Lay Styrodur under the floor covering


Styrodur is made of foamed hard plastic. He is not walkable and must be relieved when laying as an insulating layer of the tread load. There is a difference in processing between floors in the living area and perimeter insulation on floor slabs or basement floors.

Loose laying possible

Styrodur can be laid under self-supporting and rigid floor coverings as an insulating layer. In new buildings, the floor construction height can already be influenced under the screed. One common application is the laying of laminate and parquet, as the hard foam simultaneously acts as sound and impact insulation.

The panels are offered with tongue and groove or stepped edge profile. When laying no separate fastening is required. This eliminates the risk of thermal bridge formation at attachment points. The attachment of the plates can be supported by Punktverklebungen.

Thermal conductivity of different material thicknesses

In the calculation of the energy efficiency of a building, building practice approved application values ​​are assigned to the respective board thickness. The thermal conductivity in watts per meter and Kelvin is below ground plates:

Material thickness in mmwith soil moisturewith pressing water
500,0340,036
600,0350,037
800,0360,038
1000,0380,040
from 1200,0390,041

In the case of perimetrical perimeter insulations such as basement floors, the thermal conductivity values ​​for non-load-bearing functions are:

Material thickness in mmbasement floorpressing watermultilayered
500,0340,0360,039
600,0350,0380,040
800,0360,0390,041
1000,0380,0410,043
from 1200,0390,0420,044

The insulation tasks and the suitable polystyrene plates are described by the manufacturer BASF as follows:

  • For residential floors without ground contact Styrodur C 2500, 2800 and 3035
  • For perimeter insulation without water pressure Styrodur CS 4000 and 5000
  • For perimeter insulation with groundwater Styrodur CS 3035, 400 and 5000

In order to combine the calculation of the insulation effect with the location of the installation, the manufacturer BASF offers exact data collections and dimensioning aids for the selection. Single- and multi-layer assemblies under load-bearing floor slabs and installation depths in perimeter insulation can be adjusted in advance to the target values.

Tips & Tricks

Floor insulation must currently (spring 2018) meet the requirements of DIN 4108. Pay attention to any changes, as the standards DIN V 18599 and EN ISO 10456 are increasingly being applied. Despite the changes, the brand Styrodur is approved under building law.

Artikelbild: Radovan1 / Shutterstock


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