[Bryan and carol]

We have two containers on our site, one remains dry and the other suffers from severe condensation. They are placed side by side and have similar vents at opposite top corners. We've tested the vents using smoke and they appear to work. The wet container does hold a supply of timber, which may be holding water, although it appears dry to the touch.

There is no indication of rainwater leakage, we fixed the roofs of both of them over the summer.

Any ideas?

[AndyRVTR]

Is one more open to the elements than the other.. ie does one container get hit more from the wind?

[snowdrops]

Have you tried a hosepipe over the wet one to see if there are any leaks? Do the doors fit well? Do you store compost in there?

[Bryan and carol]

Thanks for your responses.

The two containers stand side by side with about a metre between them. The are oriented north south, so one sees more of the westerly wind and the other the easterlies.

We've checked for rain ingress and there is no obvious sign of leakage. We did repair a few holes over the summer, in both containers, with adhesive lead flashing and then repainted the tops, so I'm pretty confident that they are watertight.

There are rubber seals around the doors which are in reasonable condition, but probably not airtight.

There is no compost currently stored in either container, but the dodgy one has quite a bit of timber while the other has none.  A small quantity of bagged compost may have been stored over the summer, I can't recall now which container was involved.

[Subversive_plot]

I suspect it is the stored wood.  I know that long-dead wood that I have stored, or in use (deck, etc.) picks up and absorbs condensed humidity, and releases it at other times (responding to air relative humidity and changes in temperature).

[Bryan and carol]

I suspect it is the stored wood.  I know that long-dead wood that I have stored, or in use (deck, etc.) picks up and absorbs condensed humidity, and releases it at other times (responding to air relative humidity and changes in temperature).

That's what I'm beginning to think too. I might try to persuade the guys on the site to build an external wood store, with a cover to keep the rain off, but otherwise open to the elements.

We have machinery stored in there and it is rusting, and we need to find a cure.

[steven c]

might seem a bit of a faff but would swapping over what is stored prove it either way.

[Bryan and carol]

I guess that would provide a definitive answer, but we are talking about heavy kit and limited space in both containers. Not sure I could drum up the manpower to try !

[Alank]

It will be the wood mate. We once stored a lot of fence posts etc in our container when it was opened up you would think it had been raining in there.
I learned the lesson there, wood storage is now in an airy building or purpose built wood store and the container is to keep other stuff under lock and key safe and dry.

[Yorkie]

Do you think you would still get condensation from e.g. fence posts that were bought from a commercial supplier? We sell posts and canes, and are thinking of changing our shop from an increasingly dilapidated wooden shed, to shipping containers.

One will be lined etc., the other (for storage of bulkier and heavier items) will be standard but with some anti-condensation measures.

[Alank]

Yes yorkie our posts etc were supplied from a sawmill and they are pressure treated. I was informed from a landscaper friend of mine that the wood is pressure treated and the treatment they use is now a water based product which after a while appears dry until you store it in a place with inadequate ventilation/airflow and then the wood can sweat and the resulting condensation has no where to go and that's when the problems start.