what size bee was the mite on?

01-11-2003, 04:16 PM
Hi Guys,
I certainly agree that this is a great way to learn and share. What I do I learned in places like this. My system is to use the Miller feeder thats on this site (with the bee access in the middle) on all year. When the feeding stops, it provides a place for ventilation. with these and the screened bottom boards I've never seen bees cluster out side. I don't use inner covers. In the winter I left them on and filled them with ceader chips. I covered the telescoping cover with aluminum on the inside and left it on a tilt. My idea was that if some warm humid air condensed on it, it would run down the cover and not back into the hive. I worry some that I left them too much air but it seems that dampness is more dangerous than cold. I'll let you know. The bottom boards are closed up for the winter.


Dave W
01-17-2003, 09:03 AM

Your plexi-glass photos are great! The one showing the "puddles" under the glass, illustrates just how much water is in the hive.

You commented that you "see virtually no moisture under the cover once it got cold".
What do you think happen?

Are see-thru covers common?

Your cover seems to "trap" moisture (no holes). What does this say about all of the techniques of removing water, like upper entrances, air gaps between suppers and covers, absorption methods, etc.

Dave W

01-21-2003, 08:46 PM
Hi Bill -

>One question, what size bee was the mite on?

All my hives are "4.9" hives. The bee was not small in size, compared to some of the bees you will see in the spring and fall. It looked like your average bee from cells in the 5.4 range. I can say with confidence that my bees have varroa, yet they are healthy.


01-21-2003, 09:24 PM
Hi Dave -

> You commented that you "see virtually
> no moisture under the cover once it got
> cold". What do you think happen?

I don't know all the dynamics involved with ventilation, but it proved to me that the moisture inside the hive during our cold winters is not a problem. When the bees are clustered and least mobile, the moisture is not there. When I do see moisture hanging under the glass, the bees are mobile and able to work it. I really expected to see a lot more moisture the colder it got. Not the case here.

> Are see-thru covers common?

Not that I know of. You have to make one if you want one. I've never seen them available for sale.

> Your cover seems to "trap" moisture (no > holes).
> What does this say about all of
> the techniques of removing water, like
> upper entrances, air gaps between
> suppers and covers, absorption methods, etc.

Good question! To me, one can spend a lot of time and money on "gadgets" to "remove" moisture, or ventilate. However, if you really don't know what is going on inside the hive, you could very well be wasting your money. We tend to assume a lot when it comes to beekeeping and do what everyone else does because if they do it, it must be the thing to do.

I talk with Dennis M. on the phone often and I'm often challenged in my thoughts. He likes to know why things are happening, and is a very observant beekeeper. The plex cover was his idea and it is just another way for us to study the bees interacting with the moisture and mites at least. I try to see what the bees do in the feral and apply that to my hives. Maybe Dennis will share some info he has about studies done in this area. He shared them with me but I don't want to get it wrong in repeating it.


01-21-2003, 09:50 PM
> You commented that you "see virtually
> no moisture under the cover once it got
> cold". What do you think happen?

Cold air is dry air, it does not hold as much moisture as warm air does. The water you see earlier while it is warmer is evaporated in the dry cold air.

01-22-2003, 07:30 PM
Hello Everyone,

Several studies coupled with my own experience caused me question the need for upper ventilation in my location.

Rodger Morse, the late Cornell University professor, surveyed feral bee colonies and set up swarm traps around Albany, NY. Swarms generally rejected any cavaties with light entering near the top. Also the bees quickly seal any cracks near the upper part of the hive. It's the first thing they do around a plexiglass inner conver when its installed. The bottom of the hive is not propolized as screen bottom boards left open remain open.

If the bees wanted ventilation at the top they could easily make a few holes like they do when a pollen trap is installed.

A series of studies published in the American Bee Journal, July, 1998, entitled "Rethinking Our Ideas About the Winter Cluster" investigated cluster size, hive insulation, etc on overwintering. The most critical factor for successful overwintering when the cluster was big enough to keep warm was water balance. Super insulated colonies and super sized colonies did poorly.

I observed the same type of behavior when overwintering hives indoors in Alaska and again in Wyoming.

Finally, my own observations with the plex cover on a hive wintered outdoors convinced me otherwise, at least in my location.

So how do the bees get the necessary water in the wild? I speculate that very little condenses at the top of the cavity, in a tree that's where most of the insulation would be. Rather the water would condense on the vertical sides where it might be absorbed somewhat by the tree, maybe as a water source when needed.

Does it happen that way in our hives? I think so. Most of the water damage occures in hives with smaller cluster and typically affects the ends of the top bars with the central portions unaffected.

I have posted some additional pictures of my plex shots at different temperatures.

Barry, feel free to post these shots on beesource if you think they might bee of value.


01-23-2003, 10:18 AM
Hello Everyone,

I had some additional thoughts on moisture problems.

