Substrate for slate wall, wall brick

[PatrickL]

Hello

I am wondering if there is a tiler who can give me an answer to the following:

I have a wall in the V-room that is of the type board sheet (built-83) and on top of this fiberglass mesh that is painted. Question:

Can I put a slate wall on top of this or should I put gypsum on top and then the slate wall?

 

[SBH]

would put plaster on the wall

 

[PatrickL]

It ended up being OSB+Gypsum in the end.