Make sure your attic is well ventilated.
Good attic ventilation is important year-round. In summer, ventilation helps hot air to escape, keeping your house cooler and reducing the need for air conditioning, as well as prolonging the life of your roof. In winter, attic vents keep moisture from building up (wet insulation is ineffective) and prevent damaging ice dams on your roof.
Vents should be positioned low and high.
Air flows in from soffit vents along the edge of the roof and travels up and out of ridge vents and/or gable wall vents.
Keep soffit vents clear.
Make sure they are not blocked by insulation.