This roof has what would appear to be a shingle missing. But it was built up with tar. Is this a missing shingle or something else.
Here is the pic
The top row of shingles, where it abuts a wall, is often fixed over the flashing with tar only, sort of as a “glue”. That shingle piece obviously blew off, and the tar that formerly held it in place remains. What troubles me is that the flashing is not visibly apparent, and the portland plaster weep screed doesn’t appear to be there.
I also found what appears to be tar missing here. This has a leak over this area.
Here’s your missing tar:
Funny Russell
Your picture shows the headlap of the shingle, needs a piece installed over this area, best if sealed in place rather than nailed.
it looks like mastic to me
I think what I see is a laminated fiberglas shingle, and you are missing the top lamination, previously held in place with roof mastic. The good thing, maybe, is that no shingle nail heads are visible. I think I’d be more concerned that there is no separation or room for movement between the wall and the shingles.
The absence of counterflashing where the roof abutts the wall is what concerns me, and what I would identify as an amateur or sub-standard roof installation. Recommend to the clients that they request the installation permit, which would establish the age of the roof, etc, all to avoid the complaint/lawsuit that could follow a leak.