In Part 1 of this blog, we explored WHY GOOD ACOUSTICS MANAGEMENT MATTERS NOW MORE THAN EVER. In this blog, we explain why, when managing acoustics, the floor is the best place to start.
When considering acoustic management for offices and educational buildings acoustic screening, ceiling baffles and sound masking are often the first thing that spring to mind. But what about floor coverings? Whether or not you are applying these other, perhaps more familiar acoustic solutions, the material you specify for the floor will probably have the greatest impact on noise levels for busy working or learning environments. Here’s why.
Acoustics relates to the properties or qualities of a room or building that determine how sound is transmitted within it. From a physics perspective, noise is indistinguishable from sound as both are vibrations through a medium such as air or water. The difference comes when the brain receives and perceives that sound. Spaces with poor acoustics generate more sound than is comfortable to people and can quickly become problematic.
Beyond HVAC and noise from machinery and office equipment, most ambient or airborne sound is generated by people talking. Factor in the Lombard Effect, ie. the louder you hear other people speaking, the louder you naturally tend to speak yourself, and so the problem grows!
Another type of sound is that generated by people walking around a space and moving furniture, typically chairs or rolling equipment across the floor. This type of impact sound can also happen if somebody drops something that interacts with the floor.
A third type of sound is through floor transmission. This is when either someone or something touches the floor and the sound transfers between floors and adjacent spaces. For multi-level interiors, particularly those with large open atrium layouts, this can be particularly important.
Given that we are constantly in contact with the floor, not the ceilings nor the walls, it is easy to see how the choice of office carpet tiles can be a crucial starting point to managing impact noise and to some degree absorbing ambient noise in a space.
While it’s generally understood that soft floor coverings like carpet perform better acoustically than hard flooring, study this in more detail, and we find that there is a vast choice of options to choose from.
Where a hard floor look is preferred, the lowest performers acoustically are natural stone, ceramic and concrete followed by wood and its laminate alternatives, which may or not be installed with an acoustic underlay. Within this hard flooring category, resin and luxury vinyl tiles (LVT) create lower levels of impact and reflected noise.
The latest generation of LVT floor coverings, are now engineered with acoustic enhancements. This can provide a ‘best of both worlds’ solution, with impact sound absorption levels of up to 18dB and photo-realistic aesthetics of natural woods, stone, ceramics and even concrete.
For soft floor coverings, while broadloom carpet can be installed with acoustic underlays, for the workplace and educational buildings, carpet tile is generally preferred for its economy and flexibility.
While office carpet tiles with integral cushion backings will have a higher acoustic performance than hardback and felt-backed products, within this category, it is important to scrutinise the type of cushion backing being used.
An open cell cushion backed carpet tile will absorb both ambient and impact sound. This will have a dramatic effect on the acoustic and physical comfort of an interior. Compared to closed-cell or other cushioning types, open-cell cushioning will also have better compression recovery which, over time, will help to retain both the acoustic and appearance properties of the carpet.
When managing floor-to-floor transmission, carpet tiles with open-cell cushion backings will transmit around 20 times less noise between floors than hardback carpet and around 50 times less that a hard surface flooring. This can make a powerful acoustic improvement for multi-floor workspaces or learning environments.
A manufacturer’s technical specification is a good place to start when trying to determine how effective a floor covering will be for managing acoustics. Look for:
Impact Noise (ISO 10140-3) - this is essentially rated on structural vibration that occurs when one object collides with another, which typically happens in an adjacent space and is transmitted from the point of impact through the wall or floor. This noise is measured in decibels (dB) – the higher the rating the better the performance.
Sound Absorption (ISO354) - refers to the flooring material’s ability to absorb rather than reflect sound waves within a space. Its sound absorbing properties are expressed by the sound absorption coefficient, α, (alpha), as a function of the frequency. Alpha (α) ranges from 0 to 1.00 - from total reflection to total absorption.
In a world where work and learning environments are increasingly agile and collaborative, poor acoustic management can at best cause distraction, and at worst become stress and anxiety inducing. In fact, research shows that unwanted noise can reduce productivity by as much as 66% and can seriously impact employees’ health and well-being. For many neurodivergent employees, excessive noise can become extremely distressing.
In educational spaces, whether in a classroom, lecture theatre or library where careful concentration is required, good management of acoustics is equally important. Numerous studies have shown that reduced noise levels improve knowledge retention and reduce error rates among students.
Clerkenwell - Travelling Line, Triangular Path and Three Corners at University of New South Wales
Specifying the right floor covering for interiors at the design concept stage, before any other ‘additional’ acoustic treatments are considered, is clearly a valuable starting point. Depending on the building and interior environment, this should set a benchmark and help minimise, and possibly even eliminate the need for any other acoustic treatments altogether.
Learn about others ways in which flooring can impact workplace well-being in our blog: 5 WAYS IN WHICH FLOORING CAN IMPROVE WORKPLACE WELL-BEING