Complete information about extruded polystyrene foam

This synthetic thermal insulation material was created by American specialists in 1941.

As soon as it is not called: extruded or extruded polystyrene foam, EPS, EPS, XPS. But this does not change the essence, as do the widest possibilities of artificial insulation: from decorating door frames and ceilings to thermal insulation of railways, highways, sports grounds and ice arenas.

Which is not surprising, since extruded polystyrene foam has excellent characteristics (see below).

Eps insulation

It is produced by extrusion - styrene granules are mixed with an agent, which is foamed through an extruder. Thanks to this method, capillarity in the material is reduced, because all air cavities are completely closed. For this reason, very low water absorption. Foamed polystyrene foam is styrene obtained by polymerization with the addition of pore-forming pentane.

The extruder that is used to make EPS is also used to insulate water containers. Produced using this method, polystyrene foam is completely hydrophobic and almost does not absorb water. Therefore, it is used for external insulation of buildings. This material is completely resistant to corrosion, temperature changes, and mineral solvents.

EPS is now used in the construction of flat roofs. But they use it the other way around - not before waterproofing, but after it. Thereby protecting the waterproofing carpet, and a cement-sand screed is made above it. Such a roof can last about 30 years or more. The extruder is also widely used for thermal insulation of railway tracks and automobiles; when used, asphalt and railway rails deteriorate less. It is very practical, it turns out to be very hard, much harder than regular foam.

In this regard, it is used in the construction of floors, balconies, and garages. In terms of its chemical composition, it turned out to be much more practical than others.

Price

The price of extruded polystyrene foam in large shopping centers is balanced to the market level of building materials. The cost of extruded slabs depends on a set of pricing factors:

• sheet sizes;
• slab thickness;
• technical characteristics of the material;
• manufacturer's technologies.

In comparison with other types of insulation, extruded varieties belong to a high price category. The use of this heat insulator must be economically justified. For example, one slab measuring 1250×600×30 mm, Ursa brand, costs 1,455 rubles without delivery.

Application area

The extruder is used in various areas of the national economy. Two types of products are used in construction: non-pressed and extruded. Unpressed polystyrene foam is obtained when foamed styrene granules undergo polymerization in an aqueous suspension under high pressure. And extrusion is obtained when the molten mass is forced through an extruder. They are mainly used for insulation of floors and ceilings in the construction of residential buildings. Due to the fact that it is solid in structure, it can be used for insulation of those surfaces where significant loads on the surface are possible.

In addition, it can be used for thermal insulation of walls where its resistance to loads is not so important. But on the other hand, its increased thermal insulation characteristics are important. After all, when using materials with a low thermal insulation coefficient for insulation, the result is that the buildings have to be insulated with something else, since the walls do not provide normal thermal insulation. As a result of using cheap materials for insulation, it is necessary to dismantle and still use high-quality materials.

Briefly about the main thing

We can say about the EPS board that it is a universal thermal insulation material for all structural elements of buildings. It retains heat perfectly, insulates noise, is not afraid of water and weighs almost nothing. But its scope of application is limited by two factors: toxicity when heated and very low vapor permeability, due to which expanded polystyrene is not recommended for insulating wooden houses. The quality of the material depends on strict adherence to the production technology regulated by GOST. And its installation is quite simple and accessible even for beginners in construction.

Specifications

In terms of its technical characteristics, the extruder is much superior to a large number of insulation materials, and in some cases it has no equal. Technical specifications include:

• Density, kg/m3
• Thermal conductivity at 25C, W/mK
• Compressive strength during deformation, mPa
• Bending strength, mPa
• Modulus of elasticity, MPa
• Water absorption over 24 hours, %/volume
• Vapor permeability, mg/m h Pa
• Capillary humidification
• Application temperature, C

Not all characteristics are important in everyday understanding. An important indicator is vapor permeability. This is a value that is equal to the amount of water vapor in millimeters that passes through 1 m2 of an extruder 1 meter thick in 1 hour. This indicator is important when designing residential premises. This indicator shows whether the surface will “breathe” after insulation with the selected material and how normally it will breathe.

