Pallet wrapped wood seasoning

[LogGoblin]

43 minutes ago, Steven P said:

That condensation under the roof, the moisture comes from where..... If it drips back on the wood it's only going back where it started. If it worries you a lot you could get a -probably- cheap solar / battery powered fan to run on at dusk to create some air flow under the roof, will dry the wood out qucker too

 

It comes from warm humid air cooling when it meats the cold, surface. It's the same thing that happens to your cold glass of beer on a hot day. It doesn't come directly from the logs. The log store could be empty and it would still occur. 

 

It's not an issue for the intended purpose, the pros of the roof outweigh the cons and it achieves its intended purpose; however it is a consideration for anyone doing something similar, as it could be avoided. 

 

A fan wouldn't achieve anything. The issue was primarily occurring when the whole store was completely open, so a fan would do nothing to eliminate it. The pallet wrap has gaps which allow cold air in at the bottom of the stack, which then rises and exits as warm humid air taking moisture from the logs by convection. 

 

 

 

 

[sandspider]

12 hours ago, LogGoblin said:

It causes a lot of condensation. It's fine in the summer, but in autumn and winter as soon as the air cools in the evenings it condensates on the underside of the roof. It's not a major problem, but it does drip on my lovely dry wood.

 

I'm considering stapling a perforated vapour barrier up in winter. 

It may not be as big an issue if your shed doesn't cool as rapidly as mine (it's completely open front and back). Twinwall polycarbonate might eliminate some of the issue, as might a steeper pitched roof. 

 

Thinking about it though, I don't think my smaller shed suffers as badly. The only differences I can think of are that it's slatted at the rear instead of chicken wire, and the wood is generally stacked nearer to the roof.  

Thanks. I do get some condensation in the polytunnel I currently use, despite plenty of ventilation. Perils of living in Wales I suppose! But lovely and hot in Spring, Summer & even Autumn at the moment, so worth it overall, as you say.

[LogGoblin]

2 hours ago, sandspider said:

Thanks. I do get some condensation in the polytunnel I currently use, despite plenty of ventilation. Perils of living in Wales I suppose! But lovely and hot in Spring, Summer & even Autumn at the moment, so worth it overall, as you say.

If I had the room I'd use a polytunnel to season and then store the seasoned wood in a nice dry wooden store.  I think that would be the best of both worlds. 

[Steven P]

18 hours ago, LogGoblin said:

It comes from warm humid air cooling when it meats the cold, surface. It's the same thing that happens to your cold glass of beer on a hot day. It doesn't come directly from the logs. The log store could be empty and it would still occur. 

 

It's not an issue for the intended purpose, the pros of the roof outweigh the cons and it achieves its intended purpose; however it is a consideration for anyone doing something similar, as it could be avoided. 

 

A fan wouldn't achieve anything. The issue was primarily occurring when the whole store was completely open, so a fan would do nothing to eliminate it. The pallet wrap has gaps which allow cold air in at the bottom of the stack, which then rises and exits as warm humid air taking moisture from the logs by convection. 

 

 

 

 

That's the point, the logs as they dry send their moisture out into the air creating warm moist air. Warm air rises to sit just underneath the roof. If you could measure it, it will be more moist under than above the roof. If this is a problem for you then create more air flow under the roof so this moist air can escape and be replaced by drier air from outside. A cheap fan can do this, I wouldn't bother, it wouldn't cause me any worry.

[neiln]

Or the moisture comes from the ground beneath the stack of wood.

 

 

Solar kilns are definitely a good way to get very very dry wood very quickly.

[openspaceman]

1 hour ago, Steven P said:

That's the point, the logs as they dry send their moisture out into the air creating warm moist air. Warm air rises to sit just underneath the roof. If you could measure it, it will be more moist under than above the roof. If this is a problem for you then create more air flow under the roof so this moist air can escape and be replaced by drier air from outside. A cheap fan can do this, I wouldn't bother, it wouldn't cause me any worry.

If the roof is a good emitter of radiation and a poor insulator then  condensation can form even with an empty space underneath, this is because on a clear night the roof will become colder than the ground and thus as the temperature drops the dew point is reached sooner than the surrounds. I have experienced very bad dew falling from steel roofs but no found any problems with clear acrylic or polycarbonate so far.

[LogGoblin]

3 hours ago, Steven P said:

That's the point, the logs as they dry send their moisture out into the air creating warm moist air. Warm air rises to sit just underneath the roof. If you could measure it, it will be more moist under than above the roof. If this is a problem for you then create more air flow under the roof so this moist air can escape and be replaced by drier air from outside. A cheap fan can do this, I wouldn't bother, it wouldn't cause me any worry.

Thank you for your comments. They've been enlightening. 

[Rob_the_Sparky]

The other point to consider is the pitch of the roof.  If the roof is too flat then moisture will drip off, if the pitch is high enough then it will run down the surface.  I put mine at about 25 degrees as I read online that it is what you need, seemed like a lot when I did it.  We shall see this winter if that works though as I've only just put it on.  Wasn't expecting to get condensation on the under side so I'll watch out for that.

 

My other log rack has an overlapped wooden plank roof (made from pallet wood) but this one is a bit deeper and the pallets were not long enough.  Thought I'd try a clear roof on this one hoping to get more sun on the stack.

 

From what I heard wind is as important, or more important, than heat though.  Not sure what to believe but certainly wood I split in September (probably felled around June time) was dry enough to burn by March (I had run out of other wood so split and tested a few samples!).

[Stere]

Quote

The other point to consider is the pitch of the roof. 

 

Was just thinking that

[Alycidon]

On 16/09/2020 at 21:32, Squaredy said:

I don't think it is possible for firewood to be too dry.  This is a myth propagated by people selling firewood that is not dry enough!

 

If your fire burns too fiercely and hot you need to use fewer larger pieces, not wetter wood.

There are for and against s in the to dry issue.   For is that the less moisture in a log the less energy is wasted evaporating it, thus more energy is converted into heat.    

 

Against,  Research by a leading stove manufacturer advises that the optimum moisture level for minimal emissions is 10% - 12%.   Less ( or more) than that and the emissions levels increase.

 

A