Underfloor systems

Noise prevention and impact noise

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 OKB brush bar trunking system.

The transmission of air and footfall sound was investigated for both vertical sound transmission, 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 required noise measures, based on the available test certificates, for the use of the type OKB trunking system in offices can be summarised as follows:

Horizontal transmission of air and footfall sound
In comparison with other systems, the brush formation at the edge produces higher sound transmission. If the trunking system runs under partitions with noise protection requirements, then noise protection insulation (cf. Point 4.2) must be installed in the partition area. It is then suitable for achieving the evaluated noise insulation dimensions of partitions up to R‘w = 48 dB and evaluated standard footfall sound levels of L‘n, w ≤ 53 dB.

Vertical transmission of footfall sound
The OKB floor system (open trunking system, screed-flush) does not lead to a decrease of the required evaluated footfall sound reduction of a floating cement screed with regard to vertical transmission of footfall sound.

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