>    One practice that I would like to hear more about, is the use of a thin
>    (8 mm?) insulation consisting of 2 polyethylene bubble sheets, bonded
>    with aluminum on the outside. It makes a pretty durable, flexible and
>    compact insulation that is claimed to have an insulation R value of 12,
>    the same as 4 inch thick batts of glass fiber or rock wool. It's more
>    expensive (50 cents per square foot?) but should last longer and be much
>    more convenient to use and store. I've been told there are some (a few
>    hundred) in use (for 4 packs) in the Alberta Peace, and that they were
>    OK last winter.
>
>    Have Allen or Eric heard any more details about them?
 
Jean Pierre was doing something with this stuff too, I think.
 
I haven't heard anything yet.
 
I think the cheapest,  and most ubiquitous wrap - other than homemade 6
mil plastic and fibreglas wraps are the Inland plastic wraps from
Inland Plastics in Drumheller, Alberta.  They are also very tough and
long lasting.
 
I just bought another 110 of them - enough for the 440 hives that
had received my alternate treatment last year.  They seem to work
well and last forever - some of mine are 15+ years old and are just
like new in spite of often being left out in the summer sometimes and laid
on by cattle.
 
They are a trifle costly - $31 Cdn  (about $23US) for a wrap that
covers a four pack of hives.  And you still need a bag of top
insulation and plywood sheet on top (1/3 sheet)
 
I am convinced that they handle thebeehive sides just fine. Over
time I've concluded that more than just one layer of plastic is
required for best results.  Even though the hives generally survive
with little or no side insulation, they are not as good as those
with R5 or so.
 
I guess the real question that I was trying to answer was  - how much
insulation is *needed* on top?  We presently vary from R5 to R25.
 
I'm presently making up top bags and wonder if I am putting more than
necessary on top because I am going up to 5 layers of kodel (R5
each).
 
It seems to me that there must be an optimal amount that ensures
maximum survival and maximum health in the spring weighed against
feed consumption and cost, labour, etc.
 
I've seen hives so hot that they were hanging out in January at
minus 10.  A friend built an insulated cabinet that held 18 hives in
drawers (frames had to be transferred) the whole thing was 8 X 4 X 6
feet and the bees were too hot for the space.  He had thought he had
the wintering problem solved, but I guess not.
 
It seems to me that if the bees are too warm, they will be too
active, if too cold, they will be unable to perform necessary
activities and perish or succumb to diseases.
 
To pile on the insulation and then provide a 3/8 by 2 inch hole at
the front as many do would seem to be contradictory - but then I do
put on a hat and still breathe actively thru my nose (thus losing
heat), but find the hat very comforting.  I just wonder how thick
that hat must be before it is too hot, or the added thickness
provides no benefit.
 
 
 
Regards
 
Allen
 
W. Allen Dick, Beekeeper                                         VE6CFK
RR#1, Swalwell, Alberta  Canada T0M 1Y0  Internet:[log in to unmask]
Honey. Bees, Art, & Futures <http://www.cuug.ab.ca:8001/~dicka>