New Form INC

4.0 acoustic performance of composite floors

“The Acoustic performance of composite floors” (ref 4) states:

“Acoustic insulation is often associated with high mass constructions. However, this is constructionally and economically inefficient, and inappropriate for dry assembled construction. Furthermore, there is a need for resilient layers to be introduced to deal with the effect of impact sound, even in concrete floors.

Composite floor constructions provide a mixture of mass and resilient layers. Multiple layers are used to provide very good levels of acoustic insulation. The mass is provided by the composite slab, and acoustic testing in buildings has shown that generally the effective mass per m^2 of floor area can be used to predict performance.

The resilience is provided by mounting the plasterboard on a propriety metal frame ceiling. This decouples the ceiling from the slab and reduces sound transfer. In addition, a variety of acoustic floors can be used on top of the slab to decouple the floor finish from the slab.

Further, in regard to ceilings:

“The ceiling usually consists of one or two layers of Gypsum board fixed to a metal frame system that is fixed to the underside of the steel deck. This reduces the rigidity of the connection between the plasterboard and the structure above, reducing the acoustic vibration that is transmitted.