OK, here's a picture:
The first one shows what I get if I split a wall and reduce the thickness of a section.
The second is what I want to achieve (but the walls just overlap, they aren't joined).
The third is the horrid thing that happens when they are joined.
I think the problem is that sh3d always treats walls as symmetric about the centre line and that is the only join point.
I'd like to be able to move the position of the "centre line" to anywhere within the wall thus allowing a connection looking like the middle picture above.
Dave
