Nuisance noise is a common issue in multi occupancy buildings. Here, Thomas Merton, Technical Manager at Armacell®, looks at how advances in acoustic materials and a better understanding of where noise is generated are helping reduce its effect.
Noise can severely affect the quality of life for residents, leading to stress, sleep disturbances and overall discomfort. Around one in three of the population is affected by environmental noise at some stage, with many reporting that sounds from plumbing are particularly bothersome.
According to the World Health Organisation (WHO), excessive noise can seriously harm human health, disturb sleep, cause cardiovascular effects, reduce performance and provoke annoyance responses and changes in social behaviour. This chronic activation of the body’s fight-or-flight response can lead to serious, long-term health problems like heart disease, stroke, diabetes and high blood pressure.
Latest advances in acoustic lagging are helping to tackle this issue with the development of much thinner, flexible insulation materials. They combine flexible foam and a heavy eva-epm barrier. Unlike traditional thick insulation materials, thin acoustic lagging offers superior sound protection by catching the noise at the source without significantly reducing living space.
Noise sources in multi-occupancy buildings
There are many and varied sources of noise in multi occupancy buildings. Even small impact sounds like water rushing though a pipe, especially when it reaches a bend or junction, can carry and even amplify as it travels. In addition, when sound travels along elements shared by adjacent structures, flanking noise transmission occurs. Noise can also be amplified by boarding, with unsealed pipework apertures between rooms creating a pathway for sound to travel to other areas.
All buildings have the potential to generate noise disturbance for occupants if appropriate mitigation measures are not taken. Conversely, when these are incorporated into early design stage, the cost is relatively small for the benefits it delivers.
Noise disturbance is a particular concern in multi occupancy buildings such as apartments, schools, hospitals, care homes and hotels. In most of these cases, specifying acoustic insulation foams, which are relatively inexpensive and easy to install, can significantly improve occupier comfort.
Independent tests by CSTB (Centre Scientifique et Technique du Bâtiment) confirmed that these acoustic multilayers can reduce the airborne sound pressure levels of a plastic waste vertical drainage pipe by 16 dB (A) at 2 l/s water flow. Similar tests on a horizontal PVC pipe, where the vibrations caused by flowing water are stronger, achieved a noise reduction of 24.5 dB (A). The human ear perceives a reduction of 10 dB (A) as halving the volume.
Acoustic foam materials like these have very good damping and isolation properties across the frequency range relevant for building acoustics – irrespective of whether it is installed on cast iron or PVC rainwater and wastewater pipes. They also display very good fire behaviour, achieving the best fire class for organic products in the European SBI test.
Architects will find that being able to achieve the required decibel reduction using a thinner insulation makes better use of available space. It also helps during the construction phase because it makes installation in tight spaces easier.
Ultimately, this ability to achieve the required decibel reduction with thinner insulation gives architects and designers greater scope to maximise the size of living spaces.
Pipework is a common source of noise
Noise generated by water rushing through rainwater and wastewater pipes is a common compliant from resident in multi occupancy buildings that don’t incorporate appropriate mitigation measures. The noise from this moving water is transferred to wall and ceiling elements and from there to adjoining rooms.
Specifying a fully integrated acoustic lagging systems for piping networks, plant and other equipment on-site is one of the best ways of tackling noise from pipework. The NHBC (National House Building Council) guidelines 6.3.7 Sound Insulation recommends that ‘all sections of soil and vent pipes, including those in bathrooms or ground floor stub stacks, should be fully soundproofed’.
Key learnings
The key to making sure that acoustic measures are effective, yet don’t take up too much space, is to choose those that offer high performance at low thicknesses. This is also best achieved by choosing visco-elastic resilient layers between installation and structural connection points, which prevents acoustic bridges and significantly reduces breakout noise.
Noise has become one of the greatest environmental issues of our time. Whether at work, in public buildings or in the home, it has been shown to harm human health. The consequences of not specifying acoustic insulation are usually only noticed when the building is occupied, and then it is often more expensive to remedy.
It is essential that appropriate noise mitigation measures are considered at early design stages and then consistently planned and properly carried out. Effective sound protection measures are relatively inexpensive yet increase both residents’ comfort and the asset value.