Most of our work is commercial remodel so I don't use the roof very much,
but would you not want to use the Roof Join/Unjoin command and not Join
Geometry. It's too the right of all the Join/Unjoin Geometry buttons.
wrote in message news:5422544@discussion.autodesk.com...
I can't really see what you are doing from your image but join geometry
should work if the two surfaces really meet.