When constructing important objects, it is necessary to approach the choice of materials and technologies with great responsibility. One of the important parameters is the ability of all components of buildings to withstand fire. How to determine the degree of fire resistance of a building, what factors affect the limit of this property? Only a specialist can answer these questions. It is thanks to the knowledge gained during training at a higher educational institution that it is possible to think over the evacuation routes in advance, correctly arrange fire exits and do everything possible so that during a fire the building and all its inhabitants are not damaged.
Nowadays, there are many new solutions used in architecture. That is why the determination of the fire resistance of buildings and structures causes some difficulties.
Fire safety, the conditions for the propagation of flame in them directly depend on the flammability and the ability to resist fire of the materials that were used during construction and decoration. These qualities for building components are established even during the design of the object. Much depends on the category of fire and explosion hazard of the premises located in a particular building. But first things first, so that you can accurately determine the degree of resistance to fire of any structures.
What is meant by the degree of fire resistance?
Before answering the question of how to determine the degree of fire resistance, you need to figure out what it is all about. This is an indicator that allows you to determine the possible resistance of a particular room to the effects of fire. It can be calculated according to the rules of SNiP. This is a general provision that makes it possible to give an accurate assessment and establish the level of security of a building for any purpose, as well as the materials from which it was erected.
The value of fire resistance determines how quickly a fire can spread in a certain room. And this directly affects the safety of people. All types of buildings, depending on the resistance to fire and the speed of fire spread, are divided into 5 categories.
Rules for determining the fire resistance of buildings
To correctly determine the fire resistance of a particular structure (be it a residential building or an industrial building), you need to have:
- architectural plan;
- rules for ensuring the durability and safety from fire of reinforced concrete structures;
- a guide that allows you to determine the limits for these parameters of structures to SNiP;
- manual to SNiP - helping to prevent the spread of the fire source.
The endurance limit of any construction object is determined by the time of exposure of the test structure to a fire. When the state reaches one of the limits, the fire is artificially stopped. Before starting testing, it is necessary to carefully study the documents for the structure. This includes what building materials were used, the characteristics of the building, possible estimates of fire resistance and other points.
It is necessary to carefully study the presence or absence of information in the documentation for the structure of information on the use of modern technologies that could help increase the level of fire resistance. During the preliminary consideration of the structure of the structure, all premises should be examined, including utility rooms, stairways and others. It is possible that completely different materials were used during their construction. Indeed, often builders, in order to reduce the amount of the estimate, save money when arranging utility rooms and staircases, which leads to a sharp decrease in their strength and resistance to fire. In extreme situations, it is these areas of the building that cause the spread of the fire.
In the construction of modern buildings, architects often use innovation. But in most cases, certain areas are not as strong as the rest of the structure. Therefore, this point is important to consider. It is worth taking all the necessary measures in advance in order to quickly cope with the fire in the event of a fire:
- hire a fire brigade;
- check the serviceability of hoses and fire extinguishers.
- equip a fire shield.
Only after all safety standards are fully observed can you start working. After the preparatory activities, you can move on to practical.
What is SNiP?
Often answering the question of how to determine the degree of fire resistance of a building, one has to deal with such a definition as SNIP. But what is it?
"Construction Norms and Rules" is a collection of legislative documents that were previously approved by the government of the Russian Federation, and regulate the rules for the construction of urban and rural buildings. In addition, projects developed by architects and engineering searches are included in such a document.
After a careful study of such paper, any owner will be able to independently understand all the drawings and determine the state of the structures. In any situation, you need to use special reference books. This is the only way to easily determine the 2nd degree of fire resistance of buildings or any other. This is exactly what special documentation is required for.
But how to determine SNiP for a specific building using reference manuals and a building passport? Experienced specialists in this case carefully read the code of SNiP (01.21.97) "On the safety of structures and buildings during a fire." And in order to properly prepare for the tests, it is necessary to carefully study another SNiP (03/31/2001), which describes in detail all the laws relating to the construction and operation of buildings in the Russian Federation.
What are the degrees of fire resistance of buildings?
As we said earlier, there are 5 degrees of fire resistance, and they depend on the degree of ignition and the resistance limit of the main structures. Below is a table of fire resistance of buildings and structures.
