Capillary Action under lid

[BCBEE]

Whenever i take the lid of my National a trickle of water appears from between the wooden part of the lid and the metal sheet that covers it.
I reckon this may be due to capillary action where water runs down the edge of the lid and then up between the metal sheet and the wood by capillary action. the rest of the hive is dry.
Has anyone else got an view on this.

it is a case of sealing around the edge of the metal sheet?

 

[Skyhook]

Almost certain it would be condensation. I suspect inadequate ventilation within the roof. If you have open porter holes warm damp air will come up, but even if you dont, some moisture will come through the crownboard. The modern vernts look slick, but I dont think do the job. I drill a 20mm hole each side with a bit of perforated zinc to keep the wasps out.

 

[user 6228]

Almost certain it would be condensation. I suspect inadequate ventilation within the roof. If you have open porter holes warm damp air will come up, but even if you dont, some moisture will come through the crownboard. The modern vernts look slick, but I dont think do the job. I drill a 20mm hole each side with a bit of perforated zinc to keep the wasps out.

Need a vapour barrier between the bees and the roof. coat bottom of crown board with plastic expoxy etc...

 

[Midland Beek]

Remove metal covering when weather will be dry for a couple of days, and treat with waterproof timber product.

 

[tonybloke]

Remove metal covering when weather will be dry for a couple of days, and treat with waterproof timber product.

 

[alanf]

Whenever i take the lid of my National a trickle of water appears from between the wooden part of the lid and the metal sheet that covers it.
I reckon this may be due to capillary action where water runs down the edge of the lid and then up between the metal sheet and the wood by capillary action. the rest of the hive is dry.

it is a case of sealing around the edge of the metal sheet?

Not nailed through the top?

Basic Th0rnes type or similar? Galvanised steel over OSB? The metal skirt isn't deep but as long as the nails are down the sides away from the the top edge the water won't get in and up unless there is exceptionally heavy rain and wind. The fit would have to be a lot tighter than I've ever seen for capillary action. Otherwise, if you suspect a crack in the metal it might be easier to replace or put an additional layer of felt over the top than try to seal a split in the metal where an edge is going to flex.

If water is appearing daily even if it has not rained then it's condensation. Not under a boiler outlet is it? You might have sited the hive where the lid stays cold for much of the day. Try moving it to where it catches early morning sun and warms up more quickly.

If you seal the edges the wood/OSB box underneath is not airtight, warm moist air inside still rises and drops condensation inside the roof but it stays in the gap under the metal, result is more rot.

 

[oliver90owner]

If the crownboard is doing it's job, the roof vents should easily do theirs, as there should be very little moisture going through the crownboard. If that is OK, then the roof is faulty.

If you are one of those that leave a hole in the crownboard - 'don't' is the answer.

Sealing the roof timbers from the outside will not effect a cure for the symptoms inside the hive, just accelerate the rot from inside.

If the roof covering is leaking change or repair it.

 

[mexbigshow]

i have the same problem with my poly hive when its been raining and the outside is wet as soon as i unclasp the roof i get a capillary action between the roof and the super i have resorted to putting a polythene cover on the roof just overhanging the seal

 

[region2]

Condensation - cure it by wedging a square of 1" Celotex (foil | foam | foil sandwich) into the inside of the roof with small cutouts for the roof vents. Warm in winter, cool in summer - 8' x 4' sheet less than 15 quid!

R2

 

[drex]

Thinking about this, it seems the water is collecting between the metal roof cover and the wooden roof. It is therefore coming from outside the hive. With my Th****s roofs the metal roof cover does come down over the roof vents. Warm moist air might come out of these vents and I suppose then could condense on the underside of the metal roof cover. A long shot, but possible.

I would remove the metal cover and let it all dry out, and waterproof the top surface of the wooden roof ( I use old fashioned cuprinol clear), and put a small bead of silicone inside the metal cover where it goes round the roof vents ( but not so as to close the vents). I usually put a blob of silicone in each corner too as, on the metal, these are often far from a tight fit . Vents and roof can still breathe.

 

[user 6228]

If the crownboard is doing it's job, the roof vents should easily do theirs, as there should be very little moisture going through the crownboard. If that is OK, then the roof is faulty.

If you are one of those that leave a hole in the crownboard - 'don't' is the answer.

Sealing the roof timbers from the outside will not effect a cure for the symptoms inside the hive, just accelerate the rot from inside.

If the roof covering is leaking change or repair it.

Thin unsealed ply crown boards will not be vapour tight even if they have no holes.

 

[huntsman666]

If the moisture is coming from inside the hive then the timber part of the roof inside should be saturated. Easy to test with a piece of kitchen towel.

If capillary action (possible) then run sealing mastic type silicone into the gaps. Push in with a scraper or similar. Alternatively you could rub in some washing up detergent or soap to break the surface tension.

 

[Skyhook]

Remove metal covering when weather will be dry for a couple of days, and treat with waterproof timber product.

Not sure I agree. You still have all that damp in the roof space and roof timber, you just see it less. You want to prevent the condensation, not hide it.

 

[DanBee]

If you are one of those that leave a hole in the crownboard - 'don't' is the answer.

???

 

[oliver90owner]

Thin unsealed ply crown boards will not be vapour tight even if they have no holes.

Not so much that even a small amount of ventilation for the roof-space should cope with.

Even thin ply coverboards do not allow moisture through very quickly. There is glue between the layers.

 

[BCBEE]

Thin unsealed ply crown boards will not be vapour tight even if they have no holes.

Not so much that even a small amount of ventilation for the roof-space should cope with.

Even thin ply coverboards do not allow moisture through very quickly. There is glue between the layers.

Thanks for all the replies guys and gals.
It will look into whether it could be condensation, The roof seems dry otherwise but i will look closer. Its a cedar hive with a galv metal coveringf but no nails in the top only around the side.

Thanks again as ever for the all the advice.

 

[user 6228]

Thanks for all the replies guys and gals.
It will look into whether it could be condensation, The roof seems dry otherwise but i will look closer. Its a cedar hive with a galv metal coveringf but no nails in the top only around the side.

Thanks again as ever for the all the advice.

You can get condensation on the underside from outside air as well remember.

Replace metal lid (why do you need a heat sink up there?) with a sheet of correx that has a decent over hang and drip lip

Everybody probably knows this : Ventilation in the roof space needs to be above the insulation, to prevent internal condensation in the roof space. To prevent condensation in and above the crown board the bottom of the crown needs to a vapour barrier. In such a poorly insulated structure as wooden hive there will still be condensation in the bee occupied space. Consider making the underside of crown board so that water droplets forming on it will tend runoff to the side.

 

[drstitson]

"Consider making the underside of crown board so that water droplets forming on it will tend runoff to the side."

Good point - my modified insulated crown boards are built to channel damp air from above brood cluster to the sides of the hive.

 

[alanf]

"Consider making the underside of crown board so that water droplets forming on it will tend runoff to the side."

Good point - my modified insulated crown boards are built to channel damp air from above brood cluster to the sides of the hive.

I have been shown bees under a glass quilt in winter drinking the condensation that forms on it. Anyone aware of any detailed research on water circulation in a winter cluster?

 

[user 6228]

I have been shown bees under a glass quilt in winter drinking the condensation that forms on it. Anyone aware of any detailed research on water circulation in a winter cluster?

I'm almost certain bees drink the condensation since condensation attracted insects to infest the flat roof of a poorly insulated extension I had. I believe the important thing is not to have the cold water dripping on to the cluster. Lots of sources link condensation with the spread of fungal diseases in Bees. The yellow fibreglass insulation in the roof space of my extension was black with mould.