Found 6 singles on the roof that had this same granular loss in the same location. The roof as a whole was in good shape. Shingle defect?
Hi Peter,
That would be my guess.
Regards
Gerry
It is in such a straight line it looks as if it were mechanically produced, like where a bundle may have been banded or something along those lines.
I thought the same Doug, but could not explain why there were 6 of them that looked exactly the same. Same width, same side of the shingle. The six of them were in different sides of the roof.
6 different bundles…6 different bands…
Perhaps the top shingle of 3 different pallets…with 2 straps on each pallet…the possiblities are endless…
Not sure what the actual cause is, but it is a manufacturing defect when they are being made. Maybe it’s where the bond the fiberglass mats together at the end of the rolls. I see it every so often.
Just a thought.
Not seeing the whole picture, roofing brackets were used to install the roofing, and when the 16’ planks where removed from the brackets, they were lifted from one end and the metal split protectors on the end of the planks scarfed the shingles.
Just my thoughts.
Marcel 
how about… those six were the tops of the pallet (3 rows 2 deep) and the fork lift from the truck slid it’s forks across these spots???