Fire resistance | Structural characteristics |
1 degree of fire resistance of the building | Structures with load-bearing and enclosing structures, erected using artificial and natural stones, concrete or reinforced concrete, using non-combustible types of materials in the form of sheets or slabs. |
Identical to grade 1, but only steel structures are allowed to be used in the coatings of buildings. |
|
Structures with load-bearing structures and fences made of stone materials, reinforced concrete and concrete. Ceilings can be wooden, protected from above with a layer of plaster, non-combustible sheet materials, as well as slabs. There are no special requirements for coatings in terms of fire resistance, but in the attic, all wooden structures must be treated with a special protective compound against fire. |
|
The buildings are mainly of frame type. All structures are made of unprotected steel. Fences made of steel profiled sheets and other sheet materials that are not afraid of fire. |
|
Mostly buildings on one floor with a frame structure. The frame is made of wood, which has been specially treated to protect it from fire. Piecewise pre-assembled panel fencing made of wood or materials. All timber structures must be reliably protected from the effects of high temperatures. |
|
Structures with load-bearing structures and fences made of wood and other flammable materials, which are protected from fire by a layer of plaster or slab-shaped materials. There are no special requirements for overlapping. But the elements of the attic made of wood must be thoroughly treated with fire retardants or materials. |
|
The buildings are mainly on one floor with a wireframe scheme. The frame is made of steel, and the fence is made of profiled sheets or other elements with a combustible insulation. |
|
Structures that do not have special requirements for the qualities of fire resistance and fire propagation. |
Types of fire hazard of building structures
All construction sites must meet fire safety requirements. Determines the degree of fire resistance of the building FZ 123, which stipulates all the requirements and criteria. Today, there are 4 classes of fire hazard of construction objects:
- K0 is not fire hazardous.
- K1 - low fire hazard.
- K2 - moderately fire hazardous.
- K3 is fire hazardous.
When determining the fire resistance of buildings, it is necessary to take into account:
- number of floors;
- functional fire hazard;
- the area of \u200b\u200bthe building and the fire compartment;
- fire hazard of processes taking place inside the building;
- building category;
- distance to nearby buildings.
When all these factors are taken into account, it will not be difficult to determine the fire resistance.
Objectives and scope of technical regulation
As mentioned earlier, it is impossible to determine the stability of any structure in relation to fire without FZ 123, but besides this, it is imperative to take into account SP 2 13130 \u200b\u200b2012. The degree of fire resistance of buildings should be determined when:
- design, construction, overhaul, during the reconstruction, changes in the functional purpose;
- development, adoption and implementation of the Federal Law on technical regulations, which include fire safety requirements;
- at the stage of developing documentation for protected objects.
If all these requirements are met, it will not be necessary in the event of a fire to find out where the mistake was made.
Instructions for determining the limit of fire resistance
Those who are going to start construction ask themselves one of the most important questions: "How to determine the degree of fire resistance of buildings?" Using our instructions, anyone can cope with this task. Even during the execution of project documentation, the calculated indicator for each parameter is indicated. But it is better to check and compare all the data yourself, guided by SNiP. The limit for this property can be considered the time that elapses from the beginning of the action of fire on the structure and until the moment when critical changes appear. The overall indicator is determined by the maximum values \u200b\u200bof durability. At the same time, this must be taken into account for all elements: partitions, vertical structures, which are load-bearing, doors, windows and others.
The calculation should include information on the level of ignition of building materials.
Analyze the entire building project in detail. Information about the main elements used in construction may not be enough to get more real data. Therefore, it is better to review and check everything personally, examining each site, including utility rooms and stairways. To study this whole mechanism in detail and correctly carry out the calculations, you need to use the manuals for SNiP.
How can the fire resistance of a building be increased?
So that the bearing supports can withstand the fire, and everyone who is in the building at this time can escape, there are several methods of increasing fire resistance. First of all, it is worth choosing the right materials that have passed certification and fully comply with fire safety standards. Fortunately, there are plenty of such raw materials currently on the construction market. But people's lives depend on skillfully and, one might say, professionally carried out measures to protect buildings from fire.
Today, a huge variety of high-quality materials from European and domestic manufacturers are presented, with the help of which you can protect against fire.
How to carry out high-quality fire protection?
