Door frames

[Qadosh22]

Hi all,

I am renovating my bathroom and the old tile floor has been removed, leaving a large gap under the door frame as in the pictures.
I am installing 5mm of luxury vinyl tile flooring on 6mm ply.
The walls will have a 10mm bathroom wall cladding panel.
1. What should I do to fill the gap as neatly as possible?
2. Should I fill before the flooring goes down or after?

Any help would be appreciated.

[aeromech3]

1)Clean then build up layers of car body filler which can be trimmed to profile on last application.
2) Yes you don't want mess or scrape marks on new floor.

[dewaltdisney]

I would glue in some scrap wood to fill up the bulk of the void and then, as Aero says, use car body filler to get the moulding profile.

DWD