Part 2: What acoustic requirements do strata and body corporates have for hard flooring?

How is Multi-Storey Noise Tested and Assessed?

Testing for impact noise involves using mechanical "hammers" in the upstairs unit, with the monitoring of noise conducted in the unit below using sensitive and advanced listening equipment. This field test assesses not only the flooring system but also factors like concrete construction, ceiling treatments, wall cavities, window construction, external noise sources, and other irregularities that may affect the test results.

Acoustic engineers perform these tests to a given standard and provide reports based on the results across various frequencies. The test results may be weighted towards specific frequencies depending on the equation or type of test standard being followed.

Hard Flooring vs Carpet

The nature of this testing method favors carpet performance due to its cushioned surface, minimising noise generated by the hammers. No hard floor system, regardless of the system or underlay in use, matches the performance of carpet in this test.

After carpet, floating floor systems are considered the next best option due to the inherent separation of the flooring from the concrete. While not as quiet as carpet, these systems can offer an acceptable level of noise transfer in most applications.

Despite a surge in expensive "acoustic" underlay products for floating floors, their impact on the overall test result is often incremental. The thickness and density of the concrete construction and associated ceiling treatments play a more significant role in the test result.


Individual body corporate and strata committees often oversee these renovations and they generally follow the Association of Australian Acoustical Consultants Guidelines (AAAC)’s Acoustic Star Rating System, which is between 2 - 6 stars.

The majority of body corporates require a 4 - 6 star acoustic rating, but do not really know what this means. For example, requesting a 6 star acoustic test report, does not and will never guarantee your floor will actually achieve that result because every building is different i.e. slab thickness, presence of a plasterboard ceiling, cavity etc.

What acoustic result does this floor provide me?

There’s a misconception that an acoustic rating supplied by a test report will inform you of its performance in your intended place of installation.

Every building is different e.g. the concrete slab thickness, cavity, ceiling plasterboard and only an on-site test will provide you an accurate result. The way a floor is installed will also make a large difference to acoustic performance.

Regardless of the acoustic report, there is no guaranteed result, because every building is different.

Entire Flooring System

Furthermore, underlays cannot be assessed in isolation, they need to be tested together with your subfloor system (concrete, cavity, ceiling etc) as well as your flooring system (flooring, underlay).

It is crucial to note that no single building product in isolation, especially an acoustic underlay, is guaranteed to achieve a specific acoustic rating or AAAC Star Rating. The manufacturer's impact sound insulation ratings, if provided, should be supported by laboratory or field test results, with the complete floor/ceiling system build-up clearly listed.

Claims about the acoustic rating achievement of any particular building product in isolation, especially when the floor/ceiling system details differ from the initial test, should be avoided. To determine the likely acoustic performance of a specific floor/ceiling system, the commonly accepted acoustical method involves installing a sample in-situ and conducting an on-site test. During this test, various underlays can be tested and adjusted to achieve the desired acoustic performance.

EVERQUIET® Underlays

EVERQUIET® conducts a range of tests on our underlay systems with various flooring products to provide a general guide into potential performance. We look at the overall performance as well as the decibel reduction in impact noise transfer, to help you make a decision on which product will most likely achieve your requirements.

We have designed our underlay products to be able to achieve at least a 5 star acoustic rating with most flooring products in the majority of buildings. Our foam underlays are budget conscious and our rubber underlays are higher density, providing more resiliences and durability over time. However, please note that only on-site testing can "almost" guarantee acoustic performance.