Hello folks!
I think my problem is not new, and asked several times. I tried to search for solution but no success.
So my problem: I have a room segment. The 2 side has different texture. The inner side has a different texture than the outer side.
When I tried to make 2 separated room with this room segment, in the first room, everything was ok, I saw the inner side of the wall everywhere. But in the second room I saw the outer wall texture. Beside of this the wall was flickering, probably because FPSC couldnot decide what to draw out.
I tried external draw mode, internal draw mode, but not helped.
How can I make a wall separation to saw the inner texture on both side?
Here is a picture to explain my problem:

My other problem based on the problem above. If I want to make a new room using an other room segment, the new wall segment overwrites the other room wall segment. How can I make 2 different room, where the wall in the first room is different from the second room accessable trough a door?
Here is a picture:
I hope you will understand my problem. I tried to describe it as best as I can. Unfortunately I'm from abroad