Maybe I am misunderstanding your reply Hans, but my trouble is ... for example, I make a full circle of two segments like this..





And I select one side of the circle to split so that I can either paint it a different color, or delete the extra section I don't need..




And then when I split the wall, it ends up looking like this....




I can make many little walls to mimic the splitting, but I was wondering if there was a faster way to do it?