Looking at the snow -covered city, it does not think about the roofs with whitening hats about what kind of load the building structures are experienced in the winter. And the load during this period on construction projects is very large. Only one square meter of dense snow 15 cm thick has a weight of about fifty kilograms. A similar load is provided by ceramic tiles or concrete. Therefore, control over its number must be carried out constantly, and in time to clean.















