Would A Drone Inspection Be A Good Idea?
Commercial roofing is not usually that difficult to inspect because so much of it is low-pitched (no roof is truly flat; those buildings that look like they have flat roofs actually have a very gradual slope that allows for water drainage). A roof inspector can walk around easily on many surfaces. But there may be times when a drone inspection could be a helpful addition. You can't replace a human inspection completely, but a remote visual inspection definitely fills in some gaps.
Roofing is meant to hold up under tough environmental conditions, but it can be surprisingly fragile under the weight of a person. Each step increases the risk that a small crack will appear in the roofing material, leading to a leak. If the roofing material on your building is older, you may want to have a drone fly over first so that inspectors aren't crunching away at the existing roof. Inspectors may still have to walk around up there, but they may be able to narrow down the sections that they really have to look at in person.
A related issue is getting a good idea of what to expect. Instead of sending inspectors up to find damage somewhere on the roof, have a drone fly over so that inspectors can see immediately if there are spots of obvious damage. That lets them move right over to those areas when they first reach the roof and saves time.
Those Steep Roofs
Most commercial roofing might be low-sloped, but there are buildings that have a lot of steeply pitched sections, such as converted Victorian houses. While human inspectors can get to those areas with a lot of care, it's easier to have a drone fly over and record video so inspectors can see if there are any areas that look like they need more attention. Sometimes roofs are so high up and so steeply pitched that it is safer not to have someone wandering around, trying to spot damage.
Speak with some roofing inspectors to find out whether they use drones and if so, whether a drone video inspection is included with a regular inspection. Safety rules in roofing, and drones may be a very good addition. They are not necessary, of course. But they can be very helpful and may make your inspection go faster because of the added information that the videos can give to inspectors.