Do home inspectors walk on the roof? 

The Standards of Practice for home inspection include an examination of the roof and home inspectors will most often climb onto the roof with a ladder provided it is safe to do so but with today’s technology, the method of inspection often uses tools that do not require the inspector to climb onto the roof.  
Some of the reasons a home inspector would not climb onto the roof include the type and condition of the roof covering, the height or pitch of the roof itself and adverse weather conditions.

One of the tools of inspection for many home inspectors is a drone. Drones offer an up-close look at the roof from various angles and can easily take photos for the inspection report. The use of the drone as a tool may be limited by weather conditions or property location - sometimes regulations do not allow drones to be used in certain areas.

A telescopic pole with a camera attached can be raised to roof height and allow the inspector to view the roof from the ground and take photos. Binoculars can also provide a good view of most of the roof from the ground but does not allow the inspector to take pictures. A high-quality camera with a zoom lens allows the inspector to zoom in on the roof and take photos. Sometimes sections of the roof can also be viewed from nearby windows.

Your home inspector wants to do a good job for their client and they want to examine systems as closely as they can safely do so however, adverse weather conditions or snow covering can limit the extent of any roof inspection regardless of the method chosen.