Noise diffusion

Common airborne noise is absorbed by the air and is reduced

as a function of the distance from the source.

Foot traffic or classic impact noise (a glass shattering on the

floor) is transmitted to neighbouring rooms by horizontal and

vertical structures and is a function of the building structure.

Given the complexity and diversity of each structure in which

one may operate, the mass-spring-mass model is used and the

concept of floating floor is introduced.

In this model the screed of the floor (mass) is decoupled from

the underlying structure because it rests on the ACUSTIC UL-

TRA 30-2 panel with certain damping characteristics (spring)

and does not transmit sound vibrations to the underlying struc-

ture (mass).

Installation recommendations

The panels must be perfectly interlocked with each other to

create a uniform plane without thermal and acoustic bridges;

the panel must be placed on a smooth and clean sub-floor,

and must be supported at the perimeter strip; in the vicinity of

French doors and entry doors, it may be necessary to finish with

a sealant between frame and panel.

Special care must be taken in realising the screed to avoid any

contact with the surrounding walls, as this would inevitably cre-

ate acoustic bridges that would become a preferred route for

the passage of sound vibrations through the structure.

Acoustic performance of the ACUSTIC ULTRA 30-2 panel

The ACUSTIC ULTRA 30-2 panel has a dynamic stiffness class

of SD20 (dynamic stiffness ≤ 20 MN/m

3

) and a compressibility

class CP2 (the best among those established in EN 13163).

Dynamic stiffness describes the elastic and damping properties

of a material, can be related to the acoustic energy introduced

into the environment and depends on the thickness of the mate-

rial. This value can be used for the forecast calculation of the

sound pressure level from foot traffic of an individual space.

The compressibility class represents the material's ability to

maintain its properties over time when subjected to a load and

guarantees durability and physical characteristics over time.

Note that with, a dynamic stiffness class of SD20, you can ob-

tain the following levels of foot traffic sound pressure reduction:

www.wavin.it

Underfloor Radiant Systems - Product Guide

43

Surface mass*

(kg/m

2

)

90

110

130

Forecast foot traffic attenuation level (dB)

28

29

30

*The surface mass equals the mass of the screed placed above

the panel per square metre. Indicatively, for a screed of 2000 kg/

m3, the surface mass is, respectively, 50, 65 and 80 mm screed

above the panel.