We often get asked at the Trust - "Can you make a hive from pallets?"
Trustee, Jonathan Powell shows you how to build the ultimate pallet hive.
I should call this a Lockdown Hive because the coronavirus lockdown forced me to look for hive materials around the garage, otherwise I would have nowhere to put this year's swarms after disposing of my box hives. The only materials I had at hand were a couple of pallets.
The first thing to understand about building a pallet hive is that pallet wood comes in all sorts of different sizes. So this article is very much a guide and not a plan.
Never use a pallet with the marking MB on it as these have been treated with Methyl Bromide (oulawed in UK since 2010). Use pallets which have been heat treated and have HT, KD or DH markings. For more information visit Universal Pallets wonderful web site and enjoy the pallet nerdery.
To make a hive, the pallets have to be good quality, untreated and ideally use 10-20cm wide planks, that are 2cm thick. Thinner lighter wood could be used but this would need to be compensated with more insulation. Lighter hives also don't have much thermal inertia; a property that smooths out the night and day temperature fluctuations in the hive, thus reducing hive stress.
You will need two pallets, a table saw, general woodworking tools and two days to build the hive in this project. I have found that any hive worthy of bees (Sun Hive, Lazutin Hive, Zeidler Hive, log hive) takes two days. It's like a golden rule of hive making for me.
Above is the first of two pallets used in this project. We will use everything, even the sawdust for the hive insulation.
First glue the pallet separator blocks together. Be careful not to over glue as many types of wood glue contain biocides and we don't want that in contact with the bees.
Above I have glued the blocks together and then sawn them in half to make a top and bottom 'plug' for the hive. They are both about 5cm thick. I have chosen an octagon because that is the minimum shape to avoid cold corners, but nonagons, decagons, undecagons ... would all approximate better to a circle, it's just more work. Extra sides have the bonus of creating more joint cracks for bees to seal with propolis. Bees use the propolis together with the hive warmth and humidity to create a sterile medicinal atmosphere. Without good insulation the hive atmosphere cannot be easily maintained above 10c in winter, causing mould, and this drastically affects the bees' health. This is the reason I have for the first time stopped using single-walled box hives.
Two points to note here are that the rougher the wood, the better for the bees:- more propolis opportunity. Also, I have used end grain on the plugs facing into the hive to allow humidity regulation by the bees. You can blow through the wood plugs as it is made up of thousands of small capillaries.
Because pallet wood comes in all different shapes and sizes, it's not possible to give a cutting list. You have to use what you have and make that fit with parameters bees seek in the wild:
Volume ~ 40 Litres
Internal diameter ~ 24 cm
Walls - at least 5 cm thick
If your hive is based on an octagon design, I found that a 10 cm plank `of about 90 cm in length is perfect for the internals of the hive. But beware, this hive has an inner and outer sleeve, with a gap of about 1-2 cm between them. If the inner core uses ~10 cm planks, then the outer sleeve will need to be at least 20.3cm, and that is not common for pallets (only 2 of my 10 pallets were of this size). If you have smaller planks you will need to make polygons with more sides and this is where an online polygon calculator like calculatorsoup.com is invaluable. It's worth spending some time planning this out using the 'measure twice, cut once' principle. It's amazing how this project transforms humble pallets into precious resources.
Once you have the planks you can make the core:
Some notes about the core:
Did you remember the plugs take volume away from the hive when calculating the core plank lengths?
The planks can be straight-edged, this saves time
The planks can be really rough - the bees will thank you
It does not matter if there are a few gaps
Simply screw the planks into the top and bottom plugs
Keep the screws into the plugs fairly short, so you can make an access hole later
It's a good idea to recede the plug very slightly (~0.5 cm) into the core, making a 'microcavity' between the plug and an eventual outer roof or floor. This aids in the humidity regulation mentioned earlier. (The picture above does not show this, but I'll mention the microcavity again later.)
Once the core is made it can be wrapped in hessian (burlap):
The hessian is stapled on and holds the core together. It also separates the bees from the sawdust insulation.
