Technical characteristics of extruded polystyrene foam

Extruded polystyrene foam is used for ceiling insulation, walls and floors of premises

General information on expanded polystyrene

For the production of extruded polystyrene foam, the characteristics of which depend on the thickness of the material and its density, granules are used. They are composed of a polymer called polystyrene. During the production process, these granules melt, and at a certain pressure, the mass begins to boil, forming a foam. At this stage, special plasticizing additives, freon gas or carbon mixtures are added to the mixture. Then the liquid mass flows out into special forms, where it is pressed. After complete hardening, the finished material is cut into standard boards. About 90% of the total volume of the slab is air, which led to the peculiar technical characteristics of extruded polystyrene foam.

Extruded polystyrene foam specification table

Standard sizes of foam boards have a fairly narrow range. The length of one slab is 1000, 1250 or 2000 mm, its width is 500 or 600 mm, but the thickness varies in a much wider range from 2 to 10 cm. In addition, they also have differences in the arrangement of the side surfaces. In addition to straight edges, there are also structures "in the thorn", which allows you to more densely lay the material if necessary. The internal structure of the slab is a huge number of small bubbles with air, like foam, but unlike it, these granules make up a single whole, as they are connected in all directions. This is what prevents the material from crumbling like its predecessor.

Helpful advice! To insulate the outer walls of the building, it is advisable to use slabs with ledges along the edges. This will provide better protection against freezing.

Various applications of extruded polystyrene foam

The scope of application of such material as penoplex is not limited to purely household needs. It is used, and with success, for the insulation of pre-fabricated structures of shopping centers, hangars, warehouses and even buildings of small industrial enterprises. Extruded polystyrene foam, the technical characteristics of which we will consider a little later, has the following, undeniable advantages by anyone:

• The material is produced in a very convenient for the consumer format of various thicknesses, which allows you to select the most suitable option for a particular task.
• The slabs are very lightweight. With an increase in their density, the weight changes from 20 to 50 kg / m³.
• Manufacturers assure us that the boards can last 50 years without any structural changes.
• Environmental friendliness of the material.
• Chemical resistance.
• Very low moisture absorption.
• And the technical characteristics of the extruded polystyrene foam and the price are very attractive. After all, 1 m³ this material costs from $ 60 today.

Extruded polystyrene foam boards have high chemical resistance

In comparison, for example, with basalt wool, penoplex has a higher thermal conductivity, which affects its ability to keep heat. In addition, some types have low compressive strength. These facts can be considered the disadvantages of this material. Also, the disadvantages can be considered:

• Low vapor permeability, which creates a greenhouse effect in the room. In houses where there is no ventilation system, it will be very difficult to breathe due to stuffiness and you will have to constantly ventilate the rooms.
• Extruded polystyrene foam, the technical characteristics and the price of which are in a good combination, will have a thickness of 2 - 3 cm. Such plates have very weak sound insulation qualities. For this reason, they cannot be used for soundproofing purposes.
• Polyvinyl chloride is the "killer" of polystyrene foam. Long-term contact of these substances gradually destroys the latter.
• Penoplex is very poorly protected from ultraviolet radiation, which makes it impossible to use it in open places.

The use of extruded polystyrene foam for insulation of the building foundation

Helpful advice! When designing an insulation system, you must always pay attention to the density of the foam. The higher it is, the higher the thermal conductivity. Therefore, in order to achieve an optimal effect at a constant density, the heat-shielding qualities can be changed by increasing the thickness of the sheets. This makes it necessary to calculate in advance the required volume of the room, which will be "donated" in favor of heat.

Technical characteristics of extruded polystyrene foam

To fully understand the whole picture, it is necessary to understand in more detail the technical characteristics of extruded polystyrene foam. They are more than sufficient for insulation. The task of any insulation is to keep heat in a heated room. Since the rate of heat transfer changes, according to the laws of thermodynamics, depending on the density of a substance, it is obvious that gases have a lower coefficient of thermal conductivity than solids. So the coefficient of thermal conductivity of air is 0.026 W / m * ° C. Penoplex, being 90% an air mixture, has this indicator of 0.030 W / m * ° C. The difference is just tiny. This speaks of its excellent ability to retain heat.

Expanded polystyrene boards are mounted on walls using a special adhesive

Expanded polystyrene is produced in a wide range of density. It varies for different products from 25 to 47 kg / m³... This indicator greatly affects the strength of the material, which grows with increasing density from 20,000 to 50,000 kg / m²... Penoplex is a material that absorbs water very poorly. For 28 days, the plate can absorb liquids only 0.4% of its volume, and then this process stops completely.

The coefficient of such an indicator as vapor permeability is only 0.0128 Mg / (m * h * Pa). This makes, in some cases, an optional extra layer. vapor barrier when installing individual systems. The ability to withstand low temperatures down to -50 ° C and high up to + 75 ° C temperatures allows using this type of insulation in almost any climatic conditions.However, expanded polystyrene is quite flammable. Depending on the amount of fire retardants added to it, the flammability class can vary from G1 to G4.

Penoplex is widely used for insulation of balconies and loggias

Some brands of extruded polystyrene foam, the characteristics of which are beyond praise, also have an L-shaped notch along the edges. It is needed for a tighter fit of the plates to each other by strengthening the insulation of the seams. This circumstance does not allow cold bridges to form between such products.

With penoplex, tests were carried out, consisting in repeated freezing and thawing of a wet plate. Most of the tests have shown that the slab can withstand up to 80 such cycles, which in practice can correspond to the number of years of operation.

Expanded polystyrene is used for both indoor and outdoor construction work

When comparing the material in question with its counterpart foam, striking differences will immediately catch the eye. They arose as a result of the use of modern unique technology in the production of foam, which made this material thinner and more durable. Indeed, to achieve the same effect, it is necessary to double the foam layer in comparison with the foam layer, and, moreover, put it in two rows so that cold bridges are not created at the seams.

If we compare expanded polystyrene with other heaters, then such characteristics as sound permeability, it loses to some of them. But in terms of ease of installation, he has no equal. After all, it is much easier to lay hard slabs than to suffer with soft rolls of mineral wool.

Insulation of the roof of the attic room with expanded polystyrene plates

Helpful advice! When building a bath or sauna, never use extruded polystyrene foam for insulation. Its characteristics are such that it does not allow it to be placed in conditions where the room temperature rises above + 75 ° C.

The technical characteristics of extruded polystyrene foam allow it to be used in almost all areas of the construction industry, regardless of the location of the object. He will show himself equally well, both on a small balcony or loggia in his apartment, and within the walls of a huge shopping complex. Therefore, its use is more than justified.

Extruded polystyrene foam (video)