Icing: ice thickness b and wind pressure W_B

Section 10 of DBN V.1.2-2:2006 treats ice-wind loads as the combination of the weight of ice deposits and the wind pressure on iced members (cl. 10.2). Two quantities matter:

• b — ice thickness, mm, exceeded on average once in 50 years, on a 10 mm round member at 10 m height (cl. 10.7, map Fig. 10.1);
• W_B — wind pressure on iced members at 10 m, exceeded once in 50 years (cl. 10.9, map Fig. 10.2).

For cities both values are given in the norm’s reference table together with S₀ and W₀. Kyiv: b = 19 mm, W_B = 160 Pa. For the Carpathian and Crimean mountains the norm requires data from special observations.

When icing must be considered

Since Change 2, clause 10.1 limits ice-wind loads to overhead communication lines, contact networks of electric transport, antenna and mast structures, and parts of roofs and walls at 150 m and above. A ground-mounted solar table or an array on an ordinary building roof is not on that list.

b and W_B are still worth knowing: they show where most ice builds up on structures in winter, which affects maintenance and how long snow stays on the panels.

The Solispec engine does not apply ice-wind loads, because under clause 10.1 they do not cover ground or roof solar arrays. Its city table holds only S₀ and W₀; snow and wind on the structure follow S_m and W_m.

Snow and wind calculator