In the field of construction and repair, you can often hear about such a material as extruded polystyrene foam. This is a durable, high-quality and inexpensive insulation material that is widely used in private and commercial construction.
Many people call extruded polystyrene foam (EPS) foam. However, both materials differ significantly from each other. First of all, EPS is highly resistant to deformation compared to other types of insulation.
Advantages and disadvantages
If you pick up this insulation, it becomes clear that its physical properties are somewhat similar to plastic. But still it has slightly different characteristics. It is denser and lighter, but still essentially remains the same plastic we know.
Pros of EPPS:
- Resistance to fungi. Fungi are a problem for many houses, especially country houses. However, given that extruded polystyrene foam is a synthetic material, fungi do not feed on it.
- Resistant to rotting. Again, due to the fact that this product is an artificial and not a biological material, it is not subject to decomposition and rotting.
- Frost resistance. This insulation can withstand even very low temperatures. The thing is that there is no moisture in it at all, so it does not freeze through.
- Low thermal conductivity. Considering that air is the best heat insulator, and there is no air in EPS, this is the main factor due to which the insulation does not conduct heat.
- Compression resistance. This material can withstand even very heavy loads.
But, like any other material, EPS is not without its drawbacks :
- Poor sound insulation.
- Weak resistance to ultraviolet radiation.
- A little environmentally friendly.
Despite some disadvantages, most developers and owners of private houses prefer to buy extruded polystyrene foam Compared to other types of insulation, the price-quality ratio of EPS is one of the best.
Complete information about extruded polystyrene foam
Extruded polystyrene foam, what is it? Extruded polystyrene foam is a synthetic material for thermal insulation, developed by an American construction company in the 50s of the twentieth century. Manufactured using foaming technology, the composition uses polymer compositions. The material is pressed through a special mold and joined into a single piece.
Available in the form of slabs and substrates. Found on the market as a decorative element. The standard size of the slabs is 600x1200 or 600x2400 mm. Standard sizes are established by GOSTs, but many companies change the sizes, making plates of different widths. The common size is 580 mm. The thickness of the elements varies from 20 mm to 10 cm, depending on the manufacturer.
The material is delivered to retail outlets in packages of several elements. The number of units in one package depends on the thickness of the products. For example, if the thickness of the slabs is 5 cm, the package usually contains 8 units of goods. With a thickness of 10 cm, 4 plates are packed.
Additional information: it is possible to produce expanded polystyrene as a floor covering. The modern market offers materials for laminate, parquet, and linoleum. It is possible to manufacture decorative elements based on the material. They look exactly like plaster.
Advantages and disadvantages
Like any other material, extruded polystyrene foam has advantages and some disadvantages. It is worth familiarizing yourself with them before purchasing and using them.
Advantages of extruded polystyrene foam:
- Moisture absorption within 0.2%. This indicator means almost complete waterproofness.
- Minimum thermal conductivity. At a standard temperature of 25°C it is about 0.032 W/m*K. If we compare the heat conductivity, the indicators are as follows: 55 cm of brick equals 3 cm of polystyrene foam.
- Withstands deformation well. Can be used for laying under a blind area, or after the foundation.
- Does not react with inorganic chemical reagents.
- Withstands significant temperature changes, the indicators do not change at air temperatures from -50 to +75°C.
- According to the documentation, the material can be used for at least half a century. During this time, the characteristics will not change.
- Environmentally friendly substance. It is used not only as insulation, but, for example, for the production of lightweight disposable plates or other types of cheap tableware. Children's toys are made from it.
- Has minimal weight. A small thickness is enough for good insulation.
In addition to numerous positive characteristics, some disadvantages can be identified:
- comparison with other types of insulation shows that the price of the material is high;
- highly flammable. During the combustion process, harmful substances and black smoke are released;
- destroyed under the influence of infrared rays. To maintain performance characteristics, it must be hidden from direct sunlight;
- Manufacturers assure that rodents will not grow inside the insulation. Indeed, they do not live inside, but often make channels for movement;
- solvents destroy the structure.
