Mould inside roof

[Griffo]

I've been thinking about the thread that was on here a few days ago about wet roofs and mould. The recommendation seemed to be that the holes in the crown board should be closed, but this does not sound right to me.
The bees are driving off moisture from the nectar or syrup which they are putting into storage, so my question is if you close off those holes in the crown board where is this moisture going to go ? Surely it's better to have the wet up inside the roof than inside the hive. Hot moist air will rise.

 

[enrico]

If you have ever tried to use a smoker on a bunch if bees fanning, and seen how difficult it is to make the smoke go towards them, you will realise how efficient they are at moving air around!
E

 

[madasafish]

We of course insulate our houses and don't have holes in the roof..so why should a hive be any different?

 

[Arfermo]

Never have insulated a hive through winter and have always left holes in CB open - which is the same as my BKA apiary hives with a masterbeeker/SBI in charge. Not saying it is best - just your choice. I have stuffed Celotex/Kingspan in when I want to fill the void in a BB after moving a nuc in there but that is all. Have lost colonies but not, repeat not, from draughts - only from dlq, starvation, too weak.

 

[jenkinsbrynmair]

If you have ever tried to use a smoker on a bunch if bees fanning, and seen how difficult it is to make the smoke go towards them, you will realise how efficient they are at moving air around!
E

The bees can manage their own air conditioning without extra holes where they're not needed, any condensation will run down the sides of the hive and out through the OMF. Haven't got holes in my crown boards, haven't got 'vents' in my roof - don't get mould inside the roof or on the inside of the crown board either But why not just carry on on that thread? we'l have to go through the whole thing again now

 

[Griffo]

That's the trouble with being a beginner. - you have to ask those questions that have so often been asked before

 

[user 6228]

Optimal humidity for honeybee egg hatching is between 95% and 85% humidity, The dew point at 90% humidity is around 5C lower than ambient @34C. So if you insulate so that the upper internal surfaces are only around 29C, you don't get condensation and your bees are the humidity the research shows they need.
Interestingly varoa dont breed at this high humidity

 

[Arfermo]

Varroa breed inside capped cells so are protected from humidity levels I believe?

 

[pargyle]

Varroa breed inside capped cells so are protected from humidity levels I believe?

Humidity doesn't kill Varroa ... there's a Canadian study from 2004 which may throw a bit more light on the subject:

http://www.entsociran.ir/journal/files/site1/user_files_9765c9/admin-A-10-1-48-5f9b60d.pdf

I wouldn't say that high humidity levels in the hive are the total solution to combating varroa ... just another bullet in the gun...

 

[Hawklord]

My house is well insulated but all my windows are partially open to allow ventilation, this stops any mould growing or me getting ill due to chest infections. I notice on some of the new build houses there are vents in the roof. With a whole crown board any condensation will collect above the cluster and drip directly onto the cluster.

 

[Finman]

My house is well insulated but all my windows are partially open to allow ventilation, this stops any mould growing or me getting ill due to chest infections. I notice on some of the new build houses there are vents in the roof. With a whole crown board any condensation will collect above the cluster and drip directly onto the cluster.

In Finland all windows have holes in frames that there is a small air exhange there.

If condensation happens between windows, it means that warm inside air flow out via windows.
You should put weatherstrip into inside frame.
But if you let inside air rise up to loft, you surely get condensation there and loft will rotten slowly. That is why ventilation holes of houses are in the walls, and not via loft.

 

[Finman]

.
The most important thing in ventilation is the heath of brood area and bees can easily keep it on. Bees know how to control the heath of the hive room.
Huge nectar flows are short happening in hive's year cycle and most of the year bees must struggle to keep hive warm.

I use solid floor and upper entrances. They are 1,5 cm holes in front wall. If I keep holes too much open, hive is over ventilated and cold.

Normal system in July is that main entrance is open and then 7 box hive has 2-3 holes open in brood boxes. Holes open in honey boxes makes hives too cold. Then queen rises lay to upper boxes.

And when you have a mesh floor, you should not have upper ventilation holes open.

 

[madasafish]

My house is well insulated but all my windows are partially open to allow ventilation, this stops any mould growing or me getting ill due to chest infections. I notice on some of the new build houses there are vents in the roof. With a whole crown board any condensation will collect above the cluster and drip directly onto the cluster.

Does your house have an Open Mesh Floor open to the air?

just asking...

 

[user 6228]

Varroa breed inside capped cells so are protected from humidity levels I believe?

The study used humidity levels in the nest, so it is independent of the varroa being in capped cells

Here, study the methods in detail.

Kraus B., Velthuis H. (1997) High humidity in the honey bee (Apis mellifera L) brood nest limits reproduction of the parasitic mite Varroa jac

Note: The statement in the paper about the high RH only being possible in the tropics is correct only in the context of the conventional uninsulated thin wooden hives, as normally used in Apiculture research.

 

[Arfermo]

Humidity doesn't kill Varroa ... there's a Canadian study from 2004 which may throw a bit more light on the subject:

http://www.entsociran.ir/journal/files/site1/user_files_9765c9/admin-A-10-1-48-5f9b60d.pdf

I wouldn't say that high humidity levels in the hive are the total solution to combating varroa ... just another bullet in the gun...

I was only responding to Derek's post above for goodness ake!!!!