Several factors could affect the results. I overwintered five frame nucs stacked in a block on top of each other. The nucs consisted of a single deep with a divider down the middle and a standard migratory top and bottom board.

Those nucs that were on the bottom, on the shady side of the stack and that had weak clusters had mold on the covers and the typical black mildew on the ends of the top bars when unpacked in the early spring.

Moisture had condensed and remained for some time on the covers. No difference was noted in the amount of dead bees in the bottoms of the nucs were seen. The clusters were just too small.

I did notice that they attempted to dry the nucs out by fanning much like they do when drying nectare during the summer. This activity would occure on good flying days early in the spring.

I wonder if hives with other problems develop problems with moisture during the winter?


Cluster size:

Dave W
01-23-2003, 10:25 AM
In a tree cavity, feral bees are protected by approx 1" of bark and 2 or 3" (maybe more) of sap wood. Thats a lot of insulation! Wood (per-inch-of-thickness) is the best insulator known. Maybe, feral hives dont sweat.

How much condensation is collecting in the frame notch? Thats the thinnest, least insulated, part of the hive. Dont old suppers rot at the notch? Having the brood clustered over the "central portion" of the bars may warm the bars. That heat is then conducted towards the ends of the bars, and meets the cold, damp air from the notch and increases the damage problem.

Maybe there is a balance between interior warmth, and necessary insulation to prevent condensation. Is that balance constantly changing with outside temperature? Maybe the easiest way, is to provide ventilation.

I believe there are three sources of excess mositure inside a hive. Condensation, when the bees are evaporating nectar, and humidity. Will ventilation work for all three?

I'll bet the very first hive cover didnt have a hole in it, and moisture was a problem. Although, I remember my granddad's 'gums', and I dont know if they had moisture inside. Maybe there is a simple solution. Hope you can help!

Dave W

Michael Bush
01-23-2003, 10:41 AM
I have a DE ventilation unit on all of my hives. This provides some winter ventilation.

The standard inner cover provides for some of that warm moist air to go up into the space between the cover and the inner cover. I have noticed condensation there when using that arrangement.

I've never used them, but there are references to cloth inner covers in several very old books and some discussion of it on this board. I was a bit confused as to the purpose, but I think helping with condensation must be the purpose. A feral hive has a lot of rough wood inside to absorb moisture also.

02-17-2003, 10:08 AM
Hello Everyone,

I have not seen the same behavior with my small cell bees that I had seen with the larger bees concerning water usage. The small cell bees have not come up and drastically dropped the level of the water in the feeder at one time. They collect the water off the cover. A few bees drink out of the feeder but no big drink by the colony itself.

This is the second year I have observed this difference. Last year my small cell colonies were dinks and I thought that their size was a factor. This year the winter cluster are very large and still no big drink.

In previous years, all of my large cell colonies would take a big drink about every 10 days.

Just an update

Dave W
02-17-2003, 12:36 PM

Are you providing plain water OR sugar water?
How are you offering the liquid? Top feeder, Division Board?
Does it freeze?
When did you start?
When do you stop?


Dave W

Michael Bush
02-17-2003, 01:59 PM
I'm not sure what bwrangler does, but I often have water in boardman feeder for a new nuc in the summer. I just figure they spend a lot of time hauling water. When starting a small nuc I think it helps free up some field bees to more important work.

I think bwrangler is using it for winter water. The need for this probably depends a lot of the climate and the length of the winter. If you have a fairly moist climate there's likely to be too much moisture condensing in the hive anyway. If you have a very dry climate (like Casper, Wyoming) and a long winter (like Casper, Wyoming) it becomes more critical that the bees have enough water to get through the winter.

I am curious also what bwrangler does.

02-17-2003, 03:52 PM
Hello Everyone,

I use a boardman type feeder in the top box, on the sunny side of the hive. I fill the feeders in January with plain water. It does freeze at times.

I start in January and stop when the bees can freely gather water for themselves without getting chilled by a sudden squal and lost while getting moisture from a snow bank. That's a very common experience in Wyoming.

Best Wishes

Dave W
03-10-2003, 02:56 PM
Greetings . . .

BARRY: Please update all of us on your Plexi-glass Inner cover.

Dave W

03-10-2003, 06:08 PM
an old timer told me to put an empty super above your inner cover and fill it with wadded newspaper,this is supposed to take care of excess winter moisture.

03-12-2003, 07:03 PM
Update on my Plexi-glass Inner cover hive.

Thumbs up! Still not much moisture on the under side. Some frost at times when it gets down in the 20's, but the bees look fine. They are now up in the top super with bees spread across 3-4 top bars showing the top of the cluster. Have not seen any mites on the bees for over a month now.

For me here, I will not give top openings for venting. All the lids I cut notches in the bees seal up anyway. Can't wait to get bees in my TBH!