Snow, thaw and frost

Greater amounts of snow and more frequent frost/thaw episodes

Over the coming decades, we will gradually experience winters becoming warmer and wetter on average. In the milder climate, the increasing amounts of precipitation will more often appear as slush, which during a snowstorm can gather in heavy drifts and expose roofs and other structures to increased snow loads.

When designing especially halls with large roof spans, like sports halls and warehouses for agriculture and industry, the designer should consider the risk of collapse due to the structures not being dimensioned for the subsequent exposure to snow loads. Heavy snowfall, light frost, and a strong wind could cause heavy snow to form heavy drifts in exposed locations. In particular, buildings sheltered by taller buildings or roof surfaces with large level jumps are at risk.

With the rising winter temperatures, fluctuations around the freezing point will become more frequent. Thus, there will be more significant variability between periods of frost and thaw. From experience, it is a source of much frost damage to masonry, external concrete, joints, and other building parts, when water penetrates, freezes and expands. Therefore, designers and entrepreneurs shall ensure that the materials have the necessary properties concerning frost and thaw, together with a correct diversion of meltwater, so it does not moisten constructions and building parts. It requires good terrain regulation and proper dimensioned drainage systems.

Milder and wetter winters also mean that entrepreneurs and workers must take great care during construction to build soundly in terms of moisture. Storage and transport methods must protect materials and components, and the construction must remain dry until completion. Moistened materials and constructions can lead to moisture damage and mould growth.

Measures during construction must protect against moisture from snow, slush, and winter rain. Removing blowing snow in hollows and pockets is essential since it may melt later.