mould in hive

[MuswellMetro]

I found condensation underneath the space quilt on one hive - next to the blocked off feed holes. Glass / perspex / polycarbonate crown boards are not vapour permeable - another reason to start using them...

You still need a ventilated roof though. Damp + no ventilation = dry rot; I lost a roof to it last year, when the vent holes became obstructed.

From my personal notes:-

The old Min of Ag leaflets recommend a 3/4 inch (19 mm) hole in each side of the roof (total area 1134 sq mm)

The BIBBA leaflets show roofs with two such holes each side (total area 2268 sq mm)

A "shop bought" roof has typically 2 slots 25 x 7 mm on two sides (total area 350 sq mm)

Regards

Savoyard

but thats 1960 and since then most of you have an OMF floor mesh that is 420x370=155,400 sq mm of vent

things move on

it like clearing snow of the entrance it was a regular winter ordeal, now on OMF floors it is not necessary and that is beneficial as less bees die due to reflected polorized light tempting them into the coldn

 

[oliver90owner]

And 2 x 19mm diameter holes is only 567mm (squared), so similar ball park to modern production roofs.

Also no account taken as to the mesh used (open area would be less than the total). Probably perforated zinc in the 1960s, so totally incomparable with modern materials and practices.


Newbeeks - try this. With an OMF, leave a fine gauze mesh over the porter bee escape hole(s) and note what the bees do to it. They will virtually seal it off or completely seal it, dependant on the time of the year. That must tell you something! Try it!
When you see the open area left by the bees, then you will know how many matchsticks you will need to prop up your crownboard! Remember - the bees do know best!


I am confident you will not need to buy, beg, borrow or steal any matches, at all.

RAB

 

[Teemore]

Thanks to my mentor's guidance I've made OMFs for my two hives and a couple for later use; RAB's comments and those of MuswellMetro reflect what I have been advised and what I have experienced in my first year of bee keeping.
Prior to feeding, I had pieces of tile and slate covering the feed holes in my crown boards and the bees propolised these in place. When the rapid feeders went on in the late summer they sealed the crack between the base of the feeder and the crown board with propolis. I use plastic 'Haribo' sweet containers with a hole in the base as fondant feeders and the bees have used a wee bit of wax to seal them in place too.

I've never felt the need to raise the crownboard on matches and as RAB suggests, if I did so and depending on the time of year, I am confidant that the bees would soon seal the gap. Well, at least one of the colonies would - the other doesn't produce much propolis - perhaps not a bad thing - and they have been content to live with a slight (<1mm) gap under part of the crown board caused by the hive timbers flexing a little in the damp. I have shielded this gap from the prevailing winds with a strip of Damp Proof Membrane tied in place (I had it to hand). So far both colonies are alive -at least they were on Saturday past.......

 

[Poly Hive]

I once bought a colony that had a travelling screen instead of a CB.

And if you canna guess what the bees had done with it then I will tell you.

It was solid with propolis.

Bees hate draughts above their heads.

If your mentor tells you you need matchsticks and all that palaver, ya need a change of guru.

PH

 

[Erichalfbee]

oops post deleted

 

[oliver90owner]

never felt the need to raise the crownboard on matches......if I did so and depending on the time of year, I am confidant that the bees would soon seal the gap.

Thanks, Teemore. Hope some of the new beeks take note.

Further to the above: Of course, no beek in their right mind would prop up the crownboard with matchsticks during the productive season, but If they did they would likely find it propolised down in short order, with the bees being so active. Late in the autumn, the conditions are not conducive of them to fill a length about 1.2 m, of 2-3mm gap - so it remains ....all through the winter.

I pull my boxes together firmly with a strap if there is any risk of water ingress, especially if the propolis seal is cracked late in the season. Ideally, the roof should cover the crownboard joint mostly, but may not if insulated on the crownboard. The higher-riding roof has more risk of blowing off in really windy conditions but the strap, even under the roof will keep the colony safe until the next inspection. Yet another reason for me to make and use 150mm deep roofs.

Regards, RAB

(PH got there before me - I don't type and collate very quickly!)

 

[Haughton Honey]

Ideally, the roof should cover the crownboard joint mostly, but may not if insulated on the crownboard.

