A roof is the covering on the uppermost part of a building. The purpose of a roof is to
protect the building and its contents from the effects of weather. The types of structures
that require roofs range from the size of a letter box to that of a cathedral or stadium,
dwellings being the most numerous.
The characteristics of a roof are dependent upon the purpose of the building that it covers,
the available roofing materials and the local traditions of construction and wider concepts
of architectural design and practice and may also be governed by local or national
In most countries a roof protects primarily against rain. Depending upon the nature of the
building, the roof may also protect against heat, against sunlight, against cold and against
wind. If the roof is the covering for a house, then all these protective functions are called
into play. Other types of structure, for example, a garden conservatory, might utilise roofing
that protects against cold, wind and rain but admits light. A verandah may be roofed with
material that protects against sunlight but admits the other elements.