Problems with diagonal roofing.

[Jesyka]

When I try to use diagonal half roofs to attach to a wall the roof still goes through the wall and won't let me place anything inside next to the wall.

Also, is there any way to build a roof on a 135 degree angle?  like this angle \_    Every time I try when it's not the top floor, the roof again goes inside the house, if it's on the top I can't get any of the roof styles to merge properly.