Classification of building materials according to fire hazard. Groups and classes of flammability: we understand the terminology together with Promat Materials of group g1 g4

The fire safety of construction projects directly depends on the type of materials used. During the construction of structures, the latter are tested for flammability and behavior under conditions of occurrence. emergency situations, in particular, fire. The intensity, nature of the flow and the immediate outcome of the incident are determined by the totality of the properties of the raw materials that were used in the construction of the building. According to DBN V 1.1-7.2016 of Ukraine, materials are conventionally divided into flammable substances and non-flammable substances, this and a more detailed classification will be discussed further.

The main test method: how is the flammability of a material determined?

To understand the process of testing substances, it is necessary to understand the terminology. There are the following classes of flammability of materials:

• non-flammable;
• difficult to burn;
• flammable.

To determine which of them a substance belongs to, testing is carried out using a single method in the laboratory. All types of materials are subject to inspection: facing, finishing and others (including liquids, paint coatings). The process looks like this: samples in the amount of 12 pieces for each unit of the test substance are kept for three days in a room at room temperature. During this period, potentially combustible and non-combustible materials are weighed until they reach a constant mass. By “room” we mean a structure consisting of three parts: a chamber, air supply and exhaust systems.

Flammability classes of building materials: explanation of terminology

So, we figured out how to check flammability building materials, all that remains is to give a clear definition of the classification. Let's take a closer look:

• Flammable. It is obvious that such substances actively burn on their own under certain conditions. environment and continue to blaze with and/or without a flame source. It is this class that is divided into 4 groups of flammability of building materials, which we will consider in more detail below.
• Difficult to burn. This category includes compounds that can actively burn only if there is a supply of oxygen and ignition occurs at outdoors. That is, in the absence of a fire source, the material will stop burning.
• Non-combustible building materials. Do not ignite in air, however, they can enter into chemical reactions with each other, oxidizing agents, water. Based on this, certain materials pose a potential fire hazard. According to state rules and standards, the flammability group of NG substances is determined by two types of studies, based on the results of which a number is assigned (1 or 2).

Let's take a closer look at the last type of substances - non-flammable, as well as the tests that are carried out on them. In 1 case we are talking about studies in which the temperature in a special furnace increases by no more than 50 degrees, and the mass of the sample is reduced to a maximum of 50%, heat is released - up to 2.0 MJ / kg. There is no combustion process. The second group includes materials with similar indicators, with the exception of the heat generated (here it is no more than 3 MJ/kg), but there is still a flame, and it burns for up to 20 seconds.

Combustibility groups of materials according to DBN V.1.1-7-2016: main criteria

To classify raw materials used in the construction of buildings and various structures, the following characteristics are analyzed:

• the temperature of the gases that are released along with the smoke;
• reduction in material mass;
• degree of volume reduction;
• duration of flame preservation without a combustion source.

The flammability groups of materials and substances are obviously designated by the letter G. They are in turn divided into four classes. Let's look at each of them in more detail:

1. G1 flammability is characteristic of substances and materials that cannot burn without a flame source. However, under the right conditions, they are capable of releasing gases that form smoke. The temperature of the latter is no more than 135 degrees. In this case, the damage along the length caused by the flame does not exceed 65%, and complete destruction - a maximum of 20% of the total volume.
2. Group G2 includes building materials that, after eliminating the source of flame, continue to burn for no more than 30 seconds. Maximum temperature flue gases at the same time - 235 degrees, damage along the length - up to 85%, and weight loss - up to half of the total.
3. Flammability group G3 is assigned to those materials that are capable of maintaining the combustion process for five minutes after the flame source is eliminated. The temperature of the gases that are released can reach 450 degrees Celsius. Length and weight are reduced in the same way as in the case of raw materials from the G2 class.
4. Highly flammable materials are classified as group G4. In all respects, they are identical to substances from the previous group, but with one caveat: flue gases are released at a temperature of 450 degrees, or even more.

Confirming the flammability class: specifics of the process

Non-combustible and combustible materials are examined separately in laboratory conditions and in open space. Since samples can consist of several layers, each of them is tested.

First, researchers/laboratory technicians check and calibrate the equipment, warm it up, and then secure the test objects in special holders. The latter are located inside the oven, which, in turn, is equipped with recorders. The sample is kept in the heating chamber until it reaches a balanced temperature. That is, when the range of fluctuations stabilizes at around 2 degrees Celsius.

