Impact sound insulation improvement of wooden floors on concrete slabs: A pilot study on solutions and test methods

Improvement of impact sound insulation is one of the major challenges, when renovating housing. In Denmark, building regulations for impact sound in new-build were strengthened 5 dB in 2008, implying a main requirement L’n,w ≤ 53 dB between dwellings. The same value should also be a goal, when renovating housing. In Denmark, there are about 1 million dwellings in multi-storey housing. About half of the dwellings are built with timber floors, and the other half with wooden floors on concrete slabs, either in-situ cast or prefabricated hollow-core elements. In a project including mapping of sound insulation in the Danish housing stock and investigation of improvement possibilities, a pilot laboratory study of wooden floors on concrete was carried out. The laboratory study included impact sound improvement measurements of full-scale samples (10 m2) fulfilling the conditions in EN ISO 10140. The measurements indicated up to about 8 dB improvement potential compared to floor constructions typical before the latest change of regulations, namely wooden floors on joists on PE wedges or similar. In addition, tests of small-scale samples (1 m2) – unsuitable for type testing – were performed to provide a fast track ranking of different floor supports, giving also the opportunity to compare differences between small-scale floors with those from full-scale measurements. The paper presents results from the laboratory tests of different floor supports.