Confirm the location
Record the room, building layer and what sits above, behind or beside it.
◌Stains
Visual Match pattern
Diffuse yellow ceiling haze
A broad pale mark can follow condensation or historic low-level wetting.
Visual resemblance is only the first clue.Location, timing, texture and what makes it change are more useful than color alone.
Decode this pattern →Watch the trigger
Rain, water use, temperature and equipment cycles separate causes.
Verify before repair
Use the next distinguishing check instead of treating the surface appearance.
