During the installation of sound insulation in new houses, one issue to consider is the possibility of structure-borne sound. However, what exactly is this sound, and what can we do to eliminate its effects? If you are looking to reduce structure borne noise please look no further!
Definition of structure-borne sound
Normally, this is the sound that is made up of waves that are sent across a channel to a sensor system or the human ear. In most houses, the sound is either airborne or borne by the building. That said, the British Regulations Approved Document E. defines structure-borne sound as “sound transported via the structure of a building”
A perfect example of a structure-borne sound is the sound of someone walking through a room on a floor above you or next to you. Moreover, sounds of objects falling in an adjacent room are also structure-borne sounds. Consequently, this sound is produced in 5 main processes:
1. Wave generation: This is the source of the vibration which ends up causing the sound.
2. Transmitting: the movement of the vibrations or sound energy from its source (let’s say footsteps) to the structure.
3. Propagation: this is the process that spreads the sound throughout the structure making it heard in different places.
4. Attenuation: this refers to when the sound fades as waves bounce off the surfaces, effectively lowering their energy and decreasing the sound.
5. Radiation: This is when vibrations are produced by an uncovered surface.
Remember, the sound that travels through the air and that which travels through objects and structures are closely related. However, they are still different because the airborne sound is created when vibrations from a hard structure within a building bounce. Additionally, if these airborne waves come into contact with a solid object or parts of a building, they cause the structure to vibrate.
Ways of Reducing Structure-Borne Sound
Fortunately, structure-borne sound can be significantly reduced using the following tactics:
1. Adding sound-absorbing mats and cushions to the floors or walls of a structure.
2. Using elastic materials such as foam, reused rubber, or fiberglass as an underlay can go a long way into mitigating the effects of structure-borne sound in some buildings.
3. Alternatively, ceilings with spring hangers and robust mounts can be installed in a building to absorb the sound.
4. Soundproof materials can be put on hard surfaces such as the floor. The material helps in dispersing the sound waves as they travel around the building.
5. Installation of hanging ceilings and raised floors can help reduce the sound
6. Utilization of heavy and high-density materials with cavities in construction projects.
Even though structure-borne sound can be minimized through proper building design characteristics, it is still a highly complicated subject. Always remember that the nature of structure-borne sound is influenced by several elements, including:
• Structural composition
• Receiving space type and make
• The radiating surface
As such, a consultation with a specialized sound consultant may be beneficial in the design of sensitive buildings.
Standards and Regulations regarding Sound Insulation
The Building Regulations Approved Document E establishes the minimum allowable noise insulation standard. All buildings must have their structure-borne sound levels monitored and lowered where necessary. This is done by striking a test surface with tapping equipment to produce sound in a nearby location. The sound impact on the structure is then measured and monitored to ensure it adheres to the set standards.
The process of removing structure-borne sound is complicated. This is because it will be influenced not only by the source of the noise but also by the structure’s composition and the distributing surface. Luckily, some architectural design aspects can be used to help reduce noise pollution.
More importantly, many architects and construction companies use a qualified acoustic consultant. These specialists assist in the assessment, design, management, and control of structural and airborne vibration. As a result, they help in reducing the danger of noise pollution and guaranteeing compliance with building codes.