Acoustic performance of timber volume elements

Abstract: The thesis investigates the acoustic performance of light weight timber constructions known as timber volume elements and vibration insulation methods employed in these. Common materials used in light weight timber floor constructions and different floor configurations consisting of these materials were also studied. The study consists of impact sound and air-borne sound insulation measurements performed on a cross laminated timber floor in laboratory and two vertically adjacent timber volume elements in factory conditions. This thesis finds that even though elastomer intermediate layers perform better than wood based intermediate layers, especially for higher frequencies. The increase in acoustic performance provided by utilizing elastomer based intermediate layers is not that high if compared to the increased financial costs it brings. From the measurements performed in factory conditions it is concluded that the tested timber volume elements can reach sound classes up to sound class B for impact sound insulation and sound class D for air-borne sound insulation. Air-borne sound insulation did not satisfy requirements for sound class C and therefore limited the overall grade of the timber volume elements. This was however a result of leakage produced by a poor seal on the door of the sending room. With small efforts the grade of most factory configurations could be upgraded to sound class C. Furthermore it is concluded that for the floor configurations measured in laboratory, the addition of mass provided by the different material layers is the greatest contribution factor to increased acoustic performance.