The density of polystyrene and its types. Recommendations for application and material selection

The density of polystyrene and its types. Recommendations for application and material selection
The density of polystyrene and its types. Recommendations for application and material selection

When it becomes necessary to insulate the house, many choose progressive material polystyrene for this purpose. However, few buyers think about the brands and species diversity of these plates. Often the customer just goes to the store and takes what is available. But is this the right course of action?

If you know what the density of polystyrene is, what types of this material exist, what options for its use, this will help save time and get the job done as efficiently as possible.

Varieties of material

Expanded polystyrene density

Styrofoam is divided into the following categories:

  • Pressed (PS).
  • Pressless (PSB).
  • Extrusion (EPS).
  • Autoclave.
  • Autoclave extrusion.

The difference between the types of material lies only in the varieties of impurities added to the composition. It could be:

  • Fire retardant.
  • Plasticizer, etc.

The use of additionalcomponents in the composition of the mixture causes significant differences in physical and mechanical characteristics.

Let's get acquainted with the main, most common types of expanded polystyrene in more detail.


High density polystyrene

The name of the type of polystyrene speaks of the method of production of facing boards, which are so often used for facade insulation. By pressing, polystyrene is obtained, the density and strength of which are characterized by increased rates. In terms of thermal insulation properties, this material practically does not differ from non-pressed material.

PS is not widely used, because the technological process of manufacturing this kind of material is complicated compared to the type specified above, which directly affects the increase in cost.


One of the most widespread species, characterized by many advantages and differences:

  1. You can recognize the goods by the marking on the packages and the abbreviation PSB.
  2. Low cost.
  3. Simple technology for obtaining material.
  4. High density polystyrene.


Bulk density of polystyrene

What is the density of polystyrene? You can find out by the numbers after the abbreviation. The higher this indicator, the greater its thickness, that is, the positive qualities of the material are better. Expanded polystyrene foam is characterized by density indicators ranging from 15 to 50 kg/m3. The thinnest is forinsulation of household buildings, and sheets of polystyrene with a density of 30 kg/m3 are already suitable for thermal insulation of residential buildings.

Features of the material and its characteristics

The density index determines the degree of transmission and accumulation of moisture. For example, low numbers mean that the moisture permeability of polystyrene does not exceed 2% of the sheet weight, but this is only an approximate designation.

Regardless of the density of expanded polystyrene, the material is practically not affected by moisture, but it is better not to allow direct exposure to water, according to the conditions that are put forward by building codes for the use of this material.

The brand and density directly affect the flammability of the material, the higher the indicator, the safer the polystyrene. Do not forget about safety measures and prevention of possible fires. This is due to the fact that the material will not burn, but it melts perfectly. At the same time, caustic toxic fumes are released into the air, which do not have the best effect on the he alth of the human body.

Density of extruded polystyrene

Polystyrene resistance to deformation and mechanical stress

A special property that directly depends on the density of extruded polystyrene is resistance to deformation. The higher the strength and density index, the stronger the material is. Many people worry that as a result of temperature changes or individual architectural features of the structure, polystyrene will crumble or break. Toto reduce this probability, you need to choose a material with high strength indicators.

Resistance to mechanical stress and ultimate loads also depends on the indicator in question. In this case, it must be taken into account that the quality of the stability of the material depends on how high the number indicating the density is.

Given that any construction work involves loads, regardless of whether they are short-term or permanent, it is worth purchasing the right type of material, taking into account the own characteristics of the future building.

What is the density of polystyrene

Shape resistance

This is another feature of the material that is worth paying attention to. Slabs stored for a long time under improper storage conditions may cause them to passively warp or shrink.

Polystyrene is a high-quality material with a number of advantages. Its heat-insulating and noise-protective properties are exceptional, which is explained by the filling of voids between the granules with special protective compounds, usually flame retardant. The thickness of the material does not differ from traditional polystyrene boards used for finishing building facades.

The bulk density of extruded polystyrene determines the possibility of using it in outdoor architectural delights. Such a material must meet the requirements for elasticity at low temperatures so that the plates do not deform or become cracked. Based on such requests, it is preferable to applythinner slabs that fully meet thermal insulation requirements.

The density of polystyrene for underfloor heating

Features of interaction with the environment

Interaction with an aggressive environment and moisture is of no small importance, for example, for the insulation of the foundation. The condition of the soil is such that acidity or alkalinity has a negative effect on wood or other types of insulation.

In this case, the best solution would be to lay extruded polystyrene boards. Unlike the classic version, such sheets practically do not absorb moisture and do not interact with the chemical composition of the soil.

The covering surface must be resistant to significant physical conditions: compression, bending, torsion. Compared with simple polystyrene, the density of extruded polystyrene foam has a more elastic structure, able to work in all directions.

Features of the use and installation of polystyrene

You should not think that with the increase in the positive qualities and density of the material, the features of laying, transportation and other work related to installation will change. As with laying conventional foam boards, in the process of such work, a conventional saw or knife is used. To simplify the process, you can purchase a plate of the right size from the available range of products and models on the market, as well as their dimensions. This fact has already been checked in practice by buyers and craftsmen working with polystyrene, for example, when insulatingroofs where laying is carried out in uncomfortable conditions, and the roof structure consists of several slopes.

Installation of polystyrene

Material for arranging underfloor heating

Heated floors have been used more and more recently. In order for them to function normally, it is necessary to make a heat-insulating layer. For these purposes, extruded polystyrene for underfloor heating with a density of 30-40 kg/m3 is excellent. The presence of such material helps to prevent the loss of heat generated by the heating panels.

It is appropriate to say that the thickness of the material is selected individually. If it is recommended to take polystyrene with a density of 30-40 kg/m3, then this should be used.

When equipping a water-heated floor system over rooms that are not heated, it is important to know that the optimal thickness of the insulation for a warm floor should be at least 100 mm. This also applies to the arrangement of the floor on the ground.

Recommendations for material selection

When choosing a material for facade or foundation insulation, please note that the quality of the work performed depends on:

  1. Polystyrene bulk density.
  2. Possibility of material interaction with harmful conditions and aggressive environments.
  3. Material quality.
  4. Material costs.

Now you know what the density of polystyrene is and you can choose the material that is best for your needs.

Popular topic