Soundproofing - Legal requirements

A residential building, or a building for office or hotel use, needs to have a well-defined insulation system to combat the noise of footsteps. How is this problem overcome to comply with the minimum requirements of current legislation?

 The transmission of noise from footsteps can be contrasted by laying sound-absorbent material, with the capacity to cushion the sound waves that are propagated, between the load-bearing structure of the floor and the floor covering.

In new buildings, the acoustic system is usually placed under the screed, which is also known as a “floating screed”. This solution is the most widely adopted because it is easy to install, effective, economical and easy to design using special acoustic analysis software.

Can you explain the importance of acoustic insulation in a building and the difference between soundproofing and sound-absorption?

Soundproofing and sound-absorption are often thought to be synonymous, but in actual fact they express two completely different concepts. The aim of soundproofing is to reduce the transmission of noise propagated between two areas, such as a dividing wall between two adjacent rooms. The aim of sound-absorption, on the other hand, is to correct and control the propagation of sound that is reflected off the surfaces around a room in order to adapt it to specific requirements, such as in a concert hall, theatre or cinema.

What is an acoustic bridge and how does it form? Does an acoustic bridge coincide with a thermal bridge?

An acoustic bridge represents a preferential point for sound to travel through and tends to form in areas where there are gaps or breaks in the material applied to reduce the propagation of sound. An acoustic bridge does not necessarily coincide with a thermal bridge, even though both types of bridge tend to form where there is a break or gap in the geometry of a room (such as the corners between adjacent walls or between the floor and walls or windows). The presence of an acoustic bridge considerably reduces the soundproofing performance of an acoustic system, with a serious risk of comprising its compliance with legal requirements.

The acoustic performance of a building is becoming increasingly important in terms of its living comfort. What solutions does Mapei propose to achieve acoustic comfort?

The MAPESILENT system is ideal for new office buildings as a way of quickly installing floating screeds easily and reliably which are perfectly insulated from the substrate and which meet legal regal requirements as far as noise from footsteps is concerned.

Can Mapei solutions only be applied in newly-constructed buildings, or may they also be installed in existing buildings? Is the material chosen for the floor covering – wood, ceramic, vinyl – important when proposing a soundproofing solution?

 Even in the case of refurbishing an existing building, in which it is impossible or uneconomical to remove the old flooring and rebuild a new screed over an acoustic system, Mapei is able to offer specific products. MAPESONIC CR is a compact soundproofing membrane which may be applied on top of existing cementitious substrates or over old flooring before installing ceramic, stone, laminated wood and resilient flooring. The flooring can also play a part in improving soundproofing against the noise of footsteps. Surfaces dressed with carpet, resilient material (such as rubber, PVC or linoleum) and wood have a positive effect on the reduction of impact noise transmission. However, no floor covering allows legal requirements to be met or has much of an effect on the reduction of sound transmission unless it is used in combination with an appropriate soundproofing system.

Are soundproofing interventions on floors particularly complex and require specialised workers?

 All soundproofing systems for floors are simple and quick to install. It is very important, however, that the system is installed with great care and precision to prevent the formation of acoustic bridges that could compromise, either partially or completely, the benefits obtained from their use. And this is why it is always advisable to contact qualified companies.

Are the soundproofing materials used in Mapei systems eco-compatible?

 Mapei has always been committed to the development of eco-sustainable building and invests 5% of its annual turnover in Research & Development. Also, their low content of volatile organic compounds, the use of recycled and recyclable raw materials and their extended life cycle, all help reduce the impact Mapei soundproofing systems have on the environment.

Antonino Munafò. Acoustic Insulation Line Specialist for Mapei SpA