This article is semi-protected until November 13, 2019. Unsourced material may be challenged and types of roofing materials pdf. The word also denotes the framing or structure which supports that covering. There are no apparent connections outside the Germanic family.
English alone has retained the word in a general sense, for which the other languages use forms corresponding to OE. Although modern construction elements such as drainpipes may remove the need for pitch, roofs are pitched for reasons of tradition and aesthetics. So the pitch is partly dependent upon stylistic factors, and partially to do with practicalities. In regions where there is little rain, an almost flat roof with a slight run-off provides adequate protection against an occasional downpour. Drainpipes also remove the need for a sloping roof. The main factors which influence the shape of roofs are the climate and the materials available for roof structure and the outer covering.
There are many variations on these types. 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 has been used in the construction. 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. Timber lends itself to a great variety of roof shapes.
The timber structure can fulfil an aesthetic as well as practical function, when left exposed to view. A bark roof in Korea. This part of the roof shows great variation dependent upon availability of material. In many Asian countries bamboo is used both for the supporting structure and the outer layer where split bamboo stems are laid turned alternately and overlapped. 20-year shingle to the thickest which are limited lifetime shingles, the cost depending on the thickness and durability of the shingle. When a layer of shingles wears out, they are usually stripped, along with the underlay and roofing nails, allowing a new layer to be installed.