Vapor barrier vs vapor retarder

So, now the sketch fits better.

Jochen

Hello Jochen,

the applied thermal insulation must be able to dry if it is exposed to moisture "from below." Warm, moist air rises from the living area into the insulation.

You mean warm, moist air rises through the ceilings / walls of the upper attic apartments into the roof area. I think the ceilings / walls were installed with gypsum boards in the years 1961 - 1962.

Jochen

Yes, exactly. Because of the material and joints. Can't you insulate the sloping roof? Can't you reach it anymore there?

Yes, exactly. Due to the material and joints. Can't you insulate the roof slope? Can't you access it anymore?

Which roof slope do you mean?

Jochen

Actually everyone. Especially those above the converted attic. So, why is [Zwischensparrendämmung] not possible.

Actually all of them. Especially those above the converted attic. So, why is insulation between the rafters not possible.

I learned that even with insulation between the rafters, a vapor barrier / vapor retarder should be installed on the underside beneath the entire insulation. How is that supposed to be done in the area of the slope? Jochen