What exactly is the mysterious science of acoustics and why is it such a vitally important component of the construction industry? Anyone glancing at a construction site as they walk past will probably have no idea of the complex issues which will have been tackled to ensure that the occupants are comfortable with the sound levels in the building.
The word ‘acoustics’ derives from the Greek ‘akoustos’ meaning ‘heard’, and it’s a branch of physics which deals with the study of mechanical waves in gases, liquids and solids, including topics such as vibration, sound, ultrasound and infrasound.
Sound that is transmitted in buildings can be airborne and structure borne. Different developments require specific acoustic approaches, and our experience has taught us that every project has its own individual complications. We could probably write a book about it, but for this blog we’re going to look at effective acoustics and the passage of sound within a new gym, which has a multitude of challenges.
The health and safety of a building’s occupants is paramount, and the wrong acoustics can be surprisingly detrimental. Prolonged exposure to noise can hinder productivity and communication, trigger psychological stress responses such as raised blood pressure and heart rate, increase hypertension and sleep disturbance, and has been linked to depression and anxiety. Therefore ensuring exactly the right acoustic balance is very important, and if this isn’t adhered to, gym owners can be told to close down their premises.
Fifteen years ago, many gyms were in stand-alone buildings, but as they became increasingly popular, they were frequently incorporated into residential and office buildings. They have a unique mix of sound; pounding feet, equipment being dropped on the floor, loud music, machines and plant noise, and the technology to combat these issues has advanced enormously.
When planning a fit out for a new gym, input from an acoustic engineer can be valuable to confirm that the building is fit for purpose and produce recommendations for the survey.
Ensuring the floor is sufficiently robust is arguably the most important consideration. A gym floor will need to withstand weights being thrown down on it as well as feet hammering on treadmills. It’s surprising how often users end up running in synchronisation, which can cause significant reverberation, so it’s important to isolate the building structure from impact on the floor. A free weights area in a gym will contain heavy strength training equipment such as kettlebells, dumbbells and medicine balls. To allow for this, the live floor load rating should be kN per square metre or more – particularly important for a mezzanine floor. There are many solutions to containing sounds in these areas such as wood or rubber which can also be placed round columns to absorb noise. Interlocking rubber floor tiles are a popular choice and are available in various sizes of thickness. 30 – 40mm, with a rubber underlay, is a good choice.
Sound can travel through a building via its steel structure or through concrete. There are many materials to help alleviate this such as acoustic metal pads with rubber beneath to muffle sound, floating floors and isolation mounts, or a concrete sprung floating floor. For the latter, the concrete is poured in round a jack-up system, typically using 25mm deflection powder-coated springs, and then raised, providing stability and the isolation of noise.
Partitions and ceilings can also be fabricated to absorb noise. Loud music, which is used as an inspirational tool for gym-goers and is often quite heavy on the bass, must be contained within the gym unit. Walls panels must be airtight and sturdy to absorb sound and resist noise penetration. Light covers which prevent air and sound leakage through recessed lighting and rubber isolation mounts for speakers should be installed; the latter are also used for mechanical plant.
A building’s plant room is the space inside or outside the building which houses mechanical equipment such as air handling, air conditioning condensers, boilers, chillers, heat exchanges, sprinkler piping and pumps, and back-up generators. Often this is sited on a building’s roof and airborne sound needs to be attenuated to bring the decibel level down, often with the use of an acoustic enclosure round the plant. In addition, for buildings such as gyms which are open during set hours, timers can ensure that loud plant is switched off during anti-social hours.
Pipework should also be acoustically treated. A sound baffle, which is a specially engineered device to reduce the strength of airborne sound, can be installed in the ductwork. When a sound wave strikes the baffle, the fibres within it vibrate. This causes friction, converting sound energy to kinetic energy which then dissipates.
Acoustic technology is a rapidly advancing field and much of what we have described here can be applied to any kind of building fit out. At Oakwhite we pride ourselves on keeping up with the latest developments and we work regularly with acoustic engineers to apply tailored plans for each fit out we undertake. We’re experienced at perfecting the acoustics in any type of development and we like to think we achieve the ideal solution for each individual client.
If you’d like to have a chat about effective acoustics for your next project, do get in touch. We’re based in West Sussex, but we work throughout the UK. Contact us via email, or give us a call on 01403 586062 for an initial chat with one of our helpful team members.