I had an inspection done on my house last year before I bought it, and was told by the inspector that the dark discolored areas of the plywood on the bottom side of my roof was likely "dark staining cause by poor ventilation and air circulation" and that it did not appear to be mold.
I guess my question(s) are what would cause the dark stains? Moisture? What else could it be besides mold?
You can also see dark areas on the plywood on the sides too.
I've seen several pictures online that looks similar to mine that claim they have mold.
I just wanted some ideas as to what this might be before I spent a lot of money on mold testing and treatment.