Flawed floors

I’m a fan of Abelo poly National hives. They’re reasonably robust, well-insulating, correctly dimensioned 1 and pre-painted.

Abelo poly National hives ...

Abelo poly National hives …

I’ve been using these boxes for well over a year now and will review them shortly.

The review will be generally positive.

Abelo floor and entrance reducer

Abelo floor and entrance reducer

‘Generally’ as I really don’t like the floors. They are by far the weakest part of the hive design and have a number of, er, flaws making them poorly suited to my beekeeping 2.

Rather than ‘taint’ a future review with negative comments on these flaws floors I’ll deal with them in this post and ignore them in the future 3.

The poly hive retails at about £125 for a hive with 2 supers. The Abelo floor alone costs £25.

What’s the floor for?

At its most basic the floor serves as something to stand a compatible brood box on.

But it does more than that.

It allows the bees to enter and exit and it often has features that discourage the entry of other animals … like mice.

These days open mesh floors (OMF) are commonplace, allowing mites dislodged by grooming or miticides to fall out and away from the colony.

But, if you think about it in a bit more detail you realise that the floor does other things as well and therefore needs additional features:

  • it’s what’s handled if you’re bodily picking up the entire hive
  • it needs to have an entrance that is easily and securely sealed for transporting hives
  • there is often an integrated landing board (for the beekeeper, rather than the bees)
  • for convenience it should have a Varroa tray to monitor mites that fall through the OMF
  • if used when vaporising oxalic acid-containing treatments it needs to be reasonably ‘gas tight’

How does the Abelo poly National floor 4 meet these requirements?

First, the good points

The Abelo floors are sturdy, ready-painted and nicely cast (molded? moulded? formed?) from dense poly. The paint (all mine are green or yellow though they may do blue as well) is tightly bonded to the poly surface and doesn’t easily wear away. I think the white patches in the picture below were there from manufacture, not from use.

Abelo floor - drone'e eye view

Abelo floor – drone’e eye view

The floors have an reasonable area of mesh, securely held in place. The mesh area isn’t as great as some wooden floors, but is at least as good as my homemade kewl floors.

On either side of the floor, on the underside, there is a recessed handhold that really helps in lifting hives. These recesses are also convenient anchoring points for an elasticated bungy to hold the roof in place 5.

Worms-eye view of an Abelo floor

Worms-eye view of an Abelo floor

Probably the best feature of these floors is that they’re fully compatible with other National hive components. I’ve mixed them with cedar or Swienty poly brood boxes and they fit perfectly. The interface between the boxes is flat, the correct dimensions and pretty hard-wearing.

Entrance blocks

Abelo do tend to design rather ‘fiddly’ equipment and they’re very keen on ventilation.

They usually include these fiddly design features to allow increased ventilation – or at least the option for it.

The entrance block is in two parts (see photo above). A grey plastic reversible full-width block that drops into two vertical slots on either side of the landing board. One way up the entrance is reduced to ~8cm wide. Inverted and the entrance is sealed.

Well, sort of sealed 🙁

There are four vertical ventilation holes that remain open on either side of the entrance block. Are these really needed? After all, the ventilation provided by the OMF far exceeds the little bit extra through the entrance block.

There’s a second green 6 plastic slider that can be added to the entrance block to provide an integral mouse guard. Or – more options – if inverted it can be used to further reduce the entrance to one bee width (or closed off altogether).

Ventilation and Varroa trays

Returning to the underside of the floor, the weakest part of the design is the Varroa tray.

Abelo floor Varroa tray - inserted

Abelo floor Varroa tray – inserted

The tray is unpainted polystyrene, square with a shallow lip. It slots into a recess in the underside of the floor, supported by two metal runners.

The area of the tray is approximately 75% of the floor area of a National brood box. With a full colony, some of the Varroa will fall outwith this area. This isn’t a major issue, but it could lead to underestimating the mite load in the colony.

The tray slides in and out easily, facilitated by a small protruding handle on the underside.

Abelo Varroa tray half withdrawn

Abelo Varroa tray half withdrawn

Unfortunately, there are some large gaps around the tray when it’s in place. If you sublimate oxalic acid a significant proportion of the vapour escapes around the edges of the Varroa tray.

