Shower niche shelf Ytong

Hi, from the beginning we actually wanted to install a recessed shelf in our shower (see picture).

Unfortunately, we forgot this in all the stress.

The interior plaster is already done, as well as the screed.

Is it still possible to make a niche in the side wall towards the storage room?

It is a non-load-bearing Ytong wall (11.5 cm block) with plaster, so we have a 14 cm thick wall.

The idea was maybe about 70 cm long, 30 cm high (one tile height) and about 8-9 cm deep.

Would that be possible? Especially since the plaster is already on? And without me knocking through the wall?

Sure thing. In the end, it’s nothing other than pulling cables – just a bit wider. The problem is that the wall is so thin. You have to be so careful not to break through. Pick, pick, pick is all I can say. Smoothing out the frayed edges again is probably not a big deal. There are supposed to be tiles on it anyway, right?

Hm, have you already asked your bricklayer about that? We had a niche "installed" elsewhere with about 70x50x10 (h x w x d) and a lintel was placed above it right away. But I don’t know if that was only necessary because of the fresh masonry or if, in general – especially with the width you’re planning – some reinforcement of the stones above is necessary so that they won’t settle later.

No is not feasible.

No, it is not feasible.

And why?

Because the wall is simply too thin for that. With an 11.5 wall, at most a shelf with a depth of 6cm is possible, and then only with a lintel.