The best fire protection is concreting and brickwork. Another important function is structural reinforcement. Brick is mainly used for vertically located structures; reinforcement of the concrete layer is also used. Its thickness is selected individually for each object. Cladding made of sheets, plates and screens is used to protect columns, beams, posts. It is also good to use plaster.
The good thing about the finish is that it provides reliable protection against fire, but it is also inexpensive. But there are also disadvantages. Cladding requires special skills and the thickness of the layer must be chosen correctly.
Finally
It is not difficult to determine the 3rd degree of fire resistance of buildings or 5. Difficulties, of course, can arise. But if you have at hand all the necessary documents, a set of rules, then the difficulties will be quickly resolved. After studying the plan, the state of all building structures, it can be expensive to determine the fire resistance, but not so difficult. The main thing is to adhere to safety precautions during testing, be careful and be careful, control the temperature in the oven.
In modern times, with such a huge scale of construction, it is important that the fire resistance of buildings and materials from which residential buildings, offices and important institutions are constructed comply with the standards. The life of citizens depends on it. It is no secret that many accidents occur as a result of the use of unsuitable materials and violations of construction techniques.
The degree of fire resistance of buildings and structures, a table of indicators of these values \u200b\u200bare needed in order to know at what temperature the structure is destroyed by fire. Now the number of fires has increased, the cause of which is the careless handling of fire, so you need to know the level of resistance to fire of various objects.
What is the fire resistance of a building, what does this indicator depend on and what does it affect?
The intensity of fire propagation depends on the fire resistance of the object and its structures. All building materials for changing characteristics in a fire are divided into:
- non-combustible;
- slow-burning;
- flammable.
Fire resistance is the ability of a building to withstand the action of an open flame for a certain period of time, while maintaining its operational characteristics, such as thermal conductivity, bearing capacity of supports, and fire resistance. To determine this indicator, you need to know the periods during which the structure collapses to such a state when it cannot be restored.
Fire resistance of buildings is an important parameter that must be taken into account in the design and construction of buildings and structures. The fire resistance of a house depends on the level of fire resistance of its structures.
To determine the fire resistance limit, calculations or practical methods are used that allow these indicators to be obtained from the test results. After comparing the values, a conclusion is made about the state of the building and a classification is assigned to it. When assessing the fire protection of an object, it must be borne in mind that its calculation is based on classification in category C (support structures, stair spans). After that, it is determined whether the building complies with building codes in terms of the degree of resistance to combustion.
A fire is an uncontrolled process of burning and growth of a flame, which is accompanied by the destruction of property and creates a danger to the health and life of people in this area. Combustion is a chemical process of converting combustible substances into combustion products, it is accompanied by the release of fire, toxic gases, heat, which is carried out as a result of the oxygen oxidation reaction.
Fires are divided according to their intensity into the following types:
- Separate, arising in one structure. The movement of people and equipment across the area between such fires can be carried out without means of protection against fire.
- Solid, representing the simultaneous strong combustion of several structures in one area. The movement of people and equipment across the area of \u200b\u200ba continuous fire cannot occur without fire protection means.
Determination of the fire resistance limit
The fire resistance of a material is called the time during which it retains its characteristics when burning. The limit of incombustibility of materials depends on the layer of the protective coating, the cross-section of the profile, the level of fire resistance of building materials, the ability to maintain their parameters during combustion. The degree of fire resistance is characterized by the following factors:
- fire resistance;
- fire resistance level;
- level of fire spread.
There are limiting standards for fire resistance:
- Loss of technological characteristics due to collapse or the appearance of ultimate deformations - marked with the Latin letter R.
- Loss of integrity due to damage or holes through which combustion products and fire get out. They are designated by the letter E.
- Loss of insulating function as a result of an increase in surface temperature. Designate I.
The following limit values \u200b\u200bfor load-bearing structures are regulated by the degree of resistance to fire:
- beams, racks, arches, trusses; loss of bearing capacity - R;
- load-bearing walls and floors - loss of bearing capacity R and integrity E;
- external walls of the building, which are not considered load-bearing, - loss of integrity E;
- internal walls and partitions - loss of integrity E and thermal insulation capacity I;
- internal walls and fences - loss of bearing capacity R, integrity E and insulating characteristic I.
