Built-in gutters do not hang on the edge of roof, but are built into the bottom of the roof or into the roofs overhang. The foundation of most built-in gutters is wood that is then covered with a thing sheet of such as tin, copper, lead, stainless steel, or some other metal that will not readily corrode. The shape of the gutter is created by the roofer. Copper is one of the most widely used metals because it is easy to bend and solder, and once installed, it never requires any maintenance. Built-in gutters are a favorite design feature among many architects. When installed properly, built-in gutters can provide a lifetime of trouble-free service.