Fire wall: description, types, device and types

The main purpose of the fire wall is to limit the area of fire, as well as reduce the damage caused by fire. In the presence of such structures it is possible to save the burning building and premises before the arrival of firefighters. In the absence of such structures or their incorrect installation, one can face a fairly rapid spread of fire and collapse of the walls. This is only the least damage, much more terrible consequences can be human casualties. Therefore, before the construction of residential and industrial buildings should be familiar with the features of fire walls, which will allow in the event of a fire to save human lives and save property.

The main types of fire walls

The fire wall is classified by the method of placement in the building. Thus, such structures may be external or internal. It is possible to classify such walls also according to the load perception, they can be self-supporting or bearing. In the first case, the wall perceives the load from its weight and transfers it to the foundation beams. While the load-bearing walls perceive not only their own weight, but also the mass of overlapping, coatings of other building structures.

It is worth noting that such structures are also classified according to the actual fire resistance limit, which depends on the design. If the construction of the walls was carried out according to the technological regulations, then they should be built on the entire height of the building and facilities, ensuring the non-distribution of fire in the adjacent compartments. This applies to the unilateral collapse of the building, as well as the building from the side of the fire. The walls must have a height of construction or be built on the principle of fire protection overlap of the first type, ensuring that the spread of the fire to adjacent compartments horizontally. Such designs rely on the foundation or in the foundation beams, crossing floors and structures.

For reference

The fire wall can be installed on the frame structure of a structure or structure, which is built of non-combustible materials and meet certain requirements, among them: high fire resistance of the structure and fire resistance of the fastening unit. The implementation of the first factor will ensure the stability of the wall, the structures on which it relies, and the nodes of fixation between them. These units should have a fire resistance limit that will not be lower than that inherent in a fire-resistant enclosure.

Design of fire-prevention constructions

The fire wall should rise over the building by about 60 cm or more. This is true if one of the components of an uncracked or attic cover is made of materials of groups G3 or G4. The exception is the roof. Such a wall should be raised by 30 cm or more if the components of the uncrossed and attic floor are made of materials of groups G1 or G2. In this case, as an exception, again, the roof appears.

Such walls may not rise above the roof, if all the elements of the coatings are made of non-combustible materials. If the outer walls belong to the following classes of fire hazard: K1, K2 and K3 - then the wall must cross these structures and extend beyond the outer plane of the wall by 30 cm.

Sometimes the construction of external walls is carried out using non-combustible materials with tape glazing. In this case, the fire protection structures must separate the glazing, among other things, it is allowed that these structures do not extend beyond the outer plane of the wall.

Features of construction

The fire wall and its exterior parts can have doors, windows, and gates that are not subject to fire resistance limits. In this case, the distance above the roof of the adjacent compartment should not be less than 8 m vertically. As for the horizontal surface, this value is reduced to 4 m. When the building is divided into fire compartments, the wall that is located in a wider and higher compartment must have the qualities of non-combustibility.

Main types of walls

Considering the types of fire walls, it is necessary to distinguish the difference in their design. These products can be made of piece blocks or bricks. Among other things, they can be skeleton. In the latter case, the internal space can be filled with piece material or panels, then the structure will be called the frame-panel.

If we are talking about the walls of piece products, the limit of their fire resistance meets the requirements of the norms. In this case, the wall should have a width of 0.5 bricks. As a rule, fire walls have a thickness of 25, 38 or 51 cm. At the same time, the fire resistance limit exceeds REI 150. The junction of walls and coverings, interfloor overlappings is performed in such a way that the fire resistance limit does not depend on the given characteristics of overlappings and coatings. But if the frame wall was erected, then it is subjected to more stringent requirements, because the limits of fire resistance depend not only on the thickness, but also on the nodes of the articulation of the frame.

In the event of a fire, the bolt will be exposed to a flame on three sides. In order to determine the fire resistance limit, it is necessary to calculate this parameter characteristic of each joint node. The final value is taken in accordance with the lowest value.

Design features of the wall of the first type

Fire walls of the 1st type have certain design features. At the same time, roof building materials should consist of non-combustible materials, but firewalls can go beyond the roof level. If the structural elements were made of difficult combustible materials, the firewall rises 300 mm above the roof. If the walls of the building are made of flammable building materials, firewalls cross the walls and extend beyond them to the street by 600 mm.

Features of fire walls of the second type

Fire wall type 2 should be designed on the foundation, cross the entire building from top to bottom. Even if the wall corresponds to the limit of fire resistance, which is characteristic of the first type partition, it differs from the septum presence of bases. In the openings of such walls are installed fire doors. When rebuilding a building, the degree of fire resistance of a structure can be increased by the use of chemical materials, namely:

• Plasters;
• Impregnation;
• Paints and other compounds.

The fire walls in the building described should be made of non-combustible materials and have a high degree of gas-impermeability. The walls are built to differentiate the parts of the building with different fire loads.

Characteristics of fire barriers

Fire walls and partitions differ from each other. The latter are vertical fences that are designed to separate rooms within a single storey. As their function is the delay in the spread of fire within a single storey. Such structures must necessarily be located in places where mixtures can accumulate, which may prove explosive. They are also installed in niches for communications, warehouses, cellars, canals, elevator shafts, which allows to reduce the possible damage in the event of a fire.

Conclusion

The construction of fire walls should be accompanied by a quality seal of gaps between the panels, walls and ceilings of the building. There must be no emptiness in the barriers. During the work, a special fire-fighting foam is used, which is then covered with plaster made on the basis of cement and sand.