The answer to 'why is my drip edge water stains' is that the drip edge on your roof is likely not installed or sealed properly, allowing water to leak behind it and cause staining. This is a common issue that can be caused by improper installation, damage to the drip edge, or deterioration over time.
Drip edges are essential components of a roof that direct water away from the fascia and siding, preventing water damage. If the drip edge is not installed correctly or has become damaged, it can allow water to seep behind it, leading to unsightly stains on the exterior of your home.