Some authors of the Dom Praktika website have already written about how harmful polystyrene foam is or where it cannot be used. However, as an editor, over the last week I have received 4 (four) letters in the mail with reproaches that we are in vain considering this material so one-sidedly.
People write that polystyrene foam is very good as insulation, that it is cheap, and that it is indispensable in private construction. And in order to remain within the bounds of objectivity and present all points of view on our website, I asked two authors from Tver, Anatoly Rudenko And German Shevroshevich, write a full article in which foam plastic as insulation will be considered from all sides and in all respects.
Despite everything, polystyrene foam has every chance of remaining the “most popular” insulation material.
Expanded polystyrene (EPS) is popularly called “foam plastic” - after the name of the Finnish company that supplied expanded polystyrene to the USSR. Just like “copier”, the name of the company over time was transformed into the name of the material and became a household name.
Currently, hundreds of companies produce foam plastic in Russia and abroad. Equipment for the production of polystyrene foam is cheap and does not require skilled labor for operation and maintenance.
Let us now consider the main properties of polystyrene foam as insulation:
Let us now move on to the area of application of expanded polystyrene in modern private low-rise construction.
It will not be possible to use polystyrene foam as basement insulation due to its hygroscopicity. As mentioned above, expanded polystyrene (EPS) absorbs moisture. At the same time, its thermal conductivity increases sharply, and its thermal insulation properties decrease significantly.
In addition, when the foam gets wet in the spring and autumn period, then when it freezes, the water between the foam balls turns into ice and breaks it. After the first cold season, wet polystyrene foam turns into dust - individual balls that do not retain heat.
But it is quite possible to use polystyrene foam as base insulation. In this case, the PPS is covered on top with a layer of plaster, which is applied to a mesh base. The foam is attached to the base using plastic fastenings"fungi" to which it is then attached metal grid with a fine cell from 0.6 to 0.8 cm.
Then plaster is applied over the mesh and a decorative layer is mounted on it - wild stone, clinker brick, facade tiles.
You can also use it to attach foam to the base. metallic profile under plaster. But it is better to refuse to use the wooden block system. As practice shows, wooden blocks on concrete base the base begins to rot from below, moisture also gains access to foam insulation. And rodents are beginning to show increased interest in such a base.
Let us immediately make a reservation that the use of polystyrene foam as insulation for the walls of a house is only possible in a wet facade system. The use of foam plastic in ventilated facades for any facade material prohibited - it is contrary to fire regulations.
Any stray spark from your or a neighboring area from a barbecue or chimney baths or houses can be brought into the ventilation gap by the air flow. There, this spark can hit the foam that is open or covered with a waterproofing film. A constant flow of air in the ventilation gap brings the oxygen required to create an open fire and fan the source of fire. This is how everyone is respected the necessary conditions for a fire to occur inside the ventilation façade, under façade cladding. The house will burn “inside the walls”; fire crews arriving at the scene of the fire will not be able to help with such a spread of fire.
Polystyrene foam as insulation for exterior walls of a house - only in a wet façade system.
Thus, the place of foam plastic on the facade modern house– under a layer of plaster and decorative solid non-flammable coatings. When there is no access to open fire and oxygen, and there is no direct exposure to moisture, polystyrene foam as insulation exhibits its best properties - light weight, low thermal conductivity and reasonable cost.
Insulating the floor and ceiling with polystyrene foam is only possible if the foam plastic is covered with a screed on top and a layer of concrete below. That is, The best way the use of polystyrene foam for insulation of floors or ceilings is insulation concrete floors in houses made of blocks, bricks or concrete.
Polystyrene foam as floor insulation - only under screed on concrete slabs.
When using this, it is important to protect the foam from moisture that may enter it from the screed. For this purpose, waterproofing is laid on both sides. There is no need to worry about water vapor from the room in such a cake, since concrete has very low vapor permeability.
It is not at all worthwhile to insulate the following parts of the house with polystyrene foam:
Polystyrene foam (or expanded polystyrene) is a synthetic building material that is widely used for construction and repair work. Polystyrene foam as an insulation material has found its application in insulating the internal and external walls of buildings.
Properly installed polystyrene foam has a number of advantages, thanks to which it enjoys well-deserved popularity among construction companies and private developers.
Before using foamed polystyrene to insulate a facade, you need to choose it correctly. Polystyrene foam used as thermal insulation must contain fire retardants - substances that prevent its combustion.
Their presence is indicated by the letter “C” in the abbreviation (PSB-S) or the letter “R” if the material is foreign-made. Equally important are indicators such as density and thickness. To insulate the outside of residential buildings, slabs five centimeters wide, no more, are usually used.