To obtain the correct result and assign the material flammability class G1/2/3/4, it is necessary to cool the sample in a desiccator and then measure its mass and length. According to the data obtained, the test substance is classified into the current group.

Raw materials of different aggregate states in the context of flammability should be considered separately:

1. Liquids. They are considered flammable if they can ignite at a certain temperature. If there is no external source of fire and the liquid is not able to support the process, then it is considered difficult to combust. Non-flammable substances at normal conditions With a full supply of oxygen, they do not ignite at all. Those that flare up even with a slight increase in air temperature are considered especially dangerous. For example, ether and acetone ignite already at 28 degrees Celsius.
2. Solid. IN construction industry Without testing, materials cannot be used on site. The safest are those that belong to the non-flammable group or group G1.
3. Gaseous. The maximum concentration of gas contained in a mixture with air is estimated, at which the flame can spread to an arbitrarily large distance from the point of ignition. If such a value cannot be derived, the gaseous material is classified as non-flammable.

Why is it necessary to determine the flammability group of a material?

When assessing fire hazard, not only the flammability group G1/G2/G3/G4 is taken into account, but also a number of other properties of materials. Namely:

1. Flammability (difficult, moderate and flammable).
2. Speed ​​of fire spread (non-spreading, weakly, moderately and strongly spreading).
3. Smoke generation intensity (low, moderate and high).
4. The degree of toxicity of gases released during combustion (low-, moderate- and high-hazardous, extremely dangerous).

Based on the analysis of the totality of all five properties, the fire hazard class of the building is formed. The scope of use of a particular material is determined by its flammability and its group. Properly selected raw materials and adherence to technological processes not only finished design safe for operation, but also minimizes the risk of emergency situations at a construction site.

Summing up: when is testing of the flammability of building materials carried out?

For most buildings, construction by definition includes obtaining various permits, as well as restoration, expansion, technical re-equipment of the building, repairs and other activities. Also, sometimes a fire inspection is required for a certain type of building; this issue is regulated by law. The latter includes the assessment of building materials for flammability, combustibility, etc. That is, a change functional purpose design is also a sufficient reason to examine the raw materials, and, if necessary, assign the structure a different fire hazard class.

Please note that the CP for a structure is determined initially, and only then building materials are selected for it. But there are pitfalls here too: the same, for example, composite cassettes cannot be used for cladding different buildings - a shopping center (possible), a school or a medical institution - cannot. In addition, it is prohibited to decorate evacuation passages and many other public areas with materials of flammability groups 3 and 4, while in private low-rise construction they are used everywhere (MDF panels, etc., created on the basis of organic raw materials). These and other subtleties are prescribed in Ukrainian legislation; you just need to study them or entrust this matter to specialists.

Frame construction(part 2. Insulation)

In the second part of the article Frame construction dedicated to technologies used in construction frame houses, we'll talk about various insulation materials(thermal insulation materials).

We do not produce thermal insulation materials, we are not interested in selling this or that type of insulation. But before you decide on choosing insulation for your home, you should find out the truth about these materials, something that is usually modestly hushed up by manufacturers.

Of all the diversity thermal insulation materials The leading positions are occupied by fibrous insulation based on fiberglass and stone wool. At the same time, the structure of production of insulation materials in Russia is almost identical to the structure that has developed in developed countries, where fibrous materials occupy 60-80% of the total production of thermal insulation materials. According to experts, about 70% of the Russian market is divided between different types mineral wool: approximately 30% is fiberglass and 40% is stone wool. Expanded polystyrene (including extruded) accounts for about 20% of the market.

Expanded polystyrene

Expanded polystyrene (EPS, foam) is one of the most versatile thermal insulation materials, which is actively used in various industries industry and human activity for more than 60 years. Expanded polystyrene has a porous structure with blind, closed pores, which do not allow air to move inside the material.

Physico – mechanical properties	PSB-S-15	PSB-S-25
Density, kg/m3	up to 15.0	from 15.1 to 25.0
Compressive strength at 10% linear deformation, MPa, not less	0,04	0,08
Bending strength, MPa, not less	0,06	0,16
Dry thermal conductivity at (20+-2)С, W/(m.K), no more	0,043	0,041
Water absorption in 24 hours, % by volume, no more	4,0	3,0
Fire resistance category	G1, V2, D3	G1, V2, D3
Water absorption in 24 hours when completely immersed in water, no more than % of volume	3%	3%
Self-burning time of slabs, sec., no more	4	4
Application temperature, °C	-50 to +70	-50 to +70
Humidity of slabs, %, no more	12	12

Important characteristics are thermal conductivity, fire resistance category and melting point of the foam, which determine the scope of application of this material. It is worth dwelling in more detail on the category of fire resistance.

