Currently renovating a house from '58 and considering what to do with the inside of our exterior walls. The house is partially made of blåbetong, and on the inside of some exterior walls, the old plaster has come loose or is loose. Of course, the absolute best option would be to knock down all loose plaster and have a mason replaster it (it's a matter of many square meters), but we are considering if we can put up drywall instead? Can this be done, or will moisture problems follow inevitably? Should we use studs to put up drywall or can it be glued directly? If using studs, should there be plastic and insulation in between?
So many questions for someone who is a new homeowner. Grateful for any tips and advice!
So many questions for someone who is a new homeowner. Grateful for any tips and advice!
If you want a sustainable result and do not want to knock down the plaster, it is probably safest to mount the gypsum on distance battens that you fasten into the lightweight concrete. A homogeneous hygroscopic material like lightweight concrete should not have a vapor barrier on the inside. Moisture migration in an exterior wall always occurs from the inside out (if the house is heated year-round).
Thank you! Should it be metal studs or can you use wood? What do you do with old wallpaper that is on the plaster? Does it have to be removed so that as little organic material as possible remains?
A bricklayer I talked to said it was foolish to frame and place drywall against the exterior wall due to potential moisture... but of course, he probably wants to sell his services. So hard to know when everyone says different.
It may be a silly question, but what could happen? I know that many suggest that you could have moisture issues, but how do those problems arise? Shouldn't the entire construction be able to breathe when there is an air gap in between? The walls are above ground, so not in the basement. We are also going to drain around the entire house (slab on grade) as a precaution. We have also measured moisture throughout the construction, and it is dry, so no moisture problems at present.
Personally, I would also prefer to replaster as it provides a nicer result, but that doesn't mean the solution with drywall doesn't work. I think metal studs create unnecessarily large distances. Moisture migration in a homogeneous aerated concrete wall occurs from the inside out. At some point (which varies depending on the temperature differences between indoors and outdoors), the water vapor in the air will condense in the aerated concrete. The outer part of the aerated concrete will also be exposed to moisture penetration due to driving rain and similar factors. As long as the aerated concrete is thick enough, this is not a problem. A very large portion of the 1950s apartment buildings were constructed with aerated concrete in the exterior walls. On the inside, there were often wallpapers over the plaster.
The lightweight concrete is 17 1/2 cm thick. Does that indicate any potential future moisture problems? Can you leave the old wallpaper in place?
The thickness is more than sufficient. You can leave the old wallpaper in place.