Can I paint one wall?

[Dermot Dempsey]

Changing the interior or exterior surface material on a per wall basis works best when you are only concerned with cosmetic appearances. If you need to have all of the materials you are using show up in the materials list, then you should create a new wall type or use the wall covering tool.

The wall covering tool should work fine for either interior or exterior walls. Just be sure to check the appropriate Interior and/or Exterior checkbox for where you want the covering to go.