Sound Insulation Testing Explained
Sound Insulation Testing 101
Sound Insulation Testing in England and Wales is governed by Building Regulations Approved Document E. This regulation requires that all separating walls and floors between residential dwellings meets acoustic performance targets which are set out within the document.
Sound insulation testing (also know as sound testing or pre-completion testing) should be conducted by an accredited sound testing company. NCSL, for example, are accredited by SITMA (Sound Insulation Testing & Measurement Association) – our details are shown on their website here.
The testing should be conducted once virtually all other work is finished (except the laying of carpets). All walls and ceilings should be complete, the windows and doors should be fitted and any sealing and skirtings should be in place.
How Is Sound Insulation Test Conducted?
There are two types of sound insulation test, airborne noise and impact noise. The airborne noise test utilises a large loudspeaker placed on one side of the separating wall or floor with a noise measurement taken on either side (the source and receiver rooms). Additional measurements are taken within the receiver room to account for reverberation within the space and any background noise which may influence the measurements. Once all these acoustic measurements are taken, it is possible to calculate the sound reduction performance of the separating partition.
Airborne noise tests are required for walls and floors; however, impact tests are only required for separating floors. The impact test uses a small machine, known as a taping machine, which drops calibrated weights onto the floor surface in the source room. The generated noise level is measured with the receiver room below and again, corrections are made for reverberation time and background noise. The results are then calculated and can be compared to the requirements of Approved Document E.
What Are The Sound Test Requirements?
In order to pass the requirements, for newbuild premises, the airborne sound insulation performance should be 45dB DnTw or greater, with impact test results below 62dB LnTw.
For converted premises, a relaxation in these levels is introduced, with a requirement of 43dB or less for airborne test and 64dB for impact tests.
How Many Sound Insulation Tests Do I Need?
The number of sound insulation tests required is also defined by Approved Document E – with 2 floors (airborne and impact tests) and 2 walls (airborne tests only) required for every 10 dwellings or part thereof.
At NCSL we can help throughout the complete process of sound insulation testing – from acoustic design at the early stages of the project, to pre-completion testing once the dwellings are complete. For any further information, please do not hesitate to contact us.