Problem with slate roofs is that the flashing wears out first!
Paul Cummins
Jul 15, 20161 min read
Updated: Sep 22, 2019
The metal flashing wears out after about 70 years on slate roofs. To redo flashing on the valleys they have to be cut back and completely redone. Ridges can be fixed from the surface by this technique. Most of the roofing cement I see on slate roofs is on the ridges.
