Insulation

[Valleysgirl]

Good morning. I’m in South Wales, relatively new to beekeeping and I’ve only got 2 National hives (cedar). Thinking about insulation for winter - does anyone swap their sheet metal covered cedar roofs for deep poly roofs (from Abelo)? Is this a good idea or not? I understand 75% of heat is lost through the roof so an insulated roof is better than no insulation, but is the Abelo poly deep roof compatible with a cedar national? Thanks in advance - I have little experience with over wintering and rain/wet here is a bigger problem than low temperatures.

 

[Erichalfbee]

All my National hives have deep Abelo roofs on all year. They have 50mm Celotex on the crownboard in winter too. Threw the wooden ones away years ago.

 

[Valleysgirl]

Thank you. Do you wrap or insulate the brood box too? Or just rely on a well insulated roof?

 

[Amari]

Me too. I add a square of 25mm silver foil-covered insulation board eg Recticel, Kingspan, Celotex to fit within the Abelo roof.

 

[drdrday]

I just use a wooden roof, albeit a deep one, but I have a sheet of 50mm Kingspan permanently stuck inside the roof all year round, and I add another layer of 50mm Kingspan in an eke on top of the crown board over winter too.
So of course, you can use Abelo poly roofs if you've got them, but you can also vastly improve the insulation in the wooden roofs you've already got.

 

[Curly green finger's]

Can't afford numerous poly roofs but I try and use home made 6 inch roofs.
And insulation like this above the crownboard.
Insulation is cut 405mm x 405mm and I've started to just score with a Stanley knife and snap the insulation which saves on sawing and loads of insulation dust.

Edit : I wanted to add some not all roofs which are new I leave the battens out and insulate the roof like @drdrday does.
Again it's cut with a Stanley knife. The insulation in the photo is the poly wrapping from a washing machine/fridge.

 

[jenkinsbrynmair]

Thank you. Do you wrap or insulate the brood box too? Or just rely on a well insulated roof?

Just glue a slab of 50mm celotext to the inside of your roof, keep it there all year round, no need for wrapping, unless you're planning to give it away at Christmas.

 

[Curly green finger's]

The op might like the idea for peace of mind.
I can remember in my first winter using 100mm King span wrapped around a hive with bailer twine.
Even made a bodged shelter to go over the top.
@Valleysgirl you can buy winter cosys from the main suppliers or search on here @Erichalfbee has a photo somewhere of some made out of insulation.
Be as attentive to your bees as you wish

 

[drex]

I have 2 inch thick Kingspan inside my standard 4 inch wooden roofs all year round. It still overlaps the crownboard. My hives are fairly sheltered from the wind though, if not I would just put a brick on top

 

[Murox]

Just spent a couple of hours bodging together a square of insulation from scrap. Its only 25mm but its free and now wrapped in foil as well.

 

[Finman]

Just spent a couple of hours bodging together a square of insulation from scrap. Its only 25mm but its free and now wrapped in foil as well.

25 mm is good.
.

 

[pargyle]

25 mm is good.
.

50mm is better ....

 

[Nannysbees]

Used this insulation last year and they came through winter very successful so have done the same this year

 

[Finman]

50mm is better ....

How do you know?

30 years ago polyhive's wall was 20 mm. Bees wintered without promlems in -20 C temps.

I mean, 25 mm is surely enough in Britain's severe winter.

 

[Gadgetman]

If fixing inside the roof, what is the best type of glue to use? Presumably some of the strong smelling types (evostik, uhu etc) are toxic for the bees?

 

[oliver90owner]

How do you know?

30 years ago polyhive's wall was 20 mm. Bees wintered without promlems in -20 C temps.

I mean, 25 mm is surely enough in Britain's severe winter.

25mm may be ‘enough’ but 50mm will be better.

How do we know? Simple Physics would provide you with the answer. Double the thickness will halve the heat transmission.

For the OP, I made slightly deeper roofs than the standard Thorne offering. Each had 25mm of recticel under a 6mm sheet of ply. Roofs were covered with thin aluminium sheets. I still leave another 25 or 50mm sheet of EPS over the crown board (a 10mm piece of ply). Many remained in position all year round.

The standard roofs really require the roof to be held down, particularly though the winter if a 50mm slab is added. A concrete block is generally more than adequate.

 

[Curly green finger's]

If fixing inside the roof, what is the best type of glue to use? Presumably some of the strong smelling types (evostik, uhu etc) are toxic for the bees?

If you have cut the insulation to be a nice tight fit you don't need to glue it in place

 

[Finman]

How do we know? Simple Physics would provide you with the answer. Double the thickness will halve the heat transmission.

But keeping bees in Finlands climate says, that answer is not simple physics. What about size of winter cluster, if the box is half full of bees

I have 20 mm poly boxed snd 40 mm polyboxes. Fifference is not douple, when I compare foof condumption after winter.

What about ventilation, like meshfloor? What Physics say to that?

Modern polyhives have 40 mm walls. Our man Derekm doomed those boxes. He measured that handhelds leak energy.

 

[jenkinsbrynmair]

If fixing inside the roof, what is the best type of glue to use?

go to your local builder's merchant and ask for a cartridge of 'sticks like sh!t' which fits into a mastic gun, think it's also called the pink stuff nowadays

 

[drdrday]

If fixing inside the roof, what is the best type of glue to use? Presumably some of the strong smelling types (evostik, uhu etc) are toxic for the bees?

I just use double-sided tape. As Curly says, if you have a slab in one piece that fits well it doesn't need much.
If you get your Kinspan from local skips you may have to piece together a few bits, in which case I still stick it with double-sided tape but I put a bit of aluminium tape over the joins too.