Line between elements on facade

[EAttila]

How does Archicad 25 decide which line to draw between two elements on a facade? I have two completely identical walls,  and a slab. On some parts of the slab it draws the line of the slab, on some parts the line of the wall. The lines of the slab is red, i would like to see that.

 i know, I've seen a topic once, covering this problem, but couldn't find it now... Thanks for the help!

Operating system used: Windows 10

[Jeff Thompson]

So the building materials are given priority levels.  However priority levels are not only listed in the building materials, layers can also have priority levels set to them, so it can get really tricky.  I would start looking at the priority level of the building materials first.  Give the material you want to stand out a higher priority level and it should give you your desired display. 

On a side note, display order can also come into affect sometimes. Bringing somethings display order to the front or to the back can effect the display as well.

Hope this helps.