The gaps around the tray are awkwardly shaped, so it’s not straightforward to plug them … other than with foam blocks perhaps. It’s also not possible to easily temporarily replace the tray with a Correx sheet. If you did it would need holding in place so potentially putting you too close to the hive and clouds of escaping oxalic acid vapour.

Resourceful beekeepers will work out solutions to these problems, but it would have been better if the defects weren’t designed into the floor in the first place.

Abelo floor, Varroa tray inverted

Abelo floor, Varroa tray inverted

And, before you ask, inverting the tray does not significantly seal off the gaps!

Poly Varroa trays

It is possible to make reasonably ‘vapour-tight’ poly Varroa trays. For example, the Thorne’s Everynuc has one that slots neatly in place. I’ve used these dozens of times and there is very little loss of vapour in my experience.

However, the Abelo floor (and the Everynuc Varroa tray) has the additional problem of being unpainted polystyrene. These very quickly become stained, with pollen, bee faeces and all of the usual rubbish that falls through the floor.

Abelo poly Varroa tray

Abelo poly Varroa tray

This staining makes counting Varroa much more difficult.

Again, a couple of coats of white gloss paint would seal the surface of the tray. However, this rather undermines the attraction of the ready-painted Abelo hives 🙁

Alternatively, you could source some white Correx sheet to make an insert that would be easy to draw a grid on, count Varroa in and clean.

And, inevitably, easy to lose.

Floors done well

In summary, the problems with these Abelo floors are three-fold.

  1. Intentionally (the entrance block) and unintentionally (the Varroa tray) leave too much ventilation to conveniently be used when sublimating oxalic acid. The success of these depends upon retaining the vapour within the hive while it condenses on internal surfaces. Allowing it to leak out excessively simply makes the treatment less effective.
  2. Even if you don’t control Varroa by oxalic acid vaporisation the Varroa tray gets dirty quickly and is difficult to clean.
  3. Finally, it’s not possible to securely fix the entrance for transporting colonies, other than by using loads of gaffer tape. Even if you do, the large landing board on these floors makes strapping hives together awkward.

Most of my hives have homemade kewl floors. These probably cost about £6 each to make and have none of the problems listed above. They offer additional benefits as the L-shaped entrance ‘tunnel’ prevents mice from entering the hive and reduces robbing by wasps.

Kewl floor and Correx landing board ...

Kewl floor and Correx landing board …

These DIY floors have a simple, easy to clean, Correx Varroa tray that is much more ‘gas-tight’ than the Abelo design. An L-shaped wooden entrance block can be screwed in place for transport and the landing board is effectively integral to the floor, replaceable if damaged and does not project in a way that inhibits strapping hives together for transport.

Cedar floor and plywood tray ...

Cedar floor and plywood tray …

Kewl floors are unsuited to being used in the bee shed. For these hives we use slightly modified cedar floors made by Peter Little of Exmoor Bees and Beehives. These have a ply removable Varroa monitoring tray that provides an excellent ‘gas-tight’ fit when sublimating. These floors are not inexpensive, but they are very well made.

Cedar floor with closed monitoring tray

Cedar floor with closed monitoring tray

Considering the quality of the rest of the Abelo National hives, these floors are a disappointment. I use them if I’ve run out of everything else and I kick myself when I discover – as I did a few weeks ago – that there are still some in use when the midwinter mite treatment is needed.

What do you call a stack of Abelo poly floors ...

What do you call a stack of Abelo poly floors …


Hooke's microscope

Hooke’s microscope

Floor and flaw are homonyms, two words that sound the same but have different meanings. Floor, meaning in this context the ‘base of any cavity’ probably dates back to Old English (Anglo Saxon) ~317AD. Flaw in comparison is a young upstart, with the first recorded use being by Robert Hooke in 1665. Hooke was, amongst other things a microbiologist, and he used the word flaw in his book, Micrographia, which is about his observations using a microscope (and telescopes). Hooke was the first to use the word ‘cell’ following microscopic examination of plant cells, which have walls, because the appearance reminded him of honeycomb.


