The answer to 'why is my drip edge ice dams' is that ice dams are a common problem caused by improper roof ventilation and insulation. Ice dams form when heat escapes from the home, melting snow on the roof. As the melted snow runs down the roof, it refreezes at the edge, creating a ridge of ice that prevents further drainage.
This can lead to water backing up under the shingles and leaking into the home, causing damage to ceilings, walls, and insulation. Ice dams are more likely to occur in homes with poor attic insulation or ventilation, as well as in areas with heavy snowfall and fluctuating temperatures.