Why My Hives Look Like an Oil Tank

Another post about hive insulation? 'fraid so.

Having already added a layer of space board insulation beow the hive roof in December I turned my attention to the sides of the hives. My hives are single walled as are most of the hives in the UK, single walled means there's one wall between the inside of the hive and the outside world.  The now less common but more aesthetically pleasing William Broughton Carr (WBC) hives have an extra walls around the boxes the bees live in. There's a couple of reasons why he designed his hives this way but having a stack of boxes within another stack of boxes looks like quite a faff to me. However modern houses in the UK have cavity walls for extra insulation so I decided to imitate that for my bees to give them a little extra insulation especially in the light of the previous winter's months of ice and snow.

The placement of the hives means that their front wall wich faces a wall and a corner is probably quite sheltered from winds but the back of the hive and the sides get the full effect. To reduce the effect of this I built a box to go around 3 sides of the hives and boxed up the gap between the hives at the front and on top. The edges where it meets the hives have draft excluder brushes on them to reduce the escape of warm air whilst the bottom is open and it goes down a little below the hive floor. My thinking is that it should provide some insulation from the elements on the more exposed sides of the hive whilst still letting the wooden hives breathe. I'm sure it doesn't make a massive difference but I'm expecting every little helps.The edges of the outer layer reaching below the hive floors should provide some protection for the open mesh floors from the winds too.

 

You too could have hives that look like an oil tank.

I painted the outside black to help it absorb heat -although it does look pretty ugly, and the inside a gloss white to (hopefully) stop it taking any heat from the hives. There is a downside to this as the extra layer of wood also slows the warming effect of the sun on the hives so on warmer days the bees will become active a little later, this is something known to happen with WBC hives, but my hope is that this will be outweighed by the benefit of less heat being lost when it's colder.

I left the green roofs in place but to be effective insulators there needs to be air in the gaps between the particles of the substrate (soil or perlite or whatever). In the summer that's not a problem and the sections insulate the roof against the sun but in the winter when they get waterlogged they stop insulating, not a problem with the spaceboard underneath already but next year I'll have to give some thought to drainage -which will be better for the plants too.

In February I popped down to the Pearson Park Wildlife Garden to see how their bees were doing and noticed they've used straw for upper insulation on their WBC hive. Those bees should be toasty warm because as mentoned above  as the WBC hive has double walls so there's an air gap between outer walls you can see in the and the walls around the bee cluster.

WBC Hive with straw insulation

The previous winter was a particularly long one and the wildlife garden actually lost their bees so I'd expect them not to be taking any chances this year. Although it looks like there's no extra insulation on their top bar hive at all.

Top Bar Hive in the snow

I'll be interested to see how these bees have coped, although having been a mild and short winter I'd expect them to be okay. General consensus is that as long as bees are dry enough and have enough food they should be able to cope with the cold. In case anyone's wondering that rock sitting on top of the hive roof is there to stop the flat roof being lifted by the wind, it's common practice with flat roofed hives.