Pros and cons of polystyrene foam insulation. Polystyrene insulation - technical characteristics Polystyrene sheet insulation

To the question “what is polystyrene foam?” there is a short and concise answer. Polystyrene foam (insulation) is a modern, environmentally friendly material that is made from substances that cannot harm humans.

1 Features of the material

Foiled polystyrene foam, like its other analogues, can be used in places where other types of thermal insulation materials cannot be used due to the fact that capillary rise of groundwater can occur there.

Thus, the use of expanded polystyrene is due to the protection of waterproofing from environmental factors that can cause irreparable harm to it.

The presented material has its own GOST. GOST 15588-86 (it is made according to it) regulates the composition, properties and use of expanded polystyrene.

If you compare the presented insulation with a material such as mineral wool, then it is better to prefer the first.

Expanded polystyrene - thermal insulation material for walls

The fact is that mineral wool does not have such a spectrum useful characteristics, although in some respects it is still better than polystyrene foam.

In addition, mineral wool is non-flammable material and it is incapable of harming human health. All this is indicated in the corresponding GOST.

It is best to first pay attention to the moisture-resistant characteristics of polystyrene foam, which are combined with its lightness, reliability and durability.

When choosing insulation, it is best to give preference to expanded polystyrene, since these products are not as heavy as mineral wool and differ high degree ease of installation.

Externally, this insulation is presented in the form of small granules that are sintered together under the influence of high temperatures. GOST 15588-86 strictly regulates the size of granules of the substance.

Their size ranges from 1 to 10 mm and may depend on the intended purpose and the desired density of the product.

GOST also states that polystyrene foam granules may be heterogeneous in structure.

Each granule contains huge amount thin-walled microscopic cells. This greatly increases the area of ​​contact between the substance and the air.

The presented foam insulation consists of 98% air, which is why it unique properties. Reviews about this material are mostly positive; in addition to its excellent heat-insulating properties, it is often mentioned that it cannot cause harm to the human body How .

1.1 Areas of application of expanded polystyrene

The presented material, due to its outstanding technical and operational characteristics, is used almost everywhere in the construction industry.

Foamed polystyrene can be used as an insulating material. In addition, the product can successfully perform the function of a filler.

In some cases, polystyrene foam can even help solve problems associated with poor soil quality.

It can be used to form embankments during the construction of roads or bridges.

Expanded polystyrene PSB-S-35 2000×1000x180

2 Properties of polystyrene foam

The presented material has a fairly low thermal conductivity. Thus, expanded polystyrene is an almost ideal insulation material that can provide high heat conservation capabilities.

This feature is explained by the structure of the material, which consists almost entirely of air.

The thermal conductivity coefficient of a substance can vary between 0.032 and 0.043 W/(m∙K).

This figure is many times lower than that of wood, brick, expanded clay and other insulating materials. building materials.

A low level of thermal conductivity affects the possibility of a high level of energy supply.

The use of expanded polystyrene as a heat insulator during the construction of buildings allows for its further operation to significantly reduce costs associated with heating.

High energy-saving properties allow the product to be actively used to protect pipelines from excessive freezing.

The presented substance provides reliable soundproofing protection against impact noise. This effect is directly related to the ability of a substance to convert sound energy into heat energy.

Based on this, thanks to the cellular structure of polystyrene foam, the presented material has effective sound-absorbing qualities.

It is worth noting that the material has a high degree of structural stability, fluctuating over a wide temperature range.

At the same time, low temperatures are not able to influence the mechanical, chemical and physical parameters of the substance.

When the temperature increases to +90°C, even during prolonged exposure, foamed polystyrene will not radically change its properties.

Due to the fact that polystyrene foam is completely synthetic, it is not perceived as food by insects and microorganisms, which does not contribute to their reproduction.

This material is absolutely unsuitable for bacteria or harmful fungi to survive in it.

The presented product is characterized by high resistance to water vapor diffusion and an increased moisture resistance coefficient.

Products cannot be dissolved in water and are not able to absorb it. Thus, the insulation is not subject to deformation and swelling.

This high degree of resistance to moisture means that foam products can be used to... This is especially true in situations where the insulating material is in close contact with the ground.

It is worth noting that the density of polystyrene foam products is quite low and equals 15-50 kg/m³, however, along with this, the substance has high compressive, tensile and bending strength.

This facilitates the use of the product as a durable building material that can withstand mechanical loads for a long time without being subject to deformation. Thus, due to the relatively small mass of the rearranged material, it is possible:

• Do not use special equipment when moving products;
• Reduce construction costs;
• Significantly reduce the installation time of structures.

In fact, polystyrene foam elements are plastic, and therefore, when correct operation, the material is able to retain its physical properties unchanged for a long time.

It is worth noting that foam granules consist of carbon and hydrogen molecules. This is due to the high degree environmental cleanliness material.

Polystyrene foam does not exhibit toxic properties, does not generate dust and is not odorless.

