Getting the performance you want by… Getting specs right

With acoustics one of the keys to the success of any workplace design, the importance of a product’s acoustic performance cannot be understated. All too often products are tested in different ways and performance can be exaggerated. How then can specifiers compare products like-for-like?

To eliminate confusion and concerns the FIS has created the Acoustic Verification Scheme, to standardise performance data for partitions and operable walls. Joe Cilia, technical director at the Finishes & Interiors Sector looks at how designers and specifiers can use the Acoustic Verification Scheme to enable them to specify products in confidence, safe in the knowledge they have achieved the performance stated, ensuring acoustics performance is achieved.

Creating the ideal acoustic environment can be challenging for architects and designers, which is why it’s important to consider the acoustic needs of the interior office space early in the design process. Sound can be controlled either through absorption, which deals with reverberation within the space and makes it a better place to work in; and through insulation, which deals with the control of sound from one space to another.

Office buildings commonly feature hard reflective surfaces such as glass, concrete and plaster which will require specifiers to counter that with sound absorbing products such as ceilings, rafts and wall panels to reduce reverberation and dampen unpleasant noises in the environment. The sound absorption properties of these materials can be impacted on site by the way in which they are installed. For example, if products are tested with a void behind them, but installed directly against the slab or a wall, it will have a detrimental impact on the absorption performance on site.

A common source of noise disturbance is the transmission of sound through walls or floors. Poor sound insulation (also referred to as attenuation) between adjacent rooms will result in disturbance and a loss of privacy. Partitions and cavity barriers are generally used for sound insulation and provide privacy or a division from a noisy and potentially disturbing activity. The only way a specifier can evaluate and compare the performance of two products is by looking at the data provided to them. They need to be able to understand the acoustic claims, what conditions the products should be installed and ensure that the results aren’t misleading.

Acoustic Verification Scheme
With the acoustic performance of products so important and in a bid to curb growing incidents of ‘passing off’, a new Acoustic Verification Scheme has been created by the Finishes and Interior Sector (FIS) in response to confusion and concerns related to the comparability of acoustic airborne sound insulation claims.

For FIS, the journey to the acoustic verification process began with operable walls. It found users were complaining these walls were not performing in the way that was expected. This was partly due to the installation process and partly due to it being the only partition that was dismantled and re-erected on a regular basis by non-trained staff. If the acoustic seals are not exactly right, acoustical integrity can be compromised by leakage and flanking sound coming through. FIS also found evidence of falsification, and in some cases tests revealed that manufacturers were treating an operable wall like a normal fixed partition, and physically sealing every joint. It actually needed to be tested like a door and operated five times before the test commenced to demonstrate it was completely operable. This made a huge difference, enough to put some manufacturers in front of their competitors.

As part of the FIS acoustic verification scheme, which provides a method in which independent acoustic consultant Cundall verifies acoustic test data, FIS was then able to verify all of the test evidence that was being put forward and highlighted companies who had not tested operable walls as they should have done. In other words, it highlighted those who were testing an operable wall as a fixed partition. During that process, some companies withdrew from the scheme.

For contractors such as Wilmott Dixon, the verification scheme meant they could specify manufacturers in confidence that it was a level playing field. They had been tested in the same way and had comparable figures. As a result, the contractor is only using operable walls that have met the requirements of the scheme.

Kevin Dundas, Supply Chain Manager (Products) at Wilmott Dixon said: “There is a growing understanding of the intrinsic link between good acoustic management and wellbeing for occupants and this scheme helps to deliver what our customers expect from us and our industry.”

Enabling best practice
In the case of partitioning systems, verifying data was driven by FIS members who were not confident that everyone in the market was working to a level playing field. Whilst fixed partitions are different to operable walls as you can seal all the joints, FIS agreed a set of parameters that would constitute a test that could be used for comparison reasons. This would then provide specifiers and architects with assurance that if they choose a product from this list that all products will be tested in the same way and all data has been verified. It’s essentially a verification process; FIS is simply taking the data companies are providing in test reports and Cundall are verifying it meets the criteria required to meet the scheme.

The scheme has been created to ensure that those seeking to exemplify best practice are recognised and rewarded for this and prevent inaccurate or misleading information from undermining the market and responsible manufacturers. The verification framework provides consistency and enables the comparison of products and systems on a ‘like-for-like’ basis.