Roof inspection for insurance?

A condition of our buildings insurance is that we get an inspection of our flat roof done from a 'reputable contractor' to confirm it's in a decent condition. Trouble is, I can't find anyone willing to do one. Most roofers don't deal with flat roofs, those that do have said they can't do a report. I've contacted a few companies that specialise in homebuyers reports too but they've said they won't do one for insurance purposes. I've tried ratedpeople and got no replies. I've no concerns about the roof itself, we've had work done on it recently and it was fine but that guy wouldn't do a written report either.

Has anyone ever found themselves in this situation or got a recommendation of anyone that does these? We're in West London.