Depending on the type of foam, its density can vary from 15 to 35 units. And since foam plastic is quite warm material, its density should not be very high. To insulate the walls of a house, it is enough to take insulation with a compression density of 15 or 25 units. Density 35 is used for floor insulation.
In addition to density, polystyrene foam is characterized by the following qualities and characteristics:
You can insulate walls with foam plastic both inside and outside. However, most often insulation brick wall carried out outside. External thermal insulation allows you to shift the point of greatest freezing, which prevents cold from penetrating into the house. The walls of the house should be heated by internal heating. When installing foam plastic from the inside, the brick wall will be insulated from the inside, which will interfere with its heating.
As a result, the “dew point” will shift between the wall and the polystyrene foam. On inner surface walls under the insulation, moisture will begin to accumulate, saturating the walls and freezing in cold weather. As a result, all this will lead not only to freezing of the house, but also to the rapid destruction of the insulation and the brick wall itself.
Therefore, it is advisable to mount foam insulation boards on the outside of the facade. But in this case it must be covered with a layer of plaster, this will protect the material from sun rays, thereby extending its service life and also giving the structure the necessary strength.
A very common question is: “Is it possible to insulate walls with polystyrene foam? wooden house?»
. Among experts, you can find two opposing opinions on this matter: some say that it is possible, others are categorically against it. Let's try to figure it out.
One of the reasons why many speak out against insulating a wooden facade with foam plastic is its low vapor permeability, which can cause the wood to rot. At the same time, there are many people who took the risk of insulating their wooden house this material, and are satisfied with the result.
One of the main advantages of wood is its ability to “breathe”. This is one of the main advantages of building a country wooden house. In order not to lose this quality, the thermal insulation of the facade should be carried out with care. The consequence of improper insulation can be not only insufficient air flow into the room.
Proper thermal insulation technology implies that the vapor permeability of building materials should increase towards the street so as not to impede the escape of fumes from the house.
If this rule is violated, moisture will condense on a denser material, which will lead to wetting of the insulation, the formation of condensation and, as a result, rotting of the wood. That is why, when choosing insulation for your wooden facade, pay attention to the vapor permeability of building materials.
As can be seen from the table, the vapor permeability of foamed polystyrene is much lower than that of the walls of a wooden house. From this we can conclude that it is undesirable to insulate wood with polystyrene foam, unless you find this material with higher vapor permeability.
But what does practice tell us? Many people, despite recommendations or simply not knowing about them, insulate wooden facades polystyrene foam and are quite satisfied. The question arises, where does the condensate go?
It should be noted here that the rate of decay directly depends on the amount of moisture evaporating from the house. If the room is equipped good system ventilation, then the harm from a small amount of fumes, of course, will be less. However, if you insulate with foam plastic wooden sauna, the result will be obvious within the next few years.
The main reason why foam plastic as insulation is so in demand in Lately, is its low cost. That is why, in an effort to save money, many decide to insulate wooden buildings using this material.
However, over time, such savings can become ruinous. As an alternative, it is better to choose mineral wool. It does not create obstacles in the way of fumes, which perfectly reach the ventilation gap between the insulation and the cladding. The walls “breathe”, and you can enjoy life in your wooden house.
There is another method of insulation - using polystyrene foam in liquid form. This type of casting foam is made directly on the construction site and poured into pre-prepared formwork. Liquid foam can be used to insulate a brick, stone and concrete house.
Thermal insulation technology called “well” masonry is well suited for this material. It provides a three-layer structure: wall, insulation, additional brickwork. In this case, the insulation is pumped between two layers.
As advantages liquid foam can be distinguished:
Modern requirements for ensuring energy efficiency of construction projects are increasing and therefore it is necessary to use high-quality thermal insulation materials.
One of them is foam insulation. They insulate walls, ceilings, and roofs both indoors and outdoors.
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Thanks to its heat and sound insulation properties, as well as ease of installation, it has become one of the most popular materials in the world. construction market. But is this material really so ideal? When paying attention to polystyrene foam, you should study not only its basic properties, but also the conditions and requirements for its operation.It is a foamed heterogeneous cellular structure consisting of granules sintered together under the influence of high temperatures, the volume of which is filled with air. Cell sizes can be up to 1 cm in diameter, depending on technical specifications manufacturing. The raw materials for its production are polymers, the composition of which affects the basic properties finished material. Foams consist of micro-sized cells and have large area contact with air due to the presence of internal thin elastic sealed walls. The bulk of the foam is air up to 98%, which improves its insulating characteristics.