Also, thermal conductivity is an important indicator. This is the extruder's ability to transfer thermal energy. This ability also depends on such a characteristic as density. Just as EPS surpasses many materials in density, extruded polystyrene foam also surpasses many in thermal conductivity. Thermal conductivity coefficient is 0.028-0.03 W/(m •°C). This material retains heat for as long as possible, much better than conventional cheap insulation. Therefore, it is advantageous to use it when insulating both walls and, to an even greater extent, floors and ceilings of balconies and horizontal roofs.

Another important characteristic is water absorption. According to this indicator, the described material will give odds to almost all insulation materials. XPS can be used to retain water in many wet areas. It practically does not allow water to pass through.

Thermal insulation of walls. Insulation with extruded polystyrene foam.

Despite the widespread use of EPS, most people purchase it to insulate walls, which are the main source of heat loss (up to 45%). Here are some useful recommendations for those who plan to insulate the walls of their home with extruded polystyrene foam.

1. It is better to carry out work in dry weather. Air temperature - not lower than +5°C.
2. The slabs must be glued from below, in strictly horizontal rows.
3. Each top row is glued end-to-end to the bottom row. Try to install the stove correctly the first time, because after a couple of minutes it will be difficult to dismantle it.
4. If the wall is old, with peeling and falling off plaster, then the slabs must be fixed with dowels.
5. During the first three days after installation, it is necessary to protect the wall from direct sunlight. Then you can install a reinforcing mesh on it.
6. After installing the mesh, we recommend waiting another 3 days, then start plastering. Work should be carried out in a temperature range from +5 to +25°C in clear and calm weather. Apply the plaster using the wet-on-wet method. This means that until the bottom layer is dry, lay the top one.

Adhesive for extruded polystyrene foam

The author of the article, when solving this issue, chose Ceresit CT 84 (not an advertisement) - this glue was recommended three times: at a construction forum, in a store, the manager whom I trust and the head of the installation department spoke very highly of Ceresit. The glue sets very quickly and reliably - even at high humidity and is quite economical. I applied it with this thing with a 20 mm indentation from the end, and then in the center along the slab. We overwintered the first winter and the flight was normal.

Manufacturers and GOST

In Russia, as in Ukraine, many companies produce EPS. Well-known companies - Penoplex, Dom Chemical, Ursa, Teplex and many lesser known ones. They all produce materials of more or less high quality. Of course, Western manufacturers offer products of the highest quality in terms of toxicity, but domestic manufacturers are now not inferior in quality to them.

After all, the quality of manufactured products is regulated by all sorts of GOSTs and other laws that indicate what quality the manufactured products should be. Therefore, there is not much difference between domestic and imported EPS manufacturers, because GOSTs are more or less the same everywhere, and some parameters in our GOSTs are more demanding.

We apply - we insulate

And indeed it is. EPPS has become widespread in the military industry in the production of passive protection equipment, shipbuilding, and construction.

Low thermal conductivity determines the use of extruded polystyrene foam as insulation. Rigid thermal insulator produced with different densities is used to insulate buildings and structures that differ in purpose and operating procedure. Using it to insulate foundations, walls, ceilings, roofs, and linear objects allows not only to conserve heat, but also to ensure waterproofing of building structures.

Low vapor permeability allows installation without the use of vapor barrier membranes. High strength - use the material as insulation of horizontal surfaces under screeds made of concrete and cement-sand mixtures, as well as insulate open areas, roads, railways, and runways with it. Extruded polystyrene foam is convenient for insulating various life support communications, both in trenches and in technical basements and attics.

Myths about harmfulness

Expanded polystyrene is made from polystyrene and is divided into two types: foamed polystyrene and extruded. This is according to GOST 52953-2008. They differ from each other in physical characteristics. They are produced from styrene monomer. According to some myths, it is poisonous, but these are just myths. It is so toxic in the amount that it is present in polystyrene foam, like the Crystal detergent. Everyone uses it and, after washing, they eat from the dishes.

Confirmation that polystyrene foam is safe for health is the fact that food packaging is made from it . Today there is practically no question whether this material is harmful. In Europe, this chemical reaction product is used everywhere in construction. Its superior properties are used for thermal insulation of walls and floors. It can also insulate ceilings, but it is not soundproof.

