Mesh Floor - In or Out?

[beenovice]

I have a National Hive with a mesh floor. It also came with a plastic sheet that slides underneath the mesh. My question may be silly but should this plastic sheet be generally in or out. I have left it out at the moment thinking that it was for inspecting for veroa after a treatment.

 

[jenkinsbrynmair]

I have a National Hive with a mesh floor. It also came with a plastic sheet that slides underneath the mesh. My question may be silly but should this plastic sheet be generally in or out. I have left it out at the moment thinking that it was for inspecting for veroa after a treatment.

the tray should normally be left out, apart from when you are doing a natural varroa drop count (in for a week occasionally so you can count how many naturally occuring varroa end up on there thus work out the size of the infestation), then when treating with Apiguard (because you want the hive to be as fume tight as possible and after Oxalic treatment to see how many mites were in the hive.

 

[MonseigneurBienvenu]

I think a lot of answers to this question appear to miss the point a little in not noting the attitude to top ventilation. Others note this, but don't give enough information.

Correct me if I'm wrong, but one view is that the board should be left in if there is top ventilation in the hive to minimise drafts, i.e. either holes at the top with air coming through the entrance and up OR no holes at the top and an open bottom. Although I haven't seen any answer mentioning summer and how hot weather affects this. I assume it doesn't - bees can sort themselves out with either set up?

Hope this helps at least a tiny bit and that someone who actually knows what they are talking about can expand.

 

[jenkinsbrynmair]

Correct me if I'm wrong, but one view is that the board should be left in if there is top ventilation in the hive to minimise drafts, .

The board should never be left in - it would turn into a festering sump of all the detritus from the hive and harbour all kinds of nasties.
neither should there be a gaping hole in the top of the hive (open feeder hole or whatever you want to call it.) mesh floor open, top closed - and never a mention of matchsticks!! and the bees will sort out their own ventilation

 

[MonseigneurBienvenu]

Thank you, jenkinsbrynmair. The detritus issue is very logical, as bees can't clean it up as they might with a solid floor.

A

 

[Little John]

The board should never be left in - it would turn into a festering sump of all the detritus from the hive and harbour all kinds of nasties.

I don't see how you can make such a definitive statement without knowing more about the design of the base.

If the base has an open floor beneath the OMF, then any muck will drop clear, but only if the tray is not in place.

But - if the floor beneath the OMF is solid, then it clearly makes more sense to keep the tray in place in order to catch the 'muck', which can then be very easily removed by simply withdrawing the tray and wiping or scraping it.

I have recently converted to solid floors beneath an OMF, for both Nationals and Warre. Between the OMF and Base there is essentially a 3-sided 'eke', with it's 4th side removable both in order to assist ventilation in summer, and to remove the tray for cleaning periodically. In winter, the 4th side can be kept closed during periods of adverse weather.

In the Warre base, I've made the OMF removable (slides out on runners), but I don't think this is a justifiable feature for Nationals.

LJ

 

[drstitson]

"if there is top ventilation"

then you should be frequenting the BBKA forum.

 

[drstitson]

"if the floor beneath the OMF is solid"

then you basically have a solid floored hive NOT an OMF.

 

[beezers]

I leave it in for varroa counting during treatment. I've seen the gunk it accumulates if left in all the time at assoc apiary,not nice.
If a virgin queen is flying,then you can leave it in(it's said to prevent her going under the hive in error).

 

[Little John]

"if the floor beneath the OMF is solid"

then you basically have a solid floored hive NOT an OMF.

Eh ? - first, define 'the hive' ...

In my case there is a 4" gap between a solid floor and the OMF.
The solid floor is the 'bottom' of the structure (from a human point-of-view), but the OMF is the 'bottom' of the hive (from a bees' point-of-view). I think the latter is what counts.

When the 'eke' is open it affords ventilation to the OMF of some 72 square inches.

'Solid floor hive' - I don't think so.

LJ

 

[Swarm]

Shouldn't we just concentrate on the question which also sounds like it concerns standard stuff rather than confusing the issue with modifications?

 

[Goran]

To make more confusion, here many beekeepers I respect who have OMF ( wire floor I presume) leave the tray in during summer, and in winter until brood emerge in January the tray is out ( to don't encourage brood start too early). When during the summer watch the bees when the tray is out, bees cover the wire in trying to stop warm air to come into the hive ( some says there is no bearding, but with this you make more problems for bees than use..).

 

[REDWOOD]

The OMF was designed well before varroa came along as a way of keeping a hive ventilated, the board is only for inspections (most of the time),

 

[jd101k2000]

Going under the OMF

Beezers: I can understand that.
When I first moved my 5 frame nuc to their pristine national hive I left the board out, thinking they would want the ventilation (beginning of May 2013). That night many of the bees went under the OMF and hung there. They could smell their sisters above, so seemed to think they were in the hive. The following morning they had all chilled to death :-( I then left the board in under the OMF while the remaining bees got used to their surroundings. The board is now out and I have not had a repeat of the problem.

 

[oliver90owner]

Leave it out. That was the way it was designed. The clue (for those that may not have noticed it) is in the name - OMF.

 

[jenkinsbrynmair]

I don't see how you can make such a definitive statement without knowing more about the design of the base.

LJ

I have a National Hive with a mesh floor. It also came with a plastic sheet that slides underneath the mesh.

Sounds a pretty clear description to me - 'National Hive with a mesh floor' not
'National Hive with a solid floor but with mesh four inches above'

 

[drstitson]

little john - a question.

your floor is basically a deep solid wooden box with a mesh top and one removable side.

you may have say a 45x10 cm ventilation slot but that is very different to a 45x45 cm fully open OMF which benefits from essentially constant air flow beneath.

if correct then that is surely a source of stagnant air (and collector of detritus) rather than pure ventilation (as opposed to the more widespread use of an eke - or even a super - as a baffle beneath an OMF to prevent draughts but still allow full ventilation).

 

[user 6228]

if the alternatives are between floors in a high heatloss hive is a solid high heat loss, water pooling floor and a mesh high heat loss floor.... the mesh wins cos its self draining.self cleaning, even when the bees in the high heat loss hive are in cluster for most of the year,

Has anyone got a figure for the mass flow through the floor if the entrance is open.?

 

[summo]

well, here regardless of how cold, windy etc.. it is, everyone advocates an open mesh bottom. Cold feet, warm heads is the moto. So plenty of insulation on the top and sides in winter, but the bottom is always left open. I've been led to believe that apart from the cleanliness aspect year round, it also prevents damps problems during the winter too, when the bees won't actively ventilate the hive.

 

[pargyle]

Shouldn't we just concentrate on the question which also sounds like it concerns standard stuff rather than confusing the issue with modifications?

I don't see why ... there are people on here with all sorts of different types of hives and many of them are modified - there's some good ideas (and rubbish ones) that come from people reinventing 'standard' equipment.

I have the best of both worlds. My hive has an open mesh floor which can be closed off if I wish, ventilation holes above that which can be closed off, a 4" space underneath the OMF and a drawer in there that slides out (easily) and in which my sticky board sits. I put a new sticky sheet in every week or so and the stuff that drops onto the board from the hive tells me where in the hive the bees are working and to some extent what they are doing on the frames above - fascinating for a Newbie like me.