I’m a true believer in moisture quilts as the best overall ventilation and moisture reduction aid for Langstroth hives in the winter. I’m a true believer because I’ve seen soaking wet hives become dry as a bone within a week of having moisture quilts installed.
Empty moisture quilts are excellent ventilation aids in the high heat of summer too, allowing the bees to regulate the temperature of the brood nest with less fanning and to cure honey sooner. Moisture quilts are also really cheap and easy to make. Everybody wins.
I’ve used hard insulation over the inner cover to reduce condensation inside my hives too. It worked well enough to get all of my colonies through at least two long, snowy, wet winters in St. John’s, Newfoundland. I always found some condensation inside the hives, but nothing that seemed to hurt the bees. The hard insulation method didn’t fail me until I moved my bees to a community called Logy Bay, one of the foggiest places on the island of Newfoundland.
And that’s when all of my colonies (I think I had eight at the time) nearly perished from condensation soaking through every frame of their hives. I opened the hives one day and it was as if someone had sprayed the bees with a hose. Everything was dripping wet.
I immediately converted some ventilation rims to moisture quilts by stapling screen underneath them. It wasn’t pretty or neat but it did the job. I then filled them with wood chips and installed them on my hives and just like that, even during one the foggiest, wettest weeks of the winter, all the moisture was wicked away from inside the hives and my bees were saved from certain death. Hurray for moisture quilts!
So if I had to pick one piece of cheap and easy homemade equipment to keep my bees alive all winter, it’s moisture quilts. I know of commercially available ventilation hive pieces that supposedly do a good job at keeping hives dry, but they add about another $100 to the total cost of each hive. That’s not much of an option for five-figure-income people like me. Most of my moisture quilts cost me less than $10 to make, with minimal carpentry skills required. What’s not to love?
Nonetheless, a piece of hard insulation over the inner cover is even cheaper and easier to make than a moisture quilt. And because I’m more keen on demonstrating a version of beekeeping that’s accessible to as many people as possible, I’ve decided to use only hard insulation on two of my hives this year. I definitely would not do this if my hives were still in the fog-drenched region of Logy Bay. But my hives are now in Flatrock, a place that isn’t half as foggy as Logy Bay, or even St. John’s for that matter (based on my personal observations from living in Flatrock for the past five months). My hives are in a well sheltered, elevated spot where fog doesn’t stick around for long. I think they’ll do fine without moisture quilts. If I notice condensation building up inside the hives with hard insulation, it’ll take me two seconds to drop a moisture quilt on top and fix it.
So let the games begin: Round 1 of Moisture Quilts vs Hard Insulation! This is what it looks like:
I placed a rim over the top brood box to make room for dry sugar that I might have to give the bees later in the winter. The top box (or deep) should be full of honey that will keep the bees alive all winter, but I have to be ready for the worst.
I put the moisture quilt full of wood chips over the rim. The rim (a.k.a. a spacer or an eke) is about 2.5 inches or 6 centimetres high. It could be higher. The screen stapled to the bottom of the moisture quilt bows down a fair bit from the weight of the wood chips. I haven’t perfected the design of the moisture quilts, and I don’t care. The rough ones I first slapped together still work fine.
This is what it looks like just before I add the top cover:
“The wood chips are light, fluffy, and basically the same temperature as the air above the brood nest, so the moist air does not condense on the wood chips at all. Instead, the humid air rises and goes right through the canvas† and the two inches of wood chips until it hits the cold inner surface of the telescoping cover. Once it hits that cold surface, the moisture condenses (just like in a regular hive) and then rains back down. But instead of the drops falling on the brood nest, they land on the wood chips and are absorbed. It is just so cool!”
You got that right. It’s the coolest thing to open a hive in the middle of winter and notice that a round patch in the wood chips are moist, but dig a little ways underneath them and all the chips are dry, just like the warm and toasty bees down below.
The wet chips never get soggy because the moisture is pulled out through the ventilation holes. It’s brilliant.
† Rusty uses canvas in her moisture quilts instead of metal screen. Canvas is obviously better at keeping the wood chips separate from the bees. Some of the smaller particles of the wood chips fall through my screen, but it’s not much and the bees have no trouble clearing it out of the hive. Most of it falls down to the bottom board anyway.
An advantage to using screen instead of canvas: I can look through the screen and observe the bees clustering below.
Now moving onto the less scintillating but nonetheless respectable hard insulation method. The set up for this hive also starts with a rim, this time a solid rim without an entrance hole drilled into it. Then the inner cover in the winter position, which means the flat part is on top and the entrance notch opens right into the hive. I keep meaning and forgetting to tape over the inner cover hole. I don’t think it matters. Supposedly the bees can chew away at the insulation and make a mess, but I’ve never had that happen.
The thick piece of hard insulation has an R-7.5 rating. I don’t know what that means. All I know is the insulation keeps the cold out so that whatever moisture or humidity rises to the top of the hive is more likely to leave through the top entrance instead of condensing on the ceiling and dripping down on the bees. Here’s what it looks like with the cover on top:
I have five honey bee colonies going into winter this year. Three of their hives have moisture quilts set up exactly as I’ve shown. Two of them have hard insulation on top. Normally I’d use moisture quilts on all of them because I know they work no matter what the weather conditions. But I’m also aware that not everyone who takes on beekeeping as a hobby can build things. Period. Or has the money to build things. So as much as I love moisture quilts, I think it might be helpful to demonstrate the cheapest and easiest method of over-wintering honey bees in a Langstroth hive using hard insulation, and comparing those hives to the hives with moisture quilts. Let’s see what happens. To be continued…
P.S.: My hives also have quarter-inch / 6mm mesh over the bottom entrances to keep shrews out. I’ll put mesh over the top entrances soon as well. The duct tape fills in some of the cracks between the deeps, though I’m not sure it’s necessary. I’ve chosen not to wrap my hives with Bee Cozies or roofing felt or any of it this year. That could be a mistake, but I’ve had several hives over the years survive the winter without any kind of wrapping, and none have died that weren’t wrapped. So let’s see how that works out too, shall we? Either way, I’m glad to be done with the bees for the season. It’s been difficult building my colonies back up from nearly being destroyed by shrews last year. And I’m still not sure what will happen over the winter. Two of the queens are getting old and could die before the spring. The new colonies seem healthy with plenty of honey, but they’re not massive. I’m not sure how well they’ll react to extreme weather if any comes along. But in theory, I shouldn’t have to touch my hives again until April. I won’t be taking any bets on that one, though.
November 10th, 2015: I had to kill the experiment, though not necessarily because the hard insulation wasn’t working. I wrote about in Switching Out Hard Insulation for Moisture Quilts.
February 12th, 2016: I killed the experiment as a better-safe-than-sorry precaution. But I don’t think it was necessary. I think the hard insulation would have been fine.
July 2019 Postscript: I’ve had mixed results with hard insulation where I keep my bees in Flatrock, but I’m not sure I can blame those mixed results on how I winter my bees. At the moment, I would say Flatrock is the worst place I have kept bees on the island of Newfoundland. It’s the worst place because it’s close to the ocean. Specifically, it’s close to the bee-freezing Labrador Current, which I can see from my house. I keep bees in another location farther inland away from the ocean, and those bees do remarkably better than my bees in Flatrock and always have. I’m not sure if hard insulation or moisture quilts would make much difference to my bees in Flatrock. There’s only so much that can be done to fight off the Atlantic Ocean.