Next, make the outer shell. Aim to have 1-2 cm gap to the core for insulation. Use the polygon calculator to get the dimensions you need for the core size you have, and if your planks are not wide enough, add more sides to your polygon.
Here is the outer shell being glued up with waterproof wood glue. For the outer shell, you need to bevel the plank edges with a table saw. Set the table saw angle to 22.5 degrees for an octagon. I use the same straps for securing the hive to the tree, to also hold it together while gluing.
Gluing eight planks of wood together is hard ... but if you staple them together first before applying the straps it can make a difficult job very easy!
Add the core to the shell and fix them together with a ring of long screws around the top and bottom. This fixes the shell to the core and maintains that 1-2 cm insulation gap.
The picture above has jumped ahead a bit and shows the bottom detail. The key points are:
I used a large hole saw to cut a human entrance into the hive's bottom plug. This is for cleaning and inspection purposes.
I used some leftover oak planking to make a 2cm thick top and bottom. While this can block off the end grains of the plugs it's easy to create small ventilation holes to the end plug 'microcavities'.
The inner and outer cores are filled with the table saw sawdust.
Use hessian to seal the bottom of the insulation gap.
I have kept the top plug sealed/immovable as this simplifies waterproofing. While you can attach old brood comb to a removable roof plug to attract a swarm, the traditional reason for this was to guide the bee comb building so it is parallel to the tree hive's human entrance, making honey harvesting easier. However, to attract bees it is sufficient to put a couple of drops of organic lemongrass oil onto the hive entrance and smear the inner walls with old honeyed comb from the bottom. I also use an easy spreading mixture of beeswax and olive oil.
Two 25-30mm entrance holes have been added, 1/3 and 2/3rds down the hive. While I understand lower holes equals less heat loss, bees also have to get moist fresh air close to the brood. They like brood nests near entrances for a reason. As the brood field gradually moves down during the year, the two holes facilitate this. I find that bees like to use the two holes for different purposes as the year progresses. I often see them use the top entrance for expelling heat and moisture and the bottom for bringing in dry fresh air. The holes are small enough for the bees to control the size easily with a propolis curtain.
Behind the holes is a wood plate that replaces the insulation gap. This allows a clean hole from the outer shell to the inner core.
The roof is covered with a simple roofing rubber membrane, stapled on. I prefer rubber as metal is too noisy in the rain, and long-lasting wood roofs are difficult to make and keep waterproof.
The hive is painted with a non-toxic 'Scandinavian' paint based on a metal oxide. Unpainted pallet wood would not last very long otherwise.
The hive will be strapped to a tree at a bee friendly height of 3-4m. Ideally, the weight supported by a natural branch formation, or a wood step could be bolted/rebarred into the dead heartwood of the tree with little impact on the tree. Straps will hold it in place, but these should not strangle the tree. Use two or three small blocks of wood to stop the supporting straps from cutting into the tree.
Making a pallet hive can be tricky, but very worthwhile. It's important to be flexible with the design and work with what you have. I have already thought of small improvements for next one, but I'm really happy with the basic design. It's already my favourite hive and I can't wait for the bees to check it out and hopefully swarm into it.
I have come to understand the main reason we do not have many wild bees is due to there being so few natural tree cavities. In ancient forests, like Sherwood Forest, dead trees are left in place, and there are many cavities and many wild bee colonies. Here the bees find homes that are an exact match to their preferences - small warm cavities with small entrances deep inside large heavy structures. Ancient forests are rare - stupidly we are chopping them down in the UK to make way for high-speed train lines to save a few minutes commute time. Nature cannot wait 500 years for replacement forests to grow.
While nothing can replace an ancient forest habitat, installing pallet hives does give back to bees some of the opportunities they need to thrive. We are giving the bees the maximum agency to be who they are. This hive is not for honey harvest - it's for the bees and our joint future together.
Bees thrive when they are wild and free and they remind me in a time of lockdown how precious our freedom is. Let's make sure after lockdown we value our freedom all the more.