Key Points Ice dams are ice blocks at a roof’s edge that trap melted snow from draining.They are often caused by uneven attic ventilation and poor insulation.Left unchecked, they can cause long-term ...

When heavy snow piles up on your roof, it's tempting to just let it sit there until it melts. But experts say that ignoring it can lead to a much bigger (and wetter) problem: ice dams. If you've ...