ᐅ Black mold on OSB ceiling panels

Hello everyone,

We have a shed roof with a 3° pitch. OSB boards were installed on the rafters, and a layer of insulation (walkable thermal insulation panels) was laid on top.

Plastering and screed work were then carried out. Black mold has appeared all over the ceiling (due to rising moisture).

The construction company’s statement is: This can be wiped off.

I don’t agree, as even dead mold spores can be harmful to health and have likely penetrated the OSB boards.

Do you know of any court rulings, studies, technical regulations, or similarly authoritative documents stating that the boards definitely need to be replaced?

Thank you in advance for any tips or advice!

What does the construction supervisor say?

We do not have an additional construction supervisor.
I am mainly looking for facts that support the need to replace the panels.

Toni83 schrieb:
That can be wiped off again.

Then the construction company should take care of it promptly (so tomorrow, around 7 a.m.) and take measures to prevent new mold from forming. Based on your post, that would be acceptable and sufficient for me.

Bieber0815 schrieb:
Then the construction company should take care of it promptly (so tomorrow, around 7 a.m.) and take measures to prevent any new mold from forming. That would be acceptable and sufficient for me—based on your post.

???

Did I miss the sarcasm button here? I actually know you as a rather "cautious" homeowner in this forum.

When wiping off the spores, they spread into the air and can still be harmful to health—even some time after cleaning. Not to mention that this black mold almost certainly contains more than just dead spores.

Regardless: this has often been discussed here already—that OSB boards should only be installed once the house is built and has been drying for about a year.

I find it hard to understand that a construction company installed the boards even though wet plaster and screed will be applied later.

It’s almost as if the construction company called the Schimmel family and said, "We have something for you."

f-pNo schrieb:
Did I miss the sarcasm button here?

Hmm, yes, in hindsight . That would at least be a start. If the construction company casually says "You can just wipe it off," then the question arises: So what? Then just do it, you idiot, and don’t keep complaining. Maybe as a penalty for this ignorance, a full replacement should be insisted on. I don’t know....

They are planning to start heating these days. I reminded them once again that the drywall installer should come as late as possible. The site manager confirmed this, as it is his usual practice. Currently, the upper floor ceiling below is not covered. You can see the continuous vapor barrier (foil). However, it could also be a ventilation issue if drywall or OSB boards develop mold. I hope for the best...