Abstract
Clause G6 of the New Zealand Building Code, dealing with inter%tenancy noise, only provides an acceptable solution for a concrete floor with carpet and underlay and a bare soffit. However, designers and customers require a variety of floor coverings and ceilings to meet their needs and expectations. This paper sets out to address this shortfall in the code, by the provision of simple, cost effective alternatives which meet clause G6 performance requirements. The instigation of the work was essentially to investigate impact noise and various floor coverings, and the effectiveness of a proprietary concrete decking system ‘Hibond’, manufactured by Dimond Industries ltd. The prediction of impact isolation is a rather difficult issue, and therefore an empirical test program was chosen as a pragmatic option. Essentially, the project is in two parts; firstly, impact noise and secondly, airborne noise. The impact isolation items included several types and qualities of carpet and underlay, together with tiles, cork and timber surfaces. The airborne insulation items included various methods of supporting a plasterboard soffit and the effect of a cavity absorber. The outcome was a range of both commercial and residential solutions for a proprietary concrete floor system, which met the verification requirements of clause G6 in respect of both IIC and STC. Emphasis was given to the need to bridge the gap between the difficulty of prediction by acousticians and the pragmatic requirements of the end user.