beekeeping equipment ventilation

Hive five: equipment to improve summer ventilation

Summer is coming to a close even though it was nearly a “non-summer” here on the Pacific Northwest coast. The corn hasn’t tasseled; the peaches look like walnuts. Nevertheless, my bees are healthy and I had a good honey harvest—much better than expected. My honey was capped and my hives are dry inside. What more could I ask for?

This is just a quick review of ventilation equipment I used this year. Although there are others, these are my favorite five.

Screened bottom board: In my opinion, this is a must-have piece of equipment. Whether or not it effectively controls mites is anybody’s guess, but it is great for ventilation. It allows large volumes of air to enter the hive while keeping out mice, large insects, wasps, and other bees.

Screened inner cover: In order for air to move through the hive, it needs a place to go. The screened inner cover is my favorite choice for reasons similar to the the screened bottom board. It allows plenty of air movement but blocks entry to predators. Before I began using them, the tops of my section boxes frequently became stained with mildew because moisture got trapped beneath the inner cover. Now that problem is completely gone. Also see, “How to make a screened inner cover.”

Ventilation eke: I used ventilation ekes on a few hives where I was short of screened inner covers. These worked almost as well and would have worked even better with more holes. The ones I used had four holes, two on each of the long sides. In the future I will add at least one hole—and maybe two—on each of the short sides as well. The ventilation eke is an economical solution because I can staple canvas to the bottom and use them as moisture quilts in the winter.

Slatted rack: The slatted rack improves ventilation because it gives the bees a place to congregate inside the hive. This allows better air flow through the hive because the bees are not filling up the bee space between the frames. On hot days the bees hang in beards from the slats instead of jamming up the front entrance. It is especially effective when used with a screened bottom board.

Follower boards: Like the slatted rack, follower boards give the bees a place to congregate inside the hive. Unlike the slatted rack, the follower boards are at the sides of the hive. In my hives with follower boards, the bees used more vertical space for the brood nest. (Since the bees have only eight instead of ten combs per box, they expand into an upper box sooner.) This tall and slender hive structure is more tree-shaped and seems to provide a “chimney effect” that pulls the air through the hive. My hives with follower boards did especially well with honey production.

My next experiment will center on a gabled roof with ventilation ports at each end. I’m going to start with a prototype from a reader in Maryland who has had excellent success with his design. I will be using it for both summer and winter moisture management and writing about the results. Stay tuned for more about the ventilated gabled roof.

Honey Bee Suite


  • This past week has been a huge eye-opener for me. I’ve seen how humidity pours out of my hives. How do the bees live in it? I’ve had to build all my ventilation aids myself, and I’m a terrible carpenter, so it’s been a slow process of building and installing follower boards, ventilated inner covers, screened bottom boards and ventilation ekes, one piece at a time. But already I can see the difference in my hives.

    It’s kinda cool (no pun intended).

    • Good for you, Phillip. Your bees won’t care if you are a lousy carpenter; they will appreciate your efforts. They might even make you some honey.

  • Rusty, do you have any idea why a hive with a laying queen and plenty of bees and brood would have zero zip zilch stores of honey this time of year? They have several frames of pollen (I saw at least three) and several frames of brood (again – at least three full frames), almost no drones, fresh eggs in the brood nest, and not even 1 capped cell of honey. They were so angry (chasing me around the yard, stinging me at least 4 times… I almost never get stung, not to brag, just to speak to their normal temperament). I thought they were being robbed and that’s why they were so mad, but I can’t find any evidence of this in the hive (i.e. no bodies, signs of battle, ripped open cells). The hive next door to them (your former bees!) are going along swimmingly, bringing in nectar and pollen even now, building comb, and they have boxes and boxes of honey, so I don’t think it could be a summer-long dearth. I’m google-ing and researching, of course, but you know more than most of those people anyway. I guess I’m going to feed them but…

    • Jess,

      As counter-intuitive as it seems, I vote for robbing. Angry, aggressive bees are often the result of robbing and it is possible that the robbing occurred many days before you inspected the nest. If that was the case, the mess of dead bees and damaged combs may have been cleaned up by now. I would say it was invaded by bees (maybe the little darlings with all the honey?) and not wasps or yellow jackets because those probably would have taken the bee bread, larvae, and eggs as well.

