The division board is sometimes called a follower board and
as it is the full internal dimensions of the hive, with no bee spaces
around it, it can be used to 'partition off' part of a bee hive, to
render it less useful to the bees or it can be used to fill minor
gaps at the ends of groups of frames. In some circumstances it can be
used to separate independent nucs.
I have made these using 6 mm, 8 mm, 9 mm,
12 mm and 16 mm exterior grade plywood. There are always a
few spare ones in my van or in an apiary inside an empty hive, so that
I can accommodate changes in hive make up.
For National use the board should be 225 mm tall and
the width should be arranged so that it can be slid into a box without
jamming, as there is a little variability in the inside dimensions of
hive boxes, you will need to make yours to suit the boxes concerned.
I personally allow 1 mm each side as a clearance.
For complete closure if used above a floor, you will need
to fit a strip of wood to the floor or tack a strip on to the bottom
edge of the board to stop bees crawling under the barrier.
The 9 mm strip across the top serves to strengthen the lug
and increases the area of the top surface. This allows for some
misalignment, of strips fitted under queen excluders, in the case that
two nucs are being separated within one box. It also stiffens any
boards made from the thinner ply woods. For top bee space this strip
can be 28nbsp;mm wide, for normal National this can be 18 mm to
22 mm broad.
In the case where there are nucs with queens, the space
under the frame lugs needs to be blocked to avoid one queen killing
If the boards are left in place for a long time they will
attract accretions of propolis around the edges, this is of no
consequence if adequate amounts of petroleum jell have been used.
Division boards and dummy frames are often confused with
each other in beekeeping conversations.