The life of a roof depends on local weather conditions, proper building and design, material quality, and adequate maintenance.
Slate, copper, and clay/concrete roofs have the longest life expectancy--over 50 years.
Roofs made of asphalt shingles last for about 20 years while roofs made of fiber cement shingles have a life expectancy of about 25 years, and roofs made of wood shakes can be expected to last for about 30 years.
Last updated October 16 2008: 4:37 PM ET