You can insert ceilings using any of the handy Ceiling tools — Ceiling by Room, Ceiling by Perimeter, or Ceiling by Picking Points.
You can edit the thickness and appearance of any ceiling as well as lower it to create a suspended ceiling, regardless of how you created it. You can also use the Materials Paintbrush to apply different colors or materials to individual ceilings. As well, any ceiling can be converted into a tray or cathedral ceiling by simply editing the ceiling’s properties.
Tip: The underside of an upper-story floor can also serve as a ceiling. Similarly, the top side of a lower-story ceiling can serve as a floor.