Toxic substances are also not released from it. This insulation allows air to pass through quite easily, and therefore all structures in which it is included “breathe.”

Foam blocks can be easily pre-treated and do not irritate the skin and mucous membranes

As mentioned above, reviews of polystyrene foam are mostly positive.

Vitaly, 38 years old, Kaluga:

I decided to start insulating the apartment and start with the loggia. Polystyrene foam was used as insulation material. Excellent cutting and installation. I advise you to use it.

Sergey, 54 years old, Vologda:

I have an outbuilding in the courtyard of a private house. I decided to insulate its walls in order to live in it until late autumn. I used polystyrene foam boards. Now the heat stays inside very well. I recommend this material to everyone.

Vasily, 35 years old, Voronezh

I am engaged in the sale of insulation and building materials. Customers take the expanded polystyrene off the counter almost immediately. Everyone is very happy with him.

2.1 What is better to choose: polystyrene foam or mineral wool?

Mineral wool definitely loses to foam plastic in terms of thermal insulation properties. The thermal conductivity of polystyrene foam is much better.

However, mineral wool has excellent fire safety characteristics. This product has a high degree of fire resistance.

Polystyrene foam does not have such stability. The level of thermal conductivity of polystyrene foam is high and mineral wool is significantly inferior to it.

Mineral wool has a high degree of resistance to spontaneous combustion. Characteristics of vapor permeability mineral wool significantly exceeds this parameter of its competitor.

Along with this, polystyrene foam has a very high degree of hygroscopicity, therefore foam plastic can be used in environments with a high degree of humidity and is characterized by low cost.

The convenience of polystyrene foam lies in the fact that its weight is several times less than the weight of mineral wool, in addition, this material can be processed with an ease that is not possible when processing mineral wool.

There is one drawback - polystyrene foam boards have some difficulty joining each other. On the other hand, mineral wool has a high degree of resistance to almost all types of organic matter and fungi.

Along with this, polystyrene foam is significantly susceptible to all kinds of organic solvents, but fungi and mold do not take root on it.

Obviously, the process of choosing insulation is a complex and multifaceted task. In order to solve it with a high degree of efficiency, it is necessary to carefully take into account the current conditions and your own priorities, among other things.

It is important to give preference only to well-tested heating systems. We must also remember about the correct selection of the most optimal thickness thermal insulation material.

Mineral wool can easily pass moisture through itself. This indicates that this material is indispensable when insulating a house built of wood or beams.

It is important to remember that under a layer of polystyrene foam the wood quickly rots. In this case, you should first take care of installing the so-called parabarrier, and then secure the sheathing.

Mineral slabs, in most cases, are laid in two layers. This is done to prevent the creation of so-called “cold bridges”.

The material is covered with a film on top that provides waterproofing. When insulating a balcony, preference is almost always given to polystyrene foam since during installation there is no need to use lathing, which has a positive effect on saving balcony space.

You should immediately pay attention to the fact that the selected insulation must necessarily correspond to those climatic conditions in which it is used.

2.2 Pros and cons of polystyrene foam (video)

Expanded polystyrene – universal insulation, which has always been the leader in the domestic market of thermal insulation materials. The popularity of this insulation is determined by the optimal ratio of cost and functional characteristics - in this parameter, polystyrene foam is superior to all existing insulation materials.

1 Scope of application of polystyrene

Expanded polystyrene is widely used as the main thermal insulation material in private and industrial construction.

The main factor that determines the demand for polystyrene foam insulation is their minimum cost, which is an order of magnitude less than the same mineral wool and other thermal insulation materials on the market.

You should not think that since polystyrene foam is cheap, it guarantees effective insulation - on the contrary, the thermal conductivity of all insulation materials used today is approximately the same - it varies from 0.03 to 0.04 W/mk.

In practice, the difference in thermal conductivity at the level of 0.03-0.05 W/mk is simply unnoticeable; the differences between polystyrene foam and more expensive insulation materials lie not in efficiency, but in some features of this material, and which we will discuss in detail in the corresponding section of the article. This is important when.

In general, after analyzing the properties of this insulation, we can conclude that thermal insulation with polystyrene foam has the following advantages:

• Cost-effectiveness - the cost of a cubic meter of polystyrene foam is about 2-2.5 thousand rubles, while mineral wool is 5-6 thousand rubles. At the same time, the consumption of mineral wool for insulating the same object will be approximately 50% more than polystyrene;
• Easy installation and - polystyrene foam boards are installed on the insulated surface using adhesive composition, which greatly simplifies their installation. For example, to install the same mineral wool you will need to equip load-bearing frame, which entails additional costs of both time and finances.

Insulation materials based on polystyrene foam are used for thermal insulation of the following objects:

• Facade walls of houses and apartments made of any materials - brick, concrete, expanded clay blocks, foam blocks, gas blocks (including for insulation using wet plaster technology);
• Lag floors, high-density polystyrene foam can be used for thermal insulation of floors under concrete screed;
• Roofs – straight and pitched;
• Ceiling and on;
• Balcony, loggia, or attic;
• Foundation and ground floor.

