Mold inside a 3-year-old house wall/ceiling corner

Yes, but who heats a bedroom above 19 degrees, please? Often it is much cooler there. I see no sensible solution in that!

Well, and exactly for that reason you need a mechanical (central or decentralized) ventilation with heat recovery. Once again, QED: new buildings need a ventilation system.

Or a changed heating/ventilation behavior.

What once was is no more... and either you adapt or the house adapts or not.

so and precisely for that reason you also need a mechanical (central or decentralized) ventilation system with heat recovery. once again QED: new buildings need a ventilation system.

I don't see it that way across the board. Thermal bridges can be avoided and are in my opinion less common in new buildings than before, when balconies were simply concreted on without insulation!

What should cause thermal bridges in simple floor plans with very good insulation? Additionally, airtightness also has a positive effect if ensured. Since no convection can take place, there is no moisture buildup on critical components.

Well over 50% of new buildings in my construction area still lack a ventilation concept today, contrary to the regulations of the Energy Saving Ordinance. And yet, these people generally do not have problems with mold.

Uah, I’m so glad that I can sleep mold-free in a drafty old building at 17°C. This really can’t be right...

P.S. Thermal bridge or not: At the stated values (19°C air, 68% humidity), the dew point is only at 13°C. So there shouldn’t be any condensation in a corner that’s 17°C warm. Could there still be something leaking somewhere or is it really still full of construction moisture?

Hello

a little tip to at least temporarily combat the effects:
buy yourself a small fan. 5-6 watts are more than enough. Aim it from 20-30cm at the mold-infested spot and let it run. You will see, in a day or two the wall (at least on the surface) will be dry.
And at the same time start investigating the causes.

Steven

Hi,

thanks for the many tips. I am constantly learning here and realize that I (like with many things in building) was inadequately informed or misinformed... (Then do it right with the next house.

I definitely need to adjust the ventilation behavior. I already ordered a dehumidifier yesterday and of course something to temporarily deal with the mold. I will also try the fan right away.

I have already looked at some websites with decentralized ventilation systems.

What now needs to be clarified is whether there is a construction error here or if it is just a "stupid" corner. Although I wonder if that would help me – because rebuilding the corner probably won't work either.

Many thanks and best regards