In addition to the listed disadvantages, low vapor permeability can be added to them. Sometimes this is a plus, but if you insulate a wooden house, fungi and mold may develop. As a result, an unpleasant odor appears in the home and dampness is constantly felt.
Application area
Extruded gray polystyrene foam has a wide range of applications. Mainly used for insulation work. The scope of use is limited only by temperature indicators (not higher than 75°C). The material can be laid in damp places, in the ground.
Typically, the scope of use is limited only by financial capabilities. The high cost makes it impractical for use in many places. In places where there is no need for high technical characteristics, ordinary polystyrene foam is used instead of PPS, reviews of which are also positive, in order to save money.
Used for insulation:
- concrete or wooden floors;
- walls indoors or outside the building. Compatible with any material;
- wells. Often concrete rings are coated with material for additional protection;
- blind areas;
- surface of the earth. To prevent destruction of the structure, paint is applied. Even a thin layer will not allow the composition to deteriorate.
In addition to the listed areas, the material is used in road construction. Included in many refrigeration units as extruded insulation. Used in agriculture. Roofs and underground floors are insulated with expanded polystyrene. One of the promising areas is the production of sandwich panels.
Technical characteristics of extruded polystyrene foam
The material has some of the highest technical characteristics on the market of insulation products. Any gas has a much lower thermal conductivity than solids. For air, the figure is 0.026 W/m*oC. Extruded polystyrene foam is an air mixture of approximately 90%. It has a thermal conductivity of 0.03 W/m*oC. Almost like air, which means heat is retained perfectly.
The material is produced with different densities. Manufacturers offer from 25 to 47 kg/m3. The higher the number, the greater the strength. As the density increases, the strength increases from 20,000 to 50,000 kg/m2.
Water is poorly absorbed by polystyrene foam. In about a month, one tile can absorb about 0.4% of its own volume if it is completely immersed in water. Further, the percentage of absorbed liquid does not increase, but stops. Vapor permeability is minimal. It is 0.0128 Mg/(m*h*Pa). Often companies specializing in repair work suggest not using vapor barriers, limiting themselves to using only polystyrene.
The insulation is able to withstand temperatures ranging from -50 to +75°C. Its use is possible in almost any climate. The flammability is high, the class varies depending on the addition of additional substances, from G1 to G4.
Some models have a special recess along the edges. Made to increase the tightness of the slabs by insulating the seams. This innovation prevents cold layers from forming between the elements, ensuring complete heat retention.
Tests were carried out with polystyrene foam. Their meaning is repeated freezing and thawing of wet tiles. It was determined experimentally that the material can withstand 80 cycles without changing the technical characteristics. This information is useful for users: the composition can withstand approximately this number of years during operation.
Additional information: compared to polystyrene foam, polystyrene foam is approximately 2 times superior in heat retention. Increased strength, reduced thickness. Compared to other insulation materials, sound permeability is not very high. The disadvantage is compensated by ease of installation. Completely safe for health.
Material selection rules
The demand for expanded polystyrene is high and increases every year. In order for the insulation to last as long as possible and perform all the required functions without failures, you need to make the right purchase. Every manufacturer claims that their product is the best on the market, but this is not always true.
Selection rules:
- Polystyrene is designated by two numbers. If the marking is below index 28, you should refuse to purchase. Checking is mandatory; some brands of products are not suitable for façade work and will not cope with the insulation of a house. Choose material with an index of 40 and above. The PSB-S-40 brand, a self-extinguishing composition, has proven itself well.
- Before purchasing, look at the standards on which production was carried out. Many manufacturers produce slabs not according to GOSTs, but to their own specifications. Possible poor quality product. Usually the density is reduced, thereby reducing the cost. You should not rely on the brand number; be sure to familiarize yourself with the characteristics.
- To ensure the high quality of the product, you can break off a small piece from the edge. If small balls are visible at the fracture site, the polystyrene foam is probably low-grade. There should be polyhedra of the correct shape at the fracture. The broken piece is straight. The test shows the production method: extrusion performed on professional equipment, or a homemade method, like simple polystyrene foam.
