Anyone have an idea of what causes these patches on shingle roofs? This was my first roof cleaning, I just shot straight SH with elemenator on it and let it sit for 30 min and I got this result.
Straight SH as in what %?—— XJet?
Are you talking about the bottom left hand side of the roof? If so it was already like that. You can clearly see it in the before picture.
It looks like they had some patch work done to the roof or they used a different batch numbered shingle when the installed the roof. But most likely they had a repair done ay some point.
10.5%, straight x-jet no proportioner. @316
@Diamond_Soft_Wash okay that makes sense, thank you!