Tag Archives: floors

Avoiding disaster

Kewl open mesh floor showing L-shaped entrance slot

Kewl floor entrance …

Kewl floors (sometimes called Dartington-inspired floors) have an ‘L’ shaped entrance that I think offers advantages to the colony when defending against wasps (or robbing by nearby colonies) and negates the need for mouse guards. However, the very feature that provides these advantages – the ‘L’ shaped gap about 9mm high – also makes them liable to get blocked with bee corpses during late winter.

During the depths of the winter, with a relatively quiescent colony and winter bees that are only a couple of months old, this isn’t usually a problem. However, as the winter turns to spring and the colony starts to become active again the attrition rate increases. As the weather improves and the winter bees expire the corpses can block the entrance, trapping the remaining colony inside.

Blocked Kewl floor

Blocked Kewl floor …

This is the sort of thing that should only happen once. Early in the season you go and visit the apiary on an unseasonably warm and calm day. With one exception the colonies look reasonably active. Foragers are returning with pollen and there are bees setting off on orientation flights.

If you listen carefully at the hive with no activity you might be able to hear the bees panicking inside. Splitting the brood box from the floor reveals the scale of the devastation. It’s a distressing sight. If you’re lucky there will be good numbers of flying bees. If you’re unlucky the colony will have already perished or there will be obvious signs of Nosema.

Kewl floor unblocker ...

Kewl floor unblocker …

With reasonably regular visits to the apiary this is a situation that can easily be avoided. Insert a piece of bent wire – I use an old bicycle spoke – in the entrance slot, turn through 90° and drag it across the full width of the entrance. The ‘vertical’ piece of the wire needs to be longer than the depth of the entrance slot on the floor, but not so long that it fouls the bottom of the frames.

 But, do we always learn from our mistakes? I’ve had this happen a couple of times. In both cases the colony was strong going into the winter and on a double brood box. The first time the colony perished, though it’s not actually clear whether they died from being trapped or from a midwinter virus overload. The second time, April 2015 (shown in the hive photo above), the colony survived. When I discovered the blocked entrance there were still lots of flying bees. I swept the floor clean and cleared the entrance, reassembled the hive and left them to it. On checking a couple of days later they were taking in pollen and I found the laying queen, none the worse for wear, at the first full inspection the following week.



Even kewler floors

So-called kewl floors have underfloor entrances that are pretty-much rodent proof (so you don’t need mouseguards in winter) and are easy to seal when needed for transporting hives or administering vaporised oxalic acid. They are very easy and inexpensive to build. The last batch I built were all fitted with a Correx landing board that protruded a centimetre or so. It turned out that the ‘design’ (a rather grand word for the bodged solution I came up with at the time) was not ideal so I’m gradually replacing them with a modified version that corrects the worst of the faults of the original.

New Correx landing board ...

New Correx landing board …

The problem

  1. The protruding landing board inevitably got a bit bashed about when transporting colonies
  2. The gap underneath the landing board disorientated bees who climbed up the hive stand or otherwise undershot. This was particularly noticeable when reversing colonies during vertical splits. I’d previously fitted a plastic ‘skirt’ to some hives to fix this (see pic below).
  3. The ‘edge’ of the Correx provided a narrow and slippery target for heavily-laded foragers returning to the colony. Many lost their grip and fell off into the grass before having a second or third attempt at entering the hive.

The solution

An L-shaped piece of Correx (of course), though this time not protruding, with a rough textured integral ‘skirt’ to block the gap below the hive entrance works well. To make an acute bend in Correx you need to make two parallel cuts through one skin and remove the intervening ‘rib’. This takes longer to write than to do. After stapling the Correx in place I spray paint it and sprinkle sand onto the wet paint. You can use different colours to help orientate bees and minimise drifting. Alternatively, use multi-coloured ‘repurposed’ estate agent signs and a clear spray varnish of some type.

Other improvements?

The final change I’d intended to make to these floors was to add a second entrance on the opposing side. Some hive manipulations involve turning the colony 180° on the stand – these include vertical splits and using a Cloake board for queen rearing. Rather than manhandling the entire colony it would be much easier to seal off the front of the hive and open a hinged entrance at the rear (much like opening and closing the gates on a Snelgrove board). Unfortunately, this batch of floors were over-engineered, with the upper upper rim glued and screwed in place, so this modification will have to be introduced when (or if) I next build floors.

New landing board in action …

The original landing board was held in place with gimp pins. Inevitably these had rusted which made removing them a bit of a pain. When replacing them I used stainless steel staples (like these from Arrow) with the hope that this will make future removal of the landing board easier.


What was that?

