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Index established in 1978 in Italy based on the foundations of research, innovation and training, produces bituminous membrane, cement based water insulation material, acoustic membrane and sound insulation barriers.

Since 2009, Index is a member of the Italian Green Building Council, “targeting to create a sustainable building culture implementing LEED Standards.” At the beginning of the 90s, the company improved its product diversity and put to market Fonostop, the insulation material against impact noise in flooring and Topsilent sound insulation product and systems against air borne sounds in the wall.

The airborne noise is due to the difference of pressure created by sound waves. It causes the arise of vibrations at molecule level within such solid matter. Such vibrations (sound of conversation, TV, loudspeakers etc.) are transmitted to neighbouring areas through construction elements. Therefore, the separating surface has to be made of heavy and flexible material. In walls made of brick, plasterboard and reinforced concrete, TOPSILENT Bitex and TOPSILENT Duo are used. 

The amount of sound passing from one surface to the other surface of the wall is defined as the sound reduction value (Rw). Whereas in flooring, in addition to the airborne sound, a lot of impact based noise (noise of heels, pulling of furniture etc.) is created. Such noise causes a frequent and repeating effect in the flooring of buildings and has a much higher energy compared to airborne sound. It affects directly the structure and causes vibration and transmission of high noise. The continuity of the structure can be cut by soft and flexible material, so that the vibration is absorbed. Such type of flooring is called floating floor. Floating floors are created by using flexible material such as FONOSTOP Duo or FONOSTOP Act. The impact sound reduction value of the flooring is shown as (ΔLw).

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VIBRATION Control and SOUND Insulation.