On July 1st 2003 Approved document E of Building Control Regulations was revised. This meant that sound insulation testing was now mandatory throughout all developments, including conversions, refurbishments & domestic extensions. This is a pre completion test (PCT). Its objective is to raise the standard of sound insulation in all dwellings. The only alternative to PCT is to register & build a ‘Robust detail’. This is a form of construction which has been ‘site proofed’ by targeting a higher performance standard allowing only well controlled construction methods & materials. See link for more information.
Sound insulation testing takes place at a "pre-completion" stage. This means that you development needs to be almost complete with doors in place, windows and trickle vents fitted, as well as power on site. During the sound insulation tests, we will require a quiet site so as not to affect the test results.
There are two types of sound test - airborne and impact. Airborne tests are carried out on walls and floors separating dwellings, impact tests are carried out on floors separating dwellings.
2. Impact tests are only performed on floors between adjoining dwellings. The test is performed using a standard "tapping" machine and a sound level meter. The tapping machine is a device that 'taps' on the floor emulating the sound of people walking around or other objects 'impacting' with the floor. The machine is turned on in the source room and measurements are taken in the receiver room. Using additional acoustic measurements inside the receiver room, a value for the impact sound can then be calculated.
LnT,w is the weighted standardised impact sound pressure level and is used to express the amount of noise present in the receiver room. A high LnT,w value represents poor performance of the separating partition. LnT,w incorporates receiver room acoustics into its calculation and is the current standard measurement for impact noise.