Hi,
From what you’ve described, the damaged edge really needs to be repaired with a compatible roofing membrane rather than just covered with sealant or flashing tape.
If the existing roof is felt, I’d normally cut away any loose or badly torn material first, make sure the timber and existing felt are clean and dry, then install a new strip of suitable bituminous roofing felt/membrane. It should overlap well onto the existing roof covering and continue over the timber at the drip edge so water can’t work its way underneath.
Depending on the type of felt you already have, this could be done with a compatible cold-applied/self-adhesive membrane or a torch-on repair. I wouldn’t recommend torching directly around exposed timber unless you have experience with it because of the fire risk.
The important thing is also to find out why the edge ripped in the first place. If it wasn’t properly bonded or mechanically secured, simply sticking another piece over it may result in the same problem later.
If you can upload a couple of close-up photos of the damaged edge, plus one showing the whole roof edge/drip detail, I can give you a much better idea of the correct repair and what material you’ll need.
