screened bottom boards

leechmann · January 24, 2011, 05:39:39 PM

I am going to make the jump from solid bottom boards to the SBB. I have some questions about the when the tray or screen should be covered. For instance, in the spring time, in northern MN, what is the minimum night time temperature before I should open up the bottom screen. Then again in the fall, when should you close the bottom board up, for the winter?

I plan to build my own boards. How much distance should there be between the screen and the tray or cover below the screen. Any other advise you may have would be appreciated.

windfall · January 24, 2011, 06:13:48 PM

I believe I saw 2-2.5" referenced several times to keep mite from getting back up into the hive, when I was reading up earlier this year. But I am sure someone more knowledgeable will be along to confirm or correct that.

D Coates · January 24, 2011, 07:01:32 PM

I build my own with a 3/4" gap between the screen and the bottom deep. The frames are recessed up in the deep so I'm honestly not sure what the distrance betwen the bottom of the frames and the screen is. All I did was buy a couple Dadant SBB my first year and took some of the measurements and started building my own with some minor improvements. I do not put covers in there for over wintering. Others do but I don't to ensure there are no moisture issues.

Kathyp · January 24, 2011, 07:04:50 PM

i leave my bottom boards in until the temps are a pretty consistent 60ish. that means they are in until June and back on September or so. if the hive is tipped, moisture is not an issue.

wd · January 25, 2011, 12:50:29 AM

I know, I'm in CA. - for what its worth, when I used them, I left the bb under the sbb year round with a bottom entrance. used simple the dadant model. I switched to bottoms boards only to check out that aspect.

indypartridge · January 25, 2011, 07:11:55 AM

I've been leaving my SBB's open year 'round for the last six years or so. In a typical winter in my area, we'll have several spells of below freezing temps - weeks at a time - and usually a couple of spells of serious cold (subzero temps) for a week or more.

This winter, however, is making me a bit nervous, as it's been considerably colder than usual. If I have a high winter die off, I may re-think the "open all year" and close them up Dec thru Feb.

FRAMEshift · January 25, 2011, 11:23:36 AM

Quote from: indypartridge on January 25, 2011, 07:11:55 AM
I've been leaving my SBB's open year 'round for the last six years or so.

Indy, this is very interesting. How have your winter survival rates been during those 6 years compared to previous years? And when you say "open", do you mean there is nothing between the SBB and the ground or is there a bottom board or support structure that is just open to the side?

VolunteerK9 · January 25, 2011, 11:34:37 AM

The hives that I closed up the SBB have been more active recently than the one that I left completely open all winter. I'm closing it up today.

annette · January 25, 2011, 05:52:16 PM

I have been leaving them open year round and so far I can't see any problems with this. Of course, we don't get such cold winters here, although have many night into the low 30's and some into the mid 20's for about 2 months.

T Beek · January 25, 2011, 05:59:35 PM

My bees have survived AND also died either open or closed

thomas

Kathyp · January 25, 2011, 07:43:43 PM

i worry less about survival rate and more about the temps required for brood. if the hive temps are not staying up, your brood production doesn't stay up. the earlier i get good brood production, the better. in a warm place with a long season this might not be an issue.

tefer2 · January 25, 2011, 08:53:18 PM

I have the slide in boards in place just before our first hard frost ( Sept.13Th) and open again when temps hit mid fifties in the spring (mid to late May).
I also coat the plastic board with a good layer of Vaseline petroleum jelly.

backyard warrior · January 25, 2011, 09:25:55 PM

id have to say that i like to close mine up late fall threw the harsh part of winter there is something to be said about trying to help the cluster maintain heat and use up less stores mantaining hive temps. I put on a entrance reducer and a small paint stick on the top cover to vent out moisture. I think its important for early build up of brood to help them maintain a warmer hive and important in summer to open up the bottom board to help with mites and also hive temperature as well. Another good thing to do is remove your honey supers as the bees cap them. Honey holds lots of heat if you notice during the day they dont beard on the front of the hive till late afternoon when the honey heats up then it takes much of the night for the honey to cool back down then they return into the hive the bees exit the hive to maintain hive temps for the brood so they dont overheat. ;)

wd · January 25, 2011, 11:32:02 PM

if you're interested, here's some do it your self plans in pdf format for what is in the pics below and more.

http://www.tc.umn.edu/~reute001/Plans.html

indypartridge · January 26, 2011, 08:04:41 AM

Quote from: FRAMEshift on January 25, 2011, 11:23:36 AM
Quote from: indypartridge on January 25, 2011, 07:11:55 AM
I've been leaving my SBB's open year 'round for the last six years or so.

Indy, this is very interesting. How have your winter survival rates been during those 6 years compared to previous years? And when you say "open", do you mean there is nothing between the SBB and the ground or is there a bottom board or support structure that is just open to the side?

After experimenting over a couple winters, I didn't see any difference in survival rates, so I began leaving them open.
My hives are on concrete blocks, nothing between the SBB and the ground.

T Beek · January 26, 2011, 02:14:57 PM

After five winters I've had the same experience. Only have one Lang open right now, three closed. One Long hive and one tbh, both closed up. I' ve lost two Lang colonies so far this winter, both had their bottoms on, but they were weak swarms. I can't advise either way based on this :)

thomas

FRAMEshift · January 26, 2011, 02:22:00 PM

Quote from: T Beek on January 26, 2011, 02:14:57 PM
After five winters I've had the same experience. Only have one Lang open right now, three closed. One Long hive and one tbh, both closed up. I' ve lost two Lang colonies so far this winter, both had their bottoms on, but they were weak swarms. I can't advise either way based on this :)

thomas

Thomas, my memory may be off here, but I thought your long was open. Did you change your mind and close it?

T Beek · January 26, 2011, 02:25:35 PM

No, my one long hive was never open (its an enclosed top entrance hive). I'm building three more right now that will have option to leave open or close up.

We'll see how it goes.

thomas

BlueBee · January 26, 2011, 03:57:38 PM

Thomas,

We would love to see photos of your handy work if you can post them sometime. I would love to see how well your bees filled in your foundationless frames too.

T Beek · January 26, 2011, 04:56:40 PM

that may require help from my wife ;) I'm lucky I can turn the computer on.

thomas