The tutors on my bee course very much advocate having an open floor.
I could go for nailing wirecloth to the bottom instead of a board(not sure about the resulting (in)stability tho), but because the hive is so long and on a high stand (50cm), I'm a little worried about this being too drafty.
I saw an interesting way of making a bottom, its built from PVC tubing that is slotted into a bar with holes either end to keep the tubes 3.5 mm apart.
What do you think of that design?
My main worry is that if I have a comb failure with any open bottom, the entire mess will drip onto the floor below the hive and I'll have a robbing problem, and also, is a 3.5mm gap small enough to stop other bees from coming in?
Ps.: Why is it that everytime I think I've finished my hive design and made the xfig picture of it, that something else crops up and I have to change everything? :)
I had the same question about open bottoms. There was a pro-open bottom article in the latest Bee Culture. But I am concerned more about the winter cold. looks like you could make up a bottom like that pretty easy out of 1/2inch pvc with some spacers. But I wonder if you should then close it up in th ewinter. What do they do over there about that?
I just finished up my 3 tbh's with solid floors. Bbut I was thinking maybe add the pvc pipe as a "false" floor right above. that would avoid problem of heat loss in the winter.
Part of the concern some of us have had is that the failure of combs may be partly due to open bottoms and the bees not being able to control the temperature inside the hive. Normally if the outside temps are above 96 degrees the bees are actually cooling the inside of the hive down to 96 by evaporation. I'm not sure how well that works with a open bottom.
I have a three box long medium hive (with frames). It has a screened botom. I left it open all year until fall and closed it up with some cardboard. I see that the cardboard sagged a lot in the middle and had a large open area. This hive thrived and came through the winter well. I DON'T think it would have been good to leave it totally open on the bottom, but who can say? I also don't know if wax combs on bars would have done as well in the summer. This hive is all permacomb which won't collapse in the heat. My observation is that hives need some ventilation in the winter, but I think an open bottom is not controled enough and is too much draft. Perhaps if there were another box underneath to break the draft I'd like it.
[This message has been edited by Michael Bush (edited March 08, 2004).]