Beams – Lower/Upper beams
Beams above or below a ceiling behave on input similar to walls, i.e. they join up on input, and can be inserted as a polygon or individually between two points.
Beams below a ceiling are automatically placed on the underside of the ceiling, whereas beams above are placed on the ceiling structure and modify the floor of the room.
Their properties are also similar to those of walls, so refer to those chapters for further options if necessary.