Denver winters swing from 60°F sunshine to single digits within hours, and that freeze-thaw rhythm is exactly what builds ice dams. Heat escaping into the attic melts snow on the upper roof; meltwater runs down and refreezes at the cold eaves, forming a dam that forces water backward under shingles and into walls. Never let anyone chop ice off your roof with a hammer or hatchet — it destroys shingles. We use low-pressure steam to remove dams safely, then address the root cause: attic air sealing, insulation, and ventilation that keep the roof deck uniformly cold.