Copper: Copper is a roofing alternative that can be attractive to many homeowners, because copper can be such a beautiful material. However, it usually tends to be used more for decorative details rather than for the whole roof, mainly because it is very expensive. Copper can also be used to roof a small section, such as a roof of a bay window to provide an attractive trim, or for flashing on an asphalt shingle, or slate roof. A copper roof can last for hundreds of years, although there is a very minor concern that they may be subject to some damage from acid rains, which could reduce their lifetime.