The legislations Snow Wind under construction
November 7, 2018
Some natural phenomena may create risks to buildings, which can lead to the ruin of the building. This is the case of snow which can deform a roof; rain can cause flooding or water infiltration into buildings; meanwhile, the wind tends to distort the structure.
1. Regulation of the Snow – Wind action on structures
The harmonization of these rules at European level dates from the beginning of the 90s. This harmonization is illustrated by European standards, called Eurocodes, which replace the national rules in force since 2010. The idea is the harmonization of construction techniques in Europe in order, inter alia, to facilitate the free access of firms to the markets of other States. The Snow - Wind regulation puts forward a load to be taken into account in structural calculations. These calculations make it possible to ensure the stability and the dimensioning of all the elements constituting the building. For both snow and wind, the load to be taken into account varies according to some characteristics. This is particularly the case of the location of the building (some areas are more sensitive than others).
2. The wind
The NV65 standard gathers the calculation rules and indicates the conditions under which the pressure of the wind on the faces submitted to it is taken into account. Indeed, the wind causes horizontal forces through the facades in a global manner and on elements having a windward grip such as pergolas, detached roofs, or awnings. The calculation provided by Snow - Wind rules will ensure that the transmission of forces to the ground is ensured as well as the limitation of deformations.
3. The snow
The values of the snow loads are defined by region, according to the altitude of the construction. The key is to correctly size the roof and the load-bearing structure depending on the expected snow loads. On a roof, snow can arise in different ways depending on its shape, its slope, but also its exposure. Above all, the snow loads correspond to a weight to add.