Since the foam plastic is filled with air, which is an excellent thermal insulator with a thermal conductivity coefficient of 0.026 W/(m*K), depending on the size of the cells, the total thermal conductivity of the material can be achieved up to 0.043 W/(m*K). One of the closest competitors in this parameter is, but its thermal conductivity is higher and therefore it will be necessary to increase its thickness by about 5-10% compared to the thickness of the foam. In addition, using foam plastic as insulation, during installation there is no need to install sheathing, and the connecting seam can be made with a minimum gap and high accuracy.
Polystyrene foam is a lightweight but durable material that is able to retain its shape under certain loads, compressive and tensile stresses. However, it is fragile and therefore cannot be installed on an uneven surface. On the other hand, it can be cut with any cutting objects with high precision. This allows you to make a perfect fit and form the most complex joints. The density of the finished boards can be 15-50 mg/cm 3 depending on the grain size. That is, it can be attached to walls and ceilings using an adhesive connection.
Subject to operating conditions, the material is able to retain all its properties. It does not decompose and is not subject to shrinkage, which has a positive effect on its specifications such as strength and durability. Resistant to salts, weak acids and alkalis. Does not react with construction mixtures and materials and therefore can be used in the construction of any objects. It is not affected by microorganisms, and because it repels water and does not accumulate moisture inside the material. Consequently, sudden temperature changes will not be able to disrupt its structure.
The level of water absorption by a material plays an important role in the construction of objects from materials that cannot withstand the influence of moisture and deteriorate or collapse under its influence.
Note!
Foams are not non-hygroscopic, since with prolonged exposure to water they can absorb only up to 3% of the total volume.
This value depends on the technological features of production and the tightness of the cell connections, as well as their sizes. That is, water can only penetrate through the air channels that remain between the cells. Water vapor will also not be absorbed into large quantities, because the diffusion resistance coefficient of the foam is high.
Since polystyrene foam is one of the most used thermal insulation materials, the question arises: “Is foam plastic harmful as insulation?” It contains a dangerous substance - styrene. Modern technologies made it possible to significantly reduce its content in finished product, so its amount is absolutely not harmful to health. It is released only when heated above +40 0 C in small quantities. Therefore, it is used to insulate walls with outside so that the toxic vapor escapes into the atmosphere. In addition, self-extinguishing foam can be used. In case of fire, foam plastic will be the least toxic compared to other finishing materials.
Wall insulation
The duration of operation directly depends on environmental conditions and the influence of temperature or mechanical influences on it. Foam plastic is able to minimize the influence of wear factors due to its chemical neutrality to many building materials. It also has minimal shrinkage of just a few millimeters over its entire service life. However, if installation errors are made or the loads on the object’s structure are incorrectly calculated, wear may increase. That is, deformation of the walls or roof to which the insulating boards were securely attached can significantly deteriorate the properties of the insulation and reduce the service life of the foam several times.
The principle of insulation
Only those home owners who either carried out the installation themselves, following the installation technology, or had an experienced team of builders do it for them, are satisfied with this insulation. The material is relatively inexpensive, easy to install and has excellent thermal insulation characteristics. Premises after its use become energy efficient and economical.
Note!
Installation outside the main walls allows you to protect them from the influence of precipitation and extend their service life.
If you insulate the walls from the inside with foam plastic, you will reduce the amount of thermal energy spent on heating the walls of the house. Negative reviews can only be a consequence of mistakes made during installation and operation or incorrect calculations of the thickness of the insulation.
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Styrofoam is a group of materials belonging to the class of foamed plastic gas-filled masses. “Gas filling” determines the low density of this material, which explains the high thermal insulation and sound insulation qualities of the material.
Source material for foam plastics there can be a wide variety of plastics, which in “commonwealth” with technological features The manufacturing process determines the final properties of the foam (density, resistance to the environment) and its suitability for various purposes.
The foam that we are used to seeing as packaging for household appliances, is pressless expanded polystyrene.
Historical reference! “Styropor” is the brand name for pressless expanded polystyrene, invented and produced in 1951 by Basf by polymerizing styrene with the addition of pentane (a blowing agent). It is widely known due to its high thermal insulation qualities - it consists of 98% gas.
Expanded polystyrene is a petroleum refining product with very low consumption of raw materials of natural origin.
In favor of this material says a number of its properties. Namely…
Properties of polystyrene foam as insulation!
Thermal insulation. This property of foam plastic as insulation is due to the “air-filled” environment of the material, since air is already a good heat insulator, and “enclosed” in porous cells is not capable of convective heat exchange. The result is low thermal conductivity of the material, which determines their high thermal insulation qualities. The closest competitor to foam plastic in the field of thermal insulation is mineral wool, but foam plastic has advantages in ease of processing and installation.
