Any building needs reliable protection from the adverse effects of the environment. This refers to climate change, expressed in a change in wind strength and precipitation (snow, rain, hail). This protection is provided by the roof of the building, primarily the pitched roof as the most effective. The reason is that the angle of the roof, using the gravity of the Earth, allows you to quickly remove precipitation from the roof without overloading its elements.
It is reasonable to assume that a roof with as large an angle of inclination as possible will be ideally self-cleaning. But it's worth making a simple drawing on paper to see what insurmountable problems this creates.
Increasing the angle of the roof takes away higher and higher its strong point, and at the same time its construction and arrangement is growing exponentially. The larger the roof area, the greater its windage, that is, the surface that is exposed to the wind. For example, if you increase the angle of the roof by34 degrees, from 11 to 45, the wind load on the roof increases fivefold. This automatically entails strengthening the roof structure. Finally, a larger roof area means a greater consumption of materials. In sum, all this increases the cost of work at times.
The above figures - 11 and 45 degrees - are not accidental. It is in this range that a compromise is sought between the need to protect the building from precipitation and winds, on the one hand, and the structural features of the house, on the other. There are no universal recipes here, the calculation of the optimal angle at the design stage in each case must be performed separately.
Before calculating the angle of the roof, you need to know the value of the total load on the roof. It is made up of the mass of the roof per square meter and the maximum snow load in the region.
The mass of the roof is defined as the sum of the masses of all its components. As you know, the roofing "pie" is a coating, crate and insulation. But at the same time, it is also necessary to take into account a certain mass reserve, for which it is necessary to multiply the resulting amount by a factor of 1, 1.
Regulatory documentation for construction contains information on the index of the regional maximum snow load and its reduction factors, taking into account the angle of the roof.
It will need to be changed if, as a result of the calculations, it is revealed that the maximum allowable roof load is exceeded. This change will result ina reduction in snow load. If such a measure did not lead to an acceptable result, the root of the problem should be sought in an imperfect roof design.
Each type of roofing material has its own minimum roof slope. For example, tiles, slate and other materials from typesetting elements allow you to make a slope of 22 degrees. Such an angle of inclination of the roof does not allow the accumulation of moisture in the joints. Three-layer roofing from rolled materials - 2-5 degrees, two-layer - 15 degrees. Decking - 12 degrees (at smaller angles, the joints must be treated with sealant). Metal tiles - at least 14, soft tiles - 11 degrees.
When choosing the angle of the roof, you must always remember the bearing capacity of its design, which allows you to resist any loads and external influences.
Thus, determining the angle of the roof is a crucial step. A mistake can not only cost material costs for emergency repairs, but also become a threat to the he alth and life of people living in the building.
