In Allen's last 4 paragraphs he poses a question relating to Open or Closed bottoms in relation to Environment conditions or hive strength. << We want both. Can screened -- or open bottoms -- provide both? >> I have been folloing the screened bottom board thread for quite some time - Including the less active thread last year. Nonetheless, the conversation always turns to the times when a screened bottom would be detrimental to a hive (Exceedingly cold conditions, or a weak hive). Why cant a hive bottom be constructed to provide both. If the design of most screen bottoms was changed to provide for a grove within which a 1/4 thick piece of wood or other material could be slid under the screen, then adding or removing a 'solid' bottom would be very simple. The grove would be away from the bee's eliminating the chance of propolis buildup or having them glue it in place. They could be left open most of the time, but in the instances when the screen would be detrimental to the viability of the hive, a bottom could be slid in place in less than 30 seconds. Now, thats a lot easier than tearing the whole hive (or yard full of hives) down to the bottom board Granted, For the comercial folks with lots of hives this may cost more than a simple screened bottom but looking at all the cost factors included, it may be cheaper. If varoa treatments could be cut in 1/2 ( 1 treatment per year instead of 2) . And the reduced labor costs when the situation calls for quickly closing up the screened bottom. I am planning on making a couple of these bottom boards for my hives and trying them out this year. Being a hobbiest, whose pampered bees are in my backyard, its no great risk or gamble - just another excuse to 'go see the ladies'. For those of you with 100's of hives - Is something like this viable? Rod Billett Lexington, SC