THE VELT INNOVATOR

Nevima
Sound insulation

NOISE BURDEN? Nevima has the Answer

Sound insulation in commercial buildings and residential accommodation is fast becoming a major focus of attention. Not only are the demands in this sector rising, but the legal requirements have also been made considerably more stringent. No wonder, then, that the question is being asked more and more as to how sound insulation can be improved. Nevima has enormous experience in sound insulation, and provides solutions with a wide variety of products.

Situation assessment

In order to be able to improve sound insulation, a good assessment of the existing situation is required; and in this context, an important factor is a proper understanding of the aspects which influence the transmission of structure-borne sound between two areas.

The Problem

The cause of sound transmission is that air, or a structure, is sent into vibration. If air is caused to vibrate, for example by a radio or a musical instrument, we have what is termed airborne noise. If a structure is caused to vibrate, for example by walking on a hard floor, or by water flowing through a pipe, we speak of impact sound.

One problem which frequently arises is that airborne sound can easily be transferred into an adjacent area through cracks and gaps. Sometimes the problem can be solved by sealing the apertures. In most cases, there will still be a slight direct transmission of sound, and a simple seal is not sufficient. Basically, if the airborne sound collides with the existing structural elements, these may take up the vibrations, and reproduce them on the other side of the structure again, in the form of sound.

Exactly the same principle applies to impact sound; here too, the structural element which is set vibrating reproduces the sound again on its other side. We speak of a flanking transmission when the airborne or impact sound is transferred to distant locations due to the structural elements being set in vibration by adjacent structures. If vibrations are taken up by a solid structure, they can be carried a longer distance than through the air. For example, we can hear a train approaching long before it arrives, simply by putting an ear to the rails. All this means that it is always very important to try and prevent existing structures from taking up vibrations.

The solution

A flexible dry lining wall will absorb sound
A range of physical factors can help with reducing sound transmission. For example, a structure with greater mass is more difficult to set in motion, while a flexible structure will dampen the vibrations. Such points need to be borne carefully in mind with regard to the improvement of sound insulation.

The sound insulation of a structure can be improved by means of a properly designed "flexible" dry lining wall, "floating" floor, "suspended" ceilings, or a "floating" roof.

Nevima has a number of products to easily build such constructions: the IVI-Soundbatten and the IVI-Metalsystem

Ceilings Pitched roofs Walls Partition walls Floors
• Soundbatten
• Metalsystem
• Metalsystem • Soundbatten
• Metalsystem
• Metalsystem • Soundbatten
• Pro-Panel
• Nevidek

The sound insulating properties of a dry lining structure depend on two factors. The principle which applies is that the greater the cavity, the better the effect. Nevima accordingly provides the IVI-Soundbatten in three thicknesses (40, 60 and 80 mm), which have the effect of creating cavities of the same depths. With the IVI-Metalsystem the dept of the cavity can be increased to the desired depth.

In order to determine how great the existing sound transmission is, the table provided below may be of assistance. Taking the results determined as a basis, a check can be made on what improvements a sound-insulating structure will be required to provide.

 

Types of noise

Minimal sound-proofing

(RW 52 - 57 dB)

Good sound-proofing

(RW 57 - 62 dB)

Very good sound-proofing

(RW over 62 dB)

Normal conversation

Sometimes just audible, but not understandable

Not audible

Not audible

Speaking in raised voices and radio/television at normal volume

Identifiable and sometimes not understandable

Audible, but not understandable

Not audible

Very loud speaking and radio/television with the volume high

Easily understandable

Audible and understandable

Audible with difficulty

Musical instruments and parties

Very clear and sufficiently audible to be a nuisance

Easily audible

Audible

When deciding on the IVI products required, it is important to know what the sound insulation of the existing structure is, and what improvements would be possible with the use of the IVI products.
On the page describing the IVI-Soundbattensystem there is a series of examples of possible improvements for the types of existing structures which are often encountered; pay attention in particular to the differences between the Rw values of the initial structures and the new structure.

The noise insulating products of Nevima have been internationally used with great success for years, for example for the damping of noise from the surrounding environment, in the catering sector, and for reducing aircraft and traffic noise.