Vapor barrier in basement

[Styrman_jansson]

Hello,

We have a basement with exterior concrete walls, perhaps 2-3dm thick. On the outside, there is a damp-proof membrane (without insulation).

We want to make a bathroom in the basement. We want to frame the exterior walls with, for example, 45x45 metal studs to be able to insulate. Where do we place the vapor barrier? Directly behind the boards on the newly framed interior wall?

Ideally, it would be best to insulate from the outside, but we are reluctant to dig outside the exterior wall, and then have a vapor barrier directly against the inside concrete exterior wall and attach boards directly to the wall.

What type of insulation is suitable? Styrofoam?

Best regards,
- Styrman_Jansson

 

[GoForIt]

It feels like a risk construction that you're describing..
I have demolished several similar constructions with moisture and mold problems.

I read a while ago about Ytongs solution Multipor, which might be a suggestion, but I have no experience.

Do the walls absolutely have to be insulated?

 

[Styrman_jansson]

The walls absolutely do not need to be insulated. But any energy that can be saved that way. It should be added that we have just torn down previously built-up walls in the room. These consisted of wooden studs directly on the concrete, styrofoam as insulation, and chipboard. There were no signs of moisture in the material we tore down. However, there was no vapor barrier there. Perhaps one should build similarly again but with metal studs and skip the vapor barrier. It has worked for a few years before...

 

[GoForIt]

Yes, if it worked before then..
And I would have avoided the vapor barrier.

Has it been a bathroom there before?
If not, then the use of the bathroom (especially bathing/showering) will add moisture on completely different levels.