Plastic sheet (or metal sheet) excluders work best in BOTTOM bee space
hives (such as British National hives) where the top of the frames,being
level with the top of the box, support the excluder.For TOP space hives
framed wire excluders are best (though more expensive)
Here in Edinburgh ,Scotland,we use both depending on which hive type
we're using.
I believe bottom space hives are also used in New Zealand-any experience
of sheet excluders there?
Regards
Alan Riach