# r-value of straw vs. foam



## Bear Creek Steve (Feb 18, 2009)

jmgi,

The house I built and live in is an isocyanurate structural insulated panel (SIP) house. The exterior walls are ~8 inches thick (R-36) and the ceiling is ~10 inches thick (R-42) and very snug. I insulate my hives with 2 inch rigid styrofoam on all four sides plus on the outside of the OC and the sides wraped with tar paper. They have an SBB and upper and lower entrances year round. They go into winter with a double deep and an insulated/moisture absorbant IC and weigh ~150 #. I do feed 2:1 SW as necessary through the winter.

There are many straw bale houses in my county and I am familiar with them. I would think that moving straw bales in and out and restacking them every year around individual or clusters of hives would be a good bit of work. Additionally they would have to be replaced every few years due to rot and breakup. Just MHO.

Steve


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## jmgi (Jan 15, 2009)

Steve, it would be more work compared to using foam board for sure, and then reusing the same bales every year may have it drawbacks. I would only use the straw bales for my nucs, my full size hives don't get anything except tar paper and they do fine in this area. I still think that for someone with a small number of hives or nucs it may be the way to go, you get a high r-value insulator and windbreak all in one shot. John


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## ralittlefield (Apr 25, 2011)

Do you have any particular plans for the entrance, or will you just leave a gap between the bales? Or perhaps you would just insulate the top of the hive?


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## jmgi (Jan 15, 2009)

Ralph, I don't plan to insulate the south side of the hives, just use tar paper on those sides, and then straw bales on all sides and tops, the straw will be covered with tarp, plastic, etc. to keep it dry. I don't think it would be a good idea to cover the south side too, the hive needs to absorb some heat on those sunny days so the bees can move to new food if they need to. John


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## DC Bees (Sep 24, 2009)

I have been using straw bales for several years now out on the farms where it can get windy.They work great just be sure to leave some air space in between the straw and the hive.I usually leave around one inch.In the spring when i now longer need them i spread them around the hives to keep the weeds down.


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## tefer2 (Sep 13, 2009)

I found placing bales close to the hives make a great mouse nest!


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## jmgi (Jan 15, 2009)

tefer2, Rather have them in the straw than in the hive, I use screen on my entrance so mice can't get through. John


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## jmgi (Jan 15, 2009)

DC Bees, why air space between hive and straw? Do you waterproof straw? I use alot of straw in my vegetable garden, so it would come in handy for that, but then you would have to replace it every year at additional cost, after a few years of doing that foam would be a better deal cost-wise. John


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## libhart (Apr 22, 2010)

This guy liked straw 

http://books.google.com/books?id=Pri1AAAAIAAJ&&pg=PA48-IA2&ci=117,365,787,753&source=bookclip


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## DC Bees (Sep 24, 2009)

If you place them to close to the hive mold will form inside the hives.I found this out my first year using the straw bales.I have only ever lost one hive over winter when using the straw bales and it was from cold starvation!


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## jmgi (Jan 15, 2009)

I hope that's all the hives he had to insulate, can you imagine doing that even to 25 hives? John


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## jmgi (Jan 15, 2009)

DC Bees, what would be the difference between the straw up against the hive and foam board against it? If anything it seems the straw would breathe a bit at least compared to the foam. John


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## Daniel Y (Sep 12, 2011)

That is what I was thinking. Foam is a lot friendlier to handle so add three layers. Does not have the moisture and rot issues. Not so sure about the mouse thing. Might become Micky condos. I do know mice like old dog food bags like they are the Ritz. They are a mice magnet. of course it made it easy to find them and reduce their population at any time you wanted. so knowing where they are can be a plus.


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## jmgi (Jan 15, 2009)

To get the same r-value with foam it would get awfully expensive I think, I have trouble spending $30 on just one sheet of 2" foam, just does'nt seem right. John


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## sqkcrk (Dec 10, 2005)

Does r-value have any meaning w/ bales of straw? I would think the greatest value of stacking bales of straw around hives is as a windbreak and not insulation.

Daniel Y, I don't think you will find that straw rots like hay does. Straw will take on moisture and release it, whereas hay will take on moisture and rot do to mold.

A friend of mine uses black plastic sheeting made into a bag w/ rolled insulation inside like a quilt large enuf to cover the top of a wearhouse pallet of ten 5 frame nucs hanging down each end. These work well for him.


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## DC Bees (Sep 24, 2009)

Could be the moisture in the straw,i do not cover it.This year i will be trying 2" foam insulation i got free from a friend.At least the foam can be stored for next year if it works out.


