Determination of the degree of fire resistance of buildings and structures snip. Degree of fire resistance, class of structural fire hazard. SNiP. What is the fire resistance of a building and why is it determined?

During the construction of any building, the organization of emergency exits, evacuation routes in emergency cases, and the location of funds must be considered at the project stage. But these points can be considered only if you know the degree of fire resistance of the building. Difficulties may arise with this at present, since most often the same type of structures are erected in cities. But next we will try to understand how fire resistance is determined and what it depends on.

What is fire resistance?

This is the ability of buildings and individual structures to withstand the onslaught of fire without destruction or deformation. It is the degree of fire resistance of the building that will determine how quickly the fire can spread throughout the structure if a fire breaks out.

All indicators are determined taking into account SNiP. These standards make it possible to determine the level of not only the building, but also all the materials that were used during construction.

Classification by flammability

1. Fireproof.
2. Resistant to fire. They can be made of combustible materials, but which have a special treatment or covering. An example is wooden door, lined with steel or covered with asbestos.
3. Combustible. Have low temperature ignite and burn quickly when exposed to fire.

Basis for determining fire resistance

The determining basis for determining the degree of fire resistance of a building is the time that has passed from the moment of the fire to the appearance of the first noticeable defects. These include:

• Cracks and damage to the integrity of the surface, which can facilitate the penetration of flame or combustion products.
• Increasing the temperature of materials by more than 160 degrees.
• Deformation of supporting structures and main components, which causes the collapse of the entire structure.

Buildings built from wooden structures have a low degree of fire resistance; reinforced concrete ones are considered the safest in terms of fire, especially if they contain cement with high level fire resistance.

Dependence of fire resistance on materials

The ability of a building to withstand fire largely depends on the materials from which it is built. They can be classified based on the following characteristics:

The degree of fire resistance of building structures depends on the time required for the material to deform:

• Ceramic or silicate bricks begin to deform 300 minutes after the start of the fire.
• Concrete floors, more than 25 cm thick, after two hours.
• It takes 75 minutes for plaster-coated timber structures to begin to deform.
• An hour will pass before the door treated with fire retardant begins to deform.
• 20 minutes of exposure to fire is sufficient.

Fire resistance degree brick buildings quite high, which cannot be said about metal ones, which already at 1000 degrees turn into a liquid state.

Assignment of fire safety category

According to regulatory requirements, only after the structure has been assigned a certain category according to fire safety, you can determine the degree of fire resistance of a building. And this is done on the basis the following signs:

• Based on changes in thermal insulation performance when compared with the state before the fire.
• According to the barrier effect, which eliminates the formation of cracks in structures.
• By reducing the ability to perform load-bearing functions.

When determining the degree of fire resistance of a building, the area of ​​the structure and the quality of all materials used must be taken into account.

Characteristics of degrees of fire resistance

Their determination is made on the basis of SNiP; resistance to fire of the main functional designs. Let's consider how many degrees of fire resistance of buildings and structures exist and what are their main characteristics:

Types of fire resistance

Special requirements for the ability to withstand fire are imposed on all building structures. The following indicators are important for them:

• Ability to perform a load-bearing function.
• Thermal insulation.
• Integrity.

The safety of the building also plays an important role. Experts today divide the fire resistance of structures into two types:

1. Factual.
2. Required.

The actual degree of fire resistance of a building is the ability to withstand fire, which was determined during the examination. Available regulatory documents are taken as criteria for evaluation. For designs different types fire resistance limits have already been developed. This data is very easy to find and use for your work.

Required fire resistance is the indicators that a building must have in order to comply with all fire safety standards. They are determined by regulatory documents and depend on many characteristics of the structure:

• Total area of ​​the building.
• Number of floors.
• Purpose.
• Availability of means and installations for extinguishing fires.

If during the inspection it turns out that the actual degree of fire resistance of buildings and structures is equal to or exceeds the required one, then the structure complies with all standards.

Fire hazard classes

To determine the fire resistance of the entire building, structures are divided into several categories, and buildings into several classes.

1. KO - non-fire hazardous. There are no materials in the premises that quickly ignite, and the main structures are not characterized by spontaneous combustion and combustion at temperatures close to 500 degrees.
2. K1 - low fire danger. Minor damage may be allowed, but not more than 40 cm. There is no combustion, no thermal effect occurs.
3. K2 - moderate fire danger. Damage can reach 80 cm, but there is no thermal effect.
4. K3 - fire hazard. Integrity violations of more than 80 cm, there is a thermal effect and fire is possible.

