Attic Ventilation

Proper ventilation of the attic with natural air flow keeps the roof deck cool and dry, extending the life of roof shingles and preventing ice dams without using the energy needed to run an attic vent fan. Be sure attic soffit vents and gable vents are not blocked so air flows freely through them. Some homes have ridge vents or vents through the roof deck instead of gable vents.

(Energy star.gov)