Building materials are divided according to flammability. Building materials, their properties and changes in fire
I. Classification building materials By fire danger
Building materials are characterized only by fire hazard.
The fire hazard of building materials is determined by the following fire-technical characteristics: flammability, flammability, flame spread over the surface, smoke generating ability and toxicity.
Building materials are divided into non-combustible (NG) and combustible (G). Combustible building materials are divided into four groups:
P (low flammability);
G2 (moderately flammable);
GZ (normally flammable);
G4 (highly flammable).
For non-combustible building materials, other fire hazard indicators are not determined or standardized.
Combustible building materials are divided into three groups based on flammability:
81 (flammable);
82 (moderately flammable);
83 (highly flammable).
Combustible building materials are divided into four groups according to the spread of flame over the surface:
RP1 (non-proliferating);
RP2 (low-propagating);
RPD (moderately spreading);
RP4 (highly spreading).
For other building materials, the group of flame propagation over the surface is not determined and not standardized.
Combustible building materials are divided into three groups according to their smoke-generating ability:
D1 (with low smoke-generating ability);
D2 (with moderate smoke-generating ability);
DZ (with high smoke-generating ability).
Combustible building materials are divided into four groups based on the toxicity of combustion products:
T1 (low hazard);
T2 (moderately dangerous);
TK (highly hazardous);
T4 (extremely dangerous).
II. Classification of building materials by degree of fire resistance
BUILDING CONSTRUCTION
Building structures are characterized by fire resistance and fire hazard.
An indicator of fire resistance is the fire resistance limit. The fire hazard of a structure is characterized by its class.
Fire resistance limit building structures is established by the time (in minutes) of the onset of one or sequentially several, normalized for a given design, signs of limit states:
- loss of bearing capacity (R);
- loss of integrity (E);
- loss of thermal insulation ability (I).
Based on fire hazard, building structures are divided into four classes:
KO (non-fire hazardous);
K1 (low fire hazard);
K2 (moderate fire hazard);
Short circuit (fire hazardous).
BUILDINGS, FIRE COMPARTMENTS, PREMISES
Buildings, as well as parts of buildings separated by fire walls - fire compartments (hereinafter referred to as buildings) - are divided according to degrees of fire resistance, structural and functional fire hazard classes.
The degree of fire resistance of a building is determined by the fire resistance of its building structures
The class of structural fire hazard of a building is determined by the degree of participation of building structures in the development of a fire and the formation of its hazardous factors.
The functional fire hazard class of a building and its parts is determined by their purpose and the characteristics of the technological processes located in them.
Buildings and fire compartments are divided according to degrees of fire resistance according to the table.
The load-bearing elements of a building include structures that ensure its overall stability and geometric immutability in case of fire - load-bearing walls, frames, columns, beams, crossbars, trusses, arches, braces, stiffening diaphragms, etc.
Fire resistance limits for filling openings (doors, gates, windows and hatches) are not standardized, except for specially specified cases and filling openings in fire barriers.
In cases where the minimum fire resistance limit of the structure is specified as R15 (R 15, REI15), it is allowed to use unprotected steel structures regardless of their actual fire resistance limit, unless the fire resistance limit load-bearing elements building according to test results is less than R 8
The classification of building materials by fire hazard is based on their properties and ability to form fire hazards.
The fire hazard of building materials is characterized by the following properties:
1. flammability;
2. flammability;
3. ability to spread flame over a surface;
4. smoke generating ability;
5. toxicity of combustion products.
Based on flammability, building materials are divided into combustible (G) and non-combustible (NG).
Construction materials are non-combustible when following values flammability parameters determined experimentally: temperature increase - no more than 50 degrees Celsius, sample weight loss - no more than 50 percent, duration of stable flame combustion - no more than 10 seconds.
