Wind loads on guardrails: An overview of safety and planning

What are wind loads?

Wind loads are the forces exerted by the wind on structures of buildings or components such as guardrails. These forces consist of pressure and suction acting perpendicular to the surface of the structure or component. Pressure occurs when the wind hits a surface directly, while suction occurs when the wind flows past a surface and creates a vacuum.

Wind loads can significantly affect the safety of side protection systems and guardrail systems. If these forces are not taken into account sufficiently, the guardrail can be displaced, tip over or even fall down from its base. Ultimately, this means that the guardrail can no longer fulfil its function as a fall prevention (protection) system.

Role of norms and standards

Standards and norms play a decisive role in the planning and installation of guardrails, taking wind loads into account.

• In Europe, the Eurocode (DIN EN 1991-1-4) is used, which regulates the calculation of wind loads on structures and components. This code takes into account factors such as wind load zones, terrain categories and the height of the structure.
   
• In addition, the EN 13374 standard is used for testing temporary side protection systems in fall prevention systems. The standard divides the systems into three classes, which are adapted to different risk levels and work environments. The systems must be able to withstand static and dynamic loads. Compliance with this standard is crucial to ensure the safety of workers in the construction industry.

Calculation of wind load

Wind load is calculated using various factors:

• Wind speed: First, the wind speed in a specific area must be determined. This varies depending on the location and is often divided into wind zones.
• Type of guardrail: The type of guardrail plays a role. Open guardrails, which you can see through, are less susceptible to strong wind forces than closed guardrails.
• Height of the guardrail: The higher the guardrail, the stronger the wind forces acting on it.
• Wind pressure: Wind pressure is calculated by multiplying the wind speed by the air density.
• Safety factors: To ensure that the guardrail can withstand the wind, safety factors are taken into account that include short-term fluctuations in wind speed.

Practical applications

Wind load plays a role in connection with guardrails as fall prevention (protection) systems, especially in the area of flat roofs, as well as in connection with PV systems on roofs. It is particularly important to take these forces into account to ensure that guardrails and fall prevention systems remain stable and safe in wind-exposed environments. Here are some examples of practical applications in which wind loads play a central role:
 

• Buildings in exposed locations: Wind loads must be taken into account in coastal areas or other regions prone to high winds. Wind load zone 4 may be relevant here.
• Tall buildings: The height of a building affects wind loads. The taller the building, the more important it is to calculate the wind load and take appropriate additional measures when installing a guardrail as a fall prevention system.
• Roof pitch and substrate: Depending on the slope and type of substrate, different installation types must be considered for a safe fall prevention (protection) system in the form of a guardrail. The statics of the roof also determine the possible superimposed load and the component connection to the guardrail.
• Fastening: Guardrails that are permanently screwed or fastened by superimposed loads; it is important to choose the correct fastening depending on the substrate, slope and loads that occur.

Safety aspects

If wind loads are not adequately taken into account in accordance with requirements, there are significant safety risks:

• Displacement or overturning: Guardrails can shift or tip over, resulting in damage to the building or personal injury.
   
• Falling: If a guardrail becomes unstable due to insufficient consideration of wind loads, it can fall from the roof or structure. This not only poses a risk of property damage, but can also result in serious injury or even death if people or vehicles are standing underneath.
   
• Loss of fall prevention (protection) function: If a guardrail is no longer stable, it can no longer fulfil its function as a fall prevention system.

Regular inspections and servicing are crucial to ensure that fall prevention systems can withstand wind loads. These must be carried out every two years for the BARRIER and we also recommend checking after any exceptional weather events.