Nor will it if you're using a super or a 3" eke whilst feeding fondant.

Sometimes I think 8" roofs are a good investment perhaps.

 

[savoyard]

but thats 1960 and since then most of you have an OMF floor mesh that is 420x370=155,400 sq mm of vent

This is ventilation ABOVE the crown board - I expect it would still need to be the same...

And 2 x 19mm diameter holes is only 567mm (squared), so similar ball park to modern production roofs.

There are two holes in each side - making four times the area of the modern roofs.

Newbeeks - try this. With an OMF, leave a fine gauze mesh over the porter bee escape hole(s) and note what the bees do to it. They will virtually seal it off or completely seal it, dependant on the time of the year. That must tell you something! Try it!
When you see the open area left by the bees, then you will know how many matchsticks you will need to prop up your crownboard! Remember - the bees do know best!

I am confident you will not need to buy, beg, borrow or steal any matches, at all.

RAB

A very good experiment to try!

Savoyard

 

[oliver90owner]

savoyard,

Sorry,

Stand corrected if you are talking about 4 sides. Even though most of my boxes are square plan, I still think sides means sides and not front and back - like all the rectangular plan hives where front and back are automatically designated, even if reversible!

With regard to a hive with an OMF. The amount of roof ventilation is simply to keep the roof-space dry and cool, not to ventilate the bees like a chimney. Bees in trees get by very well without through-draughts. With an OMF, there is more than enough air exchange to suffice.

The products of combustion (or metabolism) of carbohydrates are water and carbon dioxide. The carbon dioxide is 'heavier' than air, so will always 'fall' out of the hive. The same with most of the water vapour. As long as their is a differential concentration and an exchange region, the water molecules will move towards the areas of lower concentration (simple kinetic particle theory at school - diffusion), an example of which is, say, vinegar from fish and chips is soon smelt throughout a room. With water vapour there is the added complication of condensation which is a function of both concentration and temperature (relative humidity and dew point).

The other point, in passing, was about keeping the colony cool. Simple here. too. Hot air (conduction through a hot roof in direct sunshine) can be ventilated to the surroundings and thus not transferred downwards into the bees' space. The bees are perfectly able to transfer energy within the hive body to control the temperature at the optimum, as long as the external heat input is not excessive and there is an avenue for gaseous exchange and thermal conduction into the surroundings.

It is not often, in the UK, when ambient temperatures exceed 35 degrees, so the bees generally have only the excess colony (mainly brood?) heat to dissipate at times. Indeed a lot of the time, the overall hive temperature is likely below the optimum, what with evaporation of water requirements. They also survive in much warmer climates than that of the UK.

So my view is: hives need ventilation, but the bees can ventilate themselves; so top ventilation is unecessary.

Regards, RAB

 

[savoyard]

FWIW

I have found something (almost) definitive in some hand-outs from a local guru about cold wintering on a mesh floor.
My notes from those hand-outs (acknowledgments to D Maslen esq)

1. MAXIMUM AREA OF OPEN FLOOR
- Stiff mesh
- No ledges to trap debris
- Circa 20mm space between bottom of frames and top of mesh

Bees cluster earlier and for longer

2. MASSIVE TOP INSULATION
- Minimum 2 inches of styrofoam.
- Hive sealed in at top - balances "cold" at floor level.
- Feed hole(s) sealed with tape.

Warm crown board - so no condensation (on C.B.)
Warm bee space above cluster - allows bees to move from frame to frame

3. FREE FALL OF MOISTURE AND DEBRIS THROUGH OPEN FLOOR.
- Water vapour condenses on the cold broodbox walls; condensate runs down the walls and out the bottom.

Reduces humidity due to condensation and wet debris.

CLAIMED BENEFITS
- Colonies come through the winter bigger and stronger
- Harmful condensation is prevented
- There is less mildew and fungus on combs

There is also a good web page at http://www.dave-cushman.net/bee/ventilation.html

In the case of a SOLID floor, ventilation is always more problematic. I was taught (35 years ago) to leave a fully open entrance (mouse guard if necessary), to seal the feed holes and to put matchsticks under each corner of the crown board; the reasoning was that any chimney effects go AROUND the cluster, and not through the middle.

Hope this helps

Sacoyard