What do you do when you are unsure the roof of a building is safe to walk on? Well…. if you are an FAA licensed Part 107 UAS pilot, you get and receive airspace authorization and put a drone up.
Looking at the results can tell you a lot about the condition of the roof and then you can make a determination if it is safe to walk on, or even if you need to walk on it.
See what conclusions you can make to the above pictures. There is a ton of information in them and could you see what all needs to be repaired/replaced from these pictures? There is a long list.