      Why couldn’t they defend themselves? I have no idea, unless the colony was just much smaller than the other one. I can’t imagine that one colony found foraging grounds and one did not, so the odds are with robbing. But, of course, no guarantees.

      I would hold back some frames of honey from your other hive for winter feed. I would also reduce the entrance to the empty hive and cross your fingers for a fall nectar flow.

      Absconding often occurs after a hive is relieved of its stores, although with eggs and brood in the nest it shouldn’t happen. In any case, a little feeding should keep them home.

      I’ve seen this happen before and it’s pain to deal with an empty hive going into winter. I think you will have to either equalize honey stores, feed like crazy, or end up combining hives unless we have a stellar fall nectar flow.

      If other folks have different opinions, I’d like to know. No matter how irritating, it is also interesting.

  • Rusty,

    Do you buy or make your bottom boards? I’m looking for a plan for bottom boards where you can insert the election sign below the screen to address excess ventilation during the winter months.

    I must agree with Phil, during the summer months the bees require additional ventilation. I have already made ventilated ekes for all my colonies but I am realizing that the ventilated bottom board is also important.

    Thanks Rusty

    • I buy my bottom boards and, yes, I have the type where the “election sign” (Varroa drawer) slides in and out under the screen. I leave the Varroa drawer out of the hive in all but the most extreme temperatures which, for me, means less than 20 degrees F (about -7). If it were extremely windy I might close them up as well, but that is rare for here.

    • Jeff, the combo screened bottom board I made has the election sign on top of the screen (because it’s easier to make it that way). Sliding the sign in will reduce the space between the floor of the hive and the bottom bars of the frames, but the reduced space probably isn’t an issue because, in Newfoundland, we’d likely only cover the screens in the winter when the bee aren’t coming and going and don’t need as much extra space on the bottom anyway.

      I don’t have my combo board installed on any of my hives yet, but I’m tempted to test it out on one of them over the winter.

      By the way, Jeff, the ventilated ekes combined with the prototype screened inner covers I put on my hives this summer was the magic combination. I can’t say anything with certainty, but my hives exploded into the honey supers with 24 hours of my installing the screened inner covers.

      It’s impossible for solid inner covers not to hold in some moisture. But screened inner covers let it all go, and then most of it escapes from the holes in the ventilation ekes (or ventilator rims as I call them). My hives this summer were dry as a bone after I put on the screened inner covers. How can that not be a good thing?

  • Phil,

    I’m going to make 8 or 10 screened bottom boards for next year and the existing boards I made this year I will use for double nuc boxes next year. I think our July, August and early September temperatures are good enough to support screened bottom boards and considering there is a major nectar flow at that time it is no better time to have good ventilation.

    Thanks again Rusty and Phil

  • Rusty . . . I am setting up my hives to follow your Hive Five: to improve summer ventilation. I have a few questions. I plan to add ventilation screens when night temperatures average 50 degrees . . . Will robbing be increased with ventilation screens? Will hive beetles be less due to less moisture and more light in top part of hive? Should ventilation screen be placed on honey box with Imirie shim and then hive top placed on it or should top just be placed on top of ventilation screen?

    • Herb,

      Your screens should have fabric that is small enough to prevent robbers, wasps, and wax moths from entering through it: 8 squares per inch works just fine. With proper screening, robbing will not occur through the top. Hive beetles don’t like light, but your screen doesn’t admit light because it is covered with a telescoping cover. However, decreased moisture can reduce the SHB population as they need quite a bit of moisture to reproduce.

      If a screen is built correctly, you don’t need the Imirie shim. See a photo here: The two end pieces hold the telescoping cover away from the screen so the air can move over the sides of the screened cover and then out from under the inner cover.

    • Rusty . . . will small hive beetles enter through the 8 mesh screen? Will I need to cover ventilation openings with screen wire? I will make ventilation screens like the picture example you provided and place hive top on ventilation screen. Thanks for advice.

