How can you tell the age of a modified bitumen roof? One of the fastest field indicators is how much granule loss. As modified bitumen systems age, the protective granules begin to wear away. When you start seeing black exposed areas, that’s a clear sign the roof is getting up there in years. If it gets to the point where you can see the fiberglass fibers, the system is typically very far along in its life cycle and should be evaluated asap That said, even when the granules still look intact mod