In accordance with SNiP 21-01-97, building materials based on fire hazard are divided into non-combustible (NG) and combustible (G). Combustible building materials are divided into four groups:

• G1 (low-flammable);
• G2 (moderately flammable);
• G3 (normally flammable);
• G4 (highly flammable).

For non-combustible (NG) building materials, other fire hazard indicators are not determined or standardized.

Combustible building materials are divided into three groups based on flammability:

• B1 (flammable);
• B2 (moderately flammable);
• B3 (highly flammable).

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);
• D3 (with high smoke-generating ability).

It is this three letter abbreviations G1, B2, D3 that are indicated in fire certificates in the fire resistance line of polystyrene foam. And it is precisely the high smoke-forming ability and low temperature melting of foam plastics limits the use of this material in insulating walls and partitions of residential buildings. And low vapor permeability makes it impossible to use expanded polystyrene for insulating wooden facades.

However, due to their low cost and high heat-saving properties, foam plastics still found their use in construction:

Insulation of foundations

Expanded polystyrene is used in foundation insulation to prevent freezing.

Insulation of floors

The use of polystyrene foam boards in floors serves effective means to insulate them and reduce impact noise transmission.

Wall insulation

Expanded polystyrene can be used for external wall insulation. The system of external insulation and decoration of facades with polystyrene foam boards retains heat and keeps the wall surface in its original form for several decades.

Fiber insulation

One of the most effective materials is fiber thermal insulation. Often the term “mineral wool” refers to glass, basalt and slag wool, since mineral raw materials are used in the manufacture of all these materials. In the production of glass wool it is sand, soda, limestone; basalt wool– gabbro-basalt mineral rocks; slag - blast furnace slag.

The basis of the technological production process stone wool(Rockwool, Paroc) is obtained by melting in an oven rocks(diabase, basalt, limestone, dolomite, clay and other rocks of the gabbro-basalt group and their analogues), thin fiber formed into a uniform “carpet”, impregnated with a binder, followed by heat treatment in a polymerization chamber, where the final formation of the product occurs. After which the material is cut into specified sizes and packaged.

Glass wool insulation(URSA, ISOVER) are available in the form of rolls, soft, semi-rigid and hard mats and slabs various thicknesses, density and size.

The main advantage of fiberglass insulation is its compression during packaging. For example, compression roll materials Isover occurs by 75%, and mats by 40%, which significantly reduces transport costs and facilitates their transportation. The materials, after unpacking, quickly restore their original shape and volume. Despite the fact that materials based on basalt wool are similar in properties to glass wool, however, these are still two groups different materials, both in properties and in areas of use. If materials based on basalt wool can be used in any area of ​​thermal insulation - from the roof to the foundation, then glass wool of standard density is not suitable everywhere. For example, for insulation external walls buildings, glass wool materials with a density of at least 35 kg/m3 are required. It is known, however, that this expensive materials, as a result of which cheap low-density glass wool materials (11-13 kg/m3) are often used, the purpose of which is completely different.

The main property that distinguishes mineral wool from other thermal insulation materials is its non-flammability combined with high heat and sound insulation ability, resistance to temperature deformation, non-hygroscopicity, chemical and biological resistance, environmental friendliness and ease of installation. Also, mineral wool is a chemically passive medium and does not cause corrosion of metals in contact with it.

Low thermal conductivity coefficient

The calculated coefficients of mineral wool thermal insulation are among the best in their class (0.042 - 0.046 W/m K). At elevated temperatures specifications mineral wool products remain very high. Thanks to this, mineral wool products can prevent not only the spread of fire and high temperatures, but also protect structures made of flammable materials, and also allow you to retain heat in cold weather, preventing structures from freezing.

Hydrophobicity and vapor permeability

Mineral wool insulation has water-repellent properties, which, together with excellent vapor permeability, makes it possible to easily and effectively remove vapors from rooms and structures to the street. These properties allow you to create a favorable indoor climate. Moisture that gets on the surface of mineral wool thermal insulation does not penetrate its thickness, due to which it remains dry and retains its high heat-shielding properties.

