Pre-Completion Testing

Part E states that 10% of all units constructed on site must be pre-completion sound tested (PCT) on site. The separating walls and floors within each unit must be tested to show compliance. A test body with appropriate third party accreditation (ANC, UKAS) to ensure that the required acoustic ratings have been achieved must carry out relevant tests. These tests must then be submitted to Building Control who will check to make sure that the performance requirements have been met.

The separating walls between flats and the communal areas do not require a sound test. These walls must however comply with the sound insulation requirements within Document E. The developer / contractor will need to make sure that the wall construction between these areas has an adequate performance to achieve the required standards.

PCT can be used on all types of building, both new build and refurbishment / materials change of use, which contain rooms for residential purposes.

There is a standard acoustic test that is carried out on residential properties which measures the performance of both airborne and impact sound levels. There are two parts to the test:

1. Airborne

The loudspeaker in the Source Room emits a loud noise, over a range of frequencies, which is known as pink noise.

The microphone in the Source and Receiving Room measures the sound pressure level. Using specialist equipment, the acoustician can then calculate the airborne sound insulation (DnT,w + Ctr).

What is being measured is the difference in sound level between the Source Room and the Receiving Room, so the greater the value the better the acoustic performance.

2. Impact

In the Source Room a tapping machine impacts repeatedly directly onto the floor structure.

A microphone in the Receiving Room measures the sound pressure level and the recorded level produces the Impact result (L’nT,w). The lower this figure is, the better the acoustic performance.