The roughness of Duct Lining. 
   Namespace:   Autodesk.Revit.DB.Mechanical  
  Assembly:   RevitAPI  (in RevitAPI.dll) Version: 2015.0.0.0 (2015.0.0.0) 
  Since:  2012 
Syntax
Exceptions
| Exception | Condition | 
|---|---|
| Autodesk.Revit.Exceptions ArgumentOutOfRangeException | When setting this property: The roughness value should be at least equal to or larger than 0. | 
| Autodesk.Revit.Exceptions DisabledDisciplineException | When setting this property: None of the following disciplines is enabled: Mechanical Electrical Piping. |