Wind and snow zones in Poland in the context of steel hall construction

The construction of steel halls requires adaptation to current standards, which in turn result from the wind and snow zones that have been demarcated in our country. Their purpose is to ensure the full safety of users by minimising the occurrence of serious wind or snow hazards.

What are wind and snow zones?

A wind zone is, in other words, a dedicated wind load zone. In Poland, there are three wind zones.

• Wind zone I covers the central part of Poland’s territory.
• Wind Zone II, on the other hand, covers the coastal strip in the north of our country.
• Poland’s mountainous areas are covered by wind load zone III.

The winds in Poland are distributed in a predictable, albeit often changing, manner, which has made it possible to separate the above zones. Each of them, according to the wind map, has strictly defined parameters. They are authoritative, as the data are collected from meteorological stations distributed throughout our country.

In the most general terms, in zones I and III, wind speed is strictly dependent on altitude – the higher the altitude, the stronger the wind. For sites in zone II, the altitude is not very important.

Snow zones, on the other hand, also known as snow load zones, are defined by EN 1991-1-3. According to this, five zones are distinguished in Poland.

• Zone I is western Poland.
• Zone II is the central part of our country.
• North-eastern, eastern and eastern-southern Poland is a zone III area.
• Warmińsko-Mazurskie and Podlaskie Voivodeships are covered by Zone IV.
• Zone V covers part of the Lesser Poland Voivodship with mountainous terrain.

Impact of wind and snow zones on steel hall construction

The wind and snow zones in Poland have a huge impact on the construction of steel halls. High wind velocity or a thick snow cover on the roof is a great danger, so the basis for this is the robust protection of the building against adverse weather conditions through appropriately selected profiles of the hall construction. The distribution of snow and ice on the roof of a structure is influenced by many factors – the shape and size of the roof, the degree of inclination and others. The distance to neighbouring buildings is also important. It is worth knowing that snow on the roof can cause damage to the roof and even cause the building to settle. The issue of regular and conscientious snow removal from the roof is specified in Article 61(2) of the Construction Law. According to its content, the owner or manager of a building is obliged to ensure its safe use.

What are the most important standards for steel hall design in Poland?

In Poland, the most important standard for the design of steel halls is PN-EN 1993-1-1:2007, known as Eurocode 3: Design of steel structures – Part 1-1: General rules and rules for buildings. It is part of the Polish edition of the European standard, which provides detailed guidance on the design of steel structures, including halls. Eurocode 3 defines rules for the calculation of load-bearing capacity and stability of steel structures, taking into account various loads such as permanent loads, variable loads, wind, snow, earthquakes etc. The standard also defines requirements for materials, fabrication technology and (erection of steel structures – EN 1090). Eurocode 3 also defines the basic concepts and terms used in the design of steel structures and provides information on the selection of appropriate resistance classes for materials such as structural steel. The standard specifies requirements for resistance to tension, compression, bending, torsion and other loads. In addition, EN 1993 also addresses fire-related design aspects, such as fire protection of steel structures and strength under fire conditions.

How do you choose a site for a steel hall?

Before starting the construction of a steel hall, the issue of atmospheric loading must be addressed and the site for the construction must be prepared accordingly. Building a hall in an area with extreme conditions is possible, but requires slightly different measures. As early as the design stage of the hall, EN 1991-1 (Eurocode 1) should be borne in mind, which specifies the snow load on the site. Steel hall structures are designed and built to withstand even the most adverse weather conditions.

Structural steel profiles, which are strong yet flexible, are the most commonly used. The use of steel profiles with a higher load-bearing capacity will guarantee greater resistance to loads in ‘higher’ wind and snow zones. Trapezoidal sheeting, steel or sandwich panels are most commonly used for roofing. Each of these is lightweight, yet very durable and easy to install. When constructing a steel hall in an area with extreme weather conditions, the issue of thermal insulation should be looked at very carefully. Choosing the right one will help to maintain the right temperature inside the building and avoid excessive heat build-up.

Wind and snow zone requirements for steel hall construction

In Poland, the standard for wind loads is PN-EN 1991-1-4:2007 (Eurocode 1: Loads on structures – Part 1-4: General loads-Wind loads). This standard specifies methods for calculating wind loads on different types of structures, including steel halls. Depending on the region in which the steel hall is located, a wind zone is defined, which affects the design calculations. Wind zones are classified based on the wind speed in the region. The standard for snow loads is EN 1991-1-3:2003 (Eurocode 1: Loads on structures-Part 1-3: General loads- Loads from snow). This standard specifies methods for calculating snow loads on different types of structures, including steel halls.