AMC-MECANOCAUCHO took part in a new study presented at the INTER-NOISE 2025 congress, in collaboration with FCBA (France) and Marshall Day Acoustics. The research was conducted in the Maquette Acoustique Bois, a full-scale 3-storey CLT building located at the FCBA acoustic testing center in Bordeaux.
The study focused on the vibroacoustic characterization of junctions between floors, walls, and ceilings, using standardized methods to predict flanking transmission in multi-layer timber buildings.
Applied methodology
A strategy based on the Statistical Energy Analysis (SEA) model and the EN ISO 10848 standard was applied. The vibration reduction between structural subsystems (Dv,ij) was measured using mechanical excitation (the “rain-on-the-roof” method) and multiple accelerometers.
From these measurements, Kij vibration reduction indices were calculated, which are used in the EN 12354 prediction model to estimate room-to-room sound insulation in real project conditions.
Tested configurations
Five structural configurations were tested, including horizontal (floor–wall–floor) and vertical (floor–wall–ceiling) junctions. All setups included mechanical decoupling systems using AMC products:
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Akustik+Sylomer® 25 Floor Mount
in floor assemblies
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Sylomer EP 500 + S35
for decoupling of wall partitions
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Fermacell and OSB boards were used as finish layers but are not the core acoustic solution, since the functional performance is provided by the elastic decoupling systems. The floor structure consisted of 140 mm CLT panels with cavities filled with mineral wool. Dv,ij was measured across each flanking path.
Key results
- Junctions with resilient materials showed significant vibration reduction, especially in horizontal configuration no. 2.
- The floor transmission path provided much higher sound attenuation (88.2 dB(A)) than other paths, thanks to the resilient components.
- The overall predicted sound insulation value (DnT,w+C = 64 dB) exceeded the regulatory threshold (53 dB), confirming the effectiveness of these design choices.
Conclusions
The study demonstrates that measured Dv,ij and Kij values can be successfully applied in standardized predictive models such as EN 12354, significantly improving acoustic design precision in timber buildings.
Looking ahead, it is essential that acoustic planning be supported by open-access databases of measured Kij values, as well as by standardized qualification methods across laboratories to ensure consistency and reliability in design data.
United Kingdom