1. CO. All utility rooms, main structures and staircases with openings correspond to class KO.
2. C1. There may be minor damage to leading structures up to K1, and external ones up to K2. Stairs and openings must be in excellent condition.
3. C2. Damage to main structures can reach K2, external K3, and stairs up to K1.
4. C3. Stairs with openings are damaged up to K1, and everything else is not taken into account.

Rules for determining the resistance of a building to fire

It is not enough to know about the importance of fire resistance of buildings and structures; it is also important to be able to determine it. And for this there are some rules:

1. Testing a building requires having a plan at hand, and you will also need:

• Code of Practice for Fire Resistance reinforced concrete structures.
• Guidelines for Determining Fire Resistance Limits.
• Manual for SNiP “Preventing the spread of fire.”

2. The fire resistance limit is determined by the time the structure is exposed to fire. When the structures reach one of the limits, the fire is stopped.

3. Before starting testing, you need to study the documentation for the building, which contains information about the materials and their approximate fire resistance.

4. It is necessary to pay attention in the documents to the existing conclusion on the application special technologies to improve fire safety.

5. A preliminary study of the building also involves consideration of all utility rooms, staircases and stairwells, attic compartments. They may be constructed from other materials or may have visible damage at the time of testing.

6. Modern architecture very often used in construction Newest technologies, which may affect strength and fire resistance. These points also need to be taken into account.

7. Before carrying out the fire resistance determination, it is necessary to prepare extinguishing agents, check the serviceability of the hoses, and call the fire brigade.

When all preliminary measures have been carried out, you can proceed directly to the practical determination of fire resistance.

Practical definition of fire resistance

When starting the practical part, it is important to take the architect's plan with you, even if it has been carefully studied. The next steps are:

An indicator of the fire resistance of a material will be the time of exposure to fire and the speed of its spread. For different buildings, this figure can vary from 20 minutes to 2.5 hours. The combustion speed is even less - from instantaneous to 40 cm per minute.

This is how the fire resistance of a building is calculated in practice.

Ways to increase fire resistance

It is not always possible to use only non-flammable or low-flammable materials during construction, so ways to increase their resistance to fire come to the rescue.

The most commonly used are the following:

If multi-component chemicals to increase fire resistance, it must be taken into account that some of them contain organic substances that decompose at temperatures above 300 degrees, releasing toxic substances. Therefore, it is better to give preference to mineral-based coatings with liquid glass.

It is not difficult to determine the fire resistance of buildings and structures. It is important to carry out all the preliminary preparations and we can consider that most of the work is done. The calculation can be considered more costly than complex. The most important thing is to be especially careful during testing and control the temperature in the oven.

The approach to the construction of any buildings and structures should be based on safety from different points of view. And not the least important place here is fire safety. In emergency situations, human lives depend on the resistance of the structure to fire.

Classification and categories of premises. The assessment and classification of explosion and fire hazards is based on determining the possible destructive consequences of fires and explosions at facilities, as well as the dangerous factors of these phenomena for people (HFP). There are two methods for assessing the fire and explosion hazard of objects - deterministic and probabilistic. Regulatory documents such as “Fire Safety Standards” (FSN) and “Rules for the Construction of Electrical Installations” (PUE) are of a deterministic nature. The probabilistic method is based on the concept of acceptable risk and involves preventing exposure of people to general physical injuries with a probability exceeding the normative one. A regulatory document based on a probabilistic approach is GOST 12.1.004-91* SSBT “Fire Safety. General requirements».

Still at the design stage industrial enterprises measures must be provided to ensure their fire safety. For example, the strength of buildings in case of fire, limiting the area of ​​fire development, preventing its spread in the building and on the territory, using appropriate technological equipment, excluding the occurrence of fire, etc.

All these requirements are included in building codes oh and the rules. In each specific case, all fire safety requirements are established based on an assessment of the category of premises and buildings in terms of explosion and fire hazard.

The categories of premises and buildings of subordinate enterprises are determined by the relevant ministries and departments, as well as technologists of design organizations at the design stage of buildings and structures in accordance with all-Union and departmental standards of technological design or special lists approved in the prescribed manner.

