Reducing noise pollution

2020-09-23T08:55:55+00:00September 23rd, 2020|News|

One of the key productivity killers, is noise!

Clay brick moderates noise and temperature extremes in higher-density residential complexes, resulting in quieter neighbourhoods. Image credit: CBA

Clay brick moderates noise and temperature extremes in higher-density residential complexes, resulting in quieter neighbourhoods. Image credit: CBA

Noise is not only irritating, it can contribute to reduced physical and mental performance.  In an acoustically comfortable environment, one hears others more easily, focuses better and feels calmer.

The density of ceramic clay brick provides an inherent resistance to the passage of airborne sound. Brick buildings reduce both high and low-frequency noise from outside. Masonry also isolates and protects against impact sounds on walls and floors inside the building

Understanding sound transmission

In their research report ‘Measurements of Sound Transmission Loss in Masonry’, William Siekman of Riverbank Acoustical Laboratories tested 15 clay brick wall types including face brick, single and double leaf walls, as well as walls with and without cavities and/or insulation.

They found that the average double-leaf plastered clay brick wall cuts over 50% of the noise from outside. Ambient noise of around 65db (moderate to loud) is reduced to less than 20db which is barely audible.

A double skin clay brick wall is therefore defined as a superior insulator even without insulation. Because the brick has mass, it has the ability to inhibit sound penetration.

Reverberation

Another factor that influences how we perceive sound and the experience of acoustic comfort is reverberation.

Reverberation is time taken for a sound to ‘fade away’. If the delay is greater than 0.6 seconds, people find it hard to distinguish between consonants. Factors that increase reverberation, sound reflection and echoing are:

  • smooth, glossy walling materials (especially glass windows and doors)
  • large, double volume rooms
  • fewer objects in the room to break up the sound

Textured rustic and face brick products are superior performers when it comes to reducing sound reflection and reverberation.

In general, masonry – whether it is clay brick, cement brick, concrete block or stone – provides superior sound control compared with ‘poured concrete’. Often the reinforcing steel required for cement structures ‘rings’ with vibration throughout a large multi-storey building.