Wintering Bees and Insulated Inner Hive Covers

This 2-minute video pretty much covers everything that I write about in this post.

(I just noticed a typo in the video. Damn. “27°C” should be 27°F.)

It’s November 2018 and I’m rewriting this post from 2010 to keep things up to date. The topic here isn’t how to make insulated inner hive covers. The topic is winter beekeeping and keeping bees alive over the winter, which includes insulating the hives in some manner. Let’s get right down to it:

Step 1: Make sure the bees have enough honey or sugar syrup to get through the winter. I do this by leaving the bees as much honey as I can and then feeding them thick syrup in the fall until they won’t take it anymore. (I often skip Step 1 when I know a hive is loaded down with honey. 10 to 12 deep frames of honey are enough to keep most honey bee colonies alive all winter, or so they say.)

Step 2: Put 6mm (quarter-inch) mesh over the bottom entrances once it becomes too cold for the clustering bees to defend the entrance, usually sometime in October. The mesh keeps mice and shrews out of the hive. The mesh can go on the top entrances too. Half-inch mesh is fine for keeping mice out, but it doesn’t work for shrews. (One statement in the above video is wrong. Drones can squeeze through the 6mm mesh. They don’t like it, but they do it.)

Step 3: Insulate and ventilate the top of the hives. Insulation on top (e.g., a piece of hard insulation) and an upper entrance or ventilation hole reduces the likelihood of condensation building up and dripping down on the bees and killing them. The goal isn’t to keep the bees warm. It’s to keep them dry. Even in the cold of winter, dry bees can usually keep themselves warm by shivering. Wet bees are dead bees because they can’t shake off the damp no matter how hard they try. Cutting out a piece of hard insulation and placing it over the inner cover (and under the top cover) will work fine under most conditions.

Hive with 1.5 inch R-7.5 insulation over inner cover. No outer cover. (Nov. 2, 2010.)

The photo doesn’t show the mesh over the bottom entrance, but close enough. The size of the bottom entrance can be reduced with a block of wood or whatever to cut down on cold wind blowing over the bees — but some kind opening on the bottom helps with air circulation which keeps the bees dry.

Step 4: Wrap the hives. People wrap their hives to create a windbreak and to keep the bees warm. I’ve always used #15 roofing felt because it’s cheap and it works. Here’s a quick video on that:

I haven’t used what some call a “bee cozy” or any other kind of blanket or insulation to wrap my hives. I’d consider it if my hives were in the path of extremely cold and consistent winter winds, but it’s an extra expense (and hassle) that I’m not sure would benefit my bees. Most of my hives are in a well sheltered area surrounded by spruce trees. They don’t need the windbreak. Most of my hives are painted dark green, so whenever the sun shines on them, they warm up. I use tight roofing felt to increase the radiant heat on any hives that don’t get much direct sunshine in the winter. Most of my hives only have a piece of hard insulation on top and mesh on the bottom and that’s it. They do fine if they get buried in snow. Snow is an excellent insulator and windbreak. Heavy snow doesn’t usually matter much as long as the hives have ventilation on top.

Cheap, homemade moisture quilts can provide ventilation and insulation up top too. Here’s a quick video demonstration of a moisture quilt:

Moisture quilts saved my bees after I moved them to an area that was swamped in fog for most of the winter. The frames, the bees, everything inside my hives was wet. I quickly converted all my ventilation rims to moisture quilts and within days, all my winter hives were bone dry. It was amazing. So for that reason, I highly recommend moisture quilts. For many people, hard insulation over the inner cover is fine. But come January, if I find any moisture inside my hives, I immediately switch over to moisture quilts. They’re easy to make and cost me maybe $15 each. It’s worth it.

A hive design that incorporates a ventilation box, based on what’s called the D.E. Hive, is sold by Gerard Smith in Placentia. It looks like this:

Single-deep hive with ventilation box on top, sold by Gerard Smith in Placentia, Newfoundland.

The ventilation box is more or less one of my patented and trademarked ventilation rims with a larger box full of holes placed on top. Apparently it works well for insulation and ventilation all year round. Which is pretty convenient. I haven’t used one yet because I put way too much time into the design of my ventilation rims and moisture quilts to just throw them to the wind. Ventilation boxes would also add at least another $60 to the total cost of each of my hives. Installing a deep with ventilation holes on top might produce a similar ventilating effect more affordably. I’m not sure. Either way, ventilation boxes work in Newfoundland.

So there are more than a few ways to insulate and ventilate a hive for the winter. I usually go with the easiest and cheapest method. But it doesn’t really matter as long as the bees are dry.