- Purchase goods from reputable manufacturers. These are “Penoplex” URSA, Knauf and “Technonikol” - Russian. "Basf" or "Novachemicals" are foreign.
Do not forget that the production of polystyrene foam is a complex technological process. Production methods differ among many manufacturers. Some are safe, others can harm human health.
Manufacturer brands
Each brand of polystyrene foam manufacturer differs from competitors in some features. To understand the variety of choices offered, it is worth considering the products of each manufacturer in more detail.
Knauf
Manufacturer from Germany. Production is represented by numerous variants of polystyrene foam.
Insulation materials used:
- Knauf Therm Compack. Universal, used for any type of household thermal insulation. It has a low thermal conductivity coefficient of 0.032 W/μ, high sound insulation properties. The airborne noise reduction index is 47 dB, impact noise is damped if the indicator does not exceed 24 dB. Due to its performance, it is well suited for insulating small rooms.
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Penoizol: self-production
Supplied in slabs 1 x 0.6 m long. Thickness 5 cm. Vapor permeability 0.033 mg/mhPa
- Knauf Therm Roof Light. The density is low, 10–15 kg/m³. used to retain heat on the rafter frames of houses. Characteristics: heat conductivity 0.034 W/μ, steam conductivity – 0.035 W/μ.
- Knauf Therm Wall - for wall insulation. The indicators are the same as previous designs, with increased mechanical strength. 60 kPa is an indicator of compressive strength. The choice of slab sizes is wide. Thermal conductivity: 0.033 W/mk, vapor conductivity: 0.032 mg/mhPa. G3 – flammability class.
There are models Knauf Therm Flor, suitable for floor insulation, with a low thermal conductivity of 0.03 W/μ and Knauf Therm 5 in 1. The latter stands out for its maximum strength among all the company’s models. Withstands up to 17 t/m2.
URSA
The Russian polystyrene foam manufacturer URSA presents several product options.
| Model/Specifications | URSA XPS N-III | URSA XPS N-III-G4 | URSA XPS NV |
| Thermal conductivity | 0.032 W/mK | 0.032 W/mK | 0.033 W/mK |
| Application temperature | from -50 to +75 | from -50 to +75 | from -50 to +75 |
| Water absorption | 0.3% of volume in 24 hours | 0.3% of volume in 24 hours | 0.3% of volume in 24 hours |
| Vapor permeability coefficient | 0.004 mg/mhPa | 0.004 mg/mhPa | 0.004 mg/mhPa |
| Compressive strength | 25 t/m² | 25 t/m² | 50 t/m² |
The products differ from other manufacturers in their increased strength. The material is indispensable for professional construction. One of the most durable options that can withstand significant loads.
Penoplex
Domestic manufacturer of expanded polystyrene. Has a wide range of models. Plates can be used for various insulation options.
The following types of products are distinguished:
- Penoplex Wall
| Characteristics | Meaning |
| Thermal conductivity | 0.03 W/(m×°K) |
| Density | 25.0-32.0 kg/m³ |
| Compressive strength | 0.20 MPa |
| Water absorption | 0,5% |
| Fire resistance | G3 |
| Temperature range | -50 … +75 °С |
- Penoplex Foundation
| Characteristics | Meaning |
| Thermal conductivity | 0.03 W/(m×°K) |
| Density | 29.0-33.0 kg/m³ |
| Compressive strength | 0.27 MPa |
| Water absorption | 0,5% |
| Fire resistance | G4 |
| Temperature range | -50 … +75 °С |
- Penoplex Roofing
| Characteristics | Meaning |
| Thermal conductivity | 0.03 W/(m×°K) |
| Density | 28.0-33.0 kg/m³ |
| Compressive strength | 0.25 MPa |
| Water absorption | 0,5% |
| Fire resistance | G3 |
| Temperature range | -50 … +75 °С |
- Penoplex Comfort
| Characteristics | Meaning |
| Thermal conductivity | 0.03 W/(m×°K) |
| Density | 25.0-35.0 kg/m³ |
| Compressive strength | 0.20 MPa |
| Water absorption | 0,5% |
| Fire resistance | G4 |
| Temperature range | -50 … +75 °С |
- Penoplex 45
| Characteristics | Meaning |
| Thermal conductivity | 0.03 W/(m×°K) |
| Density | 35.0-47.0 kg/m³ |
| Compressive strength | 0.5 MPa |
| Water absorption | 0,4% |
| Fire resistance | G4 |
| Temperature range | -50 … +75 °С |
TechnoNIKOL
Considered a leader in the field of insulating materials. Every year the volume of production increased rapidly. Now insulation products are a little more expensive than competitors on the Russian market, but the quality of the product is the highest. Specializes in the production of numerous types of various insulation materials. Expanded polystyrene is available in several models.
