Normal Life Expectancy of a Shingled Roof

Life Expectancy

• The life expectancy for an asphalt shingle roof ranges from 15 to 30 years, according the U.S. Inspect website. The life expectancy for a wood shingle roof ranges from 10 to 40 years. Factors that can affect the life span of roof shingles include the type of shingle, the slope of the roof, the directional exposure of the roof, the type of weather to which the roof is exposed and the amount of maintenance to the roof.

Type

• Not all asphalt shingles are the same. Different grades of asphalt shingles are designed to last for different lengths of time. Asphalt shingle are commonly sold based on their warranty, which can be 10, 15, 20, 25 or 30 years, according to the All Bay Home Inspection website. Wooden shingles, referred to as shakes if they are hand-cut, are usually made from either redwood or cedar. Hand-cut shakes are usually thicker than machine-sawn shingles and have a longer life expectancy -- up to 40 years.

Weather

• All types of shingles are affected by adverse weather conditions, which can shorten their life expectancy. Long dry spells can dry out wooden shingles and shakes, causing them to become brittle and subject to breaking. Excessive shade and moisture can aid the growth of mildew and moss on all types of roof shingle and can cause wooden shingles to rot. High winds, hail, excessive snow and ice as well as excessive heat can shorten the life expectancy of all types of roof shingles.

Maintenance

• You can extend the life of your roof shingles by providing regular, routine maintenance. The All Bay Home Inspection website recommends checking your roof for damaged, loose or missing shingles in the spring and again in the fall. Inspect and repair the flashings around your chimney, plumbing stacks, skylights, louvers and vents. Trim back any tree limbs that might damage your roof. Clear away debris from your roof, including the gutters, to prevent water from standing or seeping under the shingles.