The lower the density of the foam, the higher its thermal insulation qualities. A 10 cm layer of low-density foam is equivalent in thermal insulation properties to a 40 cm pine wall, a 60 cm wall made of aerated concrete, 1 m of expanded clay concrete or 4 m of concrete. This is a strong argument in favor of using polystyrene foam as insulation.
"Loyal" compatibility expanded polystyrene with other building materials, which allows the use of plastering of walls insulated with expanded polystyrene, various types plaster mixtures. Also, foam plastic does not have an aggressive effect on other materials.
Resilience material in biologically active environments, immunity to decay, the action of fungi and bacteria. But!.. Rodents may like polystyrene foam.
Long service life in critically changeable conditions up to 20 years, in normal climatic environments - more than 50 years of maintaining the properties of polystyrene foam as insulation.
Fire resistance polystyrene is ensured by the addition of special ingredients to its raw materials - fire retardants, which prevent active combustion of the material.
Good soundproofing qualities foam in the field of acoustics are determined by the density of the foam, as well as the type of porosity of the material. Let's talk about the sound-absorbing properties and sound-reflecting properties of materials.
The closed porosity of most foam plastics (expanded polystyrene, polyvinyl chloride, extruded polyethylene) contributes to high-quality sound absorption in the range from 1600 to 2000 Hz (for example, fan noise), but at the same time they reflect sound well in wide range. This determines their use as soundproofing materials.
Open porosity is present in foams such as polyurethane foam. This structure determines the excellent sound absorption of the material throughout the entire sound range, and the virtually complete absence of a reflective effect in the material. This determines the applicability of such material for organizing excellent acoustics in a room, sound speakers, etc.
Foam is capable maintain its shape and size in the temperature range from -60 O C to +95 O C., and, despite its low density, withstand quite large mechanical loads.
Surrounding yourself in modern life synthetic materials, we don’t always think about whether this familiar item is dangerous for our health?
Relatively high-quality polystyrene foam under normal conditions of its use, you can be calm, since it does not emit substances harmful to humans in dangerous concentrations.
Polystyrene foam also has a beneficial effect on the environmental balance in construction, since it is capable of recycling as a thermal insulating filler for concrete mixtures and blocks with internal voids. It can also be used to improve soil structure
Important! Use high-quality material from proven certified manufacturers.
Today, behind the word polystyrene foam there is a large group of polymer materials, similar in production methods and basic properties. How to decide on the choice of the necessary polystyrene foam for insulation or soundproofing of a house? Let's try to figure it out!..
The main types of raw materials for the production of foam plastics:
Polystyrene foam is a familiar foam plastic that can be easily seen by opening a box of any household appliances. Looks like a honeycomb when cut.
It consists of small balls interlocked with each other and can be pressed or pressless. The difference in the strength of the connection of granules with each other, which determines mechanical strength polystyrene foam for fracture and rupture.
Example of labeling of foam plastics from domestic manufacturers:
PS-4 or PS-1 is a tile foam with a closed-cell structure, made using press technology. Density from 40 kg/m 3 to 600 kg/m 3 ;
PSB-S is a non-pressure foam plastic with self-extinguishing ability.
Is foam plastic harmful as insulation? There is no clear opinion regarding the toxicity of polystyrene foam materials. Polystyrene is, in principle, non-toxic. The danger may be posed by residual styrene, which under certain conditions can be released from the foam and negatively affect the well-being of people in contact with it.
Therefore, when choosing such materials, you should give preference to high-quality and certified materials from trusted manufacturers.
The high flammability of these materials also does not speak in favor of their environmental safety. But the introduction of special additives into the raw material made it possible to obtain self-extinguishing foam insulation. But, it is still recommended to use polystyrene foam boards for external insulation.
Extruded polystyrene foam is characterized by higher strength, thermal insulation, and environmental safety. Has a higher price.
“Polyethylene” foam is an elastic, soft to the touch, translucent material. Mainly used for making food packaging.
This type of polystyrene foam is a non-flammable, elastic, low-toxic material.
Foam rubber is a typical example of polyurethane foam. Let's remember... Elastic material, easily passes air, absorbs water and water vapor and is “afraid” of exposure to sunlight, turning yellow and gradually collapsing upon contact with it. Used in the manufacture of furniture and insulating and insulating materials for windows and doors. When burned, they release toxic smoke.
Using polystyrene foam as wall insulation is cost-effective and convenient way insulation.
Walls, ceilings, roofs, floors, foundations, balconies, loggia can be insulated with expanded polystyrene...
Expanded polystyrene when insulating walls from the outside not only does not damage appearance building, but also “provides” the opportunity to model the facade at your discretion.