Expanded polystyrene has not only thermal insulation properties, but also the ability to reduce noise, which is why it is often used as a soundproofing material for insulating private houses, apartments, or soundproofing industrial premises.

2 Polystyrene foam manufacturing technology

Expanded polystyrene insulation is made using the technology of foaming and then connecting polystyrene granules together.

Briefly, the production technology of this material can be described as follows:

1. Polystyrene raw materials are loaded into a pre-expander - a unit in which polystyrene is heated with hot steam to a temperature (about 100 degrees), at which the granules expand in volume and the formation of cavities in them, which will subsequently be filled with air;
2. After the granules have expanded, they are dried from steam condensation and transported to a holding container, where they are aged for 12 hours at a temperature of 16-25 degrees. Aging of polystyrene is necessary so that the cavities inside the granules are filled with air;
3. Air-filled granules are loaded into a block mold - an aggregate where individual granules are combined into a monolithic block. After loading the granules, the sealed container is closed, and hot steam is supplied inside under pressure, under the influence of which the polystyrene granules are sintered together;
4. After drying the block, the product goes to the cutting line, where automated equipment forms slabs of the required thickness and size from the block. The block is cut with hot strings, which guarantee cutting with maximum precision.

Upon completion this stage, insulation boards are packaged in plastic film and delivered to store shelves.

3 Dimensions and thickness of polystyrene boards

Expanded polystyrene insulation is supplied to the market in the form of slabs having the following dimensions:

• 1000*500 mm;
• 1000*1000 mm;
• 2000*1000.

The thickness of the slabs varies from 10 to 100 mm, the thickness increment is usually 10 mm.

The above slab sizes refer to common standards, if you need non-standard sizes thermal insulation, then most manufacturers, when ordering a sufficiently large batch, can produce such insulation to order.

In general, for thermal insulation of vertical and inclined surfaces - facades, walls, roofs, the best option is slabs whose dimensions are 1 * 0.5 m, since large-sized products are quite difficult to work with for one person.

The thickness of the expanded polystyrene sheet, which provides effective thermal insulation, in most regions of the CIS countries varies from 50 to 100 mm.

4 Types of expanded polystyrene and their technical characteristics

The classification of polystyrene foam used for thermal insulation is based on the density of the insulation. The most popular insulation materials are polystyrene foam of the following brands:

• PSB S-15;
• PSB S-25;
• PSB S-35.

Its thermal insulation properties directly depend on the density of expanded polystyrene. The lower the density, and, accordingly, the more air in the insulation, and the fewer polystyrene walls, the lower the thermal conductivity coefficient of the material will be.

And vice versa, the more polystyrene foam is compressed, the less air closed inside the insulation cells, and the lower its thermal conductivity will be. However, it must be taken into account that the strength characteristics of insulation directly depend on its density.

Let's compare the technical characteristics of the most popular types of polystyrene foam insulation PSB-15, PSB-25 and PSB-35 in thermal insulation:

• Material density, kg/m³: PSB-15 – from 8 to 15; PSB-25 – from 15 to 25; PSB-35 – from 25 to 35;
• Thermal conductivity coefficient, W/mk: PSB-15 – 0.037; PSB-25 – 0.039; PSB-35 – 0.043;
• The vapor permeability coefficient for all types of polystyrene foam is not higher than 0.05 mg/mchPa;
• Resistance of the material to compression at a deformation of 10% of the volume, MPa: PSB-15 – 0.04; PSB-25 – 0.07; PSB-35 – 0.16;
• Material resistance to bending, MPa: PSB-15 – 0.06; PSB-25 – 0.018; PSB-35 – 0.25;
• Percentage of moisture absorption by volume for 24 hours: PSB-15 – 4, PSB-25 – 1, PSB-35 – 1.

All classes of expanded polystyrene belong to the flammability group G3 - normally combustible materials, the limiting temperature of their operation is 80 degrees, above which the polystyrene granules begin to sinter, as a result of which the insulation itself is deformed.

5 Comparison of regular and extruded polystyrene foam

Extruded polystyrene foam is made from the same polystyrene granules as the insulation discussed in this article, but at a much higher cost. complex technology, which determines the differences between these materials in price and technical characteristics.

The cost of these materials can vary by 2-2.5 times, to understand whether it makes sense to overpay, let’s compare their basic technical specifications:

• Thermal conductivity coefficient, W/μ: extruded polystyrene foam (EP) – 0.028; expanded polystyrene (P) – 0.038;
• Percentage of moisture absorption by volume for 24 hours: EP – 0.2; P – 2;
• Percentage of moisture absorption by volume for 30 days: EP – 0.4; P – 4;
• Vapor permeability coefficient, mg/mchPa: EP – 0.018; P – 0.05;
• Density, kg/m³: EP – from 28 to 45, P – from 15 to 35.

The flammability class of polystyrene-based materials is identical - G3, or, in the case of adding fire-resistant additives - G2.