Categories of explosion and fire hazards in premises and buildings are determined for the most unfavorable period in relation to a fire or explosion, based on the type of flammable substances and materials located in the apparatus or premises, their quantity and fire hazardous properties, features technological processes.

According to explosion and fire hazards, premises and buildings are divided into 5 categories: A, B, C, D, D. (Table 6.1).

When establishing the category of a room, it is necessary to know the excess pressure of the explosion. The methodology for calculating excess explosion pressure for flammable gases, flammable liquid and liquid liquid vapors, and combustible dusts is described in a number of other sources covering fire safety issues.

Characteristics of materials and structures in terms of flammability. The fire hazard of flammable substances and materials depends on their physical and chemical properties, state of aggregation, conditions of use and storage. The fire hazardous properties of materials are characterized, in particular, by their susceptibility to fire, the nature and nature of combustion, and their tendency to be extinguished by certain fire extinguishing means. The tendency to ignite is the ability of a material to spontaneously ignite, ignite or smolder from various reasons.

According to building codes and regulations, all building materials and structures according to flammability are divided into: fireproof(non-flammable), fire-resistant(low-flammability), combustible(flammable).

Non-combustible materials are those that, when exposed to fire or high temperature, do not ignite, smolder or char (for example, brick, concrete without organic fillers, etc.).

Fireproof structures- These are structures made of fireproof materials.

Refractory materials– these are materials that, when exposed to fire and high temperatures, are difficult to ignite, smolder or char and continue to burn or smolder only in the presence of a fire source. When the source of fire is removed, their combustion or smoldering stops (for example, concrete with organic fillers, wood subjected to deep impregnation fire retardant compounds etc.).

Fire-resistant structures are structures made of fire-resistant materials, as well as a combination of combustible and non-combustible materials.

Combustible materials– these are materials that ignite under the influence of fire or high temperatures and continue to burn or smolder after the ignition source is removed (for example, wood and some other materials).

Combustible structures are structures made of combustible materials and not protected from high temperatures or fire.

Table 6.1.

a) the building does not belong to category A;

b) the total area of ​​premises of categories A and B exceeds 5% of the total area of ​​all premises or 200 m2.

Categories of buildings B, D, D are determined similarly:

b) the total area of ​​premises of categories A, B and C exceeds 5% (10% if the building does not have premises of categories A and B) of the total area of ​​all premises.

It is allowed not to classify a building as category B if the total area of ​​premises of categories A, B and C in the building does not exceed 25% of the total area of ​​all premises located in it (but not more than 3500 m2) and these premises are equipped with automatic fire extinguishing installations.

b) the total area of ​​premises of categories A, B, C and D exceeds 5% of the total area of ​​all premises.

It is allowed not to classify a building as category D if the total area of ​​premises of categories A, B, C and D in the building does not exceed 25% of the total area of ​​all premises located in it (but not more than 5000 m2) and premises of categories A, B and C are equipped automatic fire extinguishing installations.

As a boundary condition for classifying premises as category B, you can use the standards according to which objects with a fire load exceeding 5-10 2 MJ for every 10 m 2 of premises are classified as fire hazardous. In this case, the fire load includes the flammable and slow-burning substances and materials present in the room, except for the enclosing structures, floors and ceilings.

Fire resistance of buildings and structures. Fire resistance means the ability structural elements buildings resist the effects of fire, maintain their load-bearing capacity and strength in fire conditions. Fire resistance building structures in fire conditions it is characterized by a fire resistance limit.

Fire resistance limit- this is the period of time (in hours) during which the structure performs its operational functions in fire conditions . The fire resistance limit is characterized by the presence of one of three characteristics:

1. Formation of through cracks in the structure;

2. An increase in temperature on the unheated surface of the structure opposite to the fire by more than 160 °C on average or by more than 180 °C at any point on this surface compared to the temperature of the structure before testing, or by more than 220 °C regardless from design temperature to testing;

3. Loss by design bearing capacity(collapse, deflection).

Practical methods for increasing the fire resistance of materials and structures are widely used. So, for example, increasing the fire resistance of jelly-concrete structures can be achieved by increasing their cross-section and the thickness of the protective layer; steel structures are faced with special materials; wooden structures can be impregnated with fire retardant compounds, sheathed with roofing iron over felt impregnated with clay, etc.

