Subject: Re: Open Mesh Floors/Large Entrances
Date: Fri, 19 Jan 2001 11:44:03 -0000
From: "Dave Cushman" <dave.cushman@lineone.net>
To: <BiologicalBeekeeping@egroups.com>

Hi Dee

----- Original Message -----
From: deelusbybeekeeper <deelusbybeekeeper@excelonline.com>

I am not an "expert" on Open Mesh Floors and their usage but I can give a
few pointers as I have followed the saga for about 19 years.
Stress is the usual cause of chalk brood, I do not think OMF makes this any
worse.

Cold climate is not a problem, these OMF have been used in Scandinavia and
Germany (where it is very cold in winter) indeed I believe they were first
tried out in these very cold locations.

> conjunction with upper hole entrances?

Most systems using OMF require NO ventilation at the top of the hive. which
means an upper entrance could not be used (I think the bees would block it
with propolis if you tried it).

> Do beekeepers using OMF take them off
> in the winter or close them up somehow?

No, the bees arrange their wintering having adapted the brood nest to cope
with the OMF, if you block it or swap it they would have to re-adjust.

How does one insulate a hive to keep
> it warm with OMF?

Insulation is only added to the top, usually 50 mm of expanded polystyrene
foam (styrofoam?) is placed between the inner cover and the roof

http://website.lineone.net/~dave.cushman/rroof.html

Gives a diagram of the insulated roofs that I use which do not reqire an
"inner cover".

If OMFs are used then entrances can be kept restricted as the ventilation is
provided by the OMF.

My mate Ken Hoare is the OMF guru.

Best regards Dave Cushman