Tiles broken, now also with breaking the substrate?

Good day,

I am now gutting my bathroom so that a tiler can lay new tiles. I have now knocked off the old tiles, so this is how it looks?

What kind of tile adhesive was this?
And does it have to be removed as well?

This material is about 3 cm thick and behind it you can see bricks.

You can also embed the images directly here ... The download takes forever :(

The tiles were laid using the thick-bed method. You will usually have to completely remove the mortar in order to be able to lay new tiles.

The tiles were laid using the thick-bed method. You will usually have to remove the mortar completely in order to lay new tiles.

It was agreed with the tiler that I would remove the old tiles and he would put on new ones. (I remove the core) Does removal also include removing the thick-bed mortar?

You can also embed the images directly here ... The download takes forever :(

Ok, I'll do that next time. Normally, the directupload server is fast ...

It was agreed with the tiler, I remove the old tiles and he puts on new ones. (I gut) Does the removal also include removing the thick-bed mortar?

Yes.