Expanded polystyrene is not a highly flammable substance. The spontaneous combustion temperature is above four hundred degrees. When ignited, it burns independently for 1 second. It can be stated that this material is one of the safest materials in terms of combustion. It is most widely used in the construction industry for thermal insulation of facades and very rarely in the decorative field. As a result of its fairly high vapor permeability, this material is used for insulating buildings, without additional air conditioning. In practice, it allows the walls to breathe approximately like wood across the grain.

Typically, walls are not thermally insulated with this material on the inside, but only on the outside. This is because it is resistant to many atmospheric conditions, especially water. If it is used for floor insulation, then a cement-sand screed should be placed on top of it. For floor insulation, this is generally the most ideal insulation.

Classification

Marking 31C

Marking 31C has established itself as a high-quality element of insulation of unloaded sections of structures. An excellent example in this direction is work with foundation walls. This marking can be found in the underfloor heating product.

31C has also found wide application in work on insulation of sewer systems. Operation is intended exclusively in structures that are protected from fire, since its fire resistance level corresponds to category G4.

Marking 35

Marking 35 has significant differences from 31C. They consist in the difference in specific gravity indicators and the general level of fire resistance. In the creation of expanded polystyrene with the marking 35, a fire retardant is used, with the help of which it is possible to increase fire resistance.

Due to its fire resistance qualities (low flammability), the product has also proven popular for roofing. The most popular work in which grade 35 polystyrene foam is used is the insulation of all kinds of structures that perform enclosing functions.

Marking 45

Expanded polystyrene with the marking 45 is superior to the first two options due to the fact that its compressive strength has a huge margin. It can be successfully used not only in insulation; it opens up all its possibilities in such large-scale work as road construction. Expanded polystyrene grade 45 is also actively used in work on runways.

Characteristics:

• The specific gravity of polystyrene foam has little effect on heat retention performance.
• The specific gravity indicator has an impact on the strength characteristics.
• The effectiveness of insulation (thermal insulation) is affected by the thickness of the sheet.

Markings of polystyrene foam 31 and 31C have basically similar qualities. The most striking difference between these two brands lies in the categories that are responsible for fire resistance. 31 has category G1, and 31C G4.

An opposite example is marked polystyrene foam 45 and 45C. Unlike expanded polystyrene 31 and 31C, these are different on literally every point. One of the few indicators that these brands of expanded polystyrene have in common is fire resistance at the G4 level.

Comparison of foam plastic and ESPP

Those who have dealt with construction are familiar with the question of choosing material for insulation. And they have heard their pros and cons more than once about both polystyrene foam and expanded polystyrene. Despite the fact that polystyrene foam is essentially a derivative of polystyrene foam, the difference lies in the production of these materials. Expanded polystyrene can be used in packaging and thermal insulation. Polystyrene foam is obtained by treating raw materials with water steam. As a result of this procedure, the volume of the molecules increases and they sinter together. But as the granules grow, they become larger than micropores - this is not very good.

The strength of polystyrene foam drops sharply over time. Under the influence of precipitation and other damage, the bond between the granules weakens, and the material simply scatters into small granules. But expanded polystyrene is produced by extrusion. This affects the structure of the material. As a result of the fact that the material melts, it has a solid structure of closed cells filled with gas among themselves.

When producing a fire-resistant version, the molecules are filled with carbon dioxide. Polystyrene foam allows water vapor to pass through better, which ultimately leads to the destruction of the foam itself. And polystyrene foam, due to the fact that it has a higher density, allows less steam to pass through and is more resistant to water, but the cost also increases because of this.

The following differences can be distinguished between polystyrene foam and expanded polystyrene:

• Expanded polystyrene is a type of polystyrene foam
• The density of expanded polystyrene is higher
• Polystyrene foam allows moisture and steam to pass through from the outside
• The density of one is 10 kg/m3, and the other reaches 40
• The foam has granules and they are clearly visible
• Expanded polystyrene is more expensive when used in thermal insulation

As a result of our conversation, we can draw the following conclusions. Extruded polystyrene foam is a very progressive material for use in thermal insulation of walls, and especially floors. It is low-toxic, fire-resistant, moisture-proof, and water-resistant. Compared to polystyrene foam, its service life is much longer. It does not break down into small granules. Therefore, although it is more expensive, its use in thermal insulation is much more effective.

