Filling a hole in the wall

[matsode]

Hello,

I need to fill a gap of approximately 30 x 70 + 2000 mm between a slag wall and a stud. This should then become a smooth (wall surface).

What should I fill with? The initial idea is some form of filler.

See also the attached image.

Grateful for some input!

 

[mugatu]

Hello,

I need to fill a gap of about 30 x 70 + 2000 mm between a slag wall and a stud. This should then become smooth on the surface (wall surface).

What should I fill it with? My initial thought is some sort of filler.

See attached image as well.

Grateful for any input!

I have used gypsum plaster, which you mix with water to the desired consistency.