Construction materials that do not satisfy at least one of the parameter values specified in Part 4 of this article are classified as flammable. Combustible building materials are divided into the following groups:
1. low-flammable (G1), having a temperature flue gases not more than 135 degrees Celsius, the degree of damage along the length of the test sample is not more than 65 percent, the degree of damage by weight of the test sample is not more than 20 percent, the duration of independent combustion is 0 seconds;
2. moderately flammable (G2), having a flue gas temperature of no more than 235 degrees Celsius, the degree of damage along the length of the test sample is no more than 85 percent, the degree of damage along the mass of the test sample is no more than 50 percent, the duration of independent combustion is no more than 30 seconds;
3. normal-flammable (G3), having a flue gas temperature of no more than 450 degrees Celsius, the degree of damage along the length of the test sample is more than 85 percent, the degree of damage along the mass of the test sample is not more than 50 percent, the duration of independent combustion is no more than 300 seconds;
4. highly flammable (G4), having a flue gas temperature of more than 450 degrees Celsius, a degree of damage along the length of the test sample of more than 85 percent, a degree of damage along the mass of the test sample of more than 50 percent, and a duration of independent combustion of more than 300 seconds.
5. For materials belonging to flammability groups G1 - G3, the formation of burning melt drops during testing is not allowed (for materials belonging to flammability groups G1 and G2, the formation of melt drops is not allowed). For non-combustible building materials, other fire hazard indicators are not determined or standardized.
6. In terms of flammability, combustible building materials (including flooring carpets) depending on the value of the critical surface density heat flow are divided into the following groups:
· hardly flammable (B1), having a critical surface heat flux density of more than 35 kilowatts per square meter;
· moderately flammable (B2), having a critical surface heat flux density of at least 20, but not more than 35 kilowatts per square meter;
· flammable (B3), having a critical surface heat flux density of less than 20 kilowatts per square meter.
7. According to the speed of flame spread over the surface, combustible building materials (including floor carpets), depending on the value of the critical surface heat flux density, are divided into the following groups:
· non-propagating (RP1), having a critical surface heat flux density of more than 11 kilowatts per square meter;
· weakly propagating (RP2), having a critical surface heat flux density of at least 8, but not more than 11 kilowatts per square meter;
· moderately spreading (RP3), having a critical surface heat flux density of at least 5, but not more than 8 kilowatts per square meter;
· highly propagating (RP4), having a critical surface heat flux density of less than 5 kilowatts per square meter.
8. According to their smoke-generating ability, combustible building materials, depending on the value of the smoke generation coefficient, are divided into the following groups:
· with low smoke-forming ability (D1), having a smoke-formation coefficient of less than 50 square meters per kilogram;
· with moderate smoke-generating ability (D2), having a smoke generation coefficient of at least 50, but not more than 500 square meters per kilogram;
· with high smoke-generating ability (D3), having a smoke generation coefficient of more than 500 square meters per kilogram.
9. Based on the toxicity of combustion products, combustible building materials are divided into the following groups:
· low-hazard (T1);
Flammability group materials are determined according to GOST 30244-94 "Building materials. Combustibility test methods", which corresponds to the International Standard ISO 1182-80 "Fire tests - Building materials - Non-combastibility test". Materials, depending on the values of flammability parameters determined according to this GOST, are divided into non-flammable (NG) and flammable (G).
Materials include to non-flammable at the following values of flammability parameters:
- temperature increase in the furnace is no more than 50°C;
- sample weight loss no more than 50%;
- Duration of stable flame combustion is no more than 10 seconds.
Materials that do not satisfy at least one of the specified parameter values are classified as flammable.
Depending on the values of flammability parameters, combustible materials are divided into four flammability groups in accordance with Table 1.
Table 1. Flammability groups of materials.
Material flammability group determined according to GOST 30402-96 "Building materials. Flammability test method", which corresponds to the international standard ISO 5657-86.
In this test, the surface of the sample is exposed to radiant heat flux and flame from an ignition source. In this case, the surface heat flux density (SHFD) is measured, that is, the amount of radiant heat flux affecting a unit surface area of the sample. Ultimately, the Critical Surface Heat Flux Density (CSHDD) is determined - the minimum value of the surface heat flux density (HSHDD) at which stable flaming combustion of the sample occurs after exposure to a flame.
Depending on the KPPTP values, materials are divided into three flammability groups indicated in Table 2.
Table 2. Flammability groups of materials.
To classify materials according to smoke generation abilities use the value of the smoke generation coefficient, which is determined according to GOST 12.1.044.
Smoke generation coefficient is an indicator characterizing the optical density of smoke generated during flaming combustion or thermal-oxidative destruction (smoldering) of a certain amount solid(material) under special test conditions.
