Plastic and wind protection in bathroom ceiling?

[abel48]

Will soon start on the bathroom on the upper floor. It's only framed by previous owners and there's a sloped ceiling in half the room. But under the insulation (cutter shavings) in the ceiling, there's Paroc wind barrier, then battens to the inner ceiling. Now I wonder if it's inappropriate to put plastic on it? So it doesn't create a double moisture barrier...
It's this one: http://www.paroc.se/losningar-och-p...entilerad-fasader/paroc-xmw-060?sc_lang=sv-SE
that's in place now. But if no plastic is used, doesn't the moisture rise to the attic since it gets humid in a bathroom?

Best regards, Anders

 

[Stefan1972]

The moisture that becomes a bathroom should be ventilated out with ventilation. Otherwise, you'll probably have problems no matter how much you plastic wrap it.
If you have an old house, I would skip all the plastic and build as usual. Then make sure to have proper ventilation.

 

[abel48]

I'm planning to install a humidity-controlled bathroom fan. So that might be enough. But there won't be any diffusion barrier against the wind then.

Best regards, Anders