How to determine the degree of fire resistance?
The classification of buildings according to the degree of fire resistance depends on:
- the number of floors in a given building;
- the area of \u200b\u200bits territory;
- production processes or other activities that take place at the facility;
- characteristics and degree of flammability of materials used in the construction of the facility.
The fire resistance of a structure characterizes the length of time during which these structures have been flame tested. Resistance of objects to fire is regulated by SNiP, where there are 5 degrees of fire resistance of buildings.
All buildings are divided into 5 categories:
- Explosive and fire hazardous, they carry out technical processes associated with the appearance of fire, flammable gases, flammable liquids with a flash point of up to + 28ºC.
- Structures where work is carried out using flammable liquids with a flash limit of more than + 28ºC, which can create explosive substances and when they burn, an explosion pressure of more than 5 kPa arises.
- Facilities where production processes take place using flammable liquids and solid materials that, when combined with oxygen, can burn. This is a fire hazard category.
- Buildings where technological actions are carried out using non-flammable materials in a hot state.
- Facilities where production processes take place using solid non-flammable substances.
Types of degrees of fire resistance
The greater the number of storeys and the area of \u200b\u200bthe structure, the higher the required degree of fire resistance of the building must be. Residential buildings are built of brick, concrete, stone, they are classified as grade 1.
Residential buildings made of bricks and concrete panels are classified as grade 2. Residential buildings with a metal frame are classified as grade 3. The cladding of these structures is made of non-combustible materials. The 4th degree includes objects with a wooden frame, i.e. it is assigned to a wooden house. The 5th degree includes all other houses that are susceptible to fire. Taking into account this classification of buildings, they carry out the design and construction of buildings.
It happens that a house has a low fire rating. Then its partitions, floors, supporting structures are treated with a non-combustible coating that protects them from fire. You can also clad the house with non-combustible materials. With the help of these complex measures, the resistance to flames of residential buildings is increased. In residential buildings of 1, 2 and 3 degrees, partitions are installed that can contain a fire for at least 45 minutes, and in houses of 4 degrees - 15 minutes.
If the structure is built of sandwich panels, then a heater is installed between them. This material can withstand frost, so they are used in construction in regions with cold climates. The material is used for the construction of rapidly erected houses, it is easy to install.
Sandwich panels are safe for human health, have excellent sound insulation and high resistance to fire. The fire resistance limit of this substance depends on its thickness: the thicker the material, the longer it will be able to withstand the effects of fire. It is impossible to build houses of the 1st degree of fire resistance from sandwich panels.
Consider the fire resistance of a brick building. Brick houses have the highest fire safety rate, so they are classified as grade 1. The indicator depends on the building material from which the structure is made. Brick is a non-combustible material, it does not smolder, it does not deform from fire, therefore it is often chosen for the construction of residential buildings. Such material will ensure the safety of people and property in the event of a fire.
Thus, any building material has its own fire resistance indicator, therefore, when choosing them for the construction of a building, one should take into account the characteristics of the materials and structural elements of which the object under construction will consist.
Fire resistance: table
Table of indicators of fire resistance of structures:
This table shows the dependence of the indicator on the fire characteristics of walls, columns, beams, stairway girders and other structures of the house. Knowing this indicator, the designers carry out the project, create schemes, carry out calculations, develop the design of a residential building, taking into account the requirements of fire safety.
The degree of fire resistance of a building is the ability of a building to withstand a fire for some time without collapsing. Based on this indicator, it is possible to assess any structure in terms of fire safety. It depends on the degree of fire resistance of the building how quickly the fire will spread through its premises and structures. For obvious reasons, this indicator will largely depend on the materials from which the structure is being built.
The definition of the degree of fire resistance of building materials must be approached from the position: are they combustible or not. Therefore, the standard classification divides them into "NG" - non-combustible or "G" - combustible. The latter are divided into several classes:
- G1 - slightly flammable;
- G2 - moderate;
- G3 - normal;
- G4 - strong.
There is another parameter that determines the fire resistance of building materials - this is their flammability, denoted by the letter "B". There are three classes here:
- B1 - materials that are flammable with great difficulty;
- B2 - moderately flammable;
- B3 is easy.
