Insulation for National Beehives

One of my favourite building materials is expanding foam and I was determined - for whatever reason I don't know - to make a beehive from it. Weeks later after I had completely forgotten about the idea, and talking to some fellow beekeepers about using rigid foam boards for insulation, I finally realised my ambition - expanding foam can be used as a glue for rigid foam boards. The whole structure would fit over a standard beehive for insulation - EUREKA!

The diagram here shows how the 50 mm rigid foam boards would be arranged. The popular trademark in the UK is 'kingspan' but there are other cheaper versions of the same thing such as 'cellotec' and 'quinn therm'. The insulation properties are pretty amazing - much better than rockwool or straw and much easier to work with. Insulation is particularly important in the Winter and means that the bees will expend less energy trying to keep warm and so consume less honey stores in the hive. The insulation costs about £10 ($15) per hive.

• Rigid foam board 8' x 4' x 1 of
• Can of expanding foam
• 5mm plywood - 570 x 570 x 5 x 1 of
• Galvanised steel sheet - 625 x 625 x 1 x 1 of
• 12mm drill
• Hand saw
• Box knife
• Hide mallet or hammer
• Piece of heavy metal such as RSJ for use as an anvil
• Hacksaw or jigsaw
• Industrial pallet wrap
• Parcel tape
• Aluminium foil tape

Also, make a cut-out in the 570 x 570 x 5 plywood sheet 50mm all the way along the edges to mate with the insulation boards. The wood will protect the foam from knocks during use.

Remove the foil to expose the foam on all mating surfaces - the expanding foam will not attach to the foil so well. Cut the foil with a box knife and peel it off.

This is the fun part where you get to be extremely messy. My can of foam decided to block up half way through and the only way of getting the foam out was to puncture the can with a 6" nail. Needless to say, the foam squirted out everywhere, covering everything within 10 foot with foam!

Start off with the plywood base, which is cut out to create a 50mm rim. This rim will protect the final structure against knocks when in use.

Squirt foam on all the mating surfaces and assemble the insulation box. 4" nails can be used to pin the boards together during this process. Don't try and remove the excess foam until it is dry or you will make a mess!

The lid will protect the box against falling branches and clumsy beekeepers.

Cut out 20 x 20 mm corners as shown in the photo and bend the edges on a bending machine if you have one or else with a hide hammer. Don't try and weld the seems - just leave them as they are.

Now, if you don't have access to a bending machine, carefully hammer the edges over with a hide mallet, using a bit of old RSJ as a former.

With the lid off, wrap up the box with industrial pallet wrap, using parcel tape to secure the edges against the wind. I also used some aluminium foil tape just for cosmetic purposes. Drill the hole and use some tape to protect the aluminium foil around the hole. The pallet wrap will keep the box water tight. The lid can now be laid on top of the box, but without any glue. Use some stones or bricks to keep the whole structure in place during the winter months.

Allow the expanding foam to dry thoroughly before using the box over a hive as the fumes may harm the bees. I would allow at least 3 weeks for every trace of fumes to have gone. Also, check that the bees have sufficient ventilation after the box is in place. Ventilation in the hive floor would be perfect.

Now please check out my other closely related instructable here: CLINKY LINKY which has recently been upgraded with all sorts of new useful ideas. And of course please VOTE as I desperately need more T shirts!