5.8 Thermal Insulation and Acoustic Absorption Combined

Thermofleece, Warmcell, Pavatex, Rockwool and other fibrous type materials all provide good levels of thermal insulation, as well as high levels of acoustic absorption. These products are therefore used to enhance the U-values of a building envelope. Fibrous materials can also be used to add acoustic absorption to a room. The acoustic absorption is achieved by installing the thermal, fibrous insulation into the building envelope and
then lining a roof/facade with an acoustically transparent finish for example a perforated or slatted finish. Note that the use of vapour barriers between the lining and the thermal insulation is seen as acceptable, but this is dependent upon the thickness of the vapour barrier.

Put simply, providing the sound within a room can reach the
fibrous, thermal insulation within the roof make-up, the thermal insulation will also provide good levels of acoustic absorption.

Case Study – Eden’s Education Buildings
The roof to Eden’s Educational Building is formed from a timber structure, see illustrations 10 and 11. The warm cell was used to provide the thermal insulation. To achieve the acoustic requirements of the exhibition space the plywood sheet used for lateral bracing was perforated to 20% open area. This principle has been used across a range of schools, higher education buildings and other MACH projects.