|Carpentry for Vocational Schools - A Teacher's handbook (GTZ, 252 p.)|
a) Gable roof: - The ordinary roof, which has two sloping surfaces extending from the eaves to a central ridge, and which forms a triangular vertical wall at each end above the wall plates. These triangular shapes are known as "gable ends", hence the name gable roof. The gable roof is most commonly used for small houses because of its simplicity of construction and low cost. This type of roof is often used as the basis of, or in combination with, other types of roofs.
b) Lean-to or Skillion roof - The lean-to roof is simply a galved gable roof. It is often used in construction for economical reasons no ridge capping, only one gutter). To pitch the roof at the right angle and to support the rafters, one of the two side walls must be build higher. Ceiling joists are as in the gable roof. When the span is more than four metre, purlins and strutts must be fitted.
c) Hipped roof: - The hip roof has four sides, all of which slope upward towards the centre of the building. The external angle where two adjacent sloping sides met is called the hip, and the inclined member at this junction is the hip rafter. The hipped roof is more expensive to build as it requires more skilled labour because of the difficult construction. On the other hand, if the complete job is done well, the roof should support itself.