Creating a Barreled Ceiling
While in the section view where you want the barreled ceiling to be located at
Architecture tab
Build section
Select down arrow on the Component function
Select Model in Place
Please note this function is not available on Revit LT
Select ceilings in the family category and parameters
Name ceiling
Extrusion
Pick a Plane
Select wall perpendicular to barreled ceiling
Draw arch using draw tool
Close the extrusion
Green Check Mark
Green Check Mark Finish Model
Adjust Ceiling as needed