The difference in thermal conductivity between EP and expanded polystyrene determines that for equal thermal insulation efficiency you will need a greater thickness of expanded polystyrene insulation than EP boards.

Density varies within 10 kg/m³, which is also quite significant. Expanded polystyrene, the density of which is minimal, cannot be used to insulate load-bearing facades, while for EP insulation, the density of which is 28 kg/m³, there are no such restrictions.

Expanded polystyrene, unlike EP boards, is eaten by mice. Despite the fact that EP is made from the same raw materials as expanded polystyrene, mice do not eat it, since the structure and density of the material does not allow them to damage the insulation.

Considering the above, if you want to install polystyrene foam insulation, all mice must be pre-poisoned. Do not neglect this, because otherwise you risk the money and time spent on insulating your home.

However, mice are mostly dangerous only for houses - rodents are extremely rare in apartments. However, even if there are mice, most likely they will initially be interested in regular food. For thermal insulation materials Rodents (mice and others) are usually rarely accepted.

When choosing between thermal insulation made of expanded polystyrene and EP, consider the conditions under which the material will be used. For example, to insulate a foundation or basement, it is better to choose EP, since it is more stable, strong and durable, while ordinary polystyrene foam is perfect for thermal insulation of a facade.

6 Review of the advantages and disadvantages of polystyrene insulation (video)

Insulation of the enclosing surfaces of the house is the key to ensuring that the costs of its heating and air conditioning are minimal. Dozens, if not hundreds of technical solutions have been developed for roofing, wall and foundation thermal insulation, but not every one of them can be called budget-friendly. Therefore, polystyrene foam boards, inexpensive and at the same time characterized by low thermal conductivity, occupy a leading position among all insulation materials. What are the nuances of foam insulation?

There is still debate about whether it is possible to insulate a house with a material containing styrene (a toxic substance belonging to the second hazard class). What speaks in favor of polystyrene foam is its excellent performance, which led to many years of use throughout the world, and against it is evidenced by the fact that even in the Soviet Union, after several fires in which people died, the use of foam plastic in construction was prohibited.

Sheet thickness varies

Advantages of insulating the roof and the entire house with polystyrene foam

Polystyrene foam (this was the name of the product of the Finnish company that was the first to supply polystyrene foam boards to the Soviet market) is a mass of polymer cells filled with gas, foamed and formed into thick sheets. Due to its unique structure, the material consists of 99% air, thanks to which it effectively retains heat and does not allow cold to pass through.

Diagram of the main heat losses at home

Thus, a 12 cm thick foam plastic slab in terms of thermal insulation is equivalent to wooden wall 45 cm thick or brick - 2.1 m thick. However, when choosing a material, it should be taken into account that the heat transfer coefficient depends on its density, and the denser and stronger the foam, the more it is able to remove thermal energy.

Comparison of the properties of mineral wool and polystyrene foam board

Lightweight polystyrene foam slabs are not problematic to transport and lay; in addition, installation does not place a significant load on the roof, walls and foundation of the building. It can absorb moisture only in direct contact with water, so the material does not need vapor protection, which means that already economical insulation is even cheaper. It is also noteworthy that polystyrene foam can not lose its properties for 80 years or more.

Defects of thermal insulation with foam boards

Savings that reduce the initial investment but increase operating costs or other additional risks appear, for example, for the health of residents or the safety of property, are always questionable. Therefore, the use of polystyrene foam in an insulating pie should be considered from another point of view - its disadvantages.

The first and probably the most significant disadvantage of traditional polystyrene foam is its flammability. The fact is that to fill styrene granules in production they use natural gas, and polystyrene foam can easily ignite from a regular match. A house that is insulated with such material burns down in a matter of minutes, and people in it die from phosgene, dioxides, hydrogen cyanide and other deadly substances released when polystyrene foam burns.

Polystyrene foam without fire retardants is prohibited from being used in construction.

The low vapor permeability of the material can be attributed to both its advantages and disadvantages:

1. On the one hand, it does not need to be protected from water vapor, which is actively emitted by humans in the process of life and is a negative factor for the same mineral wool.
2. On the other hand, there is a room insulated with polystyrene foam boards from the inside, without forced ventilation turns into a steam room, in which it is absolutely impossible to live and work.

Contrary to popular belief that polystyrene foam boards are a good noise barrier, this is not true. Moreover, they transmit sounds well from the outside, and when vibrating, they themselves are capable of producing them (creaking, rustling, friction between plates). Therefore, you should not use them for sound insulation from neighbor or street noise - not only will it not increase, but it may also decrease.

Owners of private houses who are thinking about insulating roofs and other enclosing structures with polystyrene foam should also be warned: despite the fact that it is not a breeding ground for living organisms, rodents, insects and birds often like to live in it. In some cases, colonies of microorganisms form on the surface, which do not affect function or durability.