Depending on the relative smoke density, materials are divided into three groups:
D1- with low smoke-generating ability - smoke generation coefficient up to 50 m²/kg inclusive;
D 2- with moderate smoke-generating ability - smoke generation coefficient from 50 to 500 m²/kg inclusive;
D3- with high smoke-forming ability - smoke generation coefficient over 500 m²/kg.
Toxicity Group combustion products of building materials are determined according to GOST 12.1.044. The combustion products of a material sample are sent to a special chamber where experimental animals (mice) are located. Depending on the condition of the experimental animals after exposure to combustion products (including death), the materials are divided into four groups:
T1- little dangerous;
T2- moderately dangerous;
T3- highly dangerous;
T4- extremely dangerous.
Purpose of classification substances and materials on fire and explosion hazards and fire hazards (Chapter 3, Article 10-13 of Federal Law No. 123):
1. Classification of substances and materials by fire and explosion hazard and fire hazard is used to establish requirements fire safety when receiving substances and materials, application, storage, transportation, processing and disposal.
2. To establish fire safety requirements for the design of buildings, structures and systems fire protection classification of building materials according to fire hazard is used.
Classification of building materials by fire hazard (Article 13 of Federal Law No. 123).
1. Classification of building materials by fire hazard is based on their properties and ability to form fire hazards given in Table 1 of the Appendix to Federal Law No. 123.
2. Fire danger of construction
materials are characterized by the following properties
:
1) flammability;
2) flammability;
3) the ability to spread flame over the surface;
4) smoke generating ability;
5) toxicity of combustion products.
3. By flammability of building materials are divided into: flammable (G) and non-flammable (NG).
Construction materials include to non-flammable at the following values of flammability parameters, determined experimentally: temperature increase - no more than 50 degrees Celsius, sample weight loss - no more than 50 percent, duration of stable flame combustion - no more than 10 seconds.
Construction materials that do not satisfy at least one of the above parameter values are classified as to combustibles.
Combustible building materials are divided into the following groups:
1) low flammable (G1), having a flue gas temperature of no more than 135 degrees Celsius, the degree of damage along the length of the test sample is not more than 65 percent, the degree of damage along the mass of the test sample is not more than 20 percent, the duration of independent combustion is 0 seconds;
2) moderately flammable (G2), having a flue gas temperature of no more than 235 degrees Celsius, the degree of damage along the length of the test sample is not more than 85 percent, the degree of damage by weight of the test sample is not more than 50 percent, the duration of independent combustion is no more than 30 seconds;
3) normally flammable (GZ) , having a flue gas temperature of no more than 450 degrees Celsius, the degree of damage along the length of the test sample is more than 85 percent, the degree of damage along the mass of the test sample is not more than 50 percent, the duration of independent combustion is no more than 300 seconds;
4) highly flammable (G4 ), having a flue gas temperature of more than 450 degrees Celsius, the degree of damage along the length of the test sample is more than 85 percent, the degree of damage along the mass of the test sample is more than 50 percent, and the duration of independent combustion is more than 300 seconds.
For materials belonging to flammability groups G1-GZ, the formation of burning melt drops during testing is not allowed (for materials belonging to flammability groups G1 and G2, the formation of melt drops is not allowed). For non-combustible building materials, other fire hazard indicators are not determined or standardized.
By flammability of combustible building materials (including floor carpets) depending on the value of the critical surface heat flux density are divided into the following groups:
1) flame retardant (IN 1 ), having a critical surface heat flux density of more than 35 kilowatts per square meter;
2) moderately flammable (AT 2), having a critical surface heat flux density of at least 20, but not more than 35 kilowatts per square meter;
3) highly flammable (VZ), having a critical surface heat flux density of less than 20 kilowatts per square meter.
By the speed of flame spread over the surface combustible building materials (including floor carpets), depending on the value of the critical surface heat flux density, are divided into the following groups:
1) non-proliferating ( RP1 ), having a critical surface heat flux density of more than 11 kilowatts per square meter;
2) low-spreading (RP2 ), having a critical surface heat flux density of at least 8, but not more than 11 kilowatts per square meter;
3) moderate spreading ( RPZ ) having a critical surface heat flux density of at least 5, but not more than 8 kilowatts per square meter;
4) highly spreading (RP4 ), having a critical surface heat flux density of less than 5 kilowatts per square meter.
