Roof has metal tiles and survey said they need regular cleaning. Is this right? And is it right that this roof won't last as long?

[CrapBag]

The seller actually told us they were concrete tiles but the survey has said they are metal tiles and covered in lichen and moss (which is obvious as the roof doesn't look great but I know it was replaced about 7 years ago). The survey has said that it needs regular cleaning to keep it free of the moss and lichen. Is this right? It also says it won't last as long as a concrete tiled roof. As it was only done 7 years ago I was counting on not having to have the roof done in our time there, although it is a possible forever home.

Yes it is right apparently. My DP does roofs and he reckons they are the worse choice possible, and fairly uncommon in this country.. They dent and 'moss up' and if that gets out of control they'll force gaps and it'll leak. Either you resign yourself to getting someone to clean the moss and crap off every year or so, or just bite the bullet and get it tiled or slated. Beware that if and when someone does go up there and clean it all off they don't tread between the joists and severely dent the roof. That way lies water ingress. Also they're a bugger to repair. You have to get the exact same sheet material or else they won't fit together right and there's a problem with galvanisation (or something like that). Sorry to bare the bad news.