According to SNiP 2.01.02-85, all buildings and structures according to fire resistance are divided into 8 degrees (Table 6.2). The degree of fire resistance of buildings and structures is determined by the minimum fire resistance limits of the main building structures and the maximum limits of fire propagation through these structures.

The limit of fire spread is taken to be the size of the damaged area of ​​the sample in the plane of the structure from the boundary of the heating zone perpendicular to it to the most distant point of damage (for vertical structures - upward, for horizontal ones - in each direction). Results are rounded to the nearest 1 cm big side. It is allowed to take the limit of fire spread through structures equal to zero if the size of damage to the sample in the control zone does not exceed 5 cm for vertical and 3 cm for horizontal structures. To measure the extent of damage to layered structures, it is necessary to examine all layers by opening them. Damage includes charring and burning of materials, as well as melting of thermoplastic materials.

Table 6.2.

Approximate structural characteristics of buildings

depending on the degree of their fire resistance

As already mentioned, GOST 12.1.004-91* SSBT “Fire safety. General Requirements" provides for determining the probability of exposure to general fire hazards (fire hazards) and comparing it with the standard probability of exposure (assumed equal to):

6.3. Fire safety measures during design

and construction of enterprises

Achieving the required probability of exposure of personnel to a physical activity begins with the correct design or selection industrial building. It is considered correctly designed if, along with solving functional, strength, sanitary and other technical and economic problems, fire safety conditions are ensured. Fire prevention during the design and construction of an industrial enterprise includes solving the following issues:

– increasing the fire resistance of buildings and structures;

– zoning of the territory;

– use of fire breaks;

– use of fire barriers;

– ensuring safe evacuation of people in case of fire;

– ensuring the removal of smoke from the premises in case of fire.

When planning and constructing an enterprise, correct consideration of the explosion and fire hazard of premises and buildings of production facilities is of great importance. All buildings and structures are grouped according to their functional purpose and according to the categories of their explosion and fire hazard. Thus, at mechanical engineering enterprises there are usually 3 zones:

1. Administrative zone;

2. Production area;

3. Warehouse area.

Construction site for an industrial facility, they are chosen taking into account the terrain and, most importantly, the wind rose (the dominant prevailing wind direction of the area). The enterprise is located on the leeward side in relation to the populated area.

On the territory of the enterprise, buildings with increased fire danger are located on the leeward side in relation to other objects. Fire breaks (minimum distances) must be provided between buildings to prevent the possibility of flame spreading from one building to another. These distances are taken depending on the degree of fire resistance of the protected buildings, according to Table. 6.3.

Table 6.3.

Fire gap sizes

When installing an external fire wall, more than tall building facing another building, the fire distances between them are not standardized.

The main part of the plant territory is covered by a ring road, from which direct, unobstructed entrances are arranged to all buildings.

Required condition is the equipment on the territory of the enterprise of a fire-fighting gas pipeline, which can be connected either to the city water supply network, or have independent power from the nearest natural reservoir.

Fire-fighting water supply is provided through a looped pipeline, which makes it possible to provide water supply to the source of the fire in the event of a violation of the integrity of the pipeline on one of the branches. In order to connect fire hoses to the water supply, hydrants are installed along the entire pipeline no more than 120...130 m apart.

Fire-fighting water supply systems are divided into external and internal. External water supply networks are divided into ring and branched (dead-end).

With a ring design, water can circulate through the pipes in all directions. Ring networks are used, as a rule, for fire-fighting water supply to large engineering enterprises, and dead-end networks are used for small enterprises.

The internal fire water supply system provides water supply from the external water supply system to combat local fires in their initial stages. The water pipeline along its entire length has risers with fire hydrants. The water flow from the fire hydrant must be at least 2.3 l/s, and the compact part of the stream must reach the most remote point of the protected room. Fire hydrants are installed at a height of 1.33 m from the floor on all floors indoors or on platforms stairwells, in the lobbies. The taps, along with fire hoses and nozzles, are placed in special lockers marked “PK-N”.

Fire barriers. In a fire, fire spreads throughout a building or structure. To limit the spread of fire from one part of the building to another and reduce the possible burning area, they arrange fire barriers.

Fire barriers include:

– fire walls;

– fire partitions;

– fire resistant floors;

– fire zones;

– airlock vestibules;

– fire doors and windows;

– fire gates, hatches, valves.

The scope of application of fire barriers is established by SNiP 2.01.02-85.

The same regulatory document also fully reflects the requirements for the constructive solution of fire barriers.

