Bottom Board use & management

[Valley Bee]

My question is about bottom boards. I am very confused. Should I be using #8 hardware cloth for screening? When should the bottom board be open and closed during the season? When the bottom board is in place, should it be completely sealed shut? When mine are in place, there are still small cracks around the edges of the bottom board.

When I install my package bees, should the bottom board be closed for awhile? When do I open it or do I only open it when checking for mites?

Thanks from a "newbee" in Idaho.

[Rader Sidetrack]

Welcome to Beesource!

You will find that beekeepers disagree on the value of screened bottom boards (SBB)! So there are no absolute answers.

If you are going to use SBBs, then #8 hardware cloth is the correct size. If you goal with the SBB is ventilation management, then you may wish to close it partially/fully off in colder weather. If you are using it for pest control, perhaps with an oil tray, then the tray already acts like a partial block of the screen from a ventilation perspective.

Really, before you can get good answers to most of your questions, you need to decide why you are using the SBBs in the first place.

Personally, I have built SBBs into my bottom boards, but with space for a tray below the screen, and then a solid bottom below the tray. I plan to leave the closure for the tray area permanently in place, except to periodically access the tray.

[Valley Bee]

Graham, thanks for the reply. I just realized my mistake with the SBB. We used 1/4" hardware cloth and should use #8 hardware cloth which we will do now. I would use if for checking for mites. I guess I just don't know when or if the solid bottom board should be open at all during the honey season. Is it for ventilation when it gets hot and how much do you open it if at all?

I lost both my hives last summer. One package of bees absconded within 2 weeks (didn't have solid bottom board open at all). However, we did see a flicker banging on the roof of the hive, so maybe that is why this hive of bees left.

The other hive stayed until mid-July, I had the bottom open at that time. I also know NOW that I had nosema in that hive and found a lot of dead bees along with all the diarrhea (cha-cha-cha). Do you know if I can still use that hive this year, or do I have to sanitize it somehow?

I just want to do the right thing for the bees as I can't keep buying bees every year.

I appreciate your help, Graham.

Valerie
Zone 4
Elevation 4,400 ft

[Rader Sidetrack]

From my perstpective, as I said in my first post, I do not use the screened bottom for ventilation ever. It is always closed. But I also have top entrances in all my hives. Read more about top entrances here:
http://www.bushfarms.com/beestopentrance.htm

You can read more on nosema and possible treatments here:
http://en.wikipedia.org/wiki/Nosema_apis

>The other hive stayed until mid-July,

What does this mean? They absconded in July after building comb and had open brood? Or they simply just died? Had they stored honey?

[shannonswyatt]

Valleybee, I would think that you should be fine reusing your hive. I would clean the hive. +1 on Radar about the SBB. If you use one, make sure you have a solid below it. Ventilation doesn't seem to be a problem. Now Phil Chandler has a hive with no bottom board, screened or otherwise (at least he used to have one, not sure if he still has it).

[gmcharlie]

You can get the best of both worlds by setting the hive on a piece of plywood. the screen and its space allows mites to fall and the bees are not crawling in them again, and it stops teh major air flow thu the hive.
I have both and I am actualy a bit far north for SBB in winter. we block them all. to much open space in winter. as for mite control, so far I can see no clear differences, but I only run about 100 hives....

[Michael Bush]

Close the bottom especially when installing bees. Otherwise a lot will end up hanging off the bottom. I would close it year around. Actually I wouldn't bother to put one in, but I have several top bar hives that have them from back when I did and I leave the tray in all the time. Too much ventilation on a hot day is not a good thing. Too much ventilation on a cold day is not a good thing... the brood nest needs to be heated and humidified by the bees.