Added insulation foundation wall condensation problem

[RasmusD]

Hello! I have insulated my foundation wall made of leca and discovered today when I was about to install the fiber cement boards that I've encountered some condensation problems under the metal flashing.

I'm wondering if I've done something technically wrong, and how to go about solving the issue if that's the case.

There's a small cavity between the insulation and the flashing where the air is stagnant since I've pressed the insulation all the way up against the flashing. Would it work to insulate more carefully to avoid air pockets? Or could it be warm air leakage from inside that's causing this condensation? The sill for the upper floor is resting on the leca with only sill paper, it should probably have been proper sill insulation.

I assume the problem would be solved by having an air gap between the flashing and the insulation, but then I would lose insulation and have exposed leca blocks which would get cold and create other condensation issues instead?

It's a split-level house with walls made of leca blocks on the lower floor. The inside will have framed utility walls with insulation, albeit a thinner layer than the outside walls.

I’ll upload some pictures so you can see the problem.

I hope someone has some good advice to offer.

Thank you in advance!

 

[allexx]

Warm humid air is pushed out and condenses.
What kind of ventilation do you have in the house?
Is it a regular basement or a crawl space?

 

[surris]

Are the sheet metals in contact with the outside temperature?

 

[RasmusD]

Warm humid air is pushed out and condenses.
What kind of ventilation do you have in the house?
Is it a regular basement or crawl space?

I don't have any ventilation in the basement right now, will install passive vents when the construction starts down there, have passive ventilation on the upper floor as well.

It's not really a basement as such, since all the living space on the lower floor is above ground.

 

[RasmusD]

Do the metal sheets have contact with the outside temperature?

Yes, this is outdoors.

 

[surris]

Yes, this is outdoors.

Okay, I thought it was a basement.
The metal conducts heat well and can easily become colder than the surrounding air, which makes it prone to condensation if the air is warmer.