How to prep this area of the concrete floor for tiling

[Sard]

Hi,

I had some work done a while back to convert a window to a set of patio doors and the floor was left like this. The rest of the substrate is a concrete subfloor and looks like it was previously screeded, so it won't need screeding again. The grey top layer on the right is flaking off, so it looks like it will need to be removed. Also I'm unsure what to do with the damp proof membrane? Shall I cut to where it was screeded?

 

[Wayners]

Cut dpm off
Floor leveler over
Tile sealer as recommended
Tile floor

Guess you have old and new floors there. Both have dpm under?

 

[Sard]

Cut dpm off
Floor leveler over
Tile sealer as recommended
Tile floor

Guess you have old and new floors there. Both have dpm under?

Thank you for the reply. I'm assuming I only need floor leveler for the area near the door? I don't want to screed the whole 22m2 of area that is going to be tiled. Also by tile sealer, do you mean priming the concrete subfloor? If so, I do plan on doing that. They'll floor has DPM but the new sliver does not as per the photo.

 

[dazlight]

Take them bricks out. Builders do that all the time and it’s wrong as you get water ingress under the doorframe.
remove the bricks and put some more Dpm sheet in and so it Laps up the door frame.

 

[Sard]

Take them bricks out. Builders do that all the time and it’s wrong as you get water ingress under the doorframe.
remove the bricks and put some more Dpm sheet in and so it Laps up the door frame.

Thank you, I can certainly do that. What about levelling that area? Should I just level with mortar?

 

[dazlight]

Yes sand and cement or ardex A35 As that will be fully dry in 24 hrs.
most of the time I use a compound with granno chips as we always have in stock.