Removing tiles from chipboard

I currently only have a picture that I took in poor lighting. I had started to cut into the tiles and the board a bit.

Wood wedges and muscle power

The floorboards will come down and then I wanted to put Fermacell boards on the beams and then tiles. Then we can level all the floors and the doors will fit.

Thanks for the help

Fermacell must have full-surface support. Therefore, they are not suitable.

You are already aware that you first need formwork on your beams, right? This can consist of tongue and groove boards, profiled boards, or OSB. You can then construct the floor structure on top of this.

Regards

I have now had the Fermacell boards and the leveling fill shown to me at the hardware store. Would that work? So the leveling fill on the concrete ceiling and then the dry screed elements on top of that. They would then rest on the beams and the fill.

No, to my knowledge, it does not work. The elements require a non-springy, full-surface support. So you have to panel with suitable boards/plates.