Non-flammability

The mineral fibers of the material can withstand temperatures above 1000°C without melting. While the binder evaporates at a temperature of 250°C, the fibers remain intact, connected to each other, maintaining their strength and creating fire protection. Mineral wool belongs to the group of non-combustible (NG according to GOST 30244) building materials. This property allows them to delay the destruction process for some time. load-bearing structures buildings. Possessing absolute fire safety, these materials are used in the construction of buildings of any type: both in one-story cottages and in high-rise buildings.

Soundproofing

Due to its structure - an open porous structure - mineral wool has excellent acoustic properties: it significantly reduces the risk of vertical sound waves between wall surfaces, improves the airborne sound insulation of the room, the sound-absorbing properties of the structure, reduces reverberation time, and thereby reduces the sound level in neighboring rooms .

For other types of thermal insulation materials include:

extruded polystyrene foam

The extrusion process gives polystyrene a uniform structure consisting of small closed cells measuring 0.1-0.2 mm. It is thanks to its cellular structure that insulating boards made from it have a number of advantages: low thermal conductivity; high mechanical strength; lack of capillarity; almost zero water absorption; resistance to freeze-thaw cycles; durability. The main disadvantages are the same as those of non-extruded polystyrene foam.

cellular concrete (foam concrete and aerated concrete)

Foam concrete prevents significant heat loss in winter, is not afraid of dampness, allows you to avoid too high temperatures in summer and regulate air humidity by absorbing and releasing moisture. It has a relatively high sound absorption capacity. In buildings from cellular concrete current sound insulation requirements are met. Due to its porous structure, foam concrete is both a structural and thermal insulation material. Its thermal insulation capacity is 3 - 3.5 times higher than that of brick wall. A standard foam block measuring 200x188x388 has a mass of only 11 kg, which can significantly reduce transportation and installation costs and reduce the labor intensity of work. With a low volumetric mass, foam concrete has enough high strength for compression (3.5-5.0 MPa). Maximum number of floors of a building with load-bearing walls three floors made of foam concrete D-900. Foam concrete is a non-flammable material and can withstand one-sided exposure to fire for at least 5 - 7 hours. Foam blocks are not subject to rotting and aging. Of great importance is the property of foam concrete, such as easy workability with the simplest tools.

foamed polyolefins

These are, first of all, foamed polyethylene and polypropylene. Characteristics This material is both light weight and low thermal conductivity (almost 1.5 times less than glass and basalt insulation). An important advantage is the ease of installation of this insulation. As a disadvantage, the insulation is absolutely vapor- and gas-tight, i.e. the room stops “breathing” and, if it is not ventilated, you may experience the effect of a thermos or greenhouse. The operating temperature range is also small - up to 80 °C for polyethylene foam and up to 150 °C for polypropylene foam.

polyurethane foam

Polyurethane foam is an infusible thermosetting plastic with a pronounced cellular structure. Only 3% of its volume is polyurethane foam hard material, forming a frame of ribs and walls. This crystalline structure gives the material mechanical strength. The remaining 97% of the volume is occupied by cavities and pores filled with fluorochloromethane gas with extremely low thermal conductivity, and the proportion of closed pores reaches 90-95%. Polyurethane foam is used primarily in pipe insulation. The material is attached to the pipes either in the form of shells or sprayed using special equipment. Polyurethane foam has a relatively low thermal conductivity coefficient - 0.02-0.04 W/m K, is resistant to aggressive environments, and is generally environmentally friendly. However, compared to mineral wool, it has a relatively low operating temperature, not exceeding 150 °C.

foamed synthetic rubber

Foamed synthetic rubber is used mainly in the insulation of pipelines and air ducts. Best materials Based on foamed synthetic rubber, they can withstand temperatures from -200 to +150 °C.

The applicability of various types of insulation is reflected in the following table:

	Glass wool and fiberglass (URSA, ISOVER)	Mineral wool (Rockwool Ragos, Isovol, Isoroc)	Styrofoam, Extruded polystyrene foam(Penoplex, Timplex)
Facades	Acceptable	Applicable	Recommended
External	Recommended	Recommended	Not recommended
Domestic	Recommended	Recommended	Not recommended
Masonry (middle layer)	Acceptable	Acceptable	Recommended
Sandwich panels	Not recommended	Recommended	Recommended
Roof	Recommended	Recommended	Acceptable
Floor	Acceptable	Recommended	Recommended
Ceiling	Recommended	Recommended	Not recommended
Foundation, ground floor	Not recommended	Acceptable	Recommended

Frame construction (part 1)

The previous part of the article is devoted to an overview of the technologies that are used in the construction of frame houses.