Step 5: Right, these steps for keeping bees alive over the winter. Next step: Winter feeding. Sometimes the bees run out of honey, usually because silly humans took too much honey from them in the summer. That’s when having a rim, like the one in the video below, comes in handy. Here’s a hive with a yellow rim on top (and all kinds of junk in the background):

The rim goes underneath the inner cover or the moisture quilt to provide room for some kind of sugar feed. The sugar feed can be hard candy or fondant or dry sugar poured over newspaper. They all have their pros and cons. These days I go with sugar bricks because they’re cheap and easy to make and easy to slide inside my hives. Here’s a quick video that shows how I do it:

I don’t bother with scoring the sugar to make smaller bricks. It’s easier to just put in one big brick. I sometimes mix honey in with the sugar (because I hear that honey bees really like honey), or a bit of lemon grass oil or anise extract, to encourage the bees to at least take a sniff of the sugar bricks. If the bees are below the top bars, sometimes they won’t even come up to taste the sugar (and they starve instead) because the plan ole sugar doesn’t smell like food to them. But most of the time it works.

Winter feeding can also include adding pollen supplement to the sugar or just giving the bees pollen patties later in the winter. But that’s more of a cheat to get the queen laying earlier than she naturally would so a colony can build up more rapidly in the spring. It can also trigger swarming as early as May (which I know well). It can also lead to a late-winter or early spring starvation — all the bees die. Here’s the math for that one: Winter pollen (leads to) → queen laying early → more mouths to feed → no nectar coming in until May → no honey → no food → starved out colony. When I feed pollen, I have to be ready to feed sugar or sugar syrup (and lots of it) just to keep the bees alive, and I have to be ready to deal with swarms. I’m usually not in the mood for that kind of drama, so I don’t provide pollen unless the colony seems weak and needs a boost.

THE END… unless you want to read the original post from 2010 with all the updates I added to it over the years, then okay, fine, here it is…

The two insulated inner covers with venilation holes / top entrances cut in front.  (Oct. 15, 2010.)

The two insulated inner covers with venilation holes / top entrances cut in front. (Oct. 15, 2010.)

2015 Introduction: I made these insulated inner covers once and didn’t make them again because a piece of insulation over the inner cover in the winter position works just as well and requires no work other than cutting the insulation. I also use moisture quilts instead of hard insulation. See the updates at the bottom of this post for all the details.

Winters in St. John’s, Newfoundland, provide a messy mixture of rain, snow and high winds with irregular periods of freezing and thawing. Wrapping Langstroth honey bee hives with a Type 15 asphalt felt isn’t a bad idea. Preventing condensation, though, is the top priority. A 1-inch thick piece of R5-rated hard insulation over the inner cover in the winter position apparently will prevent condensation from building up inside the hive during the winter. I used a 1.5-inch thick piece of insulation during my first winter (because I couldn’t find anything else) up until the end of January. Then I had to switch to insulated inner hive covers because the regular inner covers don’t provide enough room for candy cakes and pollen patties. A shim (or rim) lifting a regular inner cover up an inch or two would provide enough space. However, an all-in-one insulated inner hive cover might be more convenient. It requires moderate carpentry skills (which means I’ll probably go with the shims instead), and it’ll cost a little more, but here’s how I made them if anyone is interested. I’ve tested them, and they work.*

You will need a piece of lumber close to an inch thick and 2.5 to 3 inches inches high (to be cut into 20 and 15 inch long pieces). You will need some 1-inch thick R5-rated hard insulation (cut to fit inside the cover’s outer frame). You will need a thin sheet of wood or high-density fiberboard (also cut to fit inside the frame). You will need some short thin nails. You also will need some screws and maybe some carpenter’s glue.

Frame for 1 of 2 insulated inner covers. It's essentially a rim, a spacer, an eke. (Oct. 15, 2010.)

Frame for 1 of 2 insulated inner covers. It’s essentially a standard rim, a spacer, an eke. (Oct. 15, 2010.)

The following instructions aren’t precise, but they don’t need to be. What you’re aiming for is a frame the same width and length as a regular super that will hold a piece of hard insulation about two inches above the top bars in the top brood box. The insulation prevents condensation build-up. The space beneath the insulation provides room for candy cakes, pollen patties — and the bees. My bees clustered heavily at the top of the hives during the first winter, probably from running low on honey. At least 2 inches, maybe even 3 inches, of space would reduce the likelihood of the bees getting squished after the pollen patties and candy cakes are added. Without the extra space, the bees cling to the inner cover and get squished by the pollen and candy cakes when the cover is put back in place. That’s why the height of the frame can be anywhere from 2.5 to 3 inches. It depends on how much room you want to give the bees.