High quality material characterized by whiteness and uniformity

Myths and truths about chemical hazards

Many potential buyers doubt the environmental safety of polystyrene foam boards. For example, rumors are actively circulating on forums and websites, citing sources from the 80s, that expanded polystyrene is capable of releasing gaseous styrene, which, penetrating through the nasopharynx into the lungs, supposedly accumulates in vital human organs and causes cancer.

Modern research The toxicity of the material has not been proven. It must be said that in the course of most experiments they studied not domestic, but industrial premises where various plastics and rubber were made, which means that the concentration of secretions and the degree of their influence on the body was much higher than usual. As a result, the environmental friendliness of polystyrene foam boards is confirmed by the following international construction associations and ratings:

• ECOPSE is a French association of foam manufacturers that has developed the “Uni’vert PSE” standard, the label of which is placed on products that have passed a strict eco-audit;
• BRE is a British multidisciplinary research center that studies the so-called built environment and has assigned polystyrene foam a high class of environmental friendliness (A+);
• IRC is an international building code that classifies polystyrene foam as an energy-efficient and environmentally friendly insulation material.

Tests carried out prove harmlessness

Confirmation of the safety of the material is also a study for the presence of styrene vapors in a building constructed using polystyrene foam, conducted by the Moscow Research Institute of Hygiene named after. F. F. Erisman: according to the test results, they were not detected in the air samples (conclusion No. 03/PM8). Thus, we can conclude that modern high-quality polystyrene foam boards do not have any significant effect on human health.

How to choose polystyrene foam insulation

There are several types of polystyrene foam boards:

• press ( domestic brands designated by the letters PS) - mainly used as packaging material or insulation for refrigerators, thermoses, thermal booth bodies, etc.;
• pressless (EPS, PSB, PSB-S) - due to their low cost, they are used for insulation of foundations, roofs, walls, balconies and other structures more often than other materials;
• extruded (XPS, EPS) - made from the same polystyrene, but using a different technology, which makes it possible to obtain a fundamentally different insulation.

Pressless foam grades have different densities– from 15 to 50 kg/m3. The strength of the slab, its price, physical characteristics and scope of application. The density is indicated in the marking - PSB-S 15 or PSB-S 50. The letter C in the designation indicates that the material contains fire retardant additives that prevent it from igniting. It is this brand of expanded polystyrene that is recommended to be used for roof insulation.

Video: how regular and self-extinguishing polystyrene foam burns

Extruded foam differs from non-pressed foam in its fine-cellular structure and, as a result, much greater strength, but its cost also increases significantly. Due to its strength and almost zero water absorption, it is preferred to be used when arranging foundations, basements and other damp rooms, but it is undesirable to use this type of polystyrene foam as insulation for ventilated facades and roofs, since it, like ordinary foam plastic, is a flammable material.

Please review the certificate before purchasing

As for the quality of production of heat-insulating boards, it is regulated by GOST 15588-86 “Polystyrene foam” and must be confirmed by relevant certificates. It is worth purchasing products from well-known manufacturers who provide all the necessary information about their products. It also makes sense to conduct home tests of a piece of polystyrene foam for flammability before installation.

Insulation of various surfaces with polystyrene foam

The opinion that polystyrene foam is not suitable for insulating, for example, roofs or walls, is unfounded: in order to mitigate the disadvantages and evaluate all the benefits of using polystyrene boards, thermal insulation from them must be correctly installed. According to GOST, their scope of application is limited to the middle layer of building enclosed structures, so that the material cannot come into contact with air and, especially, with open fire.

Thermal insulation of roofing

Attic space after insulation it turns into an excellent living room. The use of polystyrene foam allows this to be done at relatively low cost. Denser grades (35 and 50) are used for flat roofs, including inversion roofs. In this case, it is necessary to lay a film or liquid waterproofing.

Pitched roofs can also be insulated with polystyrene foam boards, the joints of which are sealed polyurethane foam. However, it is much more rational to use them to insulate the attic floor, since this will not create cold bridges. The insulation is secured with dowels (preferably), cement mortar or glue, if the unevenness on the surface does not exceed 1 cm.

Secrets and features of wall insulation

You can cover the walls with foam plastic both from the outside and from the inside, but, following fire safety recommendations, a non-flammable heat insulator, for example, mineral wool, should be installed around the perimeter of all openings (windows, doors, ventilation) at a distance of 50–80 cm. When installing foam plastic boards as an internal heat insulator, special attention should be paid to the ventilation system of the internal space.

Scheme of thermal insulation carpet on the wall

The thickness of the slabs must be calculated based on the thickness and material of the walls, as well as the standard heat transfer resistance for a specific climatic zone. The density of the material should be different: for external work it is better to use denser slabs (grades 25 or 35), and for internal work the PSB-S 15 brand is quite suitable.

External foundation protection

It is optimal if the base of the building is insulated during the construction process. Those whose house has already been built, but the thermal protection of the foundation has not been thought through, will have to dig it deep into at least the width of the sheet (1 m). The prepared surface must be treated with bitumen mastic and, after it has dried, polystyrene foam sheets must be glued.

