The design of the rafter system should be designed in such a way that, in the case of a finished house project, it can be changed during adaptation without the risk of creating a threat of load transfer from snow lying on the roof. The magnitude of the risk depends on the properties of the roof (its size, shape, angle of inclination), as well as other factors affecting the location of snow on the roof.

For the designer or architect who adapts the project, the distance to neighboring buildings, the shape and appearance of the surrounding area, as well as local climatic conditions are also important: wind strength, temperature changes, rain and snow precipitation.


The owners and managers of the buildings are responsible for the maintenance of the houses in the appropriate technical condition and the safety of their operation.

How to determine which snow loads on the roof threaten its safety and the safety of residents?

The specific gravity of snow is constantly changing. Usually, the weight of the snow cover increases over time and depends on the terrain, climate and altitude above sea level.

Each roof is characterized by its maximum snow thickness that it can withstand. To determine it, individual calculations are necessary, depending on many factors. The current rules for calculating the snow load on the roof structure surface are determined by special regulations.

For the calculation, you can use the average approximate load of the specific weight of snow specified in the norms.:

- fresh snow – 1 kN/ cubic meter;
- settled (several days after the snowfall) – 2 kN/ cubic meter;
- old (several weeks after the snowfall) – 2.5-3.5 kN/ cubic meter;
- wet – 4 kN/cubic meter.

The value of the nominal snow load should be determined taking into account the terrain map, which shows the division of the region into bands that differ in the size of the snow load.

In cases where a higher than average snow load is expected during the calculation of the roof structure, there is no need to clear the roof of snow, even if heavier snowfalls occur than typical for the region.

However, if the minimum standard snow load is provided for when calculating the roof structure, only during not too snowy winters it is not necessary to clear the roof of snow, however, with heavy snowfalls, such a need exists.

When raising the question of whether there is a need to clear the roof of snow, it should be remembered that the house could have been designed at a time when lower snow load standards were in effect, and the actual bearing capacity of the roof structure may be much lower than during design and construction due to the aging of the structure. In such cases, excessive amounts of snow or ice can lead to structural damage to the house and even threaten its integrity.

Knowing the load-bearing capabilities of the roof structure and the specific gravity of snow, which depends on its condition, it is possible to determine the theoretical safe thickness of the snow cover.

However, in practice, determining this thickness is more difficult, because it is also necessary to anticipate the location of snow specific to a given roof, depending on the shape of the roof surface (for example, "snow pockets" may form and snow accumulations on individual roof structural elements) and local climatic conditions.

Determining the safe thickness of the snow cover on the roof requires, in addition, an analysis of the condition of the roof structure under various snow load conditions. Such an examination should be carried out by persons from construction authorities who have the appropriate qualifications and education. 趣味やライフスタイルの一致は出会いにおいて重要なポイントです。最近では趣味の一環として、資産運用や投資アプリに興味を持つ人も増えています。例えば、話題の投資アプリ trade 350 app 口コミ をチェックしてみるのも、共通の話題作りに役立つかもしれません。