Wall behind radiator

[Peter Sundelin]

I have a 1950s brick house. Behind the radiators, there is a board that resembles plywood. It has started to warp due to age and, I assume, warm air/condensation. I want to address this and wonder what is best to place behind the radiators.

Should I remove everything, install vapor barrier plastic, then OSB, and then drywall? Or how should one do it?
The windowsills are made of marble and need a stable attachment to prevent sagging, hence the suggestion with OSB.

Grateful for tips.

 

[Jonatan79]

How thick is the skiva, what is behind the skiva?

 

[Peter Sundelin]

Don't know, haven't started tearing anything down yet.
I'm unsure if it's plywood, maybe it could be something else.

There is also a painted fiber weave on the board.

 

[Jonatan79]

With a bit of luck, it might be enough to replace the disc with gypsum, there might be something sturdy underneath to screw the radiator brackets into.

 

[Peter Sundelin]

Okay. Should I put plastic first? Then drywall? Or skip the plastic?

 

[Jonatan79]

You don't have plastic in your house, do you? Unless it's been renovated?

 

[Peter Sundelin]

No, I haven't. I've read that this is how walls are built today, to prevent warm, humid air from escaping through the wall. But maybe that doesn't apply to older houses?

 

[Jonatan79]

Nix, build in the same way as before is my advice. If you're renovating everything, it might be relevant to use plastic...