Celotex insulation

[pargyle]

Steady on lad! I'll be sending you an autographed queen if you aren't careful
There may be differences in poly thickness and heat retention. But when it snowed up here last winter it stayed on the roofs and no melt, which suggest (to me at least) that the Paynes poly hive roofs are thick enough.

YES ... But .. Bill Bielby .. Page 44 ... "You can NEVER have enough insulation"... Good Yorkshire logic from a great Yorkshire beekeeper !

 

[Thymallus]

YES ... But .. Bill Bielby .. Page 44 ... "You can NEVER have enough insulation"... Good Yorkshire logic from a great Yorkshire beekeeper !

I accidentally killed a colony one night before moving them by sealing the entrance in a poly hive the night before and leaving the drop board in.
Not something I'm proud of.
As I put them in the car the next morning (drop board removed) molten honey was dripping out of the hive. Only a beekeeper can know what it feels like to open up a hive of dead bees that you killed all on your own.
You can have too much insulation.....particularly with Poly hives.

 

[beebot]

They seem to be thick enough for good heat retention. I have bees strolling around over the frame tops in the coldest of weathers. I've never tried anything thicker...they will probably be seen with sunglasses on sitting in deckchairs come mid December if gets any hotter . We need Derek to give us some facts on thickness of roofs and heat retention. I guess like double glazing triple glazing is better.
What I have seen with poly hives is a vast reduction in the amount of stores used , compared to wooden. So much so I'm at a loss to judge how much stores they need for overwintering in poly hives. I'm having to remove frames of stores each spring to give the queen room to lay.

Seem to remember them changing the thickness of the roof design a few years back so maybe depends which you are using.

 

[Finman]

I accidentally killed a colony one night before moving them by sealing the entrance in a poly hive the night before and leaving the drop board in.
Not something I'm proud of.
As I put them in the car the next morning (drop board removed) molten honey was dripping out of the hive. Only a beekeeper can know what it feels like to open up a hive of dead bees that you killed all on your own.
You can have too much insulation.....particularly with Poly hives.

"Poly hive does not kill bees but beekeeper does"

 

[Finman]

YES ... But .. Bill Bielby .. Page 44 ... "You can NEVER have enough insulation"... Good Yorkshire logic from a great Yorkshire beekeeper !

Yes, you can out 1 feet insulation, but then you keep open mesh floor.

Insulate you House and keep your door open over night. Heat your house and let the heat leak out. ... These things are not so mysterious

Remember to reduce the hive for winter and remember proper ventilation

We have here summer over. I am reducing my hives . Some have already feeding on.

Essential is that 15 cm x 1 cm is enough to ventilate even biggest hives with solid floor. Out day temps are still 20C but bees have not much to forage. Nights are about 5 C. All hives have upper entrance in front Wall 1,5 cm wide.

 

[Finman]

.
You can have too much insulation.....particularly with Poly hives.

That is not possible, even if you try.

Polybox has enough insulation in walls. Our hive can over winter freely in open air in -30C conditions.

First of all warm hive saves winter food.

What you need is better insulation value in inner cover. If value is smaller than walls, the cover is colder than walls and it condensates moisture.

Polyhive wall is 4 cm. So you need about 6 cm cellotext. 10 cm is not needed.

Then you have solid floor or mesh floor. Boath works.

 

[Madge]

... All hives have upper entrance in front Wall 1,5 cm wide.

Do you keep the upper entrance closed until snow has blocked the lower entrance? Otherwise, how do you prevent draughts?

 

[user 6228]

As stated before, the effectiveness of roof insulation is limited
by (in rough order of importance)

1. roof to wall sealing
2. the level of side wall insulation
3. the height of the roof from any openings
4. the air resistance of the openings which is dependent on
   • height
   • width
   • length of tunnel,
   • porosity (for OMF)

Putting quantitive numbers on such systems is not trivial. (see avatar on left which is visualisation of a CFD simulation of one scenario)

 

[Finman]

Do you keep the upper entrance closed until snow has blocked the lower entrance? Otherwise, how do you prevent draughts?

The upper is always open, because bees have learned to use it. Meaning is to cause a small draught and to ventilate moisture off. Like you at home have near roof some kind of ventilation hole, via which warm air gets out.

When I have fed my hives and extracted honey, I move to Helsinki to waste my time, 100 miles away.
I do not touch much hives during October - April. They are in peace.

 

[Finman]

As stated before, the effectiveness of roof insulation is limited
by (in rough order of importance)

1. roof to wall sealing
2. the level of side wall insulation
3. the height of the roof from any openings
4. the air resistance of the openings which is dependent on
   • height
   • width
   • length of tunnel,
   • porosity (for OMF)

Putting quantitive numbers on such systems is not trivial. (see avatar on left which is visualisation of a CFD simulation of one scenario)

Holy ship. You forgot the wind factor!