1) Cut the lumber into 15 and 20 inch pieces and screw them together to make a frame that will fit over your top brood box (see the above photo). The side pieces are 20 inches long. The end pieces are 15 inches long. The exact dimensions may vary depending on what kind of supers you have. I somehow managed to screw them together at more or less right angles so the frame fit right in line with the top of a super. But it was pretty rough. A T-square comes in handy.

2) Cut a piece of hard insulation so it fits snugly inside the frame.

Cutting the insulation for the inner covers. (Oct. 15, 2010.)

Cutting the insulation for the inner covers. (Oct. 15, 2010.)

The dimensions will vary. Mine turned out to be 38cm x 47cm, whatever that is in inches.

The top of the cover. The insulation is level with the wood frame. (Oct. 15, 2010.)

The top of the cover. The insulation is level with the wood frame. (Oct. 15, 2010.)

If the lumber is 3 inches high and the insulation is an inch thick, that should leave about 2 inches of space beneath the insulation (or in this photo, above the insulation). My lumber was 2.5 inches high and the insulation was 1.5 inches thick. It left me with only an inch of space, which I discovered was barely enough room for candy cakes and high clustering bees.

3) Cut your thin sheet or wood or high-density fiberboard to fit inside the frame, and place it right on top of the insulation. Brace the board in place with thin nails like this:

Then held the thin wood in place with nails. (Oct. 15, 2010.)

Then held the thin wood in place with nails. (Oct. 15, 2010.)

I drove the nails in at an angle, and then banged them down flat to hold the board in place. The board should fit a little loosely into the frame so you can see bits of the insulation through the cracks on the outer edges.

4) Cut a normal sized ventilation hole / top entrance at the front of each inner cover. Once the bees have been fed for the winter, the insulated inner cover is placed over the brood chamber to replace the regular inner cover. The top cover is placed as usual on top of the insulated inner cover. And that’s it. The top entrance may not be sheltered by the outer cover, but our bees didn’t seem to mind.


For the less carpentry-inclined beekeepers, a simple piece of insulation over a regular inner cover like this will also work (show here without the top cover on):

Hive with 1.5 inch R-7.5 insulation over inner cover. No outer cover. (Nov. 2, 2010.)

Hive with 1.5 inch R-7.5 insulation over inner cover. No outer cover. (Nov. 2, 2010.)

But when it comes time to add any pollen patties or sugar cakes, you’ll need to use a shim (or rim) to provide an extra inch or two of space.

* I tested the insulated inner covers and the simple piece of insulation over regular inner covers, and they both did a great job at preventing condensation over the winter. But note that I used 1.5-inch thick R-7.5 insulation, not 1-inch thick R5-rated insulation. I was told by a local beekeeper with over 20 years of experience that R5-rated insulation works just as well. I’m taking his word for it. But if you want to play it extra safe, use the higher rated insulation instead. I will update this post if we discover any problems with these designs.

August 9th, 2011: These ventilator rims might work just as well as the insulated hive covers. I haven’t tested them in the winter yet, and I’m not sure if I’m willing to chance it. But if they did work just as well in the winter, I’d just keep them on all year and never bother with the insulated inner covers. I’ll get back to you.

August 11th, 2011: The simple piece of insulation over the inner cover works well. The only issue with that method and the insulated hive covers is that there’s not enough space for candy cakes or pollen patties that are added around late January or February. Therefore, I would use a two-inch rim (or eke) for the simple piece of insulation set up, which would also work for the insulated inner cover set up. But if I make any more of the insulated inner hive covers, I’ll simply use a taller piece lumber, one that’s at least 4 inches high. I’ll probably just use a 2-inch high rim, though, because it seems like the simplest solution. Then don’t forget to wrap your hives.

October 18th, 2011: Some beekeepers place the piece of insulation under the inner cover, not over the inner cover like I demonstrated here. If you go that way, just make sure you still have an upper entrance for ventilation. Ventilation is key.

February 2nd, 2014: Moisture quilts can be made with a saw, a drill, a few other do-dads and minimal carpentry skills — and, for me, they’ve proven to be worth the effort (and they’re not too costly). I more or less made the moisture quilts by stapling window screen to the bottom my ventilator rims.

