Breakthrough floorboards for toilet installation

Hello,

no idea if I am in the right place in the [Sanitärforum], but I'll give it a try.

On the occasion of buying a house, the following question:
We want to retrofit a toilet in the bathroom, since there is only one downstairs on the ground floor and we also want one on the bedroom level.
Now the bathroom is nicely tiled and underneath there is a floorboard floor. Surely there is still a mat or something similar in between. Is it even possible without any problems to make a ceiling breakthrough for the drain pipe? Without having to remove all the tiles in the bathroom because of the floorboards?
So is it enough to carefully remove a few tiles at the spot (to hopefully put them back later) and then make the ceiling breakthrough through the floorboards? Or do the floorboards have to be completely removed at that spot?
Thanks in advance!!!

If I were to undertake your project, I would work only selectively. In other words: only at the spot where you want to lay the HT pipe through the ceiling, remove the floorboards. Once the pipe is laid, seal it from below (e.g., OSB board), add screed and Fermacell on top, and put tiles on - done.