| Specifications/Model | Technoplex | Carbon Eco | XPS 35-300 | Prof | |
| Thermal conductivity | 0.032 W/μ | 0.029 W/μ | 0.028 W/μ | 0.028 W/μ | |
| Density | from 26 to 35 kg/m³ | 26-32 kg/m³ | 35 kg/m³ | 30 kg/m³ | |
| Compressive strength | 200 kPa | 250 kPa | 400 Kpa | 300 kPa | |
| Water absorption | 0.2% | 0.2% | 0.2% | 0.2% | |
| Fire resistance | G4 | G4 | G4 | G4 | |
| Temperature range | -50 … +75 °С | -50 … +75 °С | -50 … +75 °С | -50 … +75 °С | |
| Vapor permeability | 0.01 mg/mhPa | 0.011 mg/mhPa | 0.01 mg/mhPa | 0.01 mg/mhPa | |
FAQ
– What is better for a screed, expanded clay or expanded polystyrene?
The thermal conductivity coefficient of expanded clay is on average 0.12, and that of penoplex is 0.03 W/m*C. Those. almost an order of magnitude. Thus, to ensure the required thermal insulation of floors, the backfill of cermatite will be much thicker than laying sheets of Penoplex and the like. And as a result, the entire structure of floors with expanded clay will be much thicker than the structure of floors with penoplex.
– Polyurethane foam or polystyrene foam, which is better?
Having carried out a comparative analysis of both insulation materials, we can say the following: polyurethane foam has higher characteristics in terms of noise insulation, moisture resistance, and heat resistance. Has a higher fire safety class. However, its thermal conductivity is an order of magnitude lower.
Considering that we are talking about choosing a material for insulation, polystyrene foam will be the best. Although, given the experience of users, there is no need to use a material with such high performance as polystyrene. Therefore, preference when purchasing should be given to polyurethane foam.
– Is polystyrene foam harmful to human health?
No, the material is completely safe to use. The only problem is that when burning, acrid smoke is released.
– What surfaces cannot be insulated with polystyrene foam?
You cannot insulate surfaces whose temperature exceeds the specified limits: -50 ... +75 °C. Another limitation: in wooden houses where good vapor barrier is required, it is not advisable to use the material. Mold and mildew may form between the wall and the insulation. No humid air will escape from the house. There will be constant high humidity in the room.
What is extruded polystyrene foam? Universal insulation. It is considered one of the modern examples of materials of this class. When using it, you must comply with the established temperature standards and other important requirements.
If EPS insulation is done correctly, manufacturers provide a guarantee for the service life of polystyrene for at least 50 years.
Where to apply?
The scope of application of this product is quite extensive. Let's list the main directions.
Floor
Quite often people decide to buy extruded polystyrene foam for floor insulation. This is a simple and profitable solution, and both private houses and industrial premises can be insulated. It is especially important to use EPS when installing a heated floor, so that only your room is heated, and not the neighbor’s or basement.
Due to its physical properties, this material will allow you to save up to 20% on heating your rooms. In addition, not only heat is saved, but also the increase in humidity in the house is prevented.
And the last pro in favor of extruded polystyrene foam in floor insulation is sound insulation and protection against impact noise.
Roof
The use of such products in roofing also reduces heating costs. And this time the savings reach 30%. Advantages of using EPS boards for roof insulation:
- protection from the adverse influence of the external environment;
- reducing the load on the structure;
- reduction of layers and reduction of construction operations.
