Revisions log for Answer #272

In your place in the bathroom – if the finished space is later sufficient to accommodate all objects, I would also work with green GK. Nevertheless, I would knock off all remnants of the former Speis; this is usually very easy and you keep – with double planking – almost the existing space.

In the kitchen, I would remove completely, create a homogeneous surface with matching plaster and then re-tile. Especially there, it often comes down to centimeters, which you "might" miss in a later kitchen planning.