Michael Chare wrote:
Is there anything better than black exterior mastic (frame sealer) to
repair a foot long crack in a bitumen felt roof? The crack is near the
edge where there is a lip to control direction of water flow.

Some has used what is now hard grey stuff to repair some previous
blemishes in the tiles. It is subsequently cracked.


You can get roof sealant cartridges which I think are bitumen based and
should retain some flexibility.