How Long Should My Roof Last?
Most of today's asphalt shingles are designed to provide satisfactory service for a period ranging from 20 to 30 years or longer. Asphalt shingles are typically referred to as a 20 year, 30 year, 40 year, etc. shingle. The number of years serves as more a general grade rating than a definite shingle lifetime.
Particularly in the Houston area and similar areas with high heat and humidity, shingle life will most definitely be lower than the given rating. On the whole, though, a 30 year shingle will outlast a 20 year, as a 40 year would a 30 year, despite the region.
Poor ventilation also adversely affects shingle life, even to the point of some shingle manufacturers voiding the shingle warranty. Proper ventilation, both intake and exhaust, can help your roof more closely approach the rated life. Types of intake ventilation used in a roof include soffits and gable vents. Exhaust ventilation would include ridge vent, turbines, air hocks, and electric turtle vents. Your sales representative can provide you with more information as well personalized recommendations concerning your home's ventilation systems.