8–12 Sept 2026
Europe/Vienna timezone

Flanking sound transmission reduction through a decoupled CLT floor

FA2026/915
11 Sept 2026, 11:00
20m
Galerie C (Messe Congress Graz)

Galerie C

Messe Congress Graz

A03 Building Acoustics A03.04 Acoustics of wooden buildings

Speaker

Vincenzo Pettoni Possenti (Department of Industrial Engineering, University of Bologna)

Description

Cross-laminated timber (CLT) is widely appreciated for its fast installation, sustainability, and lightweight properties. However, its high sound radiation efficiency makes it particularly susceptible to flanking transmission. At the same time, its aesthetic appeal often leads architects to leave surfaces exposed, avoiding additional linings.In standard design solutions, suspended ceilings are commonly installed to limit direct vertical sound transmission from the floor above while also concealing building service installations. This study explores an alternative strategy that introduces a resilient layer between floor elements to reduce lateral sound transmission between adjacent rooms via the upper floor.An experimental campaign was carried out on a horizontal X-junction mock-up. First, the vibration-reduction index (Kij) was measured on a continuous floor slab. The slab was then divided into two sections, separated by a resilient material, and the Kij for the floor-to-floor transmission path was measured again.The results demonstrate that floor decoupling with resilient material is an effective strategy, particularly at low and high frequencies, achieving improvements of up to 8 dB in the single-number Kij. The performance of this solution was further assessed through calculations in accordance with ISO 12354, based on the experimental data. These findings highlight new opportunities for acoustic design in CLT structures.

Authors

Luca Barbaresi (University of Bologna) Vincenzo Pettoni Possenti (Department of Industrial Engineering, University of Bologna) Paola Brugnara (Rotho Blaas) Alice Speranza (Rotho Blaas) Luca Sestigiani (Rotho Blaas)

Presentation materials