The next characteristic of the degree of fire resistance of building materials is the possibility or impossibility of flame propagation over their surfaces. This parameter is designated by the abbreviation "RP". So:
- RP1 - do not spread the flame;
- RP2 - poorly distributed;
- RP3 - moderately;
- RP4 - strong.
Attention! The "RP" indicator is determined only for floor bases and their coatings, as well as for roofs. It has nothing to do with the rest of the structural elements, except perhaps for wooden houses.
SNiPs do not indicate that the smoke and toxicity of the emitted combustion products affect the degree of fire resistance of the building. And it is right. But in the event of a fire, where the main task is not only to extinguish it, but also to evacuate people in time, these two factors play an important role. Therefore, they must be indicated in the building passport.
Smoke or smoke emission coefficient of building materials is indicated by the letter "D". According to this characteristic, all buildings are divided into three groups:
- D1 - with low smoke emission;
- D2 - moderate;
- D3 is a big selection.
In terms of toxicity during combustion, all building materials are divided into four groups:
- T1 - low hazard;
- T2 - moderate;
- T3 - high;
- T4 is extremely dangerous for humans.
Summarizing all of the above, we can finish about the degree of fire resistance of building materials by the fact that in SNiPs all the above-mentioned indicators (and there are five of them) are combined into one common one, which is denoted by the abbreviation "KM".
According to the "KM" indicator, building materials are divided into five classes, where the KM1 class are representatives in whom all the above characteristics have a minimum value. Accordingly, the KM5 class - with the maximum values. KM0 is a class of non-flammable.
Having dealt with the building materials, we turn to the fire resistance of buildings and structures. It should be noted that not all buildings have identical materials throughout the structure... That is, not always in all construction projects in each of their parts (floors, premises, etc.), the same building materials are used. Therefore, the classification made according to fire resistance is considered conditional. But in any case, all construction objects are divided into three classes: non-combustible, difficult to burn, combustible.
The degree of fire resistance of a building - how to determine. The calculation is based on the time from the onset of ignition to the moment of destruction or the appearance of defects. Therefore, it is important to understand which defects in the supporting structures can be taken into account in order to accurately say that the structure is at the limit of destruction.
- Through holes and cracks appear, through which fire flames and smoke penetrate.
- The heating temperature of the structures rises within the range from + 160C to + 190C. This refers to the non-burning side. For example, if a room is on fire, and the wall on the other side heats up to the above indicators, then this is a critical moment.
- The supporting structure is deformed, leading to collapse. This mainly applies to metal assemblies and structures. By the way, unprotected steel profiles belong to the KM4 category. At a temperature of + 1000C, they simply begin to melt. Reinforced concrete products belong to "KM0".
As for the speed and time of combustion, then, as mentioned above, it all depends on the materials from which they are built. For instance, concrete structure 25 cm thick burns out in 240 minutes, brickwork in 300 minutes, metal structure for 20, wooden door (entrance, treated with fire retardants) for 60, wooden structure sheathed with plasterboard 2 cm thick, burns out in 75 minutes.
Classification by the degree of fire resistance of buildings, structures and fire compartments
All construction objects are divided into five degrees. And this indicator must be indicated in the passport of the building.
Attention! The fire resistance of a building can only be determined by an authorized service. It is they who give the assessment, determine the class that is entered in the passport.
So, the degree of fire resistance of buildings and structures is a table of five fire resistance classes (I-V), which determine the fire hazard of a structure.
| Class | Design features |
| I | Objects erected entirely from non-combustible materials: stone, concrete or reinforced concrete. |
| II | Structures in which metal assemblies are partially used as load-bearing structures. Brick houses belong to the same class. |
| III |
Buildings belonging to the first category, only in their structures it is allowed to use wooden floors, covered with plaster solutions or gypsum boards. For covering wooden floors, here you can use sheet materials belonging to the group of "hard-to-burn". As for roofs, wood can be used here, only with a treatment with flame retardant compounds. |
| IIIa | Frame houses made of metal base (steel profiles), which have a low degree of fire resistance. They are sheathed with non-combustible materials. here you can also use a fireproofing material. |
| IIIb | Wooden houses or buildings made of composite materials, the basis of which is wood. Buildings must be treated with fire retardants. The main requirement for them is construction away from possible sources of fire. |
| IV |
Buildings erected of wood, the structures of which are covered on all sides with plaster mortars, gypsum boards or other insulating materials capable of holding back the effects of fire for some time. The roof must be exposed to fire protection. |
| IVa | Building structures assembled from steel profiles, untreated with protective compounds. The only thing is the floors, which are also assembled from steel structures, but using non-combustible heat-insulating materials. |
| V | Buildings and structures that are not subject to any requirements regarding fire resistance, speed of combustion and others. |
Having dealt with the classes of the degree of fire resistance of buildings, it is necessary to designate the types of this characteristic. There are only two positions here: the actual fire resistance, denoted by CO f and required - CO tr.
