Replace vapor retarder with vapor barrier? Ceiling towards cold attic

[SirKnasen]

Living permanently in an old winterized summer cottage with an additional built-on bedroom. The bedroom was added in 2000.
I'm considering replacing the ugly ceiling in the bedroom, which is similar to clapboard on an exterior wall.
It's coarse, and there are small gaps, and I suspect that it leaks heat and moisture like a sieve into the attic.
I have some moisture problems in the attic.
Currently, there is a vapor barrier in the form of a fiber cloth between the clapboard and the fiberglass mats in the attic.
The plan is to tear down the clapboard and nail up new, fine beadboard (probably white-waxed) or another suitable ceiling panel.
Should I replace the vapor barrier with a vapor retarder?

 

[Jonatan79]

Live permanently in an old winterized summer cottage with an extended extra bedroom. The bedroom was added in 2000.
I'm considering replacing the ugly ceiling in the bedroom, which is similar to a board and batten exterior wall.
It's rough and has small gaps, and I suspect it's leaking heat and moisture like a sieve up to the attic.
I have some moisture issues in the attic.
Currently, there is a vapor barrier in the form of a fiber cloth between the board and batten and the fiberglass mats in the attic.
The plan is to tear down the board and batten and nail up new nice beadboard (probably white-waxed) or other suitable ceiling panels.
Should I replace the vapor barrier with a vapor seal?

Well, it probably won't make a difference in a bedroom. How thick is the insulation in the attic?

 

[useless]

Air movement from the warm to the cold side should be prevented as much as possible. If the fabric that is there today is a "real" vapor barrier and not a simpler wind barrier, it should work as long as it is intact.

 

[SirKnasen]

Yes, it is not impossible that it is just a simple windbreak, maybe even likely. I will definitely need to investigate that.
I have measured the thickness of the insulation, and it is in some places only 20cm.
In the thickest places around 30cm.
On the skimpy side, but I don't think it has been abnormally warm in the attic this winter. Just a few degrees above the outside temperature.
However, there is high humidity and microbial growth on the inside of the outer roof.
But on the other hand, it has been almost 100% humidity outside constantly from October to the end of February, so it gets damp in the outside air-ventilated attic too.