There are many different types of roof coverings. Each one must be installed properly and has a design life expectance. Some roof coverings such has high grade slate or tile can last over 100 years! Other roof coverings such as asphalt rolled roofing last only 5-8 years. The various roof coverings are each prone to different types of problems. Usually the longer a roof covering is designed to last, the more expensive it is to repair or replace. Particular roof coverings are selected for a building based on the climate of the region, the cosmetic desire and the economic realities of matching the roof covering with the type of home. The roof surface is one of the most important components of the inspection. The protection of the inner building all starts at this point. The inspector will check the surface for any visible wear or damage. The inspector is also looking for improper installation and/or alterations which may be causing problems now or down the road. Besides end of normal life expectancy issues, bad installations are the most common reasons for roof failures. If a roof is installed improperly, repairs are usually only temporary and replacement is typically required.