Polyfoam for insulation. Characteristics, dimensions, price

Gas-filled plastics, which externally represent material from foamed cells, are classed as foams. Depending on the technology of production and the polymer used, this class includes several types of materials that have different applications. All of them have thermal insulation properties and are not toxic. Popular facade foam plastic for thermal insulation PSB-S-25 meets sanitary and hygienic requirements and is a universal basis for any kind of plaster.

General information

With the increase in the cost of energy resources, an urgent problem is the protection of the enclosing structures of the room from the unintended release of heat to the outside. Low density foam provides the material with high thermal insulation performance. Therefore, the insulation of facades with foam plastic is a modern solution for saving energy resources. Although this is not the only area of application of this material.

It is also used:

• As a filler for the compartments of ships, which ensures their unsinkability;
• In the manufacture of life jackets, buoys and floats;
• As a material for the production of medical containers, which are used to transport donor organs;
• As protection of fragile goods;
• As a heat insulator in refrigerators and other household appliances.

Types of insulation

There is statistics, no normative documents have not confirmed that heat losses through the walls are 40%, through the roof - 25%. Therefore, to achieve maximum protection of housing against heat losses can be through the insulation of walls.

Isolate the room from the penetration of moisture and cold air currents in two ways: inside and out. It is believed that to protect the wall from freezing and at the same time preserve the internal area of housing can be in choosing external insulation. And one more advantage of facade protection of the building is the fact that a condensation zone forms between the internal insulation and the supporting wall. And this is an ideal environment for the development of fungus and mold. But the wall protected from the outside retains heat longer and does not cool.

Although there are cases, for example, in the case of a beautiful finish of the house or elevator shaft, when insulation with foam plastic from the outside is technically impossible. Then apply the internal protection of the walls. In addition to polystyrene, builders use other materials.

Types of materials

Popular insulation: mineral wool, polyurethane foam and expanded polystyrene. Mineral wool is mounted only on a metal frame, which must then be gypsum board, siding or other finishing material. Polyurethane foam has a temporary advantage, because it is applied automatically, using a sprayer. In this case, the material fills all cracks in the frame, forming a monolithic coating. However, to protect the walls in this way will cost more than using polystyrene for insulation.

Polystyrene foam is produced in two ways, as a result of which there is a pressed and pressed material. Marking PS-1 means that the foam plastic is press-made, and PSB-C is a material with a self-extinguishing ability. That is, in its manufacture, polystyrene with low combustibility was used.

Qualitative characteristics

Thermal insulation of facades with foam begins with the choice of material. The main characteristics that you need to know when purchasing a heater are the dimensions of the slabs, density and thickness. According to GOST 15588-86, the nominal dimensions of the plates can be:

• By thickness with a step of 10 mm: 20-500 mm;
• Lengthwise with a step of 50 mm: 900-5000 mm;
• By width with a pitch of 50 mm: 500-1300 mm.

But it is allowed by preliminary agreement to produce slabs of non-standard sizes. Plates from foam are produced with the following density indicators: 15, 25, 35 and 50 kg / m ³ . The larger this value, the stronger the material and the lower its ability to absorb moisture. A sheet with a density of 35 kg / m3, 50 mm thick, is similar in its physico-chemical properties to a material with a density of 25 kg / m ³ and a thickness of 100 mm. However, the cost of polystyrene is higher, the greater the density of insulation.

To choose a heater of a certain thickness, it is necessary to take into account a number of factors and to make a simple calculation.

Choosing the right thickness material

The thickness of the thermal insulation depends on the value of the standard resistance of the heat transfer of the external walls, which is a constant value for different climatic zones, and the thickness of the material of the walls of the building.

For example, the minimum allowable heat resistance of walls for St. Petersburg is 3.08 m ² * K / V. There is a brick house, the walls of which are built of polutorornogo ceramic hollow brick. The heat resistance of such a structure is 1.06 m ² x K / W. It is necessary to calculate how thick to take the foam for insulation.

To achieve a value of 3.08, it is necessary to find the difference between the thermal resistance of the normative and the already existing: 3.08-1.06 = 2.02 m ² x K / W. That is, the value that a styrofoam should possess is becoming known. Heat insulator PSB-25 of the highest quality has a thermal conductivity (according to GOST) 0,039 W / (m · K).

Proceeding from the formula that the heat resistance is a particular thickness of the layer by the thermal conductivity of the material, we have: 2.02 * 0.039 = 0.078 m. In this case, we need to purchase a PSB-25 foam 80 mm thick. With this calculation, the heat resistance of the plaster layer, which is both inside and outside the building, was not taken into account. Therefore, in reality, the requirements for the thickness of the foam will be less than 80 mm.

What else can be insulated with foam plastic?

Due to the low water absorption coefficient, the material is often used in places of high humidity. Foam sheets are laid in foundation structures, used in the construction of bezpodvalnyh houses.

To prevent freezing of the foundation of the house, it is recommended to lay a cellular insulation in the horizontal and vertical parts. As sound insulation it is possible to lay foam plastic in a false wall between rooms. For the insulation of floors, balconies, loggias is also used expanded polystyrene. In addition to protecting structures from heat loss, the material is used in refrigeration plants.

Cost of foam plastic

In this section, the cost of heaters from the foam grade at November prices in 2015 is given.

Expanded polystyrene, manufactured by extrusion, is called penoplex. Such plates are stronger than polystyrene foam, and their price is much higher. The cost of one plate (1200x600x50 mm) is 183 rubles, in terms of 1 m ³ it is 5080 rubles.

On the sites for the sale of insulation often meets the name of the product, like polystyrene 50 mm. This is a regular sheet material with dimensions of 1000x2000 mm. The price of one plate is 180 rubles. Now in comparison with penoplaks it is clear that a cube of ordinary foam plastic with a thickness of 50 mm costs 1800 rubles, and this is 3200 rubles cheaper than extruded polystyrene foam.

So, a cube of expanded polystyrene, depending on density, costs:

• PSB-S15 - 2160 rubles;
• PSB-S25 - 2850 rubles;
• PSB-C35 - 4479 rubles;
• PSB-S50 - 6699 rubles.

Myths that the foam for insulation is harmful

The first invention is connected with the invented term "breath of walls". There is an opinion that when insulation with foam plastic housing reduces the penetration of water vapor, thereby worsening the microclimate, and inside the premises formed a high humidity. In construction there is no term "breathing wall", and the water vapor streams that actually circulate between the street and the house through the wall are very small. Formation of mold and fungus in the room after the insulation of the walls with polystyrene is a consequence of poor ventilation.

The second myth is the environmental friendliness of the material. Styrofoam refers to materials without harmful chemical additives. It consists of 98% air and 2% polystyrene. It does not possess radioactivity and can be subjected to 100% recycling. Operating temperature: -200 ... + 80 degrees. But polystyrene foam is exposed to acetone, benzene, so when choosing a paint for the final finishing of the facade, you should consider this fact.