Roof ventilation failures cause more shingle damage than hail in most climates

Insufficient attic ventilation traps heat (up to 150°F in summer), cooking shingles from below and voiding manufacturer warranties. Per IRC R806.1, attic ventilation requires 1 sq ft of net free area per 150 sq ft of attic floor. Balanced intake (soffit) and exhaust (ridge) is critical. Mixing exhaust types (ridge vent + power fan) short-circuits airflow. Fix ventilation before replacing shingles or you void the new warranty too.