Crown board ventilation over winter

[Jules59]

Thanks for all the advice. What do people use for tubs for fondant? I've been using the standard bags that fondant comes in like Fondabee...

My fondant is in a large block which I cut up and stuff into curry take-away containers - after cutting a hole in the lid similar to that in the CB.

 

[pargyle]

My fondant is in a large block which I cut up and stuff into curry take-away containers - after cutting a hole in the lid similar to that in the CB.

If you cut the hole in the bottom of the tub, when/if you need to replenish it, you can just remove the lid and drop some more fondant in.

 

[Newbeeneil]

If you cut the hole in the bottom of the tub, when/if you need to replenish it, you can just remove the lid and drop some more fondant in.

I just peel the lid off my containers and slap it onto the crown board. The containers can be stored full and carried around like that until required. If you leave a bee space at the top of the tub it is easy to whip the old container off and put a new one straight on without removing any bees that may be on the crown board

 

[lizzie-drippin]

Thanks all.

So when I cut the PIR, should it sit on top of the crown board leaving a small bee space or within the raised edges of the crown board leaving no bee space?

Thanks!

 

[user 6228]

Thanks all.

So when I cut the PIR, should it sit on top of the crown board leaving a small bee space or within the raised edges of the crown board leaving no bee space?

Thanks!

Using a crown board if itseals to the bee occupied chamber and if the PIR is within 5mm and sealed to the crown board then its is fine as a small horizontal air gap at these temperature differences does not have convection flows in it.


NOTE: the following is not the current convention, and will be another reason why name is mud.
Ideally the PIR should sit on the frames... but practically it needs at least a removealbe plastic film between it and the frame as the bees will propolise it to the frames. We use a sheet of correx lying either on or within a couple mm. The reason is to stop across frame convection, which doesn't occur in trees.

 

[pargyle]

Using a crown board if itseals to the bee occupied chamber and if the PIR is within 5mm and sealed to the crown board then its is fine as a small horizontal air gap at these temperature differences does not have convection flows in it.


NOTE: the following is not the current convention, and will be another reason why name is mud.
Ideally the PIR should sit on the frames... but practically it needs at least a removealbe plastic film between it and the frame as the bees will propolise it to the frames. We use a sheet of correx lying either on or within a couple mm. The reason is to stop across frame convection, which doesn't occur in trees.

That's interesting Derek ... for those who run hives with bottom bee space the crownboard sits on top of the frames and in top bar hives there are no gaps between the frames and some people put a sheet of polythene on top of the top bars. I run with top bee space and 6mm polycarbonate rimmed crown boards (which are obvviously very good insulation in their own right) to provide the bee space and at least 50mm PIR above the crown board. It seems to work for the bees and they remain active even in cold weather and I see them walking around on the top bars. They certainly seal the crownboard to the top of the brood box but I don't see much evidence of them trying to fill the space between the top bars and the crownboard.

I've seen your talk about convection inside the hive - do you really think that preventing this by sealing the top of the frames is a benefit to the bees ?

 

[ericbeaumont]

within the raised edges of the crown board leaving no bee space

This.

 

[Etton]

I cut 2.5KG bags into four for small nucs and seal cut edges with clingfilm/ quick and easy to apply.

12.5KG??

 

[jenkinsbrynmair]

for those who run hives with bottom bee space the crownboard sits on top of the frames

not in my experience - crown boards have a 6-8mm rim keeping them clear of the top bars. I should think the vast majority of beekeepers use this type of crown boards

 

[madasafish]

12.5KG??

5 bags 2.5KG each bag

 

[ericbeaumont]

within the raised edges of the crown board leaving no bee space?

the PIR is . . . sealed to the crown board

To clarify, Lizzie: yes, PIR is in direct contact with the top face of a CB, with holes closed. seal the cut edges with duck tape or ali tape.

As described earlier, if you want to cut a door in the PIR to feed fondant, do so. Keep the door and re-fit it after feeding; keep the CB insulated permanently.

 

[user 6228]

That's interesting Derek ... for those who run hives with bottom bee space the crownboard sits on top of the frames and in top bar hives there are no gaps between the frames and some people put a sheet of polythene on top of the top bars. I run with top bee space and 6mm polycarbonate rimmed crown boards (which are obvviously very good insulation in their own right) to provide the bee space and at least 50mm PIR above the crown board. It seems to work for the bees and they remain active even in cold weather and I see them walking around on the top bars. They certainly seal the crownboard to the top of the brood box but I don't see much evidence of them trying to fill the space between the top bars and the crownboard.

I've seen your talk about convection inside the hive - do you really think that preventing this by sealing the top of the frames is a benefit to the bees ?

it reduces heat loss and removes a feature not found in tree nests

 

[user 6228]

To clarify, Lizzie: yes, PIR is in direct contact with the top face of a CB, with holes closed. seal the cut edges with duck tape or ali tape.