  1. Very important … you can mix’n’match them with other National boxes in cedar or poly.
  2. But they might suit yours … read on.
  3. In much the same way as most of mine are ignored, stacked up and unused, in the corner of the bee shed.
  4. The related Abelo Langstroth poly hive floor appears to be a newer design, though some of the features of the floor are in common with the National floor.
  5. And you will need something like this as they are relatively lightweight and are easily lost in high winds.
  6. Regular readers will be aware that I’m colourblind … these could be red or brown! There’s one in the pictures.

25 thoughts on “Flawed floors

  1. Janet Wilson

    Recently there has been “buzz” that open mesh floors make no difference to mite populations in the hives. Looking forward to more research on that one. In our mild winter, rain all winter, location the chief value of mesh floors is that any water that wicks in through the “porch” drains away. So really all I’d like is a 1″ strip of 1/8″ mesh just inside and parallel to the hive entrance. The bees deal with the ventilation issue on their own, and benefit more from good insulation over the cluster than from multiple openings in the hive (most of which they try to propolize shut). A well insulated hive stays nice and dry.

    1. David Post author

      Hi Janet
      I suspect the OMF offers more benefits in terms of monitoring potentially high mite levels than actually helping to lower mite levels. However, relatively few beekeepers do the former and anything that encourages them to monitor pathogen levels has to be encouraged. My floors have an L-shaped entrance tunnel, it doesn’t matter how hard it rains it still cannot get in.

  2. Kitta

    David, I’m puzzled by as to why you feel you need to use gaffer tape to secure an Abelo hive for moving. I only turn the entrance blocks over to the shut position and have always felt safe and secure. I hope I don’t one day discover that I’m wrong while driving my bees somewhere!

    Thanks for the interesting colophon.

    1. David Post author

      Hi Kitta
      The entrance block is only held in tightly by being squeezed against the side of the brood box. Since the ‘faces’ of the boxes are flat there can be some lateral movement in the event of sudden jolts … even if the boxes are strapped up. In a trailer I probably wouldn’t worry about this. In a hatchback or estate car I want to be as certain as possible I don’t make a drama into a crisis by having bees escape should there be an accident. Belt and braces certainly, but it gives me peace of mind.
      Best Wishes

  3. Karl Kusta

    Hi David
    Another eloquent and informative post………keep them coming. I have just bought 4 Abelo Hives after many hours/days of research, so it was great to hear that you are a fan. I had not considered the tray or the oxalic angle. I will certainly be painting the trays over the next couple of weeks ready for the new season. I noticed some monitoring on the photos you posted. Please can you let me know what system/make you are using, and is it worth the investment?
    Many Thanks and Best Regards

    1. David Post author

      Hello Karl
      We’ve got some of the Arnia kit. Too early to comment yet and we have more to deploy in the season ahead. When I know more I’ll write more.

  4. Neil


    I purchased a couple of these to try this year and was generally impressed with them. In my opinion though, their worst flaw is the crown boards, they have circular vents or polystyrene bungs. Using either violates bees space meaning that the bees build brace comb and everything gets stuck down. I replaced mine with wooden ones after a couples of weeks.
    The boxes are excellent though.

    1. David Post author

      Hi Neil
      I’ve commented on the ‘fiddly’ crownboards before and agree with your comments. They do have a couple of redeeming features but are over-engineered.
      And yet more ‘stuff’ to lose … I’ve got a large box of Abelo bits in the apiary.

    1. David Post author

      Thank you John …
      The advertising revenue has taken a hit recently and I’ve had to let the proofreader go 😉

  5. Archie McLellan

    Hello David
    ‘Floor and flaw are homonyms…’
    Really?! Well, you’re absolutely right according to the audio pronunciations for UK (but not US) English at dictionary.cambridge.org.
    But In Fife?! I bet if a hypercritical local looks over your new-laid laminate and tells you there’s a flaw in your floor, you’ll not be in any doubt about what he means!

    1. David Post author

      “Hypercritical local”? In Fife? Not a chance 😉
      Actually, anyone looking at the laminate floors I’ve laid wouldn’t be able to comment … they’d be too busy laughing.

