A firewall or firewall (rarely fire wall or fire wall is called) a wall , through their special nature the spread of fire and smoke to prevent a building or part of the building to another. The fire wall must also perform this task if it is exposed to fire water and heat or if other components fall on it or collide with it.
Fire walls form an elementary component of the fire protection of structures. For this reason, the nature and requirements of fire walls are regulated by building law.
Functions of fire walls
Fire walls basically fulfill two different functions. On the one hand, they should protect (immediately adjacent) buildings from fire and heat. On the other hand, they also serve to protect the users of a building.
Protection objective building
Especially in cities with dense development ( closed construction ), fire walls make an effective contribution to preventing fire and heat from spreading to neighboring buildings. In this way, major fires , which may affect entire city districts, can be prevented.
In industrial plants, fire walls are used to prevent fire and heat from spreading to neighboring plant components or to minimize the effects. Further examples are the fire walls in oil-filled power transformers in substations and power stations, which spatially limit the practically inextinguishable transformer fire in the event of serious faults.
Protection goal user
Even more important than protecting the surrounding buildings is protecting the users of the burning building. Fire walls seal off fires within the building and thus enable the formation of fire compartments . In this case, the affected users can leave the building via unaffected sections. However, there is also the option of escaping to a safe section of the building and waiting there for a rescue by the emergency services. This case occurs in particular in facilities in which the users cannot leave the building independently (such as in nursing homes and hospitals).
Requirements for fire walls
In order to be able to fulfill the above functions, fire walls must meet certain requirements depending on the use and size of the building. These requirements are set out in building laws and building standards in Germany, Austria and Switzerland. Since the exact provisions vary depending on the federal state or canton, only basic requirements should be mentioned at this point:
- Fire walls must be fire resistant and made of non-combustible building materials (such as concrete and masonry ).
- The load-bearing capacity and stability of fire walls must be maintained even under additional mechanical stress during the fire (for a defined period of time).
- Fire walls must be sufficiently thick and consistently arranged one above the other on all floors (deviations possible if fire ceilings are present).
- Fire walls must be extended into the roof area (or even beyond).
- Fire walls must not be interrupted by combustible building materials or have cavities.
- Openings in external fire walls are not permitted. Openings in internal fire walls must be specially sealed off (see fire protection ).
Requirement of fire walls
In which case a fire wall is required is also specified in the building laws and building standards. Generally speaking, the following provisions apply:
- External fire walls are generally required if the end wall of the building is erected a short distance from the neighboring border. This is to prevent flashover .
- Internal fire walls are to be provided if fire compartments are to be created due to the size or use of a building. In this way, the risk of fire spreading can be limited in the event of a fire and the fire can remain manageable for the rescue and extinguishing forces. The distances between the fire compartments can be increased if it is proven by means of a fire protection report that the fire can be effectively contained by suitable measures (such as sprinkler systems and smoke extraction devices).
Figurative use in politics
The term fire wall is used in German politics for a consistent delimitation of democratic parties against the AfD, especially since the events surrounding the election of Thomas Kemmerich as Thuringian Prime Minister on February 5, 2020.
- Frieder Kircher, Rainer Sonntag: Die Roten Hefte, Issue 25 - Preventive Fire Protection . 1st edition. Kohlhammer, Stuttgart 2014, ISBN 978-3-17-016996-8 , pp. 32-34 .
- Further information on fire wall solutions in the roof area (with sectional drawings)
- Simon / Busse: Bavarian Building Regulations - Commentary, CH Beck Verlag, Art. 28 page 7
- Simon / Busse: Bavarian Building Regulations - Commentary, CH Beck Verlag, Art. 28, page 10 ff
- Lecture on preventive structural fire protection in the course on safety and security at the Magdeburg-Stendal University of Applied Sciences