I bought a commercial building with a sloped roof and fiberglas, 3 tab shingles. After purchasing the property, I noticed that there were some indentations in the roofing. I had a roofer come by and he said that it was hail. I notified my insurance carrier and they sent out an adjuster. He said that he wasn’t sure when the damage occurred. He had an engineer come out and this guy said he could make an educated guess as to the time hail damage occurred, but that it would be just a reasonable guess. I am wondering if there is someone who can test a sample of my roof and give us a reliably accurate date of when it was damaged by Hail? Are there consultants who can do this through some scientific method? If so, where would I look to find one of these?