  6. Dorothie Jones

    Hi David,
    I have these Lyson hives from Abelo and I love them!
    I find the entrance blocks OK and I guess you could put glue in the ventilation slits if you want. Earlier models didn’t have the slider so I stick on correx strips if I want to reduce the entrance!
    I don’t use the poly trays at all. as they seem a bit pointless! I’ve cut correx to fit exactly the slot underneath on which I have a grid for varroa counts. I only put them in for this, preferring to leave the OMF only the rest of the time.
    With regard to OA vaporising, I (or rather my handy other half!) has attached my Varrox, mounted on wood and aly, to one of the poly trays. (Sorry there doesn’t seem to be away of adding pics). I slot this in the back under the omf floor and block up the space at the rear with a small piece of foam. Invert the entrance block and hey presto! I get no leaks at all and find it works fine. I only have a small number of hives tho.
    Also I do not use the poly crown board supplied and prefer a standard wooden one (or sometimes clear polycarbonate). It’s a great advantage that standard National kit fits this hive!
    However what I’ve been doing in the winters is putting the Abelo poly crownboard on top of the wooden one for extra insulation. If I want to add fondant I put it between the two crownboards (over the holes obvs!) with an eke and fill the space with bubble wrap.
    I don’t ever need to transport them so moving them about is not a problem for me although I always strap them down in winter or if it’s windy. I guess my winters are not a patch on yours here in leafy Bucks!
    Just how I’ve used mine the last 3 years with no worries.

    1. David Post author

      Hi Dorothie
      As I said, I’m generally pretty enthusiastic about these hives and have lots of bees in them at the moment.
      You make a good point about vaporising with a Varrox-type pan machine. The distance between the runners and the OMF – perhaps 1.5-2cm – is ideal to accommodate the sort of contraption you describe to hold the Varrox and deliver the OA. My machine is ‘active’ so produces jet of vapour which I simply blast in through the entrance.
      I’ll review the other bits of the hive sometime later in the season.
      Highs of 4oC predicted for the next 10 days, so the hives will be earning their keep …

  7. Dorothie Jones

    Yes, the Sublimox apparatus is somewhat different and I guess some experimentation is required with various poly hive designs! Seems a good bit of kit if you have lots of hives; not worth it for me though.
    My bees were out briefly in the sunshine on Friday so at least I know they’ve survived thus far. Not so lovely weather predicted now though. I do think February the most dangerous time for colonies.
    Looking forward to more of your interesting posts this season.

  8. Calum

    Hi David,
    great post. Myself, I wouldnt sublime oxalic acid if I was paid to, so I am relaxed about my floors. (Bio hazard suit, gas mask – and then tell my customers I am an artisan, and their honey is all natural? The one image doesnt fit to the other.)
    I also stopped counting varroa a while ago, as it only tells you about the varroa you killed. If alot fell, well done, how many are left? / if a few fell was the colonly varroa free or the treatment just ineffective? Better for me to just uncap some drone brood in the spring and decide then if I want to cull drone brood or not.

    And due to limitations on treating, and time travel, retreating or going back and redoing it are not options. I admit I have lost one of 40 overwintered this year. But my autumn preperations were halfarsed as I work 50% in another country just now. – so my fault not the varroa.

    1. David Post author

      Hi Calum
      Another country?! It sounds like time travel would be useful. I struggle with apiaries 20 miles apart and the possibility of another 150 miles away.

      Whilst I agree that the personal protection equipment isn’t really in keeping with the public perception of what a beekeeper should look like it’s not something most of them will ever see. It’s also probably preferable (and more ‘natural’) to using something like Apistan which both accumulates in comb and is often ineffective.

      I monitor Varroa levels throughout the season so generally have a reasonable idea of whether treatment worked or not.

      Very cold snap just starting here and far too early to judge winter survival, but things are looking good so far.


  9. Keith

    Hi David. Enjoyed the article. Whilst I can see the benefits of increased hive insulation throughout the seasons, I am wondering about effectively sterilising and cleaning the components to assist with minimising disease incidents etc. I know how difficult this can be with a poly nuc, but with a full hive of bees for an extended period of time ?