Construction stages

Stages of construction In this article, using an example, we consider the sequence of construction work frame house, from the initial stage of project selection, to the completion of construction as a whole.

An important parameter of materials, especially in the construction industry, is their fire hazard. It is such a priority that the flammability groups are determined by The federal law. There are four of them: G1-G4. Separated into a separate category. It is important to understand what this classification means, this will allow specialists to correctly select and use building materials to ensure fire safety objects. The degree of fire resistance can only be determined in a special laboratory that has official specialized accreditation. The methods are regulated by GOST 30244-94.

If it is established experimentally that a building material loses no more than 50% of its weight when ignited, the temperature increases - no more than +50 degrees C, and the flame lasts no more than 50 seconds, then its incombustibility is determined and it is considered fire resistant. If one of the criteria does not meet the definition, then the substance is flammable and belongs to one of four groups:

• G1. Flammability group G1 includes materials that cannot burn on their own; smokes have a temperature of up to +135 degrees C, deform in shape up to 65% and lose up to 20% of mass.
• G2. Moderately flammable building materials can burn for half a minute, the smoke temperature can reach +235 degrees C, lose up to 50% of mass and deform up to 85%.
• G3. This group classifies normally combustible building materials that can independently maintain combustion for up to 5 minutes, lose weight up to 50%, change shape up to 85%, and smoke can reach temperature limit at +450 degrees C.
• G4. Flammability group G4 - these are highly flammable materials, the smoke temperature reaches +450 degrees C, deformation - 85%, weight loss - 50%, and they can burn independently for 5 minutes.

Important! During the tests, the following process difference is taken into account: for the first two classes the formation of molten drops is not expected, for three groups - from G1 to G3 the formation of a burning melt is not expected.

Flammability

In addition to flammability classes, flammability characteristics are of great importance. They are calculated based on the values ​​of the maximum heat flux density. There are three categories:

• IN 1. Refractory substances per 1 m2 have thermal parameters of no more than 35 kW.
• AT 2. Moderately flammable substances have indicators per 1 m2 from 20 to 35 kW.
• AT 3. Highly flammable fire hazardous materials have a heat flow density of up to 20 kW.

In addition to combustibility and flammability, the fire hazard of materials is determined by smoke-forming ability (divided into D1-D3), the possibility of flame spreading over the surface (RP1-RP4) and the degree of toxicity of combustion products (T1-T4).

For clarity, we present the definitions of fire safety classes in a tabular structure.

Fire safety criteria	KM0	KM1	KM2	KM3	KM4	KM5
Combustion potential	NG	G1	G1	G2	G2	G4
Flammability	—	IN 1	IN 1	AT 2	AT 2	AT 3
Smoke formation	—	D1	DZ+	D3	D3	D3
Degree of toxicity of combustion substances	—	T1	T2	T3	T3	T4
Fire spread through material	—	RP1	RP1	RP1	RP2	RP4

Features of the class of building materials in terms of flammability G1

When choosing building materials for a particular building or structure, their fire safety class is taken into account. Moreover, structural, finishing, insulating and roofing products must meet this criterion. Decoding G1 means that the material has the lowest flammability - first degree, that is, it is a fire-resistant product. All building materials must have certificates confirming their fire resistance group. This requirement is determined by SNiP and TNLA. Thus, the flammability of G1 means that the use of the material in construction is relevant in facilities with high fire safety requirements. That is, they can be used for the construction of ceiling structures, roofs and partition frames, which are subject to the most stringent requirements.

It should be understood. In kindergartens, schools and medical institutions, fire safety claims may be higher - only NG. The requirements for evacuation routes at any facility are similar.

Production technology and its impact on flammability characteristics

According to Wikipedia, non-flammable are mineral materials. This is ceramics a natural stone, reinforced concrete, glass, brick and analogues. But, if additives of a different nature are used in production, then the fire safety parameters change. Modern technologies involve the widespread use of polymer and organic additives. Depending on the proportions of flammable and non-flammable components in the composition, the parameters of the building material can be transformed to G1, and even to G4 flammability class.

