BOULDER –  Home inspectors should note the age of major components of a house such as the roof, furnace, water heater and exterior paint. Based on these age estimates prospective home buyers can make informed decisions on the life expectancy of these potentially expensive items. Following are some predicted life expectancy of some materials, systems and components.

Exterior paint will typically last about 8 to 12 years. Surface preparation and paint quality are the big factors in a paint’s life expectancy. Interior paint should last from 10 to 15 years with high humidity being a contributing factor. Caulking both exterior and exterior lasts about 7 to 10 years.

A well maintained furnace can last 20 to 30 years. Changing filters on a regular basis and having it cleaned and/or serviced periodically will add some longevity. While using the same delivery system as a forced air furnace central air conditioning units have a somewhat shorter life span, in the 12 to 16 year range. Regular maintenance of the compressor and pump will extend your air conditioners life.

The life of a roof depends on local weather conditions, building and design, material quality, and adequate maintenance. Slate and concrete tiled roofing has the longest life expectancy of over 50 years. Roofs made of asphalt shingles typically last between 20 to 30 years.

Conventional tank-style electric and gas-fired water heaters have an expected service life of 10 to 15 years, according to the U.S. Department of Energy. Water quality is the major factor in determining the life of these types of water heaters. A water heater that uses hard water or well water should be drained, or flushed, about once a year to help extend the life of the tank. Tankless water heaters can last 30 years or more.

For more information on home inspections contact Rick Jacquemard at 720.280.3544, e-mail [email protected] or visit