According to the smoke-forming ability of combustible building materials Depending on the value of the smoke generation coefficient, they are divided into the following groups:
1) with low smoke-generating ability (D1 ), having a smoke generation coefficient of less than 50 square meters per kilogram;
2) with moderate smoke-generating ability (D 2
),
having a smoke generation coefficient of at least 50, but not more than 500 square meters per kilogram;
3) with high smoke-generating ability (DZ),
having a smoke generation coefficient of more than 500 square meters per kilogram.
According to the toxicity of combustion products, combustible building materials are divided into the following groups in accordance with Table 2 of the Appendix to Federal Law No. 123:
1) low-hazard (T1);
2) moderately dangerous ( T2);
3) highly dangerous ( TK);
4) extremely dangerous (T4).
Table 2. Classification of combustible building materials according to the toxicity index of combustion products (Appendix to Federal Law No. 123)
The fire hazard classes of building materials, depending on the fire hazard groups of building materials, are given in Table. 3 appendices to Federal Law No. 123.
Table 3. Fire hazard classes of building materials (Appendix to Federal Law No. 123)
(Table as amended, put into effect on July 12, 2012 by Federal Law of July 10, 2012 N 117-FZ.
Note. The list of fire hazard indicators for building materials sufficient to assign fire hazard classes KM0-KM5 is determined in accordance with Table 27 of the Appendix to Federal Law No. 123.
Table 27 List of indicators required to assess the fire hazard of building materials (Table as amended by Federal Law No. 123, entered into force on July 12, 2012 from July 10, 2012 N 117-FZ)
| Purpose of building materials | Scroll necessary indicators depending on the purpose of building materials | |||||||||
| flammability group | flame propagation group | flammability group | smoke generation group | Combustion Products Toxicity Group | ||||||
| Materials for finishing walls and ceilings, including coatings made of paints, enamels, varnishes | + | - | + | + | + | |||||
| Flooring materials, including carpets | - | + | + | + | + | |||||
| Roofing materials | + | + | + | - | - | |||||
| Waterproofing and vapor barrier materials more than 0.2 mm thick | + | - | + | - | - | |||||
| Thermal insulation materials | + | - | + | + | + | |||||
Notes:
1. The "+" sign indicates that the indicator must be applied.
2. The sign "-" indicates that the indicator is not applicable.3. When using waterproofing materials for the surface layer of the roof, their fire hazard indicators should be determined according to the position “Roofing materials”.
To classify building materials should be used flame propagation index value (I)- a conditional dimensionless indicator characterizing the ability of materials or substances to ignite, spread flame over the surface and generate heat.
By flame spread materials are divided into the following groups:
1) not spreading flame over the surface, having a flame propagation index of 0;
2) slowly spreading flame over the surface, having a flame spread index of no more than 20;
3) quickly spreading flame over the surface, having a flame spread index of more than 20.
Test methods for determining fire hazard classification indicators for building, textile and leather materials are established regulatory documents on fire safety.
Ensuring fire safety is one of the key tasks in the construction and operation of modern high-rise buildings, large business centers and shopping and entertainment complexes. The specificity of such buildings - the large length of evacuation routes - dictates increased requirements for fire safety of the building structures and materials used. And only when these requirements are met along with the solution of other technical and economic problems, the building is considered to be designed correctly.
According to Federal Law Russian Federation dated July 22, 2008 No. 123-FZ “Technical Regulations on Fire Safety Requirements”, the choice of building materials directly depends on the functional purpose of the building or premises.
Classification of building materials often carried out based on the application of the product. According to this criterion, it is divided into structural, insulating and finishing solutions, as well as structural-insulating and structural-finishing solutions.
From point of view fire safety the optimal classification is suggested in Article 13 " Technical regulations", which divides building materials into two types: flammable And non-flammable. In turn, combustible materials are divided into 4 groups - slightly flammable (G1), moderately flammable (G2), normally flammable (G3) and, finally, highly flammable (G4).
In addition, they are assessed according to criteria such as flammability, ability to spread flame on the surface, smoke generating ability And toxicity. The combination of these indicators allows us to assign a fire hazard class to a specific material: from KM0 - for non-combustible materials to KM1-KM5 - for flammable materials.
