During the storms a few years back I lost some of the woodwork around my roof, a couple of ridge tiles and a few slates slipped down.
The insurance looked at it and said that I hadn't been maintaining my roof and so they were not paying out!
So, given that I am on my roof every summer repointing, reslating, clearing gutters, tidying the chimney and aerial wiring, removing unwanted plant growths, etc. I can't see what more I could have been doing to maintain my roof.
So who else does as much on their roof to maintain it each year?