Sealing entrance door to the outside area

The last shown image was the condition at which the sealing should have been done. No matter how you do it, sooner or later you will have problems with moisture. If this penetrates into the [Buntsteinputz]—and that is only a matter of time—you will have moisture behind your sealing. According to standards, none of the known sealings (Remmers, PCI, etc.) can be applied now. The procedure described by Harakiri is roughly correct but unfortunately worthless in your case. Who advised you there? If you still want to do it that way now, please don’t forget to sand the part under the door and clean it with alcohol before applying the sealing. But as I said, I would rather remove the [Buntsteinputz] partially once again. You can reapply it afterwards without it being visible. I would do it properly once, then you will have peace. Smearing it on now will backfire on you—sooner or later.