Natural properties of materials
The key factor determining the fire hazard of building materials is raw materials, from which they are made. Depending on this, they can be divided into three large groups: inorganic, organic And mixed. Let's take a closer look at the properties of each of them. Let's start with mineral materials, which belong to the group of inorganic and, along with metal structures, serve to create a rigid frame - the basis modern buildings.
Most common mineral building materials- This natural stone, concrete, brick, ceramics, asbestos cement, glass, etc. They are classified as non-flammable (NG), but even with a small addition of polymer or organic substances - no more than 5-10% by weight - their properties change. The fire danger increases, and from NG they move into the category of difficult to burn.
IN last years products based on polymers, belonging to inorganic materials and being flammable. At the same time, depending on the volume and chemical structure polymer depends on whether a particular material belongs to the flammability group. There are two main types of polymer compounds. These are thermosets that, when heated, form a coke layer, which consists of non-flammable substances and protects the material from exposure high temperatures, preventing combustion. Another type is thermoplastics (melt without creating a heat-protective layer).
Regardless of the type, polymer building materials cannot be classified as non-flammable, but it is possible to reduce their fire hazard. For this purpose flame retardants are used - various substances, which contribute to increased fire resistance. Fire retardants for polymer materials can be divided into three large groups.
The first includes substances that carry out chemical interaction with polymer. These flame retardants are used primarily for thermosets, without deteriorating their physical and chemical properties. The second group of fire retardants - intumescent additives– under the influence of a flame, it forms a foamed cellular coke layer on the surface of the material, which prevents combustion. And finally, the third group are substances that mechanically mixed with polymer. They are used to reduce the flammability of both thermoplastics, thermosets and elastomers.
Of all organic materials, wood and products made from it are most widely used in the construction of modern buildings. particle boards (chipboard), fibreboards(Fibreboard), plywood etc. All organic materials belong to the group of flammable materials, and their fire hazard increases with the addition of various polymers. For example, paints and varnishes not only increase flammability, but also contribute to faster spread of flame over the surface, increase smoke formation and toxicity. In this case, other toxic substances are added to CO (carbon monoxide), the main combustion product of organic materials.
To reduce the fire hazard of organic building materials, as in the case of polymeric substances, they are treated flame retardants. When applied to a surface, when exposed to high temperatures, fire retardants can turn into foam or release non-flammable gas. In both cases, they impede the access of oxygen, preventing the wood from igniting and the spread of flame. Effective flame retardants are substances containing diammonium phosphate, as well as a mixture of sodium phosphate and ammonium sulfate.
Concerning mixed materials, they consist of organic and inorganic raw materials. As a rule, construction products of this type are not allocated to a separate category, but belong to one of the previous groups, depending on which raw materials predominate. Eg, fiberboard, consisting of wood fibers and cement, is considered organic, and bitumen– inorganic. More often mixed type belongs to the group of flammable products.
Increased fire safety requirements for large shopping, entertainment and office centers, as well as high-rise buildings, dictate the need to develop a complex fire prevention measures. One of the most important is the predominant use non-flammable And low-flammable building materials. This especially applies to the load-bearing and enclosing structures of the building, roofing, as well as materials for finishing evacuation routes.
According to the NPB 244-97 classification, finishing, cladding, roofing, waterproofing and thermal insulation materials, as well as floor coverings are subject to mandatory certification in the field of fire safety. Let's consider these categories for fire hazard.
Finishing and facing materials
There are many finishing and facing materials, among which we can highlight polystyrene tiles, PVC and chipboard panels, wallpaper, films, ceramic tiles, fiberglass, etc. Most products of this type are flammable. In rooms with large crowds of people, as well as in buildings where evacuation is difficult due to the large area and number of floors, finishing materials can create an additional threat to the life and health of people, causing smoke, releasing toxic combustion products and facilitating the rapid spread of flames. Therefore, it is necessary to select materials not lower than KM2 class.
Depending on the surface on which they are applied, finishing materials may have various properties. For example, in combination with flammable substances regular wallpaper can manifest themselves as flammable, and applied to a non-flammable base - as low flammable. Therefore, when choosing finishing and facing materials, you should be guided not only by data on their fire hazard, but also by the properties of the bases.
