Fire protection of the structure

Every steel structure has a certain resistance to fire. The fact that steel is non-combustible does not mean that structural elements made of it are immune to the effects of fire. For this reason, steel halls, warehouses, production halls and other buildings are equipped with a number of safeguards to reduce or even eliminate the risks associated with high temperatures.

High temperature and the properties of steel

Why is fire protection of a steel structure necessary? Steel can withstand the effects of temperatures in the range of approximately up to 500 degrees Celsius. In the event of large fires, the presence of some flammable materials (such as interior design, furniture, etc.) can lead to a sharp rise in temperature, the value of which can reach up to 1,000 degrees Celsius. Under these conditions, steel structures (exposed to a range of loads) deform more easily, resulting in the collapse of the building.

Fire protection of steel structures used in large-scale construction is designed to:

• limit the rate of fire spread,
• if possible – stop the progress of flames,
• protect the steel structure from the effects of heat.

How do we divide fire protection in steel-framed buildings?

In modern construction, fire protection of steel structures is divided into two basic types.

• Passive fire protection – these are various types of protective coatings, the purpose of which is to limit the spread of fire throughout the steel structure. Thanks to them, the so-called critical temperature of steel is not exceeded, for which the structure loses its physical and strength properties.
• Active fire protection – these are widely understood systems (often automated) that limit the effects of fire by fulfilling a number of specific relationships. For example, when smoke is detected, the sensor activates the extinguishing system, as well as ventilation equipment.

Examples of fire protection – what is worth knowing about them?

• Intumescent paints – are a type of fire protection, which take the form of special paint coatings. They usually consist of three layers: load-bearing, intumescent and finishing. When the flame interacts with the structure covered with such paint, the paint immediately increases its volume (even dozens of times), so that the effect of temperature on steel is significantly reduced. Fire paint for steel forms a non-combustible and heat-insulating coating on its surface.
• Fireproof panels – are made of silicate, cement, gypsum or magnesium covers, with which the steel structure is encased. As a result, the process of its heating is significantly slowed down. Fireproof board can provide fire resistance for up to 240 minutes.
• Fire showers – is an active fire protection system. With them you can easily activate the extinguishing system. The showers can be activated in two ways: either through the action of heat, by destroying the special sealing protection, or through a set of sensors designed to detect smoke, increased temperature and other risk factors.

Classes of steel structures and fire protection

The construction industry distinguishes between so-called classes of steel structures. They differ, among other things:

• size and number of floors,
• the load acting on the building structure.

Fire protection of steel structures should take into account what type of structure we are dealing with. The larger it is, the more advanced fire protection systems should be used. A designer of steel structures has the necessary qualifications to assess what systems will be necessary for the selected buildings. Very often, this takes into account various types of simulations that assess how the stability of the steel “skeleton” will be affected by high temperatures at a particular location.

Fire protection as a whole

The effectiveness of fire protections depends primarily on their ability to work together. Passive solutions make it possible to protect the structure in the event of spot fires that could threaten the structural integrity of the building. Active systems, on the other hand, are holistic solutions that activate based on sensor data. In modern construction, all of these solutions form a unified whole that complements each other and thus ensures the safety of employees, and limits possible property damage that could occur before a firefighting operation takes place. The main advantages of this solution are:

• limiting the fire to one zone only,
• separating other parts of the building from the fire,
• providing time for evacuation and firefighting action.

In summary, in steel-framed buildings, fire protection systems play a huge role. And that is why it is worth ensuring that they work together and give the necessary time to save people, property and the building itself.