The elements in the design of a roof are:
- the material
- the construction
- the durability
The material of a roof may range from banana leaves, wheaten straw or
seagrass to laminated glass, copper aluminium sheeting and pre-cast concrete.
In many parts of the world ceramic tiles have been the predominant roofing
material for centuries, if not millennia. Other roofing materials include
asphalt, coal tar pitch, EPDM rubber, Hypalon, polyurethane foam, PVC, slate,Teflon fabric, TPO, and wood shakes and shingles.
The construction of a roof is determined by its method of support and
how the underneath space is bridged and whether or not the roof is pitched. The
pitch is the angle at which the roof rises from its lowest to highest point.
Most US domestic architecture, except in very dry regions, has roofs that are
sloped, or pitched. 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.
Some types of roofing, for example thatch, require a steep pitch in
order to be waterproof and durable. Other types of roofing, for example
pantiles, are unstable on a steeply pitched roof but provide excellent weather
protection at a relatively low angle. 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.
A person that specializes in roof construction is called a roofer.
The durability of a roof is a matter of concern because the roof is
often the least accessible part of a building for purposes of repair and
renewal, while its damage or destruction can have serious effects.
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