Zoom. Having moved back to Scotland in mid-2015 this is my first full season keeping bees here. The season has been very short. Some colonies weren’t inspected until the end of April and now, about 14 weeks later, it’s turned distinctly autumnal over the last week or so in Fife. Nectar flows have pretty much dried up, nights are much cooler and thoughts turn to preparing colonies for the winter. However, good winter preparation with strong, disease-free colonies and low Varroa levels means that, should Spring 2017 be early, the bees will be ready to take advantage of it.

The immediate priorities are to:

  • protect colonies from robbing
  • ensure colonies have enough stores
  • remove any honey for extraction before the bees use it

Robbing b’stards

Entrance reducer ...

Entrance reducer …

The very best way to protect colonies from robbing – either by other bees or wasps – is to keep them as strong as possible. Wasps can be very troublesome in the autumn. Smaller colonies and nucs are particularly susceptible to attack and can be devastated in just a day or so if not properly looked after. A block of foam or wood can easily be pushed into place on a full hive, reducing the space the bees need to defend. The underfloor entrance of kewl floors (right) have the added advantage of a narrow L-shaped tunnel that can be defended on the landing board and/or immediately below the frames.

It’s not unusual to have 2-4 frame nucs in mid-August, either being prepared for overwintering or with ‘backup’ queens while re-queening other colonies. If the colonies aren’t really strong enough to defend themselves they need to be given all the help they can. Reducing the entrance space to a single bee width helps a lot, particularly when the entrance is as cavernous as the design on the Thorne’s Everynucs that I use.

Reduced entrance ...

Reduced entrance …


There’s still sufficient time for strong nucs to be built up to occupy a full hive, but they need to be given sufficient space for the queen to lay and will probably require feeding unless there’s a good late-season nectar flow. This nuc (below) started the first week of July on just a frame of emerging brood, a frame of stores and a new queen and is just about ready for a full hive. Although not obvious from the picture, the feeder on the left contains a large block of fondant which the bees are busy with. This was added as soon as the flow stopped and before the nuc got dangerously light. The bees might have survived but the queen would have slowed or stopped laying eggs and development of the colony would have been retarded. This nuc is fast running out of space and will be moved into a full hive in the next day or two.

5 frame nuc ...

5 frame nuc …

The  integral feeder on these Everynucs has space for about a kilo of fondant. Here’s another nuc started a fortnight ago with a ‘backup’ queen that was also light on stores. The parent colony were showing signs of replacing the queen so I removed her and a couple of frames of emerging brood and left them in the corner of the apiary with the entrance stuffed with grass (to deter the flying bees from returning to the original colony). After a couple of days I removed the dried grass and they’re now ticking along nicely. As they’re a smaller colony and contain predominantly young bees they lack a strong force of foragers and so need regular feeding. If the original colony successfully rears a new queen I’ll have a spare for overwintering. If not I’ll unite them back together at the end of the month.

Nuc with fondant ...

Nuc with fondant …

This is the same nuc as shown in the top image with the reduced width entrance. One of the advantages of feeding fondant is there’s no chance of slopping it about and leaving spills to attract wasps to the apiary.

The image above also shows a ‘crossbar’ I add to the Everynuc feeders; this prevents the frames sliding backwards when the nucs are in transit between apiaries. The integral feeder is useful, but it means there’s no ‘stop’ against which the end of the frame topbar can rest. There is a stop fitted across the bottom of the face of the feeder (shown in a previous post) but my experience is that the inevitable jolting of a car journey means the frames lift above this and then can slide about too much with the risk of crushing bees.

Supers off

I’m resigned to it being a poor summer for honey this season – a combination of a late spring and consequent slow colony development, variable weather during the summer and an extended queenless period for many colonies due (again) to lousy weather for queen mating. Clearers are now on the majority of colonies with filled supers. I’ll retrieve all the filled frames for extraction and make up new supers with the leftovers (incompletely filled or too high water content). The latter will go back onto strong colonies, either in the hope of a late season top-up from the himalayan balsam or for winter stores.

Clearers on ...

Clearers on …

The opening video clip was from the second series of Fawlty Towers first shown in 1979. Immediately before it Basil and Sybil are discussing their early married life …

Basil Fawlty … “Seriously, Sybil, do you remember, when we were first manacled together, we used to laugh quite a lot?”

Sybil Fawlty … “Yes, but not at the same time, Basil.”

Just retrieving the clip from YouTube means I’ll now be spending half the evening chuckling over other bits of this classic series.