      • Herb,

        Yes, small hive beetles can get through a #8 screen or any other space that is about 1/32 of an inch (#8 screen is about 4/32″–more on the diagonal). If hive beetles are a problem you can cover the holes with window screening.

  • Hello Rusty,

    I have a ventilated inner cover, however, the “palmetto” (i.e. roaches) think it’s great to live between the ventilated cover and the top cover. I’m disgusted by the thought of the cockroach droppings going through the cover into the hive (although I know the bees will likely encapsulate it). What are your thoughts? Thank you. Loretta

    • Loretta,

      Make a ventilated inner cover by taking a small eke (a two- to three-inch super) and drilling one-inch holes along both sides and cover them on the inside with 1/8-inch hardware cloth. Then cover the bottom with 1/8-inch hardware cloth. The will give you plenty of ventilation without entertaining the palmetto bugs. See the photos here for making a moisture quilt, only use hardware cloth instead of canvas, and don’t put anything inside. I use my empty moisture quilts in place of screened inner covers all the time.

    • Jennifer,

      Not really because top-bar hives can be so different from one another. I use follower boards and a screened bottom on my top-bar hive, and it has a ventilation hole below the roof. The bees seem to do fine with that much ventilation, although my top-bar hive is in shade all day long, which keeps them cool.

  • Hello Rusty,
    I would like to start using a screened inner cover. I have realized that if I am using it that I will not be able to use my one-gallon sugar water feeder. What type of sugar water feeder do you use which the screened inner cover will accommodate?

    • Gaye,

      Use any type of feeder that you can put a box around and put the screened inner cover above that.

  • The one gallon sugar water pail fits well on top of a solid (with an oval cut out in center) wood inner cover. But, if I put the screened inner cover atop a super that houses that one gallon pail, aren’t I loosing the potential benefit of ventilation that the screened inner cover offers? I guess I could fabricate an inner cover with a slightly larger oval, in order to allow better air flow around the sugar water pail. As it is now, the pail completely covers the oval opening in the wood inner cover. Maybe I’m obsessing obsessively and there is still more ventilation offered with the screened cover atop my present set-up than if I had only the telescoping cover atop the super. Thoughts?

    • Gaye,

      I envision a solid inner cover with some large holes cut through it (say an inch or so, one in each corner) and then covered with hardware cloth or window screen. I usually just staple the screen on top of the cover. Air goes through, bees do not. If you have a hole saw, this doesn’t take long. You might get a friend to do it if you don’t have the tools.

  • Hi ,

    Thanks for this website, I really love it !!

    I just wanted to ask do you use the moisture quilt boxes all year round or just in the winter?

    I’ve just overwintered the hive (first-year keeping bees) and there was a bit of dampness.

    Not enough ventilation holes in the roof. But I think I’m going to make a quilt box.

    A friend uses hemp insulation above a starched cloth then a ventilated roof.

    I think I might research to see if I can make some kind if starched cloth, hemp insulation, wood chip quilt box combination.

    As I want to conserve as much heat as possible in the winter at least.

    In the summer keeping the hive cooler might be a priority, a lot to think over.

    Anyways thanks again for all the content you share, it’s really helpful.


  • Thank you for your excellent and helpful site!

    Question: why are my bees starting to propolize their inner cover vent hole? We think all our bee space measurements are correct and it’s up to 90 degrees and humid in the day (southern Ohio August).

    Should I clean any off? I find no info about this on the internet. Thank you

    • Kisten,

      Honey bees tend to propolize openings they think are too big. You can scrape it off or not, depending on what you want. They will most likely put it back eventually.

  • Hi Rusty,

    I am a new beekeeper. Do you use screened inner covers summer and winter. Also in what order do you place the ventilation eke, screened inner cover, moisture quilt, and feeder eke?

    • Kelly,

      I do not use a screened inner cover in winter. For overwintering, I put a candy board or feeder eke directly over the brood box. On top of that goes the moisture quilt with its build-in ventilation ports. Then an outer cover.

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