For finishing rooms with large crowds of people and escape routes, the use of organic products is unacceptable, in particular MDF panels, which most often belong to groups G3 and G4. For finishing walls and ceilings in trading floors materials with a higher fire hazard than class KM2 cannot be used.
Wallpaper on paper based are not included in the list of products subject to mandatory certification, and they can be used as finishing material for premises with increased fire safety requirements, taking into account that the base will be non-flammable.
Used as a replacement for MDF panels drywall with an outer coating of decorative film. Thanks to gypsum base plasterboard is a non-flammable material, and polymer-based decorative film transfers it to group G1, which allows it to be used for finishing premises of almost any functional purpose, including lobbies. Today, plasterboard is widely used for the construction of partitions - independent building structures. This must be taken into account when determining their fire hazard class.
Floor coverings
TO flammability of floor coverings less stringent requirements are imposed than for finishing and facing materials. The reason is that during a fire, the floor is in the lowest temperature zone compared to the walls and ceiling. At the same time, for materials serving as flooring, an important role is played by such an indicator as flame spread over the surface(RP).
Thanks to ease of installation and high performance characteristics wide application as floor coverings in corridors, lobbies, halls and foyers of buildings received linoleums– various types of roll polymer coatings. Almost all materials of this type belong to the highly flammable group (G4) and have a high smoke generation coefficient. Already at a temperature of 300°C they support combustion, and when heated above 450–600°C they ignite. In addition, the combustion products of linoleum include toxic substances - carbon dioxide, CO and hydrogen chloride.
Therefore, it is unacceptable to use them as flooring for corridors and halls, where, according to the requirements, materials no lower than KM3 must be used, not to mention lobbies and staircases, for which more stringent requirements apply. The same can be said about laminate, which consists of organic and polymeric materials and, regardless of the type, is highly flammable - unsuitable for escape routes.
The most favorable, from a fire safety point of view, are ceramic tile And porcelain stoneware. They belong to the KM0 group and are not included in the list of materials subject to fire safety certification. Such products are suitable for premises of any functional purpose. In addition, semi-rigid tiles made of polyvinyl chloride with a large amount of mineral filler (KM1 group) can be used as flooring in corridors and halls.
Roofing and waterproofing materials
Usually fire hazard of roofing materials indicated in the certificates as a flammability group. Least danger The difference is between metal and clay roofs, and the greatest differences are in materials based on bitumen, rubber, rubber-bitumen products and thermoplastic polymers. Although they are the ones who give roofing materials high performance characteristics– water and vapor impermeability, frost resistance, elasticity, resistance to negative atmospheric influences and the formation of cracks.
Some of the most fire hazardous are roofing and waterproofing materials, which include bitumens. They spontaneously ignite at temperatures of 230–300°C. In addition, bitumen has a high smoke-generating ability and burning rate.
Bitumen is widely used in the production of rolled (roofing felt, glassine, glass roofing felt, isol, hydroizol, folgoizol) and mastic roofing and waterproofing materials. Almost everything roofing materials based on bitumen belong to group G4. This imposes restrictions on their use in buildings with increased fire safety requirements. So, they should fit on non-combustible base. In addition, it is carried out on top gravel backfill, and also fire-prevention cuts are arranged, dividing the roof of the building into separate segments. This is necessary in order to localize the fire and prevent the spread of the fire.
Today, there are dozens of types of waterproofing materials on the market - polyethylene, polypropylene, polyvinyl chloride, polyamide, thiokol and other membranes. Regardless of the type, they all belong to the flammable group. The most favorable, from a fire safety point of view, are waterproofing membranes, belonging to the flammability group G2. As a rule, these are materials based on polyvinyl chloride with the addition of fire retardants.
Thermal insulation materials
Thermal insulation materials, subject to certification in the field of fire safety, can be divided into five groups. The first one is expanded polystyrene. Due to their relatively low cost, they are widely used in modern construction. Along with good thermal insulation properties, these products have a number of serious disadvantages, including fragility, insufficient moisture resistance and vapor permeability, low resistance to ultraviolet rays and hydrocarbon liquids, and most importantly - high flammability and release of toxic substances during combustion.
