Underfloor systems

Footfall sound

Minimum requirements
The minimum requirements for structural sound insulation are defined in DIN 4109 "Sound insulation in buildings". General information on the topic of sound insulation and the installation of underfloor systems can be found in the general planner section of the catalogue.

Qualified tests to determine the transmission of air and footfall sound were carried out together with the MÜLLER BBM GmbH testing institute in Planegg, Munich, for the OKA trunking system. The transmission of air and footfall sound was investigated for both vertical, i.e. from storey to storey, and horizontal sound transmission, i.e. from adjacent rooms.

The test was carried out in a floating screed construction.

Noise evaluation
The following section evaluations the test results. With regard to the evaluated reduction of footfall sound of the screed without a floor system, statements made below can be considered as approved.

The noise evaluation, based on the available test certificates, can be summarised as follows:

Horizontal transmission of air and footfall sound: The system is suitable for construction situations with partition requirements up to R‘w = 52 dB.

With horizontal transmission of footfall sound, the system fulfils the normal recommendations in the sense of Supplementary Sheet 2 of DIN 4109 [4]. Should there be requirements for increase footfall sound protection, then noise protection insulation should be added to the system in the area of the partition. Rockwool or polyester fibre materials can be used as noise protection insulation and should be inserted in the installation trunking to a length of at least 30 cm.

Vertical transmission of footfall sound: The OKA-W system (open trunking system, screed-flush) reduces the evaluated footfall sound reduction in comparison with an unaffected floor structure of a vertical screed in the vertical transmission direction by ΔLw = 5 dB.

Data taken from Report M88034/06 of 29 July 2014.


50 mm cement screed, CEMI 52.2 N, mass relative to area m'=15 kg/m²


0.2 mm PE film


30 mm noise insulation damping, dyn. stiffness s'= 15 MN/m³


40 mm heat insulation, polystyrene EPS 100/035


38 mm installation trunking