Acoustic or sound transmission considerations in building design cover the methods by which sound can be transferred from one part of a building to another, or from inside to out and vice versa.
The interest in building acoustic performance has seen an increase in recent times, and particularly in respect of amendments to Building Regulations and Part E. The regulations focus on reducing the sound transmission through walls and floors, there are no specific requirements for roofs or rooflights.
Hambleside Danelaw carried out independent laboratory testing of airborne sound transmission through in-plane glass reinforced polyester (GRP) rooflight panels in accordance with BS EN ISO 140-3 and BS 2750-3.
The airborne sound transmission through the rooflight panel samples was determined by measuring the corrected difference in sound pressure between two reverberant rooms, the ‘source room’ and the ‘receiving room’. Noise levels over a wide range of frequencies were originated in the source room and then measured on both sides of the sample.
From these measurements the Sound Reduction Index can be calculated. This kind of laboratory testing is the only method that can measure the performance of a construction element accurately. Once materials are installed and in use in a building, other areas and attributes of the building can influence the actual sound transmission performance and create false results.
To read more on sound transmission testing on insulated rooflights, you can download the section from our technical manual here.
The next section of the technical guide discusses non-fragility.