Determination of the flammability class of substances and products

There are special methods for determining substances and products in classes G4-G1. They check compositions for spontaneous combustion and ignition from a source, taking into account the ability to maintain a flame. Tests are carried out in a chamber, so the following parameters are experimentally determined:

• smoke temperature;
• level of deformation;
• How long does it take for the material to burn on its own?

After removing the samples from the chamber, the intact part is determined, that is, the percentage of the total volume that is not charred or burned. Results are rounded to the nearest 1 centimeter. Defects such as charring, swelling, chips, roughness, discoloration and warping are not taken into account. The undamaged part is weighed on scales, the accuracy of which must be at least 1%. All results obtained are included in the reporting documentation, including a photo report. When it is determined that product characteristics do not comply with safety requirements at the facility, a report is drawn up.

Requirements for testing organizations

Fire experiments can only be carried out by those commercial organizations who are accredited. Example: Kucherenko Research Institute, Ministry of Emergency Situations of the Russian Federation, ANO “Pozhaudit” and others. These enterprises are obliged to act strictly according to regulatory provisions, have full set calibrated equipment and properly qualified specialists on staff. The protocol must contain the following information:

• information about the customer;
• information about the organization performing the inspection;
• complete information about the product, material and substance;
• date and place of testing;
• equipment data;
• description and photographic documents about the initial condition of the samples and their condition after testing;
• the procedures performed and the results of each of them;
• results and conclusions.

Flammability indicators of some building materials

Here are the fire resistance parameters of popular construction products:

• all types of gypsum plasterboard, due to the large volume of gypsum, are characterized by high fire resistance, they can withstand exposure open flame from 20 to 55 minutes, the parameters are determined - G1, T1, D1 and B2, which together allow the use of drywall on objects of any purpose;
• wood is characterized by a high fire hazard, its indicators are G4, RP4, D2, V3 and T3, and the wood burns in both smoldering and open flame modes if it is used at the site this material, even for the manufacture of doors, it must be treated with special compounds;
• Chipboard belongs to the flammability class G4, although, unlike wood, it ignites and maintains fire worse - B2, but combustion products are highly toxic T4, other parameters - RP4, D2, when used in construction and repair, fire retardant treatment is recommended;
• suspended ceilings made of PVC are highly flammable materials, but after undergoing fire retardant treatment they acquire class G2; the fire hazard of a specific product can be found in the accompanying documentation;
• insulation of the facade with polyurethane foam, polystyrene foam, polystyrene foam or penoplex is regulated by SNiP 21.01.97, here the permissible flammability is from G1 to G4, flammability from B1 to B3, depending on design features, for example, the need for ventilation, and the technology being implemented;
• mineral roofing materials, such as natural tiles, are non-flammable, onduville is an organic material that is easily flammable and burns quickly, therefore its use is limited by the requirements for general security object;
• metal sandwich panels with mineral wool insulation – best option for the construction of facilities with high fire safety requirements, since they are marked NG, the use of polycarbonate sheets reduces the indicators to G2 and their use is limited;
• all types of linoleum belong to moderately combustible materials, with the exception of heterogeneous and homogeneous, they belong to KM2, their other indicators are RP1, B2, T3 and D2, the latest modifications are allowed to be used in medical and educational institutions;
• For objects with high fire safety requirements, special types of laminate have been developed, for example, Parqcolor has the following indicators: G1, RP1, B1, T2 and D2.

Note! Special requirements applied to translucent structures. Detailed standards with recommendations have been drawn up for them.

Penolex is a type of thermal insulation material, which is extruded polystyrene foam.
Most people, when choosing suitable insulation for their home, focus on various characteristics material. Many people are interested low price, some prefer ease of installation, and only a small part think about environmental safety and fire resistance. What characteristics does penoplex have? Is it combustible or absolutely non-flammable? It’s strange, but there are a lot of opinions about this indicator, so it’s worth taking a closer look at the fire safety of penoplex.

What flammability class does penoplex belong to?

When studying the flammable properties of extruded polystyrene foam, it is necessary to take into account the fact that manufacturers produce various brands this material. They all have different characteristics, which is why there are different opinions about their flammability.

All building materials are divided into several groups according to flammability:

• G1 – materials are slightly flammable.
• G2 – moderately flammable materials.
• G3 – materials with normal flammability.
• G4 – materials with highly flammable properties.
• NG are absolutely non-flammable materials.

