Damp spot near the ceiling under the shower?

Hi guys,

unfortunately, I just discovered a strange spot on the wall on the ground floor of the relatively new single-family house (built in 2018) – unfortunately, it looks like moisture to me.
Directly above is the bathroom, more precisely the floor drain of the shower.



The drainage channel is installed flush with the floor. I see no damp spots in the joints of the shower rear wall. However, in the drainage channel, there is no joint between the channel and the tile back wall:


I already mentioned this during construction; they said it was normal and that there was some kind of waterproofing behind it.

Hi guys,

unfortunately, I just discovered a strange spot on the wall on the ground floor of the relatively new single-family house (built in 2018) – unfortunately, it looks like moisture to me.
Directly above is the bathroom, more precisely the floor drain of the shower.



The drainage channel is installed flush with the floor. I see no damp spots in the joints of the shower rear wall. However, in the drainage channel, there is no joint between the channel and the tile back wall:


I already mentioned this during construction; they said it was normal and that there was some kind of waterproofing behind it.

Does anyone have information about this?

Thanks

yeah man, would have liked to have done more. Where are you from?