Fire zones They are volumetric elements of buildings that divide the building along its entire width (length) and height into fire compartments.

The fire zone of the 1st type is made in the form of an insert with a width of at least 12 m. The insert is a part of the building formed by fire walls of the 2nd type, which separate the insert from the fire compartments.

In one-story buildings of III - V degrees of fire resistance, in which flammable gases and liquids are not used or stored, and there are no processes associated with the formation of combustible dusts, it is allowed to provide fire protection zones of the 2nd type to divide buildings into fire compartments. A type 2 fire zone is a strip of covering and walls at least 6 m wide.

When designing fire zones, it is necessary to exclude the possibility of a fire occurring in them. Therefore, it is not allowed to use or store flammable gases, liquids and materials in the zones, as well as to provide for processes associated with the formation of combustible dusts.

It is allowed to provide openings in fire barriers provided they are filled fire doors, windows, gates, hatches and valves or when installing airlock vestibules in them. The total area of ​​openings in fire barriers should not exceed 25% of their area.

6.4. Organization of fire protection

Organizational matters fire safety. Successful fight against the possibility of fires and their elimination in the event of a fire is ensured by a set of fire prevention measures. These measures should prevent the occurrence of fires, create an obstacle to the spread of fire, ensure the extinguishing of the fire, as well as the evacuation of people and material assets.

The timely implementation of fire prevention measures, both at the design stage and during the operation of the enterprise, is subject to systematic supervision by the State Fire Supervision authorities.

The organization of fire protection is based on the principle of centralizing forces and resources, developing measures for the prevention and elimination of fires and fires on a unified methodological basis. Currently, State fire supervision on the territory of our country is carried out by the Ministry of Civil Defense and Emergency Situations of the Russian Federation through the Main Fire Department (GUPO) and its local authorities. In accordance with the decree “On State Fire Supervision”, it is entrusted with the following three main functions: organizational, control and administrative.

The organizational function allows you to:

– ensure full combat readiness of fire departments;

– ensure the interaction of the work of these parts;

– make full use of their technical equipment to prevent and extinguish fires;

– develop fire safety standards and regulations.

Control functions are aimed at ensuring compliance fire safety standards and rules for the design, construction and operation of industrial enterprises.

Administrative functions make it possible to influence violators of fire safety standards and regulations.

The work of the State Fire Supervision bodies clearly defines the tasks: improving the prevention of fires at national economic facilities, increasing the efficiency of their extinguishing, monitoring the implementation of preventive measures and established fire safety requirements.

Fire supervision solves these problems in close cooperation with other bodies, voluntary fire brigades (teams), with freelance inspectors at government agencies executive power, widely attracting preventive work workers and employees of enterprises, institutions and organizations, as well as the population at their place of residence. To carry out fire supervision means to prevent, identify and, in accordance with the procedure established by law, demand the elimination of violations of fire safety norms and rules.

At an industrial enterprise, responsibility for fire safety (compliance with the necessary fire safety regime and timely implementation of fire-fighting measures) is assigned to the managers of the enterprise, and in individual workshops, laboratories, workshops, etc. - to the heads of these departments.

Enterprise managers are obliged to: ensure complete and timely implementation of fire safety rules and fire safety requirements construction standards for the design, construction and operation of facilities under their jurisdiction; organize a fire department at the enterprise, a voluntary fire brigade (VFD)!? and the fire technical commission (PTK) and manage them; provide the necessary allocations for the maintenance of the fire department, the purchase of fire extinguishing equipment and the financing of fire prevention measures; appoint persons responsible for fire safety of departments and structures of the enterprise. On large enterprises, in enterprises with an increased fire hazard of technological processes or significantly remote from city fire brigades, professional departmental fire brigades are created. At other enterprises, a fire watch service is organized.

Enterprise managers have the right to impose disciplinary action against violators of fire safety rules and requirements, raise the issue of bringing those responsible for violating these rules to justice.

When entering work, all workers undergo introductory and initial (at the workplace) briefing on fire safety measures according to an approved program with appropriate registration. At facilities with increased fire danger, classes on fire safety standards are conducted. Repeated briefings must be conducted at least once a year.

For each enterprise (division of the enterprise), on the basis of the “Fire Safety Rules”, PPB-01-93, general facility and workshop fire safety instructions are developed.