Most sellers prefer to remain silent about the vapor barrier properties of polystyrene foam, since their main task is to sell it in any way. Some even claim that only they can buy non-flammable extruded polystyrene foam. As soon as you hear such statements, leave immediately. Today, there is simply no non-flammable penoplex, but it can be classified as a slightly flammable building material.

Is penoplex dangerous in a fire?

We need to figure out whether extruded polystyrene foam poses a fire hazard. Previously, all types of penoplex belonged to the group of materials with normal flammability or highly flammable properties. Such materials, in addition to their flammability, emitted dangerous gases, which made penoplex especially dangerous in case of fire. But recently, manufacturers switched to the production technology of G1 class penoplex, that is, low flammability. The insulation obtained such properties thanks to the addition of a fire retardant, a substance that can increase the resistance of building materials to open fire. According to experts, the new penoplex does not emit harmful substances, like wood, it emits only carbon dioxide and carbon dioxide.
But even with such statements from manufacturers, buyers are not inclined to believe them. This is due to the fact that, according to government regulations, extruded polystyrene foam cannot be slightly flammable. And all its types belong to group G3 or G4.

Is penoplex flammable or not?

Official manufacturers do not provide any information about absolute non-flammability. There is only mention of an independent study, according to which penoplex began to be classified as class G1. But in official government documents there are no such records. This is what causes controversy; some consumers are sure that independent examination was interested in the result, so the statement that penoplex does not emit harmful substances is simply absurd.
But based on the statements of both sides, we can conclude that opponents of the non-flammability of polystyrene are simply unfamiliar with the properties of the fire retardant. Of course, such substances will not be able to prevent fire, but will not allow the material to burn out. How to explain this? It's simple. Under the direct influence of a flame, penoplex will light up, but as soon as the fire stops affecting it, it immediately goes out. It is based on these characteristics that polystyrene foam is called non-flammable, since in itself it can cause a fire.
If we evaluate the statements that penoplex emits no more harmful substances than wood, it looks controversial. Since extruded polystyrene foam is a synthetic material, in addition to carbon monoxide, it emits other chemical compounds that can cause pulmonary edema, severe poisoning and even suffocation in humans.

Can penoplex be called non-flammable?

To summarize the above information, is penoplex non-flammable and is it safe in case of fire?

• Classic extruded polystyrene foam belongs to the groups of highly and normally flammable materials.
• Only by adding fire retardants does penoplex become slightly flammable.
• It cannot be called non-flammable, since even despite its high fire resistance, it can still be ignited under the direct influence of fire.
• Substances that are released during the combustion of penoplex are dangerous to humans.

Considering all the characteristics, experts advise buying low-flammable penoplex. It differs significantly in price, but it performance characteristics worth it. The main difference is the density of the insulation blocks; treated with anti-friction, penoplex is denser. The building materials market offers insulation from various manufacturers, which makes it possible to choose the best option.

How to choose the right penoplex?

Proper insulation should be aimed at maximizing heat retention inside the room, while at the same time not exposing it to fire hazard. In order to purchase what you need quality product, you need to contact only experienced manufacturers who have a good reputation in the building materials market.
After choosing a manufacturer, you need to read all the accompanying documents, which will indicate all state regulations and compliance with them. You can also trust the conclusions of independent expert institutions, which are often available from manufacturers. Nowadays, you can find construction companies who can conduct a small experiment, after which you will be convinced of the fire resistance of the material.

Conclusion

The main thing you need to remember is that buying insulation treated with anti-flight does not guarantee complete fire safety. To preserve all its fire-fighting properties, you need to take into account necessary instructions on installation and processing. Most often, extruded polystyrene foam is used to insulate floors, basements and foundations. It is strictly prohibited to use it to insulate walls and facades. It is precisely because of the fire hazard that this insulation cannot be used in all areas of construction. Fortunately, manufacturers are constantly working to improve it, using various technologies production and treatment of insulation with protective substances. Soon, penoplex will have everything necessary qualities for widespread use in the field of insulation of residential and industrial premises.

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 following values flammability parameters:

1. temperature increase in the furnace is no more than 50°C;
2. sample weight loss no more than 50%;
3. 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 - minimum value surface heat flux density (SDHD), at which stable flame combustion of a 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 of solid substance (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-generating 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 the 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.