The thermal conductivity of EPS is lower than that of mineral wool, but penoplex boards have high rigidity. This advantage allows it to be used in monolithic and prefabricated screeds. Also, these products are widely used where it is necessary to arrange a recreation area or parking on the roof of a building.
Walls
When it comes to increasing heat in a home by insulating walls, the first thing that comes to mind is the use of extruded polystyrene foam. It significantly saves energy, retains heat and ensures a comfortable stay in the house even at sharply negative temperatures outside the window.
The slabs are installed from the outside. In this case, the dew point remains in the heat-insulating layer, which means that heat loss is almost zero.
Foundation
Another popular area is the installation of foundations and basement floors. EPS boards are not afraid of the influence of soil, they do not rot, and have low hygroscopicity (do not absorb moisture and water).
In addition, extruded polystyrene foam prevents soil freezing and reduces soil heaving to zero.
Size and thickness of EPS sheet
The length of the sheets of extruded polystyrene foam is 1200-2400 mm, the width is 500-600 mm, and the thickness is 20-150. To select a specific value, it is recommended to start from the scope of application, for example, for thickness, the following tips:
- for the floor on the first floor - from 50 mm;
- for the second floor and above – 20-30 mm;
- for additional sound insulation on the floor - 40 mm;
- for internal wall cladding – 20-30 mm;
- for external wall cladding – 50-150 mm.
The video shows the characteristics of extruded polystyrene foam in comparison:
Specific thickness values for various thermal insulation works are presented in SNiP. You can also find online calculators on the Internet that allow you to calculate the thickness for specific tasks.
Reference: depending on the density, several classes of material are distinguished - 31, 31C, 35, 45C, 45. Classes 31 and 31C are used for insulating structures that are not subject to load - foundation walls, inverted roofing, sewerage. Models 35 are characterized by increased fire safety, so they can be used for roof insulation. Class 45 has superior compressive strength, making it an ideal material for load-bearing structures such as basement roofing, runways and foundations.
Flaws
Naturally, extruded polystyrene foam, like other insulation materials, has several disadvantages .
- Low vapor barrier, due to which it is necessary to take care of the presence of supply and exhaust ventilation. Naturally, in this case, the cost of construction work will increase, and without ventilation it will not be possible to ensure an optimal microclimate.
- Price. The slabs are quite expensive, but it is better to overpay for this high-quality material than to face the disadvantages of other more affordable insulation materials.
- The need to install a frame or use special adhesives. Both options make construction more expensive. To avoid such expenses, you can purchase sheets whose surface is embossed, which improves adhesion. Accordingly, it will be possible to use various adhesives.
- Low resistance to UV rays, which is why the surface must be additionally treated.
Application area
Extruded polystyrene foam has rapidly burst into the construction industry:
- for internal and external thermal insulation finishing of buildings;
- in the manufacture of sandwich panels, as components
- as a filler in the construction of walls with high thermal insulation properties, in the so-called well brickwork.
- for insulation of floors, roofs, walls;
- extruded polystyrene foam for the facade, for the foundation, for the roof;
- extruded polystyrene foam for the blind area around the house;
- extruded polystyrene foam for heated floors;
- during the construction of road surfaces.
Despite the great versatility of use, there is one serious limitation under which extruded polystyrene foam should not be used. The material is extremely unstable to infrared radiation; in the sun it quickly loses its exclusive properties and is subject to rapid destruction.
In sunlight, it is better to use other materials, or, as a last resort, make a coating of a layer of paint that will serve as an obstacle to the penetration of ultraviolet rays.
EPP - extruded polystyrene foam, shows excellent properties when working on roof insulation, thermal insulation of foundations or floors. At the same time, you should avoid using the material in such insulation of internal walls of the room, since vapor permeability is at an extremely low level.
The use of EPP makes it impossible for the walls to “breathe”, thus creating a favorable environment conducive to the formation of fungus and mold. Giving preference to strong and durable material, there are “cunning” people who increase ventilation, thus ensuring ventilation and increased air flow into the room.
