Brian - The time a roof lasts really depends upon the type of shingle that is used. A good double or triple shingle (high definition) roof will last 20-50 years. A single inexpensive shingle may last 10-15 years. Keep in mind that the heat is not the only contributor to roof longevity. We have strange weather here. Occasionally, we have what are known as micro-bursts. These a like small rain/hail tornadoes that may come through the area and only last 30-60 seconds, but can really take out part or all of a roof. The main thing is to have a respected home inspector inspect any home you are thinking of purchasing to assess the type of roof on that home.
Any other questions you may reach me at firstname.lastname@example.org.
Barbara Nichols, Associate Broker, CNE,CRP,CRS,GRI,SRES
Ken Meade Realty, 623-203-9195