What is the material

Strength and low thermal conductivity are due to the fine-cell structure of the material.
Among all polystyrene foams, extruded polystyrene is the strongest. This polymer is produced in the form of sheets of a certain size. The structure itself is obtained by foaming polystyrene, while it goes through the stage of heating in an extruder until it melts. Next, it is squeezed into a certain shape and, after cooling, cut.

The high strength of such a heat insulator is due to its fine-cell structure obtained at the time of sintering. The pores inside the polymer have a closed round shape, due to which extruded plastic (EPS) does not allow steam and moisture to pass through.

How to choose

To facilitate the selection of a suitable grade of polystyrene foam, it is recommended to pay attention to the following criteria

Manufacturers

To create reliable thermal protection, it is recommended to give preference to well-known brands that produce insulation that meets the requirements and declared characteristics. It is possible to produce high-quality material only if you have modern equipment and adherence to the technological process. Among the companies that deserve trust are:

• Technoplex;
• KNAUF;
• URSA;
• PENOPLEX;
• TechnoNIKOL;
• Elite-Plast.

The main argument in favor of the products of a particular manufacturer is the availability of a certificate of quality and environmental friendliness of the raw materials used for the production of expanded polystyrene.

Length, width, thickness

Manufacturers produce standard and non-standard slab sizes. The sheets have different lengths, thicknesses and widths. The predetermining parameter when choosing insulation is thickness. It varies from 20 to 100 mm. A clear understanding of the purpose for which insulation is being purchased - external or internal work, for the floor or roof - will help you decide on a purchase.

Standard sheets have a length and width of 1000, 2000 mm. Upon special order, the manufacturer cuts the slabs according to individual parameters. Sheets available for sale:

• 1200x600 mm;
• 500x500 mm;
• 900x500 mm;
• 1000x1000 mm;
• 1000x500 mm.

Interior or exterior work

Expanded polystyrene is not produced separately for interior and exterior use. The insulation is selected taking into account the brand, thickness and density of the sheet.

Sheet sizes

Extruded polystyrene foam is produced in slabs with the following parameters:

• width range – 500-600 mm;
• length range – 1200-2400 mm;
• thickness range – 20-150 mm.

At the request of the client, sheets can be cut into different sizes.

Criterias of choice

When choosing a foam adhesive, you should pay attention to its performance qualities. The adhesive composition is used for interior and exterior work

This suggests that it should interfere with heat transfer. Speed ​​is important for work. The sooner the composition is in place, the faster finishing work can continue. Adhesive for polystyrene foam must have good adhesion. The better the grip, the better the work

An equally important quality is consistency. The distribution of glue over the surface largely depends on the consistency.

Consistency

Consistency is the state of liquid and solid bodies, determined by their density. Substances with high density are thick. During the gluing process, this interferes with good distribution of the composition and increases its consumption. A substance with low density will spread. This will make the work poor quality. A good adhesive foam has a light consistency, medium thickness and a hardening density of about 25 g/cm3.

Vapor tightness

Vapor permeability is the ability of a material to pass or retain water vapor

Quality is very important for insulation and finishing of buildings. If the finishing material is vapor permeable, then this is a threat to its fragility

The settling of water vapor on the surface leads to the formation of mold. The best option is considered to be a moisture-repellent material on the surface of which condensation does not accumulate. Many adhesives have this quality. Adhesive foam is no exception.

Frost resistance

Frost resistance is the ability of a material to withstand repeated freezing and thawing. In construction, this parameter evaluates how a material retains its operational properties under the influence of moisture and low temperatures. Adhesive foam has this quality to the fullest. It can withstand temperature changes for many years.

Composition requirements

Composition is of great importance in assessing the quality of building materials. Not only operational capabilities, but also people’s health depend on it. Adhesive compositions should be odorless. The presence of toxic substances in their composition is unacceptable. The composition of polyurethane glue should not contain carbon dioxide and freon. These substances are harmful to health.

Setting period

The setting period is an important performance indicator for the adhesive mass. The speed of work depends on it. The setting period refers to the time between the connection of parts and their primary adhesion. The setting period of the foam adhesive is 10-15 minutes. This is a relatively short period of time.

Hitch level

When gluing, glue particles penetrate both materials, connecting them. The glued materials form a kind of sandwich, in the middle of which there is an adhesive composition. Substances are added to the adhesive foam that increase its surface energy and help moisturize the working surface. Due to this, foam adhesive is widely used for fixing various materials.