Adding mass to improve sound insulation can be one of the most important elements to improving precompletion sound testing results. In summary it basically means you add extra weight/mass to the construction of the acoustic wall and/or floor partition. Materials such as solid block-work masonry is best for wall construction; however it is very important that the block-work envelope is constructed out of solid concrete block work as the use of lightweight block work often ends in sound test failure.
For floor construction, solid concrete floors – min 150mm) are usually the best construction for outright mass; however soundboard, plywood and OSB can be found fairly cheaply and will also do the job – if installed as per manufacturer’s guidelines. It is very important that adequate site supervision is on hand to check the construