What is Acoustic Underlay and How Does it Work?

Acoustic underlay is a material designed to be placed under floor coverings in order to dampen sounds that would otherwise be transmitted through the floor. Learn more about how it works.

What is Acoustic Underlay and How Does it Work?

The only purpose of acoustic underlay is to reduce the amount of impact noise that passes through the floor due to falling objects, footsteps, and furniture movement in any type of building. The subfloor, the layer between the floor covering and the subfloor, adds value to commercial flooring systems in many ways. It provides cushioning to reduce foot fatigue, dimensional stability to install the floor over small subfloor imperfections, and in many cases, a high R-value to contribute to the thermal insulation of the building.

The reduction of floor noise is mainly achieved through the use of an acoustic base layer.

Installers must place rolls or sheets of subfloor above the subfloor before installing floating boards on top.

Think of the base layer as a layer of foam or rubber material that cushions any impact and blocks loud noises. Acoustic bases are materials designed to be placed under floor coverings and to dampen sounds that would otherwise be transmitted through the floor. They are made from various materials such as polyester mats and recycled rubber (and often come in composite form) and absorb the sound of footsteps and vibrations that would otherwise spread uncontrollably across the floor. The acoustic subfloor for vinyl floors must have the necessary dimensional stability to avoid crevices and the thickness necessary to absorb sound. Underlying acoustic layers usually incorporate several layers and thicknesses, and are designed to block different types of noise.

This affordable acoustic floor base made from recycled rubber is easily installed with DA-5 adhesive to reduce noise caused by vibration between floor and ceiling assemblies. Marvel hybrid floors can be installed almost anywhere, as they have the highest acoustic certification without the need for an additional base layer. Underlying acoustic layers also often have additional advantages such as increasing the thermal insulation of the floor and providing a softer surface on which to place the coating, making it more comfortable to walk on. It is usually not possible to add more acoustic base layers, as this would make the floor too unstable and raise it too high above the subsoil. Acoustic subfloors (for hard surface floors) and carpet cushions (for soft surface floors) are essential to meet these strict codes.

Special acoustic bases can reduce the amount of sound transmitted between floors by 13 dB and 25 dB, exceeding BCA requirements. This acoustic floor base is excellent at reducing vibrational noise produced by mechanical sources between floor and ceiling assemblies such as steps, gym equipment, laundry machines, speakers, printers, and much more. An acoustic base made of cork, rubber or foam can further dampen noise and prevent sound transmission. Underlying acoustic layers can prevent a good amount of sound from passing through the floor but may need to be increased in thickness for truly effective results. For example, an acoustic base can have a sound-absorbing polyester layer sandwiched between two layers of rubber sheets which dampens vibrations. You can work with your flooring contractor to choose the acoustic paving system including the floor itself, its subfloor, and installation accessories that best meet your application's specific needs.

For example, FloorVenue sells Marvel's SPC hybrid floor which comes pre-installed with a 6-star acoustic base. The base layer of gold EPE foam is 3 mm thick and offers slightly higher acoustic protection than the general silver option.

Cyril Price
Cyril Price

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