A full re-roof, tile or metal, when a roof has had its life and patching it is money spent twice.
Widespread cracking, mortar gone along every ridge, sagging battens, or a roof that has been repaired more than it has been left alone.
Both. Which one suits depends on the pitch, the frame underneath and what the rest of the street looks like — he will tell you which and why.
Old sheets or tiles, old sarking, and whatever the battens turned out to be hiding. It is quoted for what it needs once it is open, not before.
Replaced with the roof. New sheets into old flashings is how a new roof leaks in its first year.
Scope, materials and price before anything starts. Twenty-five years of doing it, and the same family the whole time.
Michael comes out, gets up there and tells you what it actually needs, in writing, for free. Usually within a day of you asking.