A 3m run of Lead is far to long. The max run of Valley Lead should be no
longer than 1.5m. Im suprised that the roof covering on a 15 year old
house
is Slate. Are you sure that it is Slate, by slate I mean natural slate and
not man made cement fibre slate or any of the poly cement type.

Sorry, I was not clear. I meant the roof had been re-laid 15 years ago. The
house is late victorian brick terrace.

Alistair