Rain impact noise on aluminium cladding and the mitigation by damping materials

Raindrops on aluminium panels generate rain impact noise. Such percussive sound may reach 70 dBA in the nearby vicinity, causing disturbances to human activities and creating a nuisance. In Hong Kong, the use of curtain walls and aluminium wall cladding as the main building envelope has become a trend. The annual rainfall of 2.4 meters (94 inches) in Hong Kong amplifies this issue. Rain impact noise is increasingly affecting people and has become a growing concern. Effectively mitigating rain impact noise has become important in modern building design. This study focuses on the effect of different damping materials on rain impact noise when tested according to ISO-140-18:2006. It also includes an in-depth analysis of the correlation between vibration levels and sound levels generated under different testing configurations. The results showed that, with suitable treatment to the aluminium panel, the generated noise can be reduced by 15 dBA.