Hello I have modeled steel decking by modeling the profile in rhino, importing it and making it into a family (mass template), place mass in my current project and then using modeling by face to create a 20’ long wall type in the shape of the decking profile.  I then grouped the walls and am trying to move them to the underside of a sloped ½” sheathing floor system I have made.  I cannot seem to get any snap points on my group or align to the underside of the floor system.  I can however align to the sides of the floor system which doesn’t help me very much.  Does anyone know a better way to do this, or how to do this?  Any help would be appreciated – thanks.