If the foundation of the house is level with the ground, the foam plastic needs to be completely covered (when backfilling it is better to use expanded clay), and it does not need finishing. In all other cases, insulation boards must be finished with plaster, brick, siding, ceramic tiles or aluminum profile. These materials are non-flammable and, in addition to their decorative function, create a protective barrier.

Thus, polystyrene foam boards are a completely economical material, the insulation of which increases the energy efficiency of the building by 3–5 times. Along with this, there is no reason to fear that polystyrene foam is not environmentally friendly and poses a threat to human health. A sufficient condition for ensuring your own safety is to give preference to well-known brands when choosing products, and to adhere to construction requirements during installation.

The modern building materials market offers many options for insulating various objects. One of the popular types is polystyrene Insulation This category is obtained by foaming the mass in a certain way. The result is a durable material that reliably retains heat inside the object.

The presented insulation has certain characteristics. To pick up the right variety, it is necessary to consider the main features of this material. Advice from professionals will help in this matter.

General characteristics

Polystyrene is a composite material. It is obtained artificially. Polystyrene insulation began to be used by humanity in the last century. Polystyrene foam and polystyrene foam are mainly made from propylene. These are insulating materials widely used in construction and other areas of human activity.

Polystyrene granules consist of pentane and isopentane. Processing of raw materials determines the subsequent qualities of the material. Polystyrene foam is obtained by treating granules with steam. Under the influence of high temperatures, pentane evaporates from the substance. At the same time, polystyrene increases in volume. This is how the well-known polystyrene foam is obtained.

A new and more advanced material is foamed (extruded or extruded) polystyrene. It was created in the 50s of the twentieth century. Invented a new type of polystyrene American company, which was able to improve existing technology.

Polystyrene insulation in this case, it is manufactured using a more complex technique. At the same time, the material receives new, improved qualities. Polystyrene is supplied to production in granules. The composite material is foamed in a special way. This technique is called extrusion. The composite is pressed through a die of a special configuration. Previously, foaming was carried out using freon and carbon dioxide. The first of the listed components is an unsafe substance for the environment. It destroys the ozone layer. Therefore, since 1999, they began to use a safer method in the production of polystyrene foam. She doesn't use freon.

Varieties

Polystyrene sheet insulation can be manufactured using different technologies. There are 5 main types of material presented. They differ in the manufacturing method. These include the following polystyrene groups:

1. Non-pressed (PSB).
2. Pressed (PS).
3. Extruded or extruded (EPS).
4. Autoclave.
5. Autoclave extrusion.

Pressed polystyrene is produced by applying high pressure to the material. This allows the structure to be compacted. By thermal insulation characteristics pressed and unpressed material are practically the same. The cost of the second type is much less. In modern construction, the pressed type is practically not used. Builders call the PSB material polystyrene foam. It is what is most often used when installing insulation for various objects.

Extruded polystyrene is one of the most popular types of insulation in this group. Autoclave and autoclave extrusion materials are very similar to the EPS group of materials. Only they are produced using an autoclave.

It should be noted that in modern construction, in most cases, EPS and PBS materials are used. They will be discussed in more detail below. The remaining rare varieties do not need detailed consideration. Meet them in modern construction stores practically impossible.

Difference between polystyrene foam and expanded polystyrene

Depending on the processing methods, the main operational characteristics that the product has are determined. polystyrene Floor insulation must have increased rigidity. The walls can be covered with a less durable material. Its cost also depends on the quality of the material.

Polystyrene foam is characterized by significant fragility and lower insulating ability. Today it is used for construction work less and less often, even despite the low cost. For example, a sheet of foam plastic 0.5 m² and 5 cm thick costs about 40 rubles. At the same time, extruded polystyrene foam measuring 0.6 m² and 3 cm thick can be purchased for an average of 120 rubles. This price difference is different performance characteristics materials.

Foam plastic is subject to deformation under load. It deteriorates and can be chewed by pests. Fungus also develops well on this material when high humidity And average temperature. For this reason, builders are increasingly using a more advanced type of material presented.

Extruded polystyrene insulation in many ways similar to the well-known polystyrene foam. However, there is a colossal difference between them. Expanded polystyrene is more advanced, universal material. It can be installed both indoors and outdoors. The main difference between expanded polystyrene and polystyrene foam is its ability to withstand heavy loads, resistance to various adverse influences and high performance.

Size and features of XPS boards

An important characteristic of EPS is size. Polystyrene insulation most often produced in the form of sheets with standard dimensions. During the production process, the hardened polymer exiting the extruder is cut into specific blocks.

Expanded polystyrene makes it different appearance. Most often these are multi-colored slabs with a uniform structure. They can be green, pink and other shades. White and transparent slabs are also produced. During the process of creating arrays, various substances can be added to the material. Fire retardants reduce the flammability of the material. Various additives prevent the development of mold and mildew on the material, and prevent pest attacks.

