Influence of floor finish structure on floor impact sound insulation in CLT model building

A floor impact sound insulation is often objection or trouble in building. The Act on the Promotion of the Utilization of Wood in Public Buildings was enforced in 2010 in Japan. As a result, measures are being taken to use Japanese wood. For effective use of the Japanese wood, mainly Japanese cedar, CLT (Cross Laminated Timber) was standardized by Japanese Agricultural Standard as a building material. We, however, have little knowledge about performance of CLT building for satisfaction of Japanese standards. Therefore, we built a 2-story CLT model building for experiments. The floor impact sound insulation of the timber constructions is low compared with that of the concrete constructions. Although this CLT model building is assumed a detached house, these performances were very low performance. In this paper, the purpose of improving the floor impact sound insulation, we report the measurement results by changing the floor finish structure to dry-type double floor structure with rubber vibration insulator. We found that the effect of the dry-type double floor structure with rubber vibration insulator on the heavy-weight and the light-weight floor impact sound insulation. Furthermore, comparison was made with the reduction of transmitted floor impact sound level obtained in other experiment building.