Acoustic comfort is an essential requirement in both home and working environments and is a major factor in determining quality of life.
Surroundings for work and daily life must be sufficiently protected from sources of noise that can lead to health risk or reduced productivity.
The project: upgrading the acoustics in the new SAP offices, located in the Torri Bianche area, Vimercate (Milan). The work was carried out by Methis - Office Furniture Division, Coopsette group - supplier of movable walls and partitions for offices.
Introduction: Once the movable walls had been installed on site it was evident that they did not meet the soundproofing requirements of the customer. Because of this, L’ISOLANTE K-FLEX was asked to suggest improvements to the acoustic performance of the walls.
In order to prove the efficiency of our proposals, a sound test was also carried out inside the offices where our product had been installed.
The environment in question raises the following challenges:
- The mobile office walls rest on a floating floor consisting of cement tiles 3 cm thick with pointed support structure and no cross members; the tiles are spaced at 2 - 3 mm, creating a funnel of noise (acoustic bridge);
- The acoustic baffles that surround the office, above the ceiling, are further hampered by a network of piping for drainage and air conditioning;
- The ceiling is made of acoustic panels, which do not appear to be adequate for soundproofing purposes.
Therefore, in order to overcome these drawbacks, K-FLEX proposed applying a layer of K-FONIK ST GK 072 to the existing structure, installed with a “C” profile inside the uprights and cross members together with a layer of K-GK FONIK (4 kg/m2) combined with a 60 mm layer of polyester fibre.
Structure of the mobile wall with innovative remedial proposals by K-FLEX:
> Framed containment structure with a metal ‘U’ shaped profile;
> Dampening panels (measuring 1.70 m x 0.55 m) faced on both sides with melamine wood particle board (chipboard), weight 12.1 kg/m2 and 18 mm thick, secured to the frame using metal fasteners and to the outer frame with Z-shaped profiles;
> The walls were insulated inside with polyester fibre panels, 60 mm thick with a density of 26 kg/m3, placed between the dampening panels;
> Sheathing, 4kg/m² applied on the inside of the dampening panels on the side of the receiving environment;
> Co-extruded PVC seals applied along the narrow sides of the uprights of the containment structure,
> At the vertical joints between the sections of the dampening panels;
> Floor dampening gasket;
> Laminated elastomeric K-FLEX ST GK 072 installed with a “C” profile inside the perimeter duct and the transoms;
> Fill in all the joints of the semi-recessed ceiling with a flexible resilient sealant
When the work was completed, the apparent sound insulation power ‘R’ on site was measured.
Sound insulation index
The partitions were intended to guarantee sound insulation with a minimum threshold of R’W 40. The apparent sound reduction index (R ‘), - a standard requirement of the DPCM 5.12.97 - is of a magnitude that is used to describe the true acoustic performance of buildings, as opposed to sound measured in laboratory conditions, being measured in standard conditions (typical values on data sheets). Measurements of the apparent sound reduction index have been taken, according to procedure UNI EN ISO 140-4. The level of background noise was measured specifically to ensure that readings taken in the receiving environment were not influenced by extraneous noises such as sounds outside the test environment. The sound pressure level was measured (dB) for each partition evaluated.
Despite the criticism expressed above, on the basis of the measurements produced, the following results were obtained:
R’w opaque insulated wall = 41 dB
We exceeded the 40 dB required by the customer and following our advice, all mobile office walls will be treated with K-FONIK products.