Fire communication and alarm. Fire communications and alarms are widely used for quick notification of a fire that has occurred in a particular production area. Fire communication and alarm devices have a significant impact on the successful extinguishing of fires.

Fire communications and alarms are a set of devices that allow you to quickly receive a message about a fire and promptly issue the necessary orders to extinguish it.

According to its purpose, fire department communications are divided into notification communications, dispatch communications and fire communications.

Technical means of security and security and fire alarm system, intended for obtaining information about the state of controlled parameters at a protected facility, receiving, converting, transmitting, storing, displaying this information in the form of acoustic or light signals, in accordance with GOST 25829-78 are classified by scope and functional purpose.

By area of ​​application technical means Alarms are divided into security, fire and security-fire; by functional purpose - on technical means of detection (detectors), designed to obtain information about the state of monitored parameters, and technical means of warning, intended for receiving, converting, transmitting, storing, processing and displaying information (SPI, PPK and annunciators). According to the principle of operation, fire detectors are divided into manual and automatic detectors. Automatic fire detectors can be thermal, responsive to rising temperatures; smoke, reacting to the appearance of smoke (aerosol combustion products); There are also flame detectors that respond to optical radiation from an open flame.

Evacuation of people. When designing and constructing industrial enterprises, it is necessary to provide emergency exits and escape routes for people. This allows for organized movement of people. Rescue of people during a fire or other emergencies depends on how correctly evacuation routes are selected and arranged. Escape routes ensure the removal of people from the building in which an accident or fire has occurred or may occur. When constructing escape routes for people, it is necessary to be guided by SNiP 2.01.02-85 and SNiP 2.09.02-85.

Escape routes must satisfy 3 conditions:

1) the shortest distance to the exit outside;

2) minimum time to leave the building;

3) safety of people's movement.

Evacuation exits include exits that lead from the premises:

1. From the first floor to the outside directly or through the corridor, lobby, landing;

2. Any floor, except the first, into a corridor leading to a staircase that has independent access to the outside or through a lobby separated from adjacent corridors by partitions with doors;

3. To an adjacent room on the same floor, provided with emergency exits in accordance with clause l and clause 2.

Evacuation exits are not allowed to be provided through premises of categories A and B and airlocks attached to them, as well as through industrial premises in buildings IIIb, IV, IVa, and V degrees of fire resistance. It is proposed to provide one emergency exit through premises of categories A and B from premises on the same floor in which engineering equipment for servicing these premises is located and in which permanent presence of people is excluded, if the distance from the most remote point of the premises to the evacuation exit from it does not exceed 25 meters.

As a rule, at least 2 emergency exits are provided. Emergency exits are located dispersedly. The minimum distance between the most distant emergency exits from the premises should be determined by the formula:

where is the perimeter of the room,

The distance from the most remote workplace to the nearest emergency exit from the premises to the outside or into the staircase should be taken according to the table. 6.4.

The width of doors, corridors or passages on escape routes should be taken at the rate of 0.6 m per 100 people.

The minimum width of escape routes must be at least 1 m. The minimum width of flights of stairs must be 2.4 m. The minimum width of doors on escape routes must be 0.8 m. Emergency exit doors must open outward in the direction of people. The height of the doors to the light should be at least 2 m.

How to determine the degree of fire resistance of a building, on what factors does the fire resistance limit depend? Any architect or owner should know the answers to these questions. Thanks to this knowledge, it is possible to easily develop a fire escape route, the position of emergency exits, etc. But nowadays there are many architectural solutions for the construction of buildings of the same type, so determining the fire resistance of each can cause some difficulties.

What is the fire resistance of a building and why is it determined?

Buildings with a capacity of more than 100 seats and a height of 3 m must have C1 fire safety and III degree of fire resistance of the building. How to determine the number of seats? This indicator depends on the population of the area. According to SNiP, the number of places in nurseries is allowed to increase to 120 per 1000 residents of the region, on average 60-90.
Gardens with a capacity of more than 150 seats must have fire resistance class II and fire safety class C1. At a height of at least 6 m.

Children's institutions with more than 350 children's places and a height of 9 m have level II or I of resistance and C0 or C1 safety.

Determining the resilience of a community hospital

It is already known how to determine the degree of fire resistance of a building, if it is a school or kindergarten, and what to do with hospitals? They have their own rules and regulations.
U public buildings of this type, the maximum permissible height is 18 m, and the degree of fire resistance should be I or II, and safety C0.
At a height of up to 10 m, fire resistance is reduced to II, and structural safety to C1.

