I've been looking at what looks to me like a good quality felt roof comprising a plywood base, several layers of felt topped by the heavy duty stuff with small white stones all over it. It's quite a large roof and generally seems in good mature condition.
Along just one edge where it gets the sun, it appears to have split in places where it turns over the small upstand and over the edge. The splits are from pinholes to about a foot long and the longer ones can almost be pushed back together, but have curled up slightly at the tears.
It looks as though it should be possible to pour something glutinous to set in these small breaks and form a pretty permanent seal. I'm a bit scared of things like hot tar. Is there some suitable pourable gunge?