    1. David Post author

      Hello Keith
      If you’re meaning cleaning/sterilising poly hives then scrubbing them with bleach or strong soda solution should be satisfactory. You obviously cannot ‘torch’ them as you would cedar boxes. I think my poly boxes, for whatever reason, don’t get as encrusted with propolis and other gunk from the hive. They’ve not been in use for as long, but the cedar boxes are reasonably regularly swapped out and torched, but still look a bit tatty in places. I’m certainly not aware of any greater transfer of infection or disease from poly than cedar.
      The increased insulation is a definite help in cold or exposed locations. Particularly for smaller colonies. I no longer use wooden nuc boxes and instead use ~40mm thick Everynucs. Colonies overwintering in these look excellent this season.
      5 frame poly nuc, early January 2019

  10. Tom

    Hi David
    Can you give more information on ventilation for winter and year round. I like all the reading and agree with all Especially the floor. I modified and will remove and create better in spring. Thanks and keep up the great work-help. Tom

    1. David Post author

      Hello Tom

      Ventilation isn’t something I take a lot of notice of … all my floors are open mesh and they’re left open almost all year. ‘Almost’ because I leave Varroa monitoring boards in post-treatment and for one or two weeks during the season to get an idea of natural mite drop.

      We don’t get really hot weather. The only time I ever provide any top ventilation is in my bee shed on the very hottest days (when it’s in the low 30’s in the shed). When they’re evaporating off the water from nectar I sometime leave the roof ajar over a ventilated crownboard to give them some help.

      In winter you sometimes see advice to provide ventilation by putting matchsticks under the crownboard. I think this is a daft idea and reflects what might have been once been needed with solid floors, but is now just nonsense. It’s repeated ad nauseam every winter by some experienced beekeepers. There’s very good evidence from the bees that it is not wanted or needed.

      My setup is simple. Open mesh floors and a big block of insulation over the crownboard. It works really well and I see no reason to change it.


  11. Tom

    Hi David
    Thanks for the fast reply Does that mean the inspection board stops direct draft Thus allowing some convection occurance I have read and re read so much and taken the option to follow insulate poly box is the way year round. But bottle them up or full screen open on floor or open but don’t allow direct up draft. I like the idea of the tree thought but this all conflicts with venting the bottom so obviously I re question my final thoughts. My Alyson box is new and I revised a few things to seal it up but bottom is the main area I am lost ( zero air flow from top to screen board and I was going to put a 1/2” hole just above the single bee entrance ( which I know will be blocked with dead bees) thus allowing a single air entrance until spring. Allowing convection to occur. Any thoughts. Eastern Pa. weather hot cold damp wet with a few days of normal weather a year 😊

    1. David Post author

      Hi Tom

      I suspect you’re overthinking things … the inspection board will prevent some updrafts, but it depends on how well it fits. In some of mine it’s great, in others (including the Abelo floors referred to in the post above) there are cavernous gaps which allow all sorts of draughts to enter. My hives spend 80% of the year with nothing below the open mesh floor. Yes, there will undoubtedly be draughts and no, it’s not like a tree cavity, but the bees do just fine. There’s a lot of insulation over the crownboard and the winter cluster is tight up against the underside of the crownboard, right by the top bars of the frames. Colonies that lack this top insulation usually end up with the cluster in the middle of the hive.

      I always check my hives every couple of weeks during the winter to ensure that the entrance isn’t blocked. My entrances usually have an L-shaped channel and I’ve built a no-expense-spared gadget to keep the entrance clear.


      In reality, the only hives I ever have a problem with are those on double brood. The underfloor entrance provides ample space for the bees to clear the corpses on the days when flying is possible.

      Finally, I’d note that we never have large amounts of snow, so the entrances are never blocked. If your weather includes lots of snow in the winter I’m not the person to ask. Check Michael Palmer … he has real winters!


  12. Tom

    Over thinking comes from over reading. Over reading comes from my common sense verse what I know verse what I need to know or experience. Since experiencing has a filler cost and the sadness of colony loss I reach for experienced persons who are kind enough to share all theirs. For which I am grateful for you and the others. Thanks as it’s a good thing. Especially when I am only a year into it and lost both hives last year. Mostly by following reading It’s hard to learn when failure happens with so many variables and minamal knowledge. Again leads to over thinking and searching of knowledge. Thanks again for the help and thanks for sharing with the world. Have a sweet healthy prosperous year 😊 Tom

    1. David Post author

      Thanks Tom

      Very best way to learn is to find an experienced mentor … nothing beats a second pair of eyes when things need to be checked. A much better solution to books or the internet, but not always available of course.

      Look after the mites and the bees will look after themselves … is always a good place to start 😉


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