cold,ventilation,tarpaper

[beebalm]

    i said on another post that to much ventilation could be a problem, in the winter. and
  could be a problem with winter hive deaths. years ago  we just had bottom boards and
  did not use screen on bottoms like today. this was because of mites. if the screen is left
  open all winter, hard for bees to keep temp. up. { my opinion}  need some ventilation
  because of moisture. but i also think to much use of tar paper can cause problem with
  moisture. black paper will increase hive temp on warm days. condensation can foam on
  inside of hive.  better off with wind break. also stated that i have taken bees from trees and cut
  outs. always a small entrance hole only.  maybe some of you who have been into bees
  long enough can give some advice on your experience. and thoughts   

[Jerrymac]

Perhaps the bees in the wild have their honey sealed up and not fed a lot of syrup causing lots of moisture in the hive. Perhaps the tree above keeps the roof of hive from getting cold and causing condensation to occur.  Perhaps if one was to place insulation on the top and let the water condensate only on the walls all would be fine. 

[Michael Bush]

I only tried tar paper once and the condensation convinced me not to do it again.

[Brian D. Bray]

In the wild, the living tree actually absorbs a good portion of the moisture that is produced by the bees.  When looking at places bees have chosen for homes, ie walls, ceilings, under flooring, and hallow trees the entrance us generally above the body of the hive.
Open bottoms (screened or otherwise) will not harm a hive, especially if there is an air space between the bottom of the frames and the actual bottom of the hive. The moisture produced in the hive rises to the top where, in the cold, it condenses into water.  With a top entrance that moisture is vented, without some vent at the highest point in the hive the condensed moisture rains on the bees soaking them and more cold freezes them to death. 

I overwinter my bees with unobstructed SBB and top entrances and have lost hives from wind damage (80-100 mph windds) but not freezing.  Starving is a different kettle of fish.

[beebalm]

         brian d bray

         thank you for your reply.  i have done several cut outs and tree removals
  and did not give much thought to the location of the entrance hole. but now that
  i think about it, you are correct.  the feral bees vent at the top, i guess. what  kind of
  top entrance do you use on your hives, and what size. :?

        thanks  much        bill

[Michael Bush]

I find feral hives have entrances where ever they happen to be.  Top, bottom, middle.

Here's my top entrances:

http://www.bushfarms.com/beestopentrance.htm

And why I like them:

http://www.bushfarms.com/beeslazy.htm#topentrance

[Brian D. Bray]

I like the KISS method (Keep It Simple Simon) of doing things--I'm handycapped so easier means doable.  One way to make very effective top entrances is just to take an old solid bottom board, turn it over and set it on top of the hive.  The overhang even provides a porch.  When I make top entrances that's what I do, make a solid bottom board and put it on upside down.