If the height of the building is 5 meters or less, then the degree of fire resistance can be III, IV or V, and the level of structural safety, respectively, is C1, C1-C2, C1-C3.
There is nothing more difficult in studying the topic “The degree of fire resistance of a building”, how to determine the RB (district hospital) safety level.

Conclusion

It is actually not that difficult to determine the fire resistance rating of a building. Difficulties only arise when practical stage, however, this is less than half and even less than a third general work. After studying the architectural plan, the condition of the building as a whole and the condition of the supporting structures, the tester has already done most of the work!

1.1. Buildings, structures, as well as parts of buildings and structures, separated by fire walls of the 1st type (fire compartments), are divided according to degrees of fire resistance. The degree of fire resistance of buildings is determined by the minimum fire resistance limits of building structures and the maximum limits of fire propagation through these structures.

The fire resistance limits of self-supporting walls, which take into account the rigidity and stability of buildings when calculating, must be taken according to gr. 2 tables 10.1.

In cases where in the table. 10.1. The minimum fire resistance limit of structures is 0.25 hours; it is allowed to use unprotected steel structures, and in hard-to-reach construction areas, in addition, external enclosing structures made of aluminum sheets, regardless of their fire resistance limit.

In buildings of the 2nd degree of fire resistance for industrial and warehouse purposes, it is allowed to use columns with a fire resistance limit of 0.75 hours.

It is allowed in buildings of all degrees of fire resistance to use plasterboard sheets in accordance with GOST 6266 - 89 for cladding metal structures in order to increase their fire resistance limit.

In buildings of all degrees of fire resistance, partitions (glazed or with mesh with a blind part height of no more than 1.2 m, collapsible and sliding) with non-standardized fire resistance limits and fire spread limits are allowed to be used to separate workplaces within the premises.

1.2. The degree of fire resistance of buildings is adopted in the project depending on their purpose, category of explosion and fire hazard, number of floors, floor area within the fire compartment, except for cases established in regulatory documents.

Approximate structural characteristics of buildings depending on their degree of fire resistance are given in Table. 10.1.

Table 10.1. Fire resistance limits of building structures

Table 10.2. Approximate structural characteristics of buildings depending on their degree of fire resistance.

When constructing important facilities, it is necessary to approach the choice of materials and technologies with great responsibility. One of 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 influence the limit of this property? Only a specialist can answer these questions. It is thanks to the knowledge acquired during higher education educational institution, you can think through evacuation routes in advance, correctly position fire exits and do everything possible so that during a fire the building and all its inhabitants are not harmed.

Currently there are many the latest solutions, used in architecture. That is why determining the fire resistance of buildings and structures causes some difficulties.

Safety in case of fire, the conditions for the spread of flame in them directly depend on the flammability and ability to resist fire of the materials that were used during construction and finishing. These qualities for building components are established during the design of the facility. Much depends on the fire and explosion hazard category of the premises located in a particular building. But first things first, so that you can high accuracy determine the degree of fire resistance of any structures.

What is meant by fire resistance rating?

Before answering the question of how to determine the degree of fire resistance, you need to understand what it actually is. 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 general position, which makes it possible to accurately assess and establish the level of safety of a building for any purpose, as well as the materials from which it was built.

The fire resistance value 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 their 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 industrial building), Must have:

• architectural plan;
• rules for ensuring the durability and safety of reinforced concrete structures from fire;
• a manual that allows you to determine the limits for these parameters of structures to SNiP;
• a guide to SNiP - helping to prevent the spread of a fire.

The durability limit of any construction project is determined by the time of exposure to fire on the tested structure. When the state reaches one of the limits, fire artificially stop. Before you begin testing, you must carefully study the construction documents. This includes what building materials were used, the characteristics of the building, possible estimates of fire resistance and other points.

It is necessary to more carefully study the presence or absence of application information in the documentation for the structure modern technologies, which could help improve fire resistance levels. During the period of preliminary consideration of the structure's design, all premises should be examined, including utility rooms, stairwells and others. It is possible that completely different materials were used during their construction. After all, builders often, in order to reduce the amount of the estimate, save 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 fire.

When constructing 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 so that in the event of a fire you can quickly deal with the fire:

• hire a fire brigade;
• Check the serviceability of hoses and fire extinguishers.
• equip a fire shield.

