Help with flush sliding door threshold that is not flush

[emmsbutcher]

Hello

I wonder if anyone can help with this.

I've got 5m sliding doors that should have been flush with the patio on the outside but for a number of reasons the patio is now lower and is shingle. See pic.

Below the door threshold sticking out is the damp proof membrane (or something like that) which had to be cut a bit when the rendering was done. I'm just wondering what I should/could do now. The patio will be lower but wondering if there is a nice way to make it look. E.g. I can cut the black stuff off all along but it still looks a bit rubbish. Could/should I add some kind of sill? Is that even poss?

Door threshold

• emmsbutcher
• 11 Aug 2020

Any thoughts welcome.
Thanks