As I mentioned above: keep the overhang to 30mm - 40mm.
Ignore the 60mm nonsense.
A 60mm overhang depending on the fixing height of the gutter on the fascia, and the pitch of the roof then the 60mm overhang is more likely to interfere with any flow of debris swollen water in the gutter than a smaller overhang.
Ignore the 60mm nonsense.
A 60mm overhang depending on the fixing height of the gutter on the fascia, and the pitch of the roof then the 60mm overhang is more likely to interfere with any flow of debris swollen water in the gutter than a smaller overhang.