One of the varieties of expanded polystyrene is extruded polystyrene foam. It has a more ordered structure of small closed pores. This production technology increases the moisture resistance of the material, but does not reduce its fire hazard, which remains just as high. Ignition of expanded polystyrene occurs at temperatures from 220°C to 380°C, and self-ignition corresponds to a temperature of 460–480°C. When burned, polystyrene foam releases a large number of heat, as well as toxic products. Regardless of the type, all materials in this category belong to the G4 flammability group.
As thermal insulation in plastering facade systems, it is recommended to install polystyrene foam with mandatory device fire-fighting cuts made of stone wool - a non-flammable material. Due to the high fire hazard, the use of materials of this group is unacceptable in ventilated facade systems, since they can significantly increase the rate of flame spread along the building facade. When using combined roofing coverings expanded polystyrene is laid on a non-combustible base made of stone wool.
The next type of thermal insulation material is polyurethane foam– is an infusible thermosetting plastic with a cellular structure, the voids and pores of which are filled with gas with low thermal conductivity. Due to the low ignition temperature (from 325°C), strong smoke-generating ability, as well as the high toxicity of combustion products, which include hydrogen cyanide (hydrogen cyanide), polyurethane foam has an increased fire hazard. In the production of polyurethane foam, flame retardants are actively used, which reduce flammability, but at the same time increase the toxicity of combustion products. In general, the use of polyurethane foam in buildings with increased fire safety requirements is severely limited. If necessary, it can be replaced with a two-component material - polyisocyanurate foam, which has lower flammability and combustibility.
Resol foams, made from resol phenol-formaldehyde resins, belong to the group of low-flammable resins. In the form of slabs medium density they are used for thermal insulation of external fences, foundations and partitions at surface temperatures not exceeding 130°C. Under the influence of flame, resol foams become charred, generally retaining their shape, and have low smoke-generating ability compared to polystyrene foam. One of the main disadvantages of this category of materials is that upon destruction they release a set of highly toxic compounds, which, in addition to carbon monoxide, includes formaldehyde, phenol, ammonia and other substances that pose a direct threat to human life and health.
Another type of thermal insulation is glass wool, for the production of which the same materials are used as in the manufacture of glass, as well as waste from the glass industry. Glass wool has good thermal characteristics, and its melting point is about 500°C. However, due to certain features, the NG group includes thermal insulation with a density of less than 40 kg/m³.
Stone wool– one of the most fireproof thermal insulation materials
Add to list thermal insulation materials included stone wool , which consists of fibers obtained from rocks of the basalt group. Stone wool has high heat and sound insulation characteristics, resistance to stress and various types impact and durability. Materials in this group are not distinguished harmful substances and do not provide negative impact on environment. Stone wool is the most reliable material in terms of fire safety: it is non-flammable and has a fire hazard class of KM0. Stone wool fibers can withstand temperatures up to 1000°C, making the material effectively prevent the spread of flame. Thermal insulation made of stone wool can be used without restrictions on the number of floors of the building.
The assessment of the fire hazard of thermal insulation was carried out within the framework of specialized seminars organized by VNIIPO EMERCOM. They were accompanied by full-scale fire tests, which involved common types of thermal insulation materials - polystyrene foam, polyurethane foam, resole foam and stone wool. Under influence open flame burner, polystyrene foam melted with the formation of burning drops during the first minute of the experiment, polyurethane foam burned within 10 minutes. In 30 minutes of testing, the resol foam was charred, and the stone wool did not change its original shape, proving that it belongs to non-combustible materials. The second part of the tests - simulating a fire on a roof with a heat-insulating layer - showed that the burning melt of polystyrene foam, penetrating into interior spaces, contributes to the spread of fire and the emergence of new fires. Thus, based on the test results, conclusions were drawn about the high fire hazard of the most commonly used thermal insulation materials.
To summarize, it is necessary to once again note the importance effective fire prevention measures in the process of design and construction of buildings. One of the central places is occupied by the assessment of fire danger and the competent selection of building materials based on current standards and standards and taking into account the functional purpose and individual characteristics building. Application modern materials allows for complete compliance with fire safety requirements, guaranteeing the safety of life and health of people who will be in the building after completion of construction.