The roofs are structures that are defined by its shape, characteristics of function and architectural style of the buildings. The main function of the roofs are the protection of the buildings against the action of the weather, besides the utilitarian, aesthetic and economic functions. In summary, the coverages must meet the following conditions: A) utilitarian functions: impermeability, lightness, thermal and acoustic insulation;

B) aesthetic functions: shape and harmonic aspect with the architectural line, dimension of the elements, texture and color;
C) economic functions: cost of the solution adopted, durability and easy conservation of the elements.
 
According to the constructional systems of the roofs, the structural characteristics determined by the application of a constructive technique and / or materials used, we can classify the roofs in many categories showed in the pictures bellow.

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