The answer to 'why is my roof vent ice dams' is that ice dams are a common problem that can form around roof vents, particularly in areas with heavy snowfall and freezing temperatures. Ice dams occur when heat escapes through the roof vents, causing the snow on the roof to melt and refreeze at the edges, creating a barrier that prevents proper drainage.
This can lead to water backing up under the roof shingles and causing leaks, damage to the roof structure, and even interior water damage. Some common causes of ice dams around roof vents include poor insulation, inadequate ventilation, and clogged or blocked vents.