A snow removal professional at work on the roof of a building housing the Finnish Financial Supervisory Authority (Fiva) in Helsinki on 22 January 2019. (Credit: Antti Aimo-Koivisto – Lehtikuva)


THE FINNISH Environment Institute (Syke) has drawn attention to the dangers posed by the accumulation of snow on rooftops across Finland.

Syke on Monday reminded that the latent structural defects in the roofs of large halls such as retail and sports facilities typically begin to manifest themselves once the snow load increases to approximately 80–100 kilos per square metre.

The snow load on roofs is currently an estimated 60–100 kilos in Eastern and Northern Finland, and 30–60 kilos in Western Finland. The load is also expected to increase substantially – by over 30 kilos – in most parts of the country during the course of this week.

Roofs in eastern and south-eastern parts of the country may be supporting over 100 kilos of snow per square metre.

“The long-span roof structures of large-body buildings such as sports halls, large retail facilities, equestrian manèges and agricultural facilities, as well as air-supported domes, are most prone to risks and in need of monitoring,” Syke stated on Monday.

While the current snow loads do not pose a threat to the roof structures of detached homes, terraced houses and other free-standing residential buildings, ice and snow falling from roofs can be dangerous, it added.

“The owners of halls should monitor the snow loads actively and ensure snow is removed from the roof whenever necessary, also when snow has accumulated particularly on a certain part of the roof,” instructed Bertel Vehviläinen, a senior hydrologist at Syke.

The weight of snow depends on its density and the depth of the snow cover.

“The rule of thumb is that you should remove snow covers deeper than 50 centimetres and that you should hire a professional to carry out the snow removal,” said Vehviläinen.

Aleksi Teivainen – HT
Source: Uusi Suomi