Need some advice on how to fill a large gap please

[Morcas]

Howdy all, I really need some advice on how to fill a large gap between two walls, let me explain.

The building in question is not in the UK. Its an apartment block typical of the country, basically its just blocks of reinforced concrete held together with brackets! Scary stuff...

Anyway I am decorating one of the apartments and where an internal wall joins the external wall, at right angles, there is a gap of approximately 2cm top to bottom and approximately 10cm deep (this is where the brackets attach the internal wall to the external wall) originally it was filled with mortar, but that has crumbled away.

Question is, what to replace it with, more mortar or something like expanding foam?

Thanks for any help.

 

[countygardens]

Howdy all, I really need some advice on how to fill a large gap ?

Don't tempt me!

 

[Morcas]

Perhaps I could have phrased that a little better

 

[TexMex]

What sort of finish do the walls have?

 

[Morcas]

Basically, its just smooth'ish concrete, people here mostly use wallpaper and I may well continue with that, although I was toying around with the idea of skimming the walls. depends if I can find what I need.