In the Memphis Tn. and Mid-south area we have very hot and humid summers. Roofs with little to no ventilation hold heat in the attic which causes your shingle roofs to prematurely age and actually burn up from the inside out. This can knock years off your shingle life, cause unsightly black streaks on your shingles, and allow the granules that give the shingles there color to fall off. A well ventilated roof can also help your house cool better in the summertime. So it is very important to make sure your roof is well ventilated. There are several ways to ventilate your roof.
The first and most inexpensive is to add whirly birds. Whirly birds are easily installed on the roof and are better than nothing. They will help extend the life of your shingles. The downside of whirly birds are that they work year round unless the hole is covered up during the colder months. They also need to be replaced every ten years or so due to the bearings in them going bad.
The second option is power vents. Power vents are motorized and work on a thermostat making them a much better option than a whirly bird. They only come on when the attic reaches above the set temperature and cut off after the temperature drops below the desired level. They pull air up from your soffit vents significantly cooling off the attic. They also have a down side one of which is the motors only last about ten years or so and you will have to have them changed out. Also when you have a roofer install them you will also have to have a licensed electrician come and run power to them.
The third and best option is to add ridge vent to the highest points of your roof. Ridge vents work due to the fact that heat rises and is let out through them. Ridge vents are maintenance free and last the life time of your shingles. Today’s ridge vent is also very low profile and blends in well with your shingle roof.