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## jim lyon (Feb 19, 2006)

We used to winter bees in central Minnesota by moving two doubles together side by side, replacing the wooden lids with "buffalo board" type of sheeting with a generous flake (about 6") of flax straw when we could find it as it was much better than wheat or oat straw that got soggy while flax straw would always retain its "body and springiness" We put a few pellets of mouse poison under the straw. Then a wrap of tar paper or wax treated cardboard carton with tar paper layed over the top and the hive lids with rocks over the paper. It worked really well, the bees seemed to stay warm and dry. On a real cold day the straw might have ice on top but be warm and dry when you felt underneath. Ideally in the fall the bees would have full frames of honey on the inside next to it's companion hive as the cluster would inevitably sense it was warmer there and move to that side.


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## Bear Creek Steve (Feb 18, 2009)

jmgi,

The pix below illustrates what I described in post #2 above.

The colony on the left will be wrapped with tar paper similar to the one on the right. On the left the stack is: SBB, pollen trap(which I failed to get off in time) a slatted rack, two deeps, a medium, a ventilated/insulated IC, an empty medium super, the OC, foam on the outside, and a gallon can of sand as a dead weight. The upper and lower entrances and the two (there are eight total) round moisture vents from the ventilated IC. The colony on the right is similar but with fewer compnents is wrapped with tar paper plus a rain/snow shield and is ready for winter. This setup permits easy winter replacement of the syrup feed can and the addition of fondant/pollen patties with minimal invasion.

The second pix illustrates an earlier version of a similar setup in dead winter 2011-2012.

Steve


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## Bear Creek Steve (Feb 18, 2009)

jmgi,

Sorry, only the second pix came across. Will try again here.

This should be the first pix.

Steve


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## julysun (Apr 25, 2012)

I think you know that if any cold air penetrates between your insulation and the hive you lose all insulation value.


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## sqkcrk (Dec 10, 2005)

Used to be that no insulation was necassary to overwinter bee hives. Then some time ago, a half century maybe, or maybe longer ago, wrapping w/ tar paper w/ a leaf of straw on top was found to increase successful Wintering in the North. Now, instead of straw on top people use more convenient and available material, like foam board.

I guess it is entirely possible that insulating the wals of a hive may mean the difference between starvation and survival for some colonies, but, for the most part, the greatest benefit of insulation appears to be at the top of a hive where a colony seems to lose the most heat. Just like me, being bald headed.

I seriously doubt that we will be seeing Michael Palmer, one of our more prominent northern beekeepers, insulating the walls of his hives. Which doesn't mean someone else shouldn't. But, just think about it before you spend time and money needlessly. Or, maybe experiment. Equalize two colonies and insulate one and not the other and see what happens.


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## Daniel Y (Sep 12, 2011)

julysun said:


> I think you know that if any cold air penetrates between your insulation and the hive you lose all insulation value.


If you want an example of this. try sleeping by hanging your blanket a couple of inches over yourself and see how warm you stay. Same idea. any gap means you wrapped your hive in air. You can do that without any foam or straw.


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## jmgi (Jan 15, 2009)

Daniel Y, I don't know if you would lose that much as long as the air space wasn't more than a inch or so, and you would have to make sure that the air space was a dead air space, in other words, you wouldn't want fresh air to have easy access into the area between the insulation and the hive. Obviously, you wouldn't be able to get it airtight, but an effort to isolate that area from the outside needs to be done as best you can. John


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## Acebird (Mar 17, 2011)

You can create a dead air space but the hive needs an upper entrance because the bottom would be sealed off. I don't think this would be healthy for the colony so in a sense it would be better to construct it like an inside hive with a pipe through the bale of hay on a bottom entrance.

Our club has had a problem with caulk brood on the inside hive that we have at the cooperative extension building. I don't know if the same would happen on an outside hive insulated to the hilt.


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## sqkcrk (Dec 10, 2005)

jmgi said:


> Daniel Y, I don't know if you would lose that much as long as the air space wasn't more than a inch or so, and you would have to make sure that the air space was a dead air space, in other words, you wouldn't want fresh air to have easy access into the area between the insulation and the hive. Obviously, you wouldn't be able to get it airtight, but an effort to isolate that area from the outside needs to be done as best you can. John


What would you expect to gain by insulating the walls of a hive of bees?

If folks are going to do this, why don't people simply buy the hives made out of foam to begin with.


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## imkerwannabee (Feb 27, 2012)

We live in a strawbale house with an estimated R-value of 45. Of course our walls are plastered inside and out, so I'm guessing simply stacking bales would be considerably less. I think it would be worthwhile using bales if you have a use for the straw in the spring. I don't think I'd want to save those weathered bales for the following year. Also if you are using straw in the spring anyway this would be more environmentally friendly than using foam board. I haven't insulated my four hives, but have put up a tarp windbreak for those that are more exposed. I am wondering how those tarps will hold up to hurricane Sandy today. If anyone sees a few hives flying hanging from a blue tarp sailing somewhere over SE PA, they are likely mine....

