Storage shed insulation or ventilation?

[MysterG]

I have a newish timber shed which I got purely for storage. 10x6, no windows, apex roof.
Made sure it was well sealed at joints during erection, fitted Epdm roof as I can't be replacing the cheap shed felt that came with it in a few years time.

Today went out there for the first time in a week or two and the ceiling and walls are damp/wet, as are some of the contents. Car seats, timber, some garden tools.

I've never experienced condensation in a timber shed before.

Should my first port of call be insulation or ventilation?
I'm thinking the latter.

 

[minimutly]

Insulation would be my advice. Moisture comes in with the air...

 

[CompoSimmonite]

Never had a problem with the timber sheds I've owned.
It could be the shed parts were stored outside before being build at you property and the condensation is just the moisture from that. Maybe try a dehumidifier for a few days ?

 

[bricol]

Had the same problem in a 10X8 shed. No problem in a 8x6 shed next to it. The difference is the roof of the 8x6 shed has an inch gap to the walls all round.

 

[chrismac]

I have a wooden shed, a gale blows through it, no issues apart from the tin roof in frosty weather.

 

[bricol]

The other solution is to no go in there all winter . . .

I wasn't aware of the problem in the bigger shed until a few years ago - I've never had reason to look up or get stuff out of the roof of it in the previous decade or so.

 

[Morrisman]

Sudden temperature changes causes condensation, so if something has been at 3° all night and a warm wind blows over it as the sun comes up you’ll have warm moist air passing over cold surfaces: condensation.
Even if the shed is sealed, airtight and insulated, when you open the door in the morning outside air can get in a bam, everything can be dripping wet in a minute.

 

[iNf]

I would've thought cross flow ventilation would be the easiest and certainly cheapest option. My shed has several inches gap at the eaves and I have never had condensation in there.

 

[Farside]

I would've thought cross flow ventilation would be the easiest and certainly cheapest option. My shed has several inches gap at the eaves and I have never had condensation in there.

Yes, my workshop still has a couple of airbricks front and rear that I never bothered blocking up. When the outer workshop walls are streaming with condensation, the inner shop is pretty dry. Insulating the inside of the front and rear external walls helps, of course.
Strangely, the air flow doesn't seem to adversely affect heating effort much at all.

 

[Gareth J]

If it's unheated, ventilation won't cure the problem. Ventilating it more will let warm moist air in after a cold snap, which will condense water out on your cold things. More ventilation will help that condensation clear more quickly though.

Insulation might help buffer the temperature swings a bit. But again, if it's unheated, it'll still cool down.

What insulation would do is make it possible to run a small heat source that stops the stuff really cooling down, without costing a bomb.

But, as you've sealed it reasonably well, you could run a dehumidifier. That would heat the space a bit and keep humidity low. If you insulated it too, it would stay a bit warmer too.

 

[minimutly]

Cue 20 pages on which type of dehumidifier is best...

 

[MysterG]

Only issue is no power, so no dehumidifier.

 

[More Amps]

A large sack of silica gel...

 

[Morrisman]

A large sack of silica gel...

And a double airlock so no soaking wet external air gets inside when you open the door.