Vapor barrier on wooden beam ceiling before plaster and screed?

Hello forum,

Our windows will arrive soon and the interior construction is about to start.

My question is whether I should insulate the wooden beam ceiling before plastering and screed or after?

Construction from top to bottom
Cold attic
OSB boards
240mm collar beam
240mm insulation clamp fleece
Vapor barrier
Battens
Drywall/Fermacell

Thank you

What does the site manager say about that? If the vapor barrier is not yet installed, all the moisture from the plaster and screed goes into the attic and can lead to mold there if the moisture is not removed. It also depends on how the attic is ventilated. Aren't vapor barriers often plastered over and therefore necessarily have to be installed before the plaster?

Somehow I ended up in the wrong forum, this should actually be in the insulation department.

The construction manager says before the plaster, then it will be plastered in.

I have only read so much on this topic that I am uncertain.
You read that there is too much water for the vapor barrier to cope with, etc.

We have a "town villa" and the ETICS is still missing there, which is to be installed in the upper third of the house due to the cold temperatures.

In other words, there is space between the masonry and the roof structure.

We did the plastering before you, precisely also for the reason that the foil is then embedded in the plaster at the ends.

Vapor barrier before plaster and screed
Vapor retarder after plaster and screed.