The first is the actual indicator of the erected building or structure, which was determined based on the results of a fire-technical examination. The results are based on the tabular values \u200b\u200bshown in the photo below.
The second is the implied (planned) minimum value of the fire resistance of the building. It is formed on the basis of regulatory documents (industry or specialized). This takes into account the purpose of the building, its area, number of storeys, whether explosive technologies are used inside, whether there is a fire extinguishing system, etc.
Attention! Comparing the two types of fire resistance, it is always necessary to take as a basis the ratio that CO f should not be less than CO tr.
Conclusion
The classification of buildings and structures according to the degree of fire resistance must be taken seriously. Given this indicator, it is necessary to determine the requirements for the fire safety system. And the lower the limit of fire resistance of the building, the more investments will have to be made when organizing a fire protection system.
The degree of fire resistance is an important parameter that is determined during and after construction work. It is very important for builders to know that this or that building structure has its own degree of fire resistance. How to determine the fire resistance of a building, you will learn from this article.
The expression fire resistance means the ability of certain elements of a building to maintain strength in the event of a fire. Moreover, fire resistance has its own limit, which is determined in hours, i.e. specific figures to the fire hazard of the building. It is generally accepted to denote the degree of fire resistance by Roman values: I, II, III, IV, V.
Fire resistance is divided into two types:
- Actual (SOF). How is it determined? Mainly based on the result of technical and fire safety expertise of building structures. Also, calculations are made based on regulatory documents. The level of fire resistance is clearly regulated and known. In accordance with the official information, the SOF is calculated.
- Required (Sotr). This concept includes the level of fire resistance at a minimum value. In order for a building to meet all safety requirements, the structure must comply with them. This degree of fire resistance is determined on the basis of regulatory documents that have industry and specialized values. In this case, the key role is played by the direct purpose of the building, its area, the availability of fire extinguishing equipment, the number of floors, etc.
To consolidate all this, consider an example. To make the building comply with the fire safety requirement, the SOF must be greater than or equal to Sotr. The limit of resistance to flame occurs at the moment when the building does not fully or partially fulfill its functionality in the event of a fire. This happens when compartments or cracks form in a building. Flame penetrates directly through them into neighboring rooms, the surface heats up to 140–180 ° С, and also if the load-bearing parts of the building are completely eliminated.
Method for determining fire resistance
Adequate tests are carried out to determine the limits of fire coverage as well as damage caused by fire. This is realized in practice as follows: a fire is started in specially equipped furnaces. The furnace is processed exclusively with refractory bricks. Kerosene is burned inside the furnace using special nozzles. Using thermal vapors, the temperature inside the oven is controlled. With all this, the work of the nozzles must be carried out so that they do not come into contact with thermal vapors and do not come into contact with the surface of the structure. So, based on the basic rules, then calculating the degree of fire resistance has two tasks:
- Heat engineering.
- Statistical.
To make the determination of the degree of fire resistance, it is important first of all to obtain an architectural design. Next, you need to adhere to the standard scheme.
As for the scheme, it looks like this:
- Turning to the firefighters, they will conduct an examination of fire resistance. If deficiencies are found, they should be eliminated immediately.
- Already at the stage of drawing up sketches, the degree of fire resistance will be indicated. And for this you should contact only competent architects who will take into account all these nuances.
In practice, the whole process, according to the definition of fire resistance, looks like this:
- The fire resistance limit is calculated in hours or minutes. The timing should start from the moment of a critical situation when the structure does not withstand the test, namely, it collapses or the integrity is violated.
- One of five steps is taken for the calculation.
