Ceiling Cracks: A Structural Warning Sign or Cosmetic ...
Ceiling cracks running diagonally across the ceiling. A crack (of a 16th of an inch or larger) that runs at a diagonal angle through a sheet(s) of drywall requires a lot of force to create this crack. It's like the drywall is ripped apart. This type of crack generally would be considered a "red flag", depending on width, length, and location.