Acoustics

Kalzip roof constructions can be modified to accommodate various acoustic performance requirements, by incorporating other layers such as high density insulation, acoustic boards and flexible membranes to provide increased sound reduction performance and by perforating the liner to provide improved sound absorption performance.

Over 120 tests have been conducted worldwide on Kalzip roof constructions for airborne sound reduction and sound absorption levels. By using its different system variations Kalzip can assist in achieving the right sound reduction and/or absorption levels required for specific applications. 

Sound absorption
Sound absorption is achieved by perforating the metal liner sheet and incorporating a ‘soft’ absorbing material behind it. Different combinations of perforations and levels of insulation will give varying results of sound absorption.

Air-bourne sound reduction
A standard insulated Kalzip roof construction will have an approximate weighted sound reduction (Rw) of 33dB with an aluminium trapezoidal liner and 36dB with a steel trapezoidal liner. The Rw can be increased by varying the number and the densities of the insulation layers as well as adding additional mass into the construction.

Recent tests carried out incorporating varying types and levels of mass have recorded sound reduction rates of between 33dB and 52dB depending on the product combinations applied.

A valid consideration is Kalzip Nature Roof which adds weight and therefore ‘mass’ to a Kalzip system build up.

Impact noise and flanking
For information on impact noise and flanking or further details on acoustics, please contact the Kalzip Technical Department.