It is but sounds very complex even to adult people.
.i do not understand nothing about that above.

 

[Thymallus]

As stated before, the effectiveness of roof insulation is limited
Putting quantitive numbers on such systems is not trivial. (see avatar on left which is visualisation of a CFD simulation of one scenario)

Yes quite, but does it (in general) increase with thickness? and over normal winter temperatures is there an optimal thickness beyond which additional thickening would make little difference?
I figured that Paynes roof was good enough insulation as the snow on it melted at the same rate as that on the ground.

 

[user 6228]

Yes quite, but does it (in general) increase with thickness? and over normal winter temperatures is there an optimal thickness beyond which additional thickening would make little difference?
I figured that Paynes roof was good enough insulation as the snow on it melted at the same rate as that on the ground.

The optimal roof thickness will vary on entrance opening/configuration, varroa tray position and wall thickness.

All I can say is that I didnt get much improvement above 75mm of polystyrene
in one set of generic OMF polystyrene hive simulation runs... but thats dependent on so many things is its worthless as a guide to action.

 

[Finman]

.
Listen now. We have often -20C to -30 C during December to February. More usual -10C.
We have permanent snow from December to half of April. In April nights are often -6C.

You should look more carefully what is winds' influence on wintering. You have not cold out there.

Our former polyhives were such that they had wall panel, which thickness was 2 cm. Only few years we have had hives, where the whole wall is 4 cm thick.

Hives overwinter splended in those 2 cm thick hives. It is important that food lasts from September feeding up to willows' blooming start first of May.

Question is not about optimal insulation but practical.

.hive needs 20 kg sugar in one box Langstroth from September to end of April. In May hives consumes 0.5 kg food in a day when broodinghas good speed.

But the most important thing is spring build up. In warm hives colony develops fast to foraging condition. Question is not only about dead or alive after winter.

.

 

[user 6228]

.
Listen now. We have often -20C to -30 C during December to February. More usual -10C.
We have permanent snow from December to half of April. In April nights are often -6C.

You should look more carefully what is winds' influence on wintering. You have not cold out there.

Our former polyhives were such that they had wall panel, which thickness was 2 cm. Only few years we have had hives, where the whole wall is 4 cm thick.

Hives overwinter splended in those 2 cm thick hives. It is important that food lasts from September feeding up to willows' blooming start first of May.

Question is not about optimal insulation but practical.

.hive needs 20 kg sugar in one box Langstroth from September to end of April. In May hives consumes 0.5 kg food in a day when broodinghas good speed.

But the most important thing is spring build up. In warm hives colony develops fast to foraging condition. Question is not only about dead or alive after winter.

.

You are right current practice in Finland is irrelavent to the future practice in the UK.
UK has less hours of sunshine, higher winds and higher rainfall. Temperature is only one part of the heat budget equation.
its practical to have the equivent of 75mm of polystyrene on the roof its practical to have the equivalent of 150mm of polystyrene and its cheap and readily available its called PIR. The debate here is whether its effective desirable

 

[Finman]

.
Some of you use 75 .mm cellotext, some 20 mm ply.
Some use 1 metre long mesh floors in long hives and some use what ever .

A big mess.

Last night I took from one hive 100 kg capped honey and I put the hive in feeding condition. It was guite a job. Sun was going down. In the middle of sunny day robbing might be impossible thing in that case.

But the result tells me, am I right in my lowsy beekeeping.
In Finland too young guys say that I do everything wrong, like old farts use to do, but I get over double yields compared those "young innovative forces"

 

[BeeJayBee]

Out of interest, has anybody tried painting Reticel, Celotex or Kingspan, so hives would be less shiny, and so less visible in an out-apiary?

- standard gloss paint

- Hammerite works very well and adheres to the aluminium so one coat (thick) is OK> I use Green - Hammerite Garage Paint. (ebay - cheap)

- Coloroll Garden Shades. This is water based so occasionally does not adhere to parts - so second coat is needed. Once dry, it lasts 2-3 years especially on sides.

- Shades [...] .. works a treat ... no primer needed just a couple of coats. (well - three actually but I'm a bit fussy !).​

Thanks for your help.

 

[Cussword]

INTERESTING = Carrying a 2400 x 1200 Celotex sheet home on the roof rack on a windy day.

Next time I'll work out a cutting list beforehand.

 

[SiOakleaf]

Evening, I'm all new to this bee keeping malarky and this will be my first wintering of a colony. I made a cellotex bonnet this morning and was just wondering at what sort of temperatures do you swap your roof for this bonnet?

 

[Erichalfbee]

I overwintered three of mine with cosies. I asked Derekm about it and he said to keep it on all the time; difficult with supers so I took mine off at first inspection.
So....you can put it on once you have the hive in winter configuration?
I waited for a dry spell so that I wasn't putting it onto a wet hive.

 

[SiOakleaf]

Thank you, I shall pop it on soon then.