I made the switch from simple hard insulation over the inner cover to moisture quilts about a month ago because I noticed the insides of my hives were soaked (possibly because they were moved to an exceptionally foggy location this past year). A month later my hives are dry inside, dryer than I’ve ever seen them.

It’s still too early to make the call, but so far I’m very impressed, almost astonished at how well these things wick away all the moisture from inside the hives. Even after a month of rain, high winds and crazy temperature fluctuations, my hives are dry as a bone.

I held out on the moisture quilts until now because I was tired of always having to build something new for my hives (beekeeping isn’t the most affordable hobby for working class folk), but the moisture quilts, probably more than anything else I’ve built, seem to be worth the extra effort.

November 10th, 2015: See Moisture Quilts vs Hard Insulation for an explanation and demonstration of both methods.

November 2018 Postscript: I hope I never say things like, “Then you should do this and that,” etc. again. This post was originally written when I was bit too taken with my vast knowledge of beekeeping, as is often the folly of novice beekeepers with an academic past.

9 thoughts on “Wintering Bees and Insulated Inner Hive Covers

  1. I checked under the hood and noticed lots of condensation building up under the outer covers this morning (some earwigs too). So I cut two pieces of hard insulation to fit over the top hive feeders in both hives and placed them under the top covers. Neither hive is taking up much syrup. It’s below 10° C most days, so they’re just not making the move up to the feeders too fast. Plenty of drowned bees, but I’m not worried. Only another week until November. At this rate, I doubt either hive will be taking up much more syrup.

    I’m going to install the mouse-proof winter entrance reducers the next warm day we have. I’ll check to see if any mice are already in the hive first. (I’ve also pulled out large slugs from the bottom of the hives. Newfoundland is wonderful like that.)

    Then sometime in the first week of November, I’ll remove the top hive feeders, install the insulated inner hives covers (or I might just put a piece of insulation over the regular inner covers and be done with it) and wrap the hives in felt (or tar paper). And then I won’t touch them again until probably February 2011.

    That’s the tentative plan anyway.

  2. We just finished building 16 of your lid design. We left a 1.5 inch gap for the bees above the frames. When do you place these lids on? Are they able to winter the bees all through the winter or just early Feb onward? Currently my hives have an inner cover with screen empty box with burlap and the 1.5 inch polystyrene sheet on top of the burlap before the lid. Works great here. But I’m looking forward to the potential to feed early and safeguard against starvation.

    • When do you place these lids on?

      This is only our second winter of beekeeping, but around here we put them sometime in November.

      Are they able to winter the bees all through the winter or just early Feb onward?

      We kept them on the hives from November to early April last year.

      I’m looking forward to the potential to feed early and safeguard against starvation.

      We added four pounds of dry sugar to each of our hives on Dec. 31 as a precaution. We’ll check them again sometime in February, though I’m not convinced they’re running low on honey. The hives seemed full of honey back in the fall.

  3. Phil,

    I pulled the outer cover, Insulated cover(eke) then inner cover off several of my colonies last weekend when it was 5°C to take a quick peak. While the bees are are the top they have hardly made a dent into the candy cakes. It was good to see. If anything I have a concern they will have to much stores come spring and I need to get it out of the cells before things crystallize.

    I assume if the honey crystallized in the comb when the weather gets warm enough the bees will collect water to redissolve it? I hope.

  4. I’ve seen my bees hanging off the bottom bars in the bottom box from time to time. So even though they’re also clustering over the top bars in the top box and eating some sugar, I don’t think they’re necessarily up there because they’re low on honey. They may be up there simply because it’s warmer up there. I wish I could see how much honey they have in the bottom box.

    I’ve read Canola honey will often crystallize in the comb. I suppose golden rod honey might do the same. I have no idea what bees do with crystallized honey in the comb, but millions of years of evolution have likely provided them with some kind of solution to it. Like you said, probably water to redissolve it.

    [A few minutes later…]

    Yup, it’s not a problem:

    “…the bees will expand, consume, and clean up the crystallized honey, nicely. If they truly have to expand in a hurry, they will carry the honey crystals and dump them outside the entrance of the hive on the ground.”

    At least that’s one beekeeper’s opinion.

  5. Perfect, I have a couple of foundation frames left in the colonies that need to be drawn out. That gives the bees the chance to make some space and use up the resources. Also I plan to remove a couple of empty frames this spring to have some excess drawn foundation just in case.

    I’m hoping to have 12 – 14 drawn empty comb just in case.

    • That’s cool.

      Sorry I haven’t touched base lately. I’ve been run ragged with work. It’s feast and famine in this freelancing business. It tires me out sometimes.

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