Are polystyrene and thermocol the same

Styrofoam or Styrodur: a comparison

Styrofoam vs. Styrodur: comparison, information and alternatives

On the one hand, Styrofoam and Styrodor sound almost the same on the other hand they also have similar properties. Nevertheless, it makes a difference whether you use Styropr or Stryrodur to insulate walls. What are the different characteristics of both insulation materials? We deal extensively with these two types of insulation. Are there certain alternatives to Styrofoam or Styrodur with which insulation can also be carried out professionally?

Explanation of terms with special information

It is important to note that Styrofoam and Styrodur are special brand names for polystyrene rigid foam boards. Both insulation panels are petroleum-based and are considered rot-resistant and inexpensive. They are characterized above all by the fact that they can be used in a variety of ways.

Styrofoam is considered a brand name for expanded polystyrene (EPS). Styrodur, on the other hand, is the common brand name for extruded polystyrene (XPS). The biggest and most obvious difference between these two well-known insulation materials is the look. Individual small pearls can be seen on EPS. XPS, on the other hand, has a continuous foam structure.

Info: Styrodur rigid foam panels are usually marked in color by the manufacturer.

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Comparison: The different characteristics of Styrofoam and Styrodur

The following table provides an overview of the key differences between the two insulation materials Styrofoam and Styrodur.



Delivery type: EPS panels and EPS granules

Delivery type: XPS plate

Gross density: 15-60 kg / m³

Gross density: 25-50 kg / m³

Thermal conductivity: 0.032-0.04 W / (m * K)

Thermal conductivity: 0.023-0.04 W / (m * K)

Building material class: B1 and B2

Building material class: B1 and B2

Application: Above-rafter insulation, flat roof insulation, impact sound insulation, facade insulation behind a curtain facade, thermal insulation composite system (ETICS)

Application: above-rafter insulation, flat roof insulation (under waterproofing and inverted roof), insulation of the floor under screed, insulation of a facade as core insulation, perimeter insulation

Price: 70-100 euros per m³

Price: 200-260 euros per m³

Styrofoam vs. Styrodur: advantages and disadvantages at a glance

If we look at the special different properties of Styrofoam and Styrodur, certain advantages and disadvantages become apparent. The following overview gives you an overview of the individual characteristics of the two insulation materials.

Advantages - styrofoam:

  • is cheaper to buy than Styrodur
  • Less energy needs to be used in production

Advantages - Styrodur:

  • is more resistant to moisture than styrofoam
  • can withstand external pressure better than styrofoam

Cons - styrofoam:

  • In the case of special CFC foamed styrofoam, special disposal must take place
  • is not as resistant to moisture
  • is less pressure-resistant than Styrodur

Disadvantages of Styrodur:

  • Styrodur is more expensive than Styrofoam
  • The energy consumption in production is higher

The production of Styrofoam and Styrodur

The basic basis used in the manufacture of Styrofoam and Styrodur is the same. In the first step, styrene is produced from crude oil. A large use of toxic substances is necessary, such as B. benzene. Polystyrene is then made from the pure styrene with the aid of polymerisation. From then on it is decided whether Styrofoam or Styrodur is produced.

Styrofoam production

In the production of Styrofoam, which is also called EPS, polystyrene granules are treated with steam and propellants. In the process, the individual grains expand - that is, they expand. This also gives rise to the name "expanded" polystyrene. As a result of this process, the typical styrofoam beads are created. Then the pearls are foamed a second time and then welded together. The resulting blocks can be easily cut into panels.

Styrodur production:

In this manufacturing variant, viscous hardenable materials are pressed through a nozzle. The special process is called extrusion. This is how the so-called "extruded" polystyrene is created. In order to produce Styrodur, the plastic polystyrene must first be melted. Then a special propellant and fire retardant are added. With the help of a slot nozzle, the liquid polystyrene is discharged on a conveyor belt. Then it is foamed and pressed into special plate shapes.

Application examples for Styrofoam and Styrodur

Use of styrofoam (EPS):

  • Styrofoam is usually offered for sale in the form of panels as insulation
  • For cavity insulation, however, EPS is also available in spherical form (they are blown into the cavity)
  • in the case of footfall sound insulation, it is on rollers such. B. offered for laminate

Styrofoam can be used for the following types of insulation:

The use of Styrofoam in thermal insulation composite systems:

The core of many ETICS are thick Styrofoam panels. These systems have been around since the mid-1960s. The individual styrofoam plates are glued on the one hand or pegged to the wall on the other. The panels are usually around 14 cm thick. A reinforcement layer that is between 1.5 and 5 mm thick is then placed on top of these styrofoam sheets. A layer of fiberglass fabric is embedded in the process. In this way, the mineral plaster that is later applied to this layer can adhere well and the substrate is evenly pronounced.

Info: Nowadays, composite systems can only be classified as optimal to a limited extent, because their residues later have to be disposed of later as hazardous waste.

Use of Styrodur (XPS):

Nowadays, Styrodur is usually used as perimeter insulation in residential buildings on the cellar wall. Due to the high compressive strength, it is possible in this way to absorb the load of the earth on the cellar wall. It is even possible to use Styrodur under the floor slab. XPS is able to withstand high loads and is therefore also used in warehouse or production halls in the floor construction.

The use of Styrodur indoors and for core insulation:

Styrodur can also be used in several layers indoors. It is also possible to mount the Styrodur between two wall layers. It is mainly used in the area of ​​thermal bridges.

The use of Styrodur on flat and inverted roofs:

On flat roofs, the Styrodur is used under the roofing felt. However, Styrodur unfolds its full potential with inverted roofs. Here the seal is under the insulation. For this reason, the waterproofing must be able to withstand constant moisture and wetness. In addition, the insulation due to gravel or stone slabs is exposed to a very high weight. This weight can be absorbed without any problems through an insulation layer with Styrodur.

With pitched roofs, it is also possible to use Styrodur as an insulating material for above-rafter insulation. This is a solution that is energy efficient and practical, even for new buildings.

Alternatives to Styrofoam and Styrodur

As an alternative to insulation systems with Styrofoam or Styrodur, z. B. Thermal insulation composite systems with materials such as rock wool or mineral foam can be used. Before deciding on an alternative solution, you should find out whether the building material in question is approved for use in Germany. Information about this can be obtained from the German Institute for Building Technology (DIB), which is located in Berlin, or from the manufacturers themselves.

As renewable raw materials z. B. wood fibers, wood wool, coconut fibers, cork, sheep wool, hemp, straw or cellulose can be used to perform insulation. Here too, however, special conditions for installation must be observed.

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Tags:Insulation, insulation guide