Basil Fawlty … “Well… may I ask what you were expecting to see out of a Torquay hotel bedroom window? Sydney Opera House, perhaps? The Hanging Gardens of Babylon? Herds of wildebeeste sweeping majestically…”

Winter checks for kewl floors

Kewl floor

Kewl floor …

The majority of my full colonies are on kewl floors. Some call these ‘floors with underfloor entrances‘, which is a bit more of a mouthful. These floors have narrow ‘L’ shaped entrances; the bees are forced to access the brood box through a 8-9mm high or wide slot, negotiating a 90º bend en route. For the majority of the season these offer more than enough advantages to easily outweigh their slightly more difficult construction (though you can buy something broadly similar if needed). These advantages include:

  • integral (and readily replaceable) Correx landing board
  • no need for mouseguards – even determined mice can’t negotiate an 8mm right angle
  • guard bees can occupy both the landing board and brood box entrance so far fewer problems with robbing or wasps (and if these are really a problem a simple 9mm lathe can be pushed into the entrance leaving a single bee gap at one end)
  • easy to seal for transport

Other users of these floors also claim the absence of draughts is a benefit but, since they also have open mesh floors, I don’t think this is likely to make much of a difference.

I’m only aware of three disadvantages of this type of floor.

  • they are not suited to the Varrox-type OA vaporisers i.e. the passive heating pan that is designed to be pushed through the hive entrance. This is not an issue if you use a Sublimox-type ‘active’ vaporiser I’ve described previously
  • bees can be confounded by the gap under the landing board when reorientating to these floors, though there are quick’n’dirty fixes to this and it’s only ever an issue for a few days. For the same reason, clipped queens might – on returning to the hive – miss the entrance and end up underneath the floor (though this happens with floors and normal entrances)
  • during long cold winters the entrance can become blocked with bee corpses – the only really significant problem and easily avoided

Bring out your dead

Blocked Kewl floor

Blocked Kewl floor …

There can be a high loss of bees from the colony during long cold winters. This is generally not an issue during the depths of winter, but as the weather warms slightly and the colony becomes more active – and, inevitably, the overwintering bees get older – the attrition rate rises. If the weather still isn’t warm enough for the corpses to be removed they can end up blocking the entrance. Twice in recent years I’ve had colonies trapped inside. In both cases these went into the winter as strong double-brood colonies and – due to work commitments – weren’t checked for 4-6 weeks in late January-early March. In both cases I managed to save the colonies, but they were severely stressed by the situation, with signs of Nosema, and needed mollycoddling for several weeks at the start of the season proper.

Fortunately there’s an easy solution. On your weekly apiary winter checks (or however frequent they are) push a bent piece of wire into the entrance, turn it to project up through the vertical part of the entrance slot and slide it along the full width of the hive to ensure the entrance is clear. Any old piece of wire should be suitable as long as it it short enough not to foul the bottom of the frames. For a few years I used an easily-lost piece of wire coat hanger. More recently I added a handle to a stainless steel bicycle spoke … with a little hook so it can hung up in a “safe place” (which, of course, is no guarantee whatsoever that it won’t be lost 🙁 ).

Kewl floor unblocker ...

Kewl floor unblocker …

Floor change

Old floors …

Old floors …

At the beginning of the season it’s a good idea to move colonies onto a fresh, clean floor, removing the old one for cleaning and sterilising. Having built a number of new Kewl floors this winter I made did the floor change a fortnight or so ago. A couple of colonies had clear evidence of a chalk brood problem which should be rectified by requeening later in the season. The new Kewl floors have a Correx landing board with a large gap separating it from the hive stand. Colonies that had previously had floors with other types of entrance, particularly where the bees had landed on the stand and walked up and in, experienced some confusion with the new raised entrance. To avoid the bees clustering under the floor I pinned a strip of DPM (damp proof membrane – used to wrap the hives up in winter to avoid woodpecker damage) across the front and so encouraged them to choose the correct route home.

Kewl floor - fixed ...

Kewl floor – fixed …

Kewl floors

Kewl floor

Kewl floor

Floors can be as simple as a sheet of ply with three lengths of softwood to raise the brood box up slightly. However, open mesh floors are increasingly preferred, providing good air circulation and easy Varroa monitoring. Inevitably the design of the floor also influences the entrance to the hive. Dartington-type hives incorporate an underfloor entrance that offers several advantages. They negate the need for mouse guards in the winter and provide additional protection against wasp attack. I’ve used this type of entrance on floors of National hives for a few years having read a description of them online by Graham White of Edinburgh beekeepers. The style I now use is slightly improved (or at least altered) and is inexpensive and easy to construct.

Note … I’ve recently discovered that these floors and entrances have been referred to as Kewl, for reasons that are not entirely clear, in posts on the BKF by Hombre and others. This is certainly less of a mouthful than ‘Dartington-inspired’.