- These calculations / calculations include the flammability level of the various materials that were used in the construction of the building.
- Surface information is not enough to accurately determine fire resistance. It is important to have a complete picture here, even for such structures as: additional staircases, staircases, partitions and all other structures. Even the material from which these structures are made is taken into account.
- It will also be useful to study additional and mandatory materials that relate to the rules for ensuring the fire resistance of reinforced concrete structures. As a basis, for example, you can take the manual to SNiP dated January 21, 1997 "Preventing a fire".
- Thus, to determine the fire resistance, a wide range of planning and technological aspects are taken into account. But at the same time, one should not forget about the primary fire extinguishing means - fire extinguishers.
As a result, you need to make a list of building requirements, which are clarified in the process of determining the fire resistance. The building's documentation and design are taken as a basis.
SNiP
In most cases, structures and buildings have type 1 walls, i.e. fire compartment. As for the minimum threshold of resistance to fire of a building, it is equal to 25. As a result, it is allowed to use unprotected metal structures.
Building codes allow the use of drywall as a cladding material. This increases the fire resistance of the building to some extent.
If we talk about building materials and the degree of their combustion, then they are divided into 3 groups:
- Non-flammable.
- Hardly combustible.
- Fireproof.
If you are building a frame, it is better that it be made of non-combustible material. For buildings from 1 to 5 degrees, combustible materials can be used, but not in the lobbies. This is important, because, in addition to everything, building materials are divided into classifications such as:
- Forming smoke.
- Toxic.
Below we will consider an algorithm for calculating the degree of fire resistance of a building and premises of different types. Based on this, you can find out the basic requirements for certain buildings.
Residential buildings
The house fire resistance index has 5 degrees. According to these degrees, a characteristic is given for each building material from which the house was built. Below are the structural characteristics of residential buildings:
- For residential buildings, preference is given to non-combustible materials.
- Construction is best done with concrete blocks, stone or brick.
- Use fire-resistant material to insulate walls, roofs and other structures.
- Roofing should be made of materials that are resistant to fire, namely slate, corrugated board, metal or roof tiles.
- Overlappings are made of reinforced concrete slabs.
- If the floors are wooden, then they should be covered with non-combustible materials, for example, non-combustible slabs or plaster.
- The wooden truss system must be treated with impregnations that prevent the spread of fire.
It is not necessary to use non-combustible materials for insulation. You can use items that are resistant to fire categories G1 and G2.
Public buildings
The degree of fire resistance of public buildings is divided into 5 groups: I, II, III, IV, V. Thus, according to the class of constructive fire hazard of a building, the following are determined:
- I-C0.
- II-C0.
- III-C0.
- IV-C0.
- V- is not numbered.
As for the permissible height of the room in meters and the area for the fire compartment, there are the following data:
- I-75m;
- II-C0-50, C1-28;
- III-C0-28, C1-15;
- IV-CO-5-1000 m 2;
- C1-3m-1400 m 2;
- C2-5m-800 m 2.
In terms of clubs, pioneer camps, hospitals, preschools and schools, they often use wooden partitions, ceilings and walls. Their processing must be carried out with fire-resistant materials.
Industrial buildings
- Metallurgical.
- Instrumental.
- Chemical.
- Weaving.
- Repair and others.
And for such establishments, the degree of fire resistance is more important than ever. Plus, some work with toxic and explosive substances that can have a negative impact on humans and the environment.
The production buildings are also subdivided into 5 steps. Fire resistance is determined based on the building materials used. Hence the conclusion: the degree of fire safety of an industrial building directly depends on the fire resistance of the building materials used.
Warehouses
As a rule, the most vulnerable are those warehouses that are made of wooden materials. However, if they are treated with plaster and special impregnations, then their degree of fire resistance increases. Also for this purpose, concrete or ceramic tiles are used.
For warehouses, bloated paints or polymer foam are considered the most effective. Their action extends the period of raising the critical temperature.
In general, a number of measures are being taken to increase the degree of fire resistance of rooms built of wood. They can also be fitted with aluminum doors, and glass blocks instead of wooden windows.
So, it is worth noting that before determining the fire resistance of a building, it is important to take into account the characteristics and purpose of each building, as well as methods and materials that have different specifics.