John Rumm wrote:

If you want to make a "drip" easily, they normally suggest a strip of
hardboard or 3mm ply - nail through it, through some felt (underside
facing out) into the side of the roof, then lift the felt up and over it
so that it defines a nice neat edge.

I'll re read that when I am feeling a bit better. My chest is getting me
down again. This has been going on for over 14 months now, hence the
lack of the drill grinding guide.

Dave