The answer to 'why is my fascia water stains' is that water stains on the fascia board are typically caused by leaks or moisture issues. The fascia is the horizontal board that runs along the edge of the roof, and it can become discolored or stained if water is able to get behind it.
Common causes include clogged gutters, damaged roof flashing, or improper roof installation. Over time, the fascia can rot and deteriorate, leading to water infiltration and unsightly stains. Addressing the root cause of the issue is important to prevent further damage and maintain the integrity of your roofing system.