Most often, expanded polystyrene is sold in blocks of several slabs. The number of sheets depends on the thickness of the material. So, for example, polystyrene insulation 50 mm supplied for sale in a block of 8 slabs. For insulation that is twice as thick, the number of sheets in the package can be reduced to 4 pieces.

Mostly 60 cm wide EPS sheets are on sale. Some manufacturers may supply products with other dimensions. In this case, the width can be 58 cm. When purchasing, you should pay attention to this special attention. The length of the slabs can be 120 or 240 cm.

Main characteristics of EPS

Studying size of polystyrene insulation type EPS, it is necessary to consider its thickness. This indicator determines the main characteristics and scope of the material. Slabs with a thickness of 2 to 15 cm are available for sale. This will allow you to choose polystyrene foam for almost any object. The most popular sheets are 3-5 cm thick.

Packaging of polystyrene foam can weigh from 9 to 30 kg. This is influenced by the overall dimensions and density of the material. The last of the presented characteristics affects the performance of the insulation. Its thermal conductivity depends to a lesser extent on thickness. The only important thing is the density indicator.

When installing an insulation layer for structures that are not subject to load, you can use EPS sheets with a density of 30 kg/m³. This, for example, could be underground premises, pitched roofs, floors without screed, water tanks.

Choosing insulation for exterior walls of a house, polystyrene can have a density of 35 kg/m³. This material is suitable for vertical walls, shallow foundations, as well as moderately sloped roofs and ceilings.

For roads and runways, slabs with a density of 45-50 kg/m³ are used. Such slabs are used when arranging floors with screed (including underfloor heating systems). The material can withstand high loads. Therefore, it can also be used for deep foundations and flat roofs.

Advantages and Disadvantages

Knowing the required dimensions, density and thickness of polystyrene insulation, it is also necessary to consider the basic qualities of this material. It has a lot of advantages. The material has become popular due to its low thermal conductivity. It is not subject to destructive effects chemical acids, ammonia and other substances. Expanded polystyrene repels moisture well. It is quite dense, which avoids deformation and destruction even under high loads.

Expanded polystyrene is highly durable when exposed to pressure. He is not afraid of temperature changes and adverse environmental influences. Even in severe frost, the composite material does not lose its original characteristics. Thanks to the listed qualities, XPS is a very durable material. Its service life is estimated at tens of years.

At the same time, the installation of such plates is very simple. The sheets are light in weight. The cost of such finishing remains acceptable for many buyers.

Among the disadvantages of EPS, a number of facts should be noted. If no special substances are added to the composition, it is highly flammable. When heated, it releases toxic fumes. This material is not recommended for use in the construction of a bathhouse. Also, sheets must be protected from direct contact with sun rays. Polystyrene is negatively affected by various solvents (tar, gasoline, methane, etc.).

Scope of application

Characteristics of polystyrene insulation allow its use in various fields of human activity. It is used both in industry and in everyday life. One of the main areas of application is construction. Among other things, polystyrene insulation is actively used in the military industry, especially in the creation of passive protection means. Also in the aviation and shipbuilding industries, polystyrene is widely used as insulation materials.

The presented material is suitable for finishing foundations, ceilings and walls, as well as roofing of various types. It is used as insulation on linear objects, also providing good waterproofing for various designs.

The material does not require the use of additional vapor-permeable membranes. High strength allows the use of polystyrene foam on various vertical and horizontal surfaces under concrete or cement-sand screeds.

Using sheets of the presented material, you can isolate open areas, roads and stripes. Various communications are also insulated using the presented material.

Choosing floor insulation, rigid extruded polystyrene should be considered as one of the preferred options. It is in this area of ​​construction that its use will be fully justified. Foam or other materials will not provide sufficient rigidity for such foundations.

Polystyrene is a modern polymer that is insoluble in water, but soluble in acetone, toluene, dichloroethane and gasoline. In its initial state, it is slightly heavier than water and very fragile, but when heated it easily changes shape, and the addition of various additives turns products from it into very durable products. However, neither polystyrene itself nor products made from it are used for insulation due to too high thermal conductivity. Therefore, expanded polystyrene (foamed polystyrene) is first obtained from it, for which the molten polystyrene mass is saturated with air and additives that do not change the chemical composition of the substance.

Chemically, this substance remains polystyrene, but the physical properties change greatly. The density decreases several tens of times, mechanical strength and rigidity increases, and fire resistance also increases. Then it is used to produce such types of insulation as:

• sheets;
• granules or balls;
• permanent formwork.

Material characteristics

Despite the fact that granules, sheets and permanent formwork are made of the same substance (foamed polystyrene), their characteristics are very different. First of all, this concerns cost, secondly, such important parameter, as the ability to transmit water vapor. The only parameter that unites products of different types is the brand, indicating the density in kg/m 3. The most popular brands for insulating houses are 15, 25, 35, 50.

