I’m always surprised to hear that a number of H.I.'s don’t walk the roof. When weather or pitch of the roof prevents safe walking then sure, but just a general operation not to walk is I think a law suit waiting to happen. Even with binoculars its just not possible to see all the defects IMHO. Maybe with the spectoscope you can see some of these but still think its better to walk the roof. I like to walk it last as by then I have ensured the roof structure as viewed from the attic is ok. I walked a roof recently that was 4 months new. Everything looked good otherwise but around the main stack vent was a complete lack of flashing or sealant etc. Ideal entry point of water. See attached photo.
Do you walk or not walk the roof?