Screen in Bottom of TBH

[gregsky88]

I am a newbee getting my bees in about two weeks. My son built a top bar hive from a design on the internet. I have seen some designs with a screen in the bottom to catch mites. I am getting my bees from an organic apiary that has been chemical free for 10 years. I would like to get some experienced TBH keeper input on the need for screen in TBH bottoms.

[taydeko]

Screened bottom boards are not NEEDED. They can be used as part of a mite control program. However, there seems to be evidence that packages installed in hives with SBBs are more likely to abscond. In my area, I haven't seen anyone using a screened bottom board. One of the local "gurus" had plans on the internet for a hive with screen bottoms, but he doesn't use them any more, they are hard to build, and he is going to be publishing a new plan, much simpler, without SBB.

[Steven Ogborn]

I know first hand about absconding packages and screened bottoms.
The bees don't like them. I tried to install two packages with them
last spring. Both of the packages tried to abscond. They couldn't
because, my queens were clipped. It really messed up the balance
of my hives populations though. They drifted together when they
came back, and I ended up with a really big package and almost no
package from the two 3# packages that I had.
If you do use screened bottoms, keep them
covered until the colony is well established. I took mine off last summer,
thinking that it would help and started to get honeycombs collapsing.
Put the bottom boards back on and everything went well afterwards.
I'd use them just to do sugar dusting or mite counting. But after
that I'd keep them covered.
There's other threads that you can search for that will give you
a lot more information.

[rtoney]

The method I use for the screened bottom is to just cut the bottom board after I have build the hive, screen it and use the board that was cut to go back with hinges that way I can close it and only open it if I feel they need the ventilation. And leaving it closed until they are well on thier way is right they seem to build comb on either side of the screen until they run out of space.

[gregsky88]

The method I use for the screened bottom is to just cut the bottom board after I have build the hive, screen it and use the board that was cut to go back with hinges that way I can close it and only open it if I feel they need the ventilation. And leaving it closed until they are well on thier way is right they seem to build comb on either side of the screen until they run out of space.

Good idea on a hinged door over the bottom screen that opens in hot weather AFTER they are established. I read Steven Ogburns post about losing his package and I do not want that to happen.
I am unclear on your comment about them building comb on either side of the screen until they run out of space. Are you talking about the divider board or am I missing something?

[rtoney]

I cut the middle out of the bottom of the hive so it left so many inches on either side of the screen. The bees prefer the solid bottom and thats where they would work the comb when I would leave the bottom open. If you close the bottom door they are fine I just noticed that when I had it opened in the summer for a new hive that they did not like to work over the screen when the door was open. Once the ends are built out they have no place else to build so they will build over the open screen.
Hope this helps

[gregsky88]

I cut the middle out of the bottom of the hive so it left so many inches on either side of the screen. The bees prefer the solid bottom and thats where they would work the comb when I would leave the bottom open. If you close the bottom door they are fine I just noticed that when I had it opened in the summer for a new hive that they did not like to work over the screen when the door was open. Once the ends are built out they have no place else to build so they will build over the open screen.
Hope this helps

Thank you, I now can visualize what you mean. I may just forgo a bottom screen and ventilate with entrances on both ends of the hive once it is established.

[conifer]

They aren't needed, but they do help to with keeping varroa under control as part of an IPM. As others have mentioned, keep the bottom board closed until the bees are well-established in the hive.

Our KTBHs have 1/8" screen stapled to the bottom of the sides, and we have an adjustable solid wood bottom board that we can remove, close, or partially open. Details and photos here http://thehoneybeat.com/2011/07/our-...-bottom-board/