Hi
I m from the launcher version and I m doing rebuld solution in visual studio build menu.
The action should clezr the solution of all intermediates files and build the whole solution.
Are you using a source built version of the engine or are you using 4.11 from the Launcher? Are you referring to Rebuilding a project or Rebuilding the engine in VS?
I went ahead and entered a bug report (UE-29648) about the Rebuild option. Though it is a two step process, you should be able to select Clean followed by Build instead.