Hey Lec,
Let's see if we can sort out this mess you're in!
Firstly, the layer intersection number works as an on/off switch - they either do intersect if the LIGN is the same, or they don't. In your case you
do
want them to intersect so put all the walls on the same layer, or ensure the layers they are on have the same layer intersection number!
Secondly, you are experimenting with the
skin priorities
, so you need to have 'enable
skin priorities
' ticked in all walls to correctly see the effect!
Thirdly, all your walls should have the same
wall
priority for this exercise, so leave the wall priority for all walls at 8 for the moment.
Now all the other settings are equal, your skin priorities should behave predictably and correctly.
As Brandon has pointed out, the main problem is that your horizontal wall has the same intersection number throughout. Give the core a higher number than the 'finish' and it should work fine. Give your vertical walls the same settings and everything will join beautifully.
Try using the guide in Archibens post
here as the basis for any new profiles and composites, and you'll find it should work in the majority of cases.
Good luck!