As described earlier, if you want to cut a door in the PIR to feed fondant, do so. Keep the door and re-fit it after feeding; keep the CB insulated permanently.

a raised lip on the crown board that gives a 5mm gap between board and the PIR actually give an extra 5mm of good insulation.

 

[Gilberdyke John]

To clarify, Lizzie: yes, PIR is in direct contact with the top face of a CB, with holes closed. seal the cut edges with duck tape or ali tape.

As described earlier, if you want to cut a door in the PIR to feed fondant, do so. Keep the door and re-fit it after feeding; keep the CB insulated permanently.

Pictures of just such an arrangement have been posted by many of us over the years. I know I've posted quite a few. I can't help thinking of many of RABs posts which suggested reading/searching the forum history would provide excellent guidance and information

 

[robmort]

Thanks all.

So when I cut the PIR, should it sit on top of the crown board leaving a small bee space or within the raised edges of the crown board leaving no bee space?

Thanks!

You can seal the edges with ordinary packing tape, sticks well and is waterproof. no need for anything more special.

 

[jenkinsbrynmair]

So when I cut the PIR, should it sit on top of the crown board leaving a small bee space or within the raised edges of the crown board leaving no bee space?

cut a piece to fit snugly inside the roof space then fix it permanently in place - cut another piece to sit on the crownboard with a hole to put the fondant in

 

[robmort]

it reduces heat loss and removes a feature not found in tree nests

It's not usually found in tree nests because bees have to fix the comb to the roof rather than anywhere else, but if they had a series of slats with a bee space above to fix them to they may well use them, and are certainly happy with this arrangement in hives. There's no significant convection between frames as convection acts vertically.

 

[pargyle]

it reduces heat loss and removes a feature not found in tree nests

I understand that .. but, in my experience, if bees really don't like something they tend to remodel it with wax and propolis .. if they were desperately concerned about the gap between the top of the frames and the underside of the crownboard would they not fill this space in themselves ?

I'm a very light touch beekeeper - I leave them be from September onwards and surely, if this was something that they considered productive use of their energy they would be filling the gap above the frames. I've followed you for more than 10 years now, right back to the early days when you were looking at PIR as a cheap but highly effective material to build hives from and comparing heat and humidity inside the hives, you have always made sense talking about insulation and well insulated hives...

Long before you, in1972, Bill Bielby said 'You can never have too much insulation' and 'the most effective way to overwinter bees is to ensure that the hive is well insulated and as draught free as possible' - he was a beekeeper and found this by practical beekeeping - you have done a great deal to prove it scientifically and you are probably rght that the bees WOULD prefer a no bee space crownboard at the top of their home.

But ... from a practical beekeeping point of view there seems little evidence, to me, that a sheet of polythene on the top bars with a flush crownboard on top is going to be something the bees actually NEED or at least view as essential - if they did our top bee space hives would have comb and propolis filling the gap, but it does not happen.

From the average beekeeper's point of view it would make life more difficult - disturbing the top seal perhaps in early spring to feed fondant, varroa treatment from the top down in winter by sublimation - both require disturbance at the top of the hive which I think may be less desirable from the bees point of view.

I keep insulation on my hives all the year round, I run polystyrene hives ... I see massive benefits to the bees from them being able to control the temperature and humidity and I came to this conclusion with my super insulated Long Deep Hive and rudimentary temp and humidity recording before I heard you speak at our association around 2013/2014 and what you said then was a real light bulb moment for me.

But, beekeeping is often about compromises and not ideals... I could easily turn my polycarbonate crownboards over, put some polythene sheeting on the top bars and meet exactly what you are proposing .. but, from a practical beekeeping viewpoint - not sure the benefits outweigh the disadvantages. Although, I do accept that what you are saying makes good sense from a scientific viewpoint.

 

[pargyle]

It's not usually found in tree nests because bees have to fix the comb to the roof rather than anywhere else, but if they had a series of slats with a bee space above to fix them to they may well use them, and are certainly happy with this arrangement in hives. There's no significant convection between frames as convection acts vertically.

Actually, Derek's in-hive measurements have shown that there are convection currents around the hive and the space above the top bars contributes to this convection. With the top of the frames sealed off there would be less convection and less heat loss as a result so I can see the logic and the benefits. As I've just said though .. from a practical beekeeping POV it's less than ideal.

 

[user 6228]

Actually, Derek's in-hive measurements have shown that there are convection currents around the hive and the space above the top bars contributes to this convection. With the top of the frames sealed off there would be less convection and less heat loss as a result so I can see the logic and the benefits. As I've just said though .. from a practical beekeeping POV it's less than ideal.

Having a propolised rip off correx coverboard works from a practical beekeeping point of view. Been using it for several years. Try it