I do quite a few shingle inspections for insurance companies, mainly hail, wind, etc. I have run across a problem with shingles a few times that Im not real sure how to explain. I thought I had it figured out but now Im not so sure. The problem is the exposed tabs on the shingles form little raised areas that look like blisters…sometimes alot of them. When the blisters “pop” they look just like small hail hits. Anyone else seen this and know what the cause is??
don't know what the cause is , but it is a mfr. defect warranty issue, and they've always taken care of it when i report it...
i've also seen what you describe in the vicinity of wood burning chimneys.. and there it is the cinders...