Insulation and moisture barrier roof

Hello,

we have an extension on our house that is to be converted into a living space (kitchen). Until now, the roof was constructed with a simple board structure and roofing felt (double layer). Now we have had exterior insulation installed on the roof including everything that belongs to it (Image 1).

We are now wondering how we have to/can seal everything from the inside so that we do not get mold problems. Until now, this was not a heated room and the roof itself was well ventilated – on the outside, the unplastered part + the wood (see Image 1) was only clad with wooden boards. We would like to suspend the ceiling again from the continuous lower beam (green) inside (Image 2). Now we still have to make the roof structure airtight. At the moment, you can still look outside through the front side between the roof beams (Image 3).

Does anyone have advice for us on how to best build up the ceiling from the inside including sealing? (Keyword vapor barrier)?


We are open to all ideas. Thanks!

Would stuff wool into the gaps and then put a vapor barrier underneath (klimamembran), stick it to the mw, then plaster over it. Gypsum board from below, with counter battens.

Ah great, that was our thought too - we were just not sure if that's okay, since we want the ceiling to be straight and the roof slopes. Then we would have to stuff a lot of wool towards the house wall.

How could we then close the "gaps" towards the front so that it is also moisture-proof? We thought of Powerpanel Aqua, but that is not diffusion-open, which will probably cause a moisture problem in summer that won't be able to escape.

I took a picture from the outside. We are basically between two layers of wood, so stones won't hold

I would clad with wood, one in front, one below. A bit nicer, but more elaborate, would be to saw off the overhangs, put [steinwolle] in between, then plaster upwards with [Gewebe].

mhh, before I saw off anything there, I would want to be sure that the overhang is not the support for the roof.

if you cut it flush, it will support just like it does now