The key feature is the L shaped entrance. Bees land or enter via a narrow, horizontal aperture, walk to the back wall of the entrance and then climb vertically to enter the hive somewhere in the region of the second or third frame (warm way). The vertical part of the entrance is no more than 8-9mm wide. My preferred floors also have the horizontal aperture only 8-9mm high. I also like landing boards despite the fact they make hives more difficult to transport. I’m slowly converting the landing boards on these Kewl floors to Correx … they are easy to replace, totally weatherproof and come in a range of colours.

No mouse guard is needed because a mouse cannot squeeze through the tight angle in the L-shaped entrance. In addition, bees are able to defend the entrance against wasps both at the external opening and at the point at which the entrance joins the brood box. However, if wasps are really troublesome,  you might still need to reduce the entrance to a single bee space and this is easily achieved by simply blocking most of the external aperture with a piece of 8-9mm softwood.


Construction is simple. Two side rails of pressure-treated wood, cross pieces from readily-available softwood, some scraps from the offcuts box, a piece of Correx and a suitably sized piece of mesh. The following list of parts is for a National hive (planed softwood unless specified) :-

  • 2 x 46cm long 38mm x 63mm pressure-treated decking wood (B+Q)
  • 2 x 46cm long 46mm x 21mm
  • 1 x 46cm long 21mm x 21mm
  • ~1m of 21mm x 9mm
  • ~2m of 21mm x 21mm
  • Correx sheet 10cm x 45cm
  • A few 40mm x 4mm screws, four 50mm x 4mm screws, a few gimp (frame) pins, exterior wood glue, a bee friendly preservative, a drill and bits, tenon saw, small hammer, knife,  screwdriver, Elastoplast (just in case)

Remember, with woodworking for beekeeping, propolis is your friend.  Build flat and square and the bees will fill in any imperfections in the joints!

  1. Join one piece of 46mm  x 21mm and one of 21mm x 21mm (both 46cm long) with two short pieces of 21mm x 9mm, each 60mm long. Glue and screw as appropriate. This forms the vertical part of the entrance (shown second from the right in Fig. 1).
  2. The pressure treated decking wood forms the side rails of the floor. This is the only part of the floor in contact with the hive stand/floor. Cut a 76mm x 21mm section from one end of each piece and a 46mm x 21mm section from the other end. These respectively form the front and rear attachment points for the cross pieces and are also shown in Fig. 1.
  3. Using a flat, square and true template (such as a 46cm square piece of ply; Fig. 2) glue and screw the cross pieces to the side rails. Clamp everything down and leave it all to dry.
  4. Turn the floor upside-down. Add 21mm x 9mm spacers to the underside of the entrance cross piece (see Fig. 3) using gimp pins only. The landing board will be attached to these spacers in due course. Only fix them in place with gimp pins so you can replace them should the wood rot … they are exposed to water if rain is driven in through the entrance.
  5. While the floor is inverted add two short (16mm) screws equally spaced as ‘stops’ to prevent an entrance block being pushed back too far.
  6. Turn the floor the right way up again and add a strip of 21mm x 21mm all around the edge, glued and screwed down (see Figs. 4-8). The brood box will stand on these. The easiest way to do this is to cut them a few millimetres too long (say 45cm or so) then cut them down to length after fixing them in place (I never suggested this was going to be ‘proper’ woodwork!).
  7. Give the entire thing a couple of coats of bee-safe preservative such as Ronseal Fence Life (Fig. 9). Once it has dried cut the Correx landing board to size and fix it in place using gimp pins (Fig. 10 & 11). I usually have the landing board can protrude from the front by a couple of centimetres. However, if you move your hives a lot it can get in the way (and prevents them being packed together in the trailer) and so can be simply flush with the front of the floor. If it does get damaged it can easily be replaced.
  8. Cut a piece of mesh to fit and fit it in place with roofing nails. Remember to leave the upper entrance to the L-shaped entrance slot clear!

You can create an entrance block from an offcut of 21mm x 9mm softwood, about 1cm narrower than the width of the entrance slot. When in place this provides a narrow entrance on one or other side of the hive front (Fig. 12). To allow the use of a Varroa monitoring board add horizontal runners on either side of the side rails.  Make the board out of Correx.

When you first switch over to this type of floor bees may cluster under the entrance, particularly if they’ve been used to landing on the hive stand and then walking up … help them by packing the space under the landing board with grass for a few days (or use this quick fix).  They soon learn.

Check the entrance remains clear in the winter …

The only problem I’ve encountered using this type of floor is that, rarely, the entrance gets blocked with corpses during a long, cold winter. The best way to prevent this is to periodically clear the entrance using a bent piece of wire – a cut down coat hanger is ideal. If you do this on your fortnightly checks things should be fine.

A version of this article first appeared in Dr. Bodgit’s DIY column in Bee Talk, the monthly newsletter from Warwick and Leamington Beekeepers.