The answer to 'why is my shingles ice dams' is that ice dams form when snow on your roof melts and refreezes at the edge, causing a buildup of ice that prevents proper drainage. This is often caused by poor insulation or ventilation in your attic, which allows heat to escape and melt the snow on the roof. Ice dams can lead to water leaks, damage to your roof and interior, and even structural issues if left unchecked.
To solve the problem, you'll need to address the root cause by improving your attic insulation and ventilation. This may require calling in a professional roofing contractor, especially if the job requires extensive work. In the meantime, you can try to temporarily remove the ice dam using a de-icing product or by carefully chipping away at the ice with a tool. However, be very cautious when working on a slippery, icy roof, and consider hiring a professional if the job seems too dangerous.