Roofs

roofs

A roof is the covering of the uppermost part of a building. The purpose of the roof is to protect the building against the rain, snow and other influences of weather. The form and covering of roof structures are important elements in the design of the buildings. A roof must have a good strong frame to resist winds and sustain snow loads and serve as an insulation to prevent transmission of heat. The roofs must tic the walls and give strength to the structure. The design of the roof includes some complex problems, such as:
1) Selecting the materials, engineers must consider their strength, weight and the risk of fire.
2) Insulation against heat losses in the winter and heat gains in the summer should be provided.
3) The quality of the material used for the roof system should suit the standard of the building and the cost of its maintenance;
4) Some protection must be provided against the possible effects of air moisture upon the materials of the roof. Forms of Roofs The chief factors determining the form of the roof are structural or aesthetic. Roofs may have flat, pitched, vaulted or domical surfaces. They may be supported on walls, columns, piers or they may extend directly to their foundations.