The Difference Between Laboratory and Site Sound Testing
Many suppliers of acoustic insulation products quote laboratory sound test results to demonstrate the performance of their systems. This often causes considerable confusion regarding how well products will perform as there are usually large differences between the laboratory and site conditions. For instance laboratory sound tests do not take account of flanking sound and therefore produce sound insulation figures that would be very difficult to achieve on site.
Despite site contractor’s best endeavours, it is extremely difficult to build to the stringent exacting standards of the test laboratory. When the construction assembly is undertaken in the lab, it has gone through an exacting installation technique prior to the sound test, which is also a contributing factor why better sound testing levels are achieved.
Throughout the acoustic installation the manufacturer’s guidance is followed to the letter by the lab technicians. Although, this should be replicated on site, it seldom is due to time constraints etc. and so a design which can be easily in excess of the requirements of approved document E, can often lose approx. 8-10dB compared to the laboratory results. Unfortunately there may be many reasons for poor sound test results such as poor quality site installation as well as other on-site issues where cost, time and programming constraints may come into play.
One important thing to consider is that most building structures will be subject to varying amount of flanking sound, so field sound test data should show the real performance of a system in a building. Laboratory sound insulation tests simply measure sound and do not account for flanking sound transmission.
If you are worried about your projects acoustic design and/or have questions about the precompletion sound testing, please don’t hesitate to contact us now at: info@aptsoundtesting.co.uk or Darren direct on 07775623464.