Analysis of acoustical behavior of bare cross laminated timber floors for the evaluation of the improvement of impact sound insulation

The estimation of impact sound insulation of horizontal partitions, evaluated from the performance of basic components using EN 12354-2 Standard, do not actually provides satisfactory results when applied to the floors realized with cross laminated timber (CLT) elements. Among the possible reasons of this limited correspondence between predicted and measured impact noise values, one of the most interesting is the difficult to correlate the reduction of the impact sound pressure level of the floor covering, measured in laboratory on a concrete slab, with the actual behavior on a bare CLT floor. In this paper the results of a laboratory evaluations independently managed by different researchers on similar CLT structures is reported. The purpose of this study is to identify an empirical spectrum of the normalized impact sound pressure level of a reference floor realized based on CLT technology, in order to provide an useful and simple tool for estimate the noise insulation performances for this type of building element.