New layers (what) in interior walls?

[berraX]

Hello

We have a house from the 1800s. In one room, three walls are made of soft Treetex. The fourth wall is a plastered surface that is now wallpapered.

Treetex is too soft as an outer layer, and the "stone wall" is in such poor condition that new plaster must be applied if the layer is to be retained.

What should be done?
Can one put OSB on the Treetex walls and also directly on the plastered wall? How to fasten on a plastered surface in that case?
Then a thin gypsum board on the outside of the OSB?

This will add some thickness, so there will be some fiddling around doors and windows.

I'm unsure about removing Treetex because the house is probably not well insulated. The layer likely has some insulating function at least.

These are completely new questions for me, so there's a lot to consider.

Any suggestions for possible solutions?

 

[Mazen]

I have done a similar maneuver in one of the rooms, 2 outer walls with tretex on a timber frame and 2 inner walls with both standing planks and plastered part (the chimney). I chose to put 6mm fiber gypsum (not loved by everyone) just to "avoid" tearing off casings, baseboards, and ceiling moldings.
I also channeled new electricity into the tretex, though it creates an awful lot of dust.
It became a good, smooth surface to paint and wallpaper on.
The only downside with fiber gypsum is that it can bend and follow if the base is very wavy.
There, a standard 13mm gypsum is much better if you can use that instead.

 

[berraX]

I am also considering thin repair plaster. It doesn't need to be thick, just a good surface to paint on.

How did you attach it to the plastered chimney breast?

 

[Mazen]

After a tip, I glued it with tile adhesive and it holds really well... I also think you can use something like plaster, but it all depends on how firmly the plaster is attached.

 

[Larsa]

Have a lot of paper-faced gypsum board in my house, works great on old walls with various layers. On plaster/brick, you can attach it with gypsum mortar.

 

[berraX]

Should one skip the OSB board on the plastered wall and just go with drywall?

Otherwise, the idea with OSB is to have something robust underneath where you can easily insert screws if needed.

 

[Larsa]

Should one skip the OSB board on the plastered wall and just use gypsum?

Otherwise, the idea with OSB is to have something robust underneath that can easily hold screws if necessary.

Agree, missed that in my comment. OSB is unnecessary if the substrate under tretex etc. is solid.

 

[Mazen]

If the idea is to save the tretex and you have a robust "wall" underneath, then yes, skip the OSB as Lars mentioned above.

 

[PNO]

It can be difficult to screw 13mm gypsum onto Tretex. There's a high risk of screwing through. The 6mm gypsum is considerably harder, so it usually works better. On the other hand, 6mm gypsum on Tretex looks about the same as Masonite on Tretex, i.e., wavy.

I've tried both options, and it ended with me eventually tearing down the Tretex completely and screwing the gypsum into the underlying raw planks instead.

If you're going for 13mm gypsum, you should probably choose the hardest boards you can find. There's quite a bit of difference between different brands.

However, for a plastered wall, I would primarily recommend re-plastering. It's not that difficult.

 

[berraX]

On the plastered wall, there will be expansion plugs in the plaster if there is no OSB. I might be able to live with that if it's inappropriate to have OSB on the innermost layer.

Treetex is probably not strong enough to screw into. I don't know what's behind it. It could very well be a timber frame like Mazen's house. If the screw is long and reaches all the way here, it will of course be strong. Should I forgo OSB here?

 

[berraX]

PNO, there you see....there are always other angles to the problem......The really simple way is not so easy to find.

What do you think about plastering with gipsbruk? I found an article that was clearly positive.