ᐅ The floor tiles have been removed; how can the leveling compound be removed?

Many tiles have lifted extensively after 27 years. I have now removed almost all the remaining tiles. Nearly all of them could be removed easily without breaking.
The affected area is about 4 m² (43 sq ft) in a small bathroom in the attic studio.

15 m² (161 sq ft) of floor tiles of the same type in a total of two guest toilets and two bathrooms show no problems at all.

1) How should I proceed with the construction layers?
2) In the pictures, there is a gray substrate. Is that the screed?
3) I could also leave the work to the flooring installer. What would be the approximate cost for tile removal?

4) Is it sufficient to remove the layers with a scraper, or is a grinder needed?

One photo shows the transition to the parquet flooring in the adjacent room.

Thank you

Gerd53 schrieb:

1) How should I proceed with the construction?

(Putty knife or) rotary hammer, and off you go

Are you sure the substrate is in good condition? If tiles lift and can be removed entirely after just 27 years... that would make me think twice. Could there be moisture in the substrate?

Winniefred schrieb:

Are you sure the subfloor is okay? If tiles start coming loose and can be removed entirely after only 27 years, that would concern me. Could there be moisture in the substrate?

The area between the tiles and the subfloor was very dry. There is hardly any adhesive left on the tiles (see photo). Only one tile has some material from the subfloor still attached. This was the last room to be tiled. It’s possible the tiler ran out of adhesive and used it sparingly.

However, a tenant once left the roof window open during heavy rain. A neighbor noticed it. That was several years ago.

Multimaster putty attachment and apply it.

If the screed is in good condition, why should it be removed? What is your plan?