Next comes the difference in the production method - non-pressed (PSB) and pressed (PPS) foamed polystyrene. The difference between them is that in the first case granules are used, which are heated to high temperature in air before sintering. This expanded polystyrene foam is characterized by low mechanical strength and low price. Pressed expanded polystyrene is made from a molten mass of polystyrene, which is first filled with air and then pressed into molds of the desired size. The main difference between type 2 foamed polystyrene is its greater fracture and compressive strength. The materials also differ in appearance; PSB looks like it consists of separate, clearly fragmented balls. Expanded polystyrene of the second type is often sold under the XPS brand, which means that the material meets the requirements of the EN 13164:2008 standard adopted in the EU.

The letters after the indicator of the method for producing polystyrene foam mean:

1. C is a low-flammable, self-extinguishing material to which a fire retardant is added.
2. P - the material is obtained by cutting large pieces finished products into blocks of the required size.
3. RG - the same as P, only from graphite-containing material.
4. A – with a smooth side edge.
5. B - with a side edge chosen as a quarter.
6. F - intended for insulating facades under plaster.

Insulating sheets

Typically, insulating sheets are made in dimensions of 1x1 m, but other sizes are possible. For their manufacture, both types of polystyrene foam are used. PSB-15 sheets are used for insulating floors and ceilings, and occasionally for walls (if you need to save a lot on material). PSB-25 and PSB-35 are most often used for external insulation of walls, attics and roofs, and PSB-50 is used to reduce heat loss from the foundation. PPS sheets are used in cases where it is necessary to ensure maximum thermal efficiency at minimum thickness. The advantage of insulating sheets is their ease of installation - they are nailed to the wall using special anchor nails. A significant disadvantage is the low vapor permeability of the material, therefore wooden house, sheathed with such slabs, loses its main advantage - the ability to pass excess moisture through the walls, providing a dry microclimate in the rooms.

Approximate cost of insulating sheets made of foamed polystyrene of various brands per 1 m3:

Granules

To produce granules from foamed polystyrene, defective PSB products are used, which are crushed using special devices. The resulting balls retain all the properties of the original product, with the exception of vapor permeability, which increases sharply. Therefore, granules are well suited for insulation even wooden houses. Granules are used to create polystyrene concrete and for filling into the internal cavities of brick and wooden houses. The cost of granules depends on the material from which they are made and amounts to 500–2000 rubles per 1 m 3.

Permanent formwork

Permanent formwork made of foamed polystyrene is a ready-made block that simultaneously performs two functions - it creates a perimeter (formwork) for pouring concrete and provides insulation concrete wall. The advantage of using formwork is the reduction in labor intensity, the disadvantage is the high price. For the manufacture of such formwork, polystyrene foam of the PPS-35 and PPS-50 types is used. You will find the dimensions of the most popular types of formwork in this photo:

Locks are cut on the upper and lower planes, as well as on the front and rear ends, which allow you to securely connect both blocks in one row and adjacent rows. The full range of expanded polystyrene blocks includes corner and transition elements, so they can be used to create a wall of any configuration. After assembling one row of formwork, reinforcement is inserted into it, then either 3-5 rows or the entire wall are erected, after which it is poured with concrete and compacted with vibrators. The thickness of the internal insulating layer is 50 mm, the thickness of the outer layer is 50–100 mm (depending on the formwork model). The cost of any formwork element depends on:

• manufacturer's brand;
• material density;
• shapes and sizes.

The average price of foamed polystyrene formwork is 500–900 meters per 1 m2, but there are samples 2–3 times more expensive. In addition, the cost is affected by the presence of an additional insulating layer if the standard dimensions are not enough. Such blocks are produced to individual order, so the thickness of the outer insulating layer can be any.

Where else is foamed polystyrene used as insulation?

Foamed polystyrene is used to create sandwich panels and heat blocks, as well as for internal insulation of frame houses, including those built using double-timber technology. Where it is important to maintain a high coefficient of vapor permeability, granules are used; in other cases, slabs are used. Expanded polystyrene is also used in the creation of polystyrene concrete - one of the types of lightweight concrete of low strength with a very low heat transfer coefficient. Such concretes are used to create screeds for heated floors and pour walls in houses with reinforced concrete frames.

Comparison of polystyrene foam with other insulation materials

We have compiled a table that includes the most important parameters. Due to restrictions on table width, each parameter is assigned a number:

1. Specific thermal conductivity coefficient (the lower it is, the higher the thermal insulation properties of the material).
2. Vapor permeability (the higher, the better).
3. Ability to absorb water.
4. Hydrophobicity (some materials sharply reduce their characteristics if even a little water gets into them).
5. Is the material suitable for foundation insulation?
6. Cost per 1 m3 (due to the fact that many materials are represented by samples with different levels of density, we took polystyrene foam of the PSB-25 and PPS-S-16 brands and samples of other materials as close as possible to them in thermal conductivity as the standard.
7. The need to use highly specialized equipment during installation that cannot be used for other work.
8. Difficulty of installation (relatively, on a 5-point scale).
9. Flammability.