The life expectancy of the average roof is 25 years.
The lifespan of a roof is determined by a number of factors, like: roof design, building structure, material quality, material suitability, proper installation, periodic maintenance, and local climate. Roof material quality is especially important because some roof types such as clay tile, slate and certain metal roofing systems can last longer.
When choosing the materials for a new roof or when shopping around for a roofing contractor, make sure to check the warranties on the materials. Most roofing manufacturers offer warranties on their products and you should be wary of any manufacturer that doesn’t.