Attach thin light concrete to uneven solid brick wall with gypsum mortar?

[Fredric Berling]

Hello. I want to attach a layer of 50mm leca/lightweight concrete to a rough solid brick wall dated before 1900. This is the inside of an exterior wall (not basement). The wall is built with lime mortar and is partially/mostly without plaster. It seems dry, but now it's summer.
The wall feels too uneven for adhesive, but now I'm thinking it might work with gypsum plaster?

Will this work?

It's to fill the space behind the studs. This part of the wall lacks a layer of brick compared to the adjoining wall.

 

[Alexn72]

I think a picture and further description of the purpose are needed.

 

[Fredric Berling]

I think a picture and further description of the purpose are needed

Updated the post with a picture and purpose.

 

[Alexn72]

Should the wooden studs remain?

 

[Fredric Berling]

Should the wooden studs remain?

Yep. There is a 7cm cavity between the studs and the brick.

 

[Alexn72]

Then it sounds like a complicated solution.
Will everything then be covered with plaster?

 

[Fredric Berling]

Then it sounds like a complicated solution. Is everything going to be covered with gypsum?

Yes, that's the idea. OSB + gypsum. Do you mean it's unnecessary? Should it just be left empty?

 

[petererlandsson1194]

Yes, that's the idea. OSB + plasterboard. Do you mean it's unnecessary? Should it just remain empty?

Yes, just cover it up again. Add insulation if you want.

 

[Fredric Berling]

Yes, just slice it again. Put in insulation if you want

O

Yes, just slice it again. Put in insulation if you want

A bit afraid to insulate with regular insulation against the wall if moisture might migrate there. Thought that lightweight concrete was a more secure alternative. Nervous to additionally insulate the wall from the inside regardless.

 

[Claes Sörmland]

Isn't it just a matter of building up the lecan with mortar on the old wall? If it's going to be built anyway, follow the standard, I think.

 

[Fredric Berling]

Isn't it just a matter of bricking up the leca with mortar on the old wall? If it's going to be bricked anyway, follow the standard I think.

The problem with this is that I would then have to use lime plaster/mortar because you can't use anything harder than what it was originally bricked with (?) . And lime mortar apparently adheres poorly to leca. According to the lime mortar documentation.

 

[Alexn72]

Yes, that's the idea. OSB + plasterboard. Do you mean it's unnecessary? Should we just leave it empty?

If you're going to have wood in the walls anyway, I would say it doesn't matter. I would have used stone or fiberglass insulation and plasterboard on them.

 

[Fredric Berling]

If you're going to have wood in the walls anyway, I would say it doesn't matter. I would have gone for stone or fiberglass insulation and drywall on them.

Directly against the brick?

 

[petererlandsson1194]

O


A little afraid to insulate with regular insulation against the wall in case moisture would migrate there. Thought that aerated concrete was a safer alternative. Nervous about insulating the wall from the inside regardless..

Then I would be more worried about the wooden studs, by the way...
If it's above ground, just board up and forget about the hole behind.
If it's below ground, mistake no.1 is the wooden studs.

 

[Fluxor]

Steel studs should work. Wood fiber or cellulose insulation if you want to insulate.