House With A Beautiful Thatch Roof, England, United Kingdom

The basic shapes of roofs are flat, skillion, gabled, hipped, arched and domed. There are many variations on these types. Roofs constructed of flat sections that are sloped are refered to as pitched roofs (generally if the angle exceeds 10 degrees). Pitched roofs, including gabled, hipped and skillion roofs, make up the greatest number of domestic roofs. Some roofs follow organic shapes, either by architectural design or because a flexible material such as thatch is used in the construction.
Parts of a roof
There are two parts to a roof, its supporting structure and its outer skin, or uppermost weatherproof layer. In a minority of buildings, the outer layer is also a self-supporting structure.