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Ensuring control of noise leakage through acoustically rated walls

Phonic Acoustic Flush Box is designed for mounting switches and outlets in walls that need to maintain their acoustic attenuation performance and/or have a specified Fire Rating.

Product datasheet Published Paper

Reducing Acoustic leakage through inter-tenant walls

With the increasing density of the built environment, the need for acoustic separation is as critical as ever. Electrical outlets are a well-known source of acoustic leakage.

Generally, acoustically rated partitions in commercial or residential situation will have penetrations in them for electrical outlets. There are limited products available to address this leakage, most lacking in useful acoustic performance data, despite being labelled “Acoustic” flush boxes. They have either had no acoustic performance stated or quoted an STC, which is inappropriate for this type of element.

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Ad hoc solutions are used, such as plasterboard packing or flexible mass barriers applied to the back of the flush box, but are cumbersome and problematic to install, with no quantitative acoustic or fire testing. Electrical outlets are often located in fire rated walls. Fire testing for the flush box was also an important requirement in the development of the new Phonic Acoustic Flush Box. Previous testing has shown, there is a significant decrease in performance in mid to high frequencies from flush boxes. Typically, flush boxes are attached to the partition framing and a hole is cut out in the partition linings to mount a face plate, for electrical plugs or light switches. A fire certified acoustic flush box has been developed that does not reduce the overall performance of a tested STC 54 wall, either as a single, or back-to-back installation. Composite transmission loss calculations have also shown that there is no reduction in the single number rating of up to a STC 62 wall.

Australian Design - App. No. 202216095 

Easy Installation

Designed to be installed discreetly within mounting switches and outlets, the Flush Box is easy to install and requires no maintenance once in place. The Phonic Acoustic Flush Box can also be easily repaired if damaged.

Watch the video below

PFB Installation

Fireproof certification

The Phonic Acoustic Flush Box (PFB) is designed to protect against the spread of fire through walls, making them ideal for application in buildings that require a high fire rating. The PFB has a intumescent pad installed; the intumescent material expands when exposed to fire and covers up all the holes, providing a tested system for up to 60 minutes.

PFB Fire demonstration


HOW DOES the Phonic Acoustic flush box ACHIeVE ACOUSTIC PERFORMANCE?

The Phonic Acoustic Flush Box has the addition of an outer flange, designed to compresses to the plasterboard. This limits air gaps that cause sound leakage while damping vibration in the flush box.

For higher rating wall systems do I have to do anything different?

The Phonic Acoustic Flush Box does not compromise the acoustic performance of any acoustic rated plasterboard system and will maintain rating for all wall systems.

Why use the Phonic Acoustic Flush Box?

Other acoustic/fire Flush Boxes can be messy to install and often require silicon products for either fire or acoustic performance. Our Phonic Acoustic Flush Box is a simple install, user-friendly product that will save on install time and doesn’t require any additional products to achieve the fire and acoustic performance required.

How does the fire rating work?

The Phonic Acoustic Flush Box has a intumescent pad installed; the intumescent material expands when exposed to fire and covers up all the holes providing a tested system for up to 60 minutes. Tested to AS15.30.4:2014 and AS4072.1:2005.

Can the Phonic Acoustic Flush Box be used for lights and power points as well as back-to-back applications?

Yes. These Phonic Acoustic Flush Boxes (PFB) discreetly replace any standard flush box. The PFB can be used back-to-back but a minimum 92mm stud is required to fit the boxes into the wall cavity.