Only after all safety standards have been fully complied with can you begin work. After preparatory activities You can move on to practical ones.

What is SNiP?

Often answering the question of how to determine the degree of fire resistance of a building, one has to come across such a definition as SNIP. But what is it?

"Building norms and rules" is a collection of legislative documents that were previously approved by the authorities of the Russian Federation and regulate the rules for the construction of urban and rural buildings. In addition, such a document includes projects developed by architects and engineering studies.

After carefully studying such paper, any owner will be able to independently understand all the drawings and determine the condition 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 precisely why special documentation is required.

But how to determine SNiP for a specific building using reference manuals and a passport for the building? In this case, experienced specialists 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, you need 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 levels of fire resistance of buildings?

As we said earlier, there are 5 degrees of fire resistance, and they depend on the degree of fire and the resistance limit of the main structures. Below is a table of fire resistance of buildings and structures.

Types of fire hazards of building structures

All construction projects must meet the requirements fire safety. Determines the degree of fire resistance of a building under Federal Law 123, which specifies all the requirements and criteria. Today there are 4 classes of fire hazard for construction projects:

• K0 - not fire hazardous.
• K1 - low fire hazard.
• K2 - moderately fire hazardous.
• K3 - fire hazard.

When determining the fire resistance of buildings, it is necessary to take into account:

• number of floors;
• functional fire hazard;
• area of ​​the building and fire compartment;
• fire hazard of processes taking place inside the building;
• building category;
• distance to the nearest buildings.

When all these factors are taken into account, determining fire resistance will not be difficult.

Objectives and scope of application of technical regulations

As mentioned earlier, it is impossible to determine the resistance of any structure in relation to fire without Federal Law 123, but in addition, it is necessary to take into account SP 2 13130 ​​2012. The degree of fire resistance of buildings should be determined by:

• design, construction, overhaul, during reconstruction, changes in functionality;
• development, adoption and implementation of Federal Laws on technical regulations, which include fire safety requirements;
• at the stage of developing documentation for protected objects.

If all these requirements are met, in the event of a fire you will not have to find out where the mistake was made.

Instructions for determining the fire resistance limit

Those who are about to start construction ask themselves one of critical issues: "How to determine the degree of fire resistance of buildings?" Using our instructions, anyone can complete this task. Even during registration project documentation the calculated indicator for each parameter is indicated. But it’s better to check and compare all the data yourself, guided by SNiP. The limit for this property can be considered the time that passes from the beginning of the effect of fire on the structure until critical changes occur. General indicator determined by maximum resistance values. In this case, this must be taken into account for all elements: partitions, vertical design, which are load-bearing, doors, windows and others.

It is worth including information about the ignition level of building materials into the calculation.

Analyze the entire building project in detail. Information about the main elements used in construction may not be enough to obtain more realistic data. Therefore, it is better to review everything and check it personally, examining each area, including utility rooms and stairwells. To study this entire mechanism in detail and carry out calculations correctly, you need to use the manuals for SNiP.

How can you improve the fire resistance of a building?

So that load-bearing supports can withstand a fire, and everyone who is in the building at that time can escape, there are several methods for increasing fire resistance. First of all, it is worth choosing the right materials that have been certified and fully comply with fire safety standards. Fortunately, there are currently plenty of such raw materials 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 there is a huge variety quality materials European and domestic manufacturers, with the help of which fire protection can be carried out.

How to carry out high-quality fire protection?

The best protection against fire is concreting and brick finishing. Another one important function- This is a strengthening of the structure. 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, slabs and screens is used to protect columns, beams, and posts. It is also good to use plaster.

The finishing is good because it provides reliable protection from fire, but it is also inexpensive. But it also has its drawbacks. Cladding requires special skills, and the thickness of the layer must be selected correctly.

Finally

It is not at all difficult to determine the fire resistance level of buildings 3 or 5. Difficulties, of course, may arise. But if you have all the necessary documents and a set of rules at hand, then the difficulties will quickly be resolved. After studying the plan and the condition of all building structures, determining fire resistance can be expensive, but not that difficult. The main thing is to adhere to safety precautions during testing, be careful and attentive, and 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 they are constructed residential buildings, offices and important institutions complied with the standards. The lives of citizens depend on it. It is no secret that many accidents occur as a result of the use of inappropriate materials and violations of construction techniques.