The roof is indeed a confusing part of Warr
é s design for beginners. It is an issue that comes up over and over again in the Warr
é e-group (
http://uk.groups.yahoo.com/group/warrebeekeeping/).
Basically the hive is not a chimney. It happens to comply with what J. Th
ür called
Nestduftwärmebindung, 'retention of nest scent and heat'. If any significant flow takes place through the top-bar cover cloth, quilt contents retention cloth, quilt contents and 'mouse board' (cover board inside the roof) then it must largely be by diffusion. Water vapour can pass through all these layers. My mouse board comprises strips of narrow, thin recycled planking that I happen to have lying around the workshop. The edges are butted but not sealed. I expect that some mass flow of water vapour an air may occur here. Those who use a sheet of plywood in their roofs often drill a number of small holes to allow water vapour transit. They do this because the sometimes see condensate under the plywood. After a particularly cold winter, I checked all my mouse boards for condensate but found none. Nor was there any dampness in the quilt contents. However, please bear in mind that my hives are in a relatively mild maritime climate.
There is something else in Warr
é's book
Beekeeping for All which could be blamed for giving the impression that there is mass flow of air through the quilt. On page 53 he writes:
'Furthermore, the main quality of this cloth is its permeability that the bees can modify, augment
or reduce, adding to or removing from the cloth the propolis that they deposit everywhere. This
propolis allows the bees themselves to ventilate the People's Hive as they did in the old skeps.'
People rightly question this by saying that if the quilt contents are sitting on top of the cloth, how can removing propolis from the gaps in the weave improve ventilation?
In my view, the only ventilation, especially in quilts such as mine, which are filled with shavings from an elctric planer, must be by diffusion only. Anyway, I do not see any unpropolising of top-bar cloths. The gaps between the bars are well smeared with the substance.
The modified Warr
é hive of Fr
èr
ès & Guillaume (
http://warre.biobees.com/guillaume.htm), the one with windows in each box, deliberately makes use of the bees' ability to unpropolise the top-bar cloth. Instead of hessian/burlap (old sack material) they use plastic fly screen (moustiquaire). But they have a very different top-of-hive setup from Warr
és that allows for mass flow of air.
Incidentally, Jean-Calaude Guillaume is looking for a French to English translator of his book on his 'ecological hive' which now runs to two volumes totallin 800 pages altogether. If anyone is interested they may contact me for his address and phone number via my web site www.bee-friendly.co.uk . He does not use email.
He has recently started to produce a series of 'Chroniques' about his hive, often called in France 'Warr
é-FG'. I have translated the first 'Chronique' and put a PDF of it at:
http://www.users.callnetuk.com/~heaf/j-cg_chronique_1.pdf .
I attach a photo of an absurdly tall Warr
é-FG in Quebec that was sent to me by Jean-Claude..