Additional improvement of airborne and impact sound insulation of ceilings in prefabricated standard house-buildings

Abstract

Earlier studies for the improvement on airborne and impact noise insulation of ceilings in prefabricated standard house-buildings has been continued by the support of the German Ministery of Building. The investigated slab blocks were erected in 1987 in Potsdam. The raw ceilings made of solid concrete have a thickness of 140 mm. These realized ceilings have a weighted airborne sound insulation of Rw′=49 dB and a normalized impact-sound pressure level of Ln,w′=77 dB (averaged over nine measurements). A selection of floating floor materials were built in and measured: dry laser constructions (with plaster and compound cement slabs), asphalt applied by melting, and anhydrite layers. The aim of the project was to fulfill the requirements (Rw′=54 dB, Ln,w′=53 dB) of German Standard DIN 4109 from 1989, minimizing construction height and cost. Based on earlier studies (Scholze, DAGA ’94) all floating floors with a height larger than 45 mm (asphalt floor 40 mm) have been improved to reach the requirements of DIN 4109. Using mineral wool as sound insulation material below the floating floor gave results up to Rw′=56 dB (maximum value) and Ln,w′=48 dB.