Innovative solutions to improved sound insulation of CLT floors

Building with cross laminated timber (CLT) has gain increased interest over the last years, but in common to other wood-based building systems, inadequate low-frequency sound insulation is seen as a problem. This paper deals two methods improve of CLT panels, normally made from spruce: 1) heavy CLT, introducing compressed, i.e. densified, spruce well alternative wood species, and 2) elastic layer based upon shear motion. In addition series laboratory measurements, full-scale floor 60 mm birch panels 12 between was tested two-room test mock-up. The results acoustical measurements showed that about 7 dB greater airborne impact for one-third octave bands, 50–3150 Hz, compared standard same total height.