Imkerwannabee


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## Barry (Dec 28, 1999)

They're bees. They've lived thousands of years without humans making it warm for them during the winter.


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## libhart (Apr 22, 2010)

True, but they also didn't have ventilation to let out moisture but most of us think that's important. Fact is they lived in trees with absorbent, multiple-inch-thick walls. Now we want them to live in 3/4" thick hives with smooth planed walls, so adjustments really shouldn't be deemed folly because of the bees' ability to live in natural cavities.


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## Barry (Dec 28, 1999)

And you think the bees aren't free to leave a man-made hive if they think it isn't suitable to live in? What about all the bees that take up residence in soffits and sheds, etc.? Still 3/4" lumber and no one forced them there. And studies that show bees heat themselves, not their cavity.

Ventilation is another man-made "problem" for the most part. SBB's aren't found in trees either.


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## crofter (May 5, 2011)

Barry said:


> They're bees. They've lived thousands of years without humans making it warm for them during the winter.


Not where I live! 

Mine got a wrap of tar paper yesterday and an empty medium box up top with a burlap pillow of shavings. Screened hole inner cover and telescoping cover propped up a bit. Wrap to limit over ventilation by wind and insulated venting with surface area to allow moisture escape without freezing inside to melt and drip back on the bees. They are on their own now for 6 and a half months till dandylion bloom mid May. Sleep tight girls!


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## Barry (Dec 28, 1999)

Yeah, I wasn't including our Canadian friends!


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## jmgi (Jan 15, 2009)

Those that think that no insulation is necessary must not have tried to winter nucs in a northern climate without it, because I can tell you that a 5 frame nuc sitting outside with no insulation or tar paper in my area likely won't be alive in the spring. More northerner's are making up their own nucs and wintering them instead of buying package bees nowadays, and so wintering nucs poses more challenges than wintering full size hives because of the smaller clusters. Small clusters are more vulnerable in extreme cold than large clusters, so anything we can do to help them is to our benefit, it doesn't matter if wild bees don't have insulation and never did. John


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## libhart (Apr 22, 2010)

Barry said:


> And you think the bees aren't free to leave a man-made hive if they think it isn't suitable to live in? What about all the bees that take up residence in soffits and sheds, etc.? Still 3/4" lumber and no one forced them there. And studies that show bees heat themselves, not their cavity.


I never said we're forcing the bees to live anywhere.

Don't make the assumption that I'm saying that the bees *need* to be insulated in order to survive. Clearly lots of people have hives that they don't insulate and have bees that survive. What I believe insulation does is keep the hive warmer in the winter, and the bees do heat the hive, not on purpose, but they're not perfect insulators or we could use them to make perpetual motion machines. So the air inside the hive is warmer than the outside temp. It's not mid 70s to low 90s, so the air isn't the temp of the cluster's center, but it is warmer than outside. So IMHO, insulation means that the bees have to consume less and/or shiver less in order to keep the cluster at those temperatures. If this is the case, then looking at changing a single variable in our thought experiment, my hypotheses are these:

Given the same amount of food stores and the same winter conditions across an insulated and uninsulated hive, the insulated hive could help a smaller cluster of bees survive.

Given the same cluster size and the same amount of food stores across an insulated and uninsulated hive, the insulated hive could help the bees survive harsher winter conditions.

Given the same cluster size and the same winter conditions across an insulated and uninsulated hive, the insulated hive could help the bees survive with less food stores.

So bees will live in a soffit or shed, yes. If you insulated that soffit/shed around the hive (not that you'd ever do that ), would those bees have a better chance of survival than if you hadn't? I believe yes.


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## Bear Creek Steve (Feb 18, 2009)

libhart,

I fully agree with your points.

Steve


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## jmgi (Jan 15, 2009)

It has been shown using experiments that bees that experience cold winters are in better condition come spring than hives that are prevented from experiencing long periods of cold by use of too much insulation. Someone here recently quoted Brother Adam saying basically the same thing. Even in normally cold areas of the country, they have the occasional winter that is above normal where insulation probably is not needed at all, and then there are the below normal winters when your regular insulating routine is not nearly enough. Nobody likes to see a colony die during the winter because of small clusters not able to generate enough heat to keep the cluster warm and for the cluster to move to new food supplies, so this is where insulation may be helpful. I plan on making up lots of nucs each summer and wintering them over to increase the size of my operation, I plan on making spring splits too, but I need to come up with an insulation plan for my wintered nucs, one that obviously gives me high survivor rates. I will have to try different methods until I come up with one that gives me that. John


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