On Thu, 17 Jul 1997, Aaron Morris wrote:
 
> The discussion of width of hive opening has touched on ventillation,
> which has also been discussed a bit on this list.  Vince Coppola
> posted he's unable to notice a difference between solid and screened
> bottom boards.  I'm wondering about slatted bottom racks.  Killion's
> _Honey_in_the_Comb_ says they are REQUIRED EQUIPMENT, both to improve
> ventillation and to give bees room to hang out in a crowded comb
> honey production hive.  I've grown into the habit of using slatted
> bottom racks on all my hives but have never done any "scientific"
> studies to determine if they improve things for the bees.  Any opinions
> or hard facts?  For those who are not familiar with slatted bottom
> racks, they're a piece of equipment that goes on top of the bottom board.
> They're the same size as an inner cover, but about 2 inches thicker.
> The front end has a slat about 4 inches wide and then there are 13 3/4
> inch slats spaced with 1/2 inch gaps between the slats.  Bees land on
> the bottom board and get into the hive bodies through the gaps between
> the slats.
>
> This ventillation issue is funny to me.  Most books warn against drafts
> (mainly a winter concern), yet it seems that more and more things are
> leaning towards increased and improved ventillation.  Seems there is
> a dichotomy here.  Perhaps the "best" hives are the old drafty ones!?
>
> Anyway, any comments on slatted bottom racks?
>
 Hello All,
 
 I have have talked with Jim Bach our (Washington State Apiarist ) at some
lenght about slatted racks. He uses them on all of his hives. I will be
making some for my hives before winter. They have to have a positive
affect on the hives in the summer also.Bees cannot be bunched up on the
brood in the bottem box or you will have a swarming problem. I have looked
at some other peoples bees this year that were swarming with the bottem
box full and room in the second box.Congestion in the brood box will
trigger swarming , even with a new queen.
 Ventilation is a must. Moisture needs to be removed or you will have sick
bees. I came up with a top board that would get the moisture out but keep
the heat in , with the contol left up to the bees.They can cover a screen
that I have in the middle of my top and cut down the air flow. The slatted
rack will slow down the cold air before it gets to the bottem bars of the
lower brood box. That has to be a plus for winter. You are better off with
a full 3/8 inch opening at the bottem and a slatted rack than cutting down
the enterance to a couple of inches. I have left my enterance open without
a slatted rack and lost one out of 50 last winter. I had 3 feet of snow on
them at one time and still had no problem. I think the slatted rack will
give you a larger brood nest in the early spring.
 Best Regards
  Roy