Typically, it is walked on, checked from a window from above, by a ladder at the eave, or from the ground with binoculars. If at all possible, the roof should be walked on, unless it would damage the material, such as older slate, or it would be unsafe or dangerous to the inspector. As a minimum, a ladder should be placed at the eaves, and the evaluation performed from that location. Windows from above provide an excellent opportunity to evaluate as much of the roof as possible from that location. The last resort is inspecting it from the ground with binoculars.
Inspectors carry extension ladders in some markets.
Florida communities are mostly ranch or one-story homes. Most home inspectors in Florida carry folding ladders. Many northeastern markets, such as Philadelphia, have mostly two-story homes, so many home inspectors carry extension ladders. Townhouses and inner city houses frequently have flat roofs that are difficult to get on without an extension ladder. In many cases, there is a hatch on the second or third floor that provides access to the roof.