Moisture problems garage

[JonnyN80]

Hello.
I have a problem with moisture in my garage and I'm hoping someone can help me resolve it. The garage is insulated, sits on a concrete slab, but without heating. It has exterior wood paneling, 100mm insulation, then plastic, and then drywall. There was wallpaper on the interior walls that I decided to remove. Then I noticed there were black spots underneath. Not everywhere, but in quite a few places. I assume it's mold. I remember that last winter there was sometimes water on the inside of the windows!!! Now to my questions...

1. How do I get rid of it???
2. I plan to either put up renovation wallpaper or a new sheet of drywall and just paint it.
3. How do I prevent the mold from coming back? There are 2 ventilation vents, one on the short side and the other on one of the long sides. There is also a vent hole in each of the two doors at the bottom.

Hope you understand Regards, Jonny Nilsson

 

[racer]

Either turn on some heat or remove the plastic!
Kind regards

 

[Mats]

Chlorine is reportedly (not tested myself) effective on black spots

 

[JonnyN80]

Either add some heat or remove the plastic!
Best regards

So you mean the insulation would be directly against the drywall?? Would that really help?? Best regards

 

[Jan-Å]

From the discussion in previous threads, you have to choose between plastic and heat or no plastic and no heat. I'm not an expert in the area, but cold spaces should not have plastic, that's what was said. So "racer" is not advising on how the insulation should be laid out; it's the plastic that should be removed if you don’t plan to heat the space.

 

[JonnyN80]

From the discussion in earlier threads, you have to choose between plastic and heat or no plastic and no heat. I'm no expert in the area, but cold spaces shouldn't have plastic, that's what was said.
"racer" isn't advising on how the insulation should be placed but rather that the plastic should be removed if you're not planning to heat the space.

Okay. You seem sure. But still, it sounds strange that removing the plastic would help:S But I'll tear down the gypsum and put up new without plastic.
Regards

 

[JonnyN80]

I spoke with a "builder" I know. He thought it might be the fabric and the glue that caused the mold, or trapped moisture. What do you think about that??? Made holes in a couple of places today and there was no moisture or mold on the back of the drywall? I thought there should be if it was the plastic that caused it.. Best regards, JonnyN

 

[flygrc]

If you only want to remove black spots, this product works perfectly, better than chlorine even though it smells like chlorine. It even removes iron deposits on, for example, shower curtains

http://www.spangajarn.se/kemtekniskt/rengoring/mogelbort

 

[Jan-Å]

As I said, not exactly an expert but the plastic prevents moisture from migrating out of the house and when it is not heated, the temperature differences during especially spring and fall become so large that the ventilation cannot handle the condensation that forms. There will be moisture on the wall that molds.