Improving the sound insulation of existing wooden floor constructions – experiences from a laboratory study

Many Danes live in older apartment buildings with wooden floor constructions with timber joists. Common for these is that the sound insulation is poor. However, these floors often have a regular design, which indicates that a good improvement strategy would work for many apartments. Moreover, the simple wooden flooring makes it possible to dissemble down to the load-bearing beams. In this paper we report experimental laboratory work investigating how to improve the sound insulation of such wooden floors by renovation. The goal is to improve the sound insulation to fulfill the Danish building regulations, considering both airborne and impact sound insulation. The main test specimen is a replica of the traditional wooden floor, built in 1998 in connection to another project. A few different floor renovations have been chosen for this laboratory study and the floor construction has been made both with and without an added acoustic ceiling. Comparisons are made to the results in the previous projects.