Wind uplift, humidity and attic moisture
Strong wind finds weak spots in a roof. Shingle tabs that have lost their seal can flap, crease and finally tear away. Ridge caps and edge pieces are the first to go, and a lifted corner lets rain and snow blow in.
Humidity matters in the attic. Warm, moist air from the house rises and meets a cold roof deck, leaving frost in winter and dampness in thaws. Poor ventilation or a bath fan that vents into the attic worsens it. Over time that can rot sheathing and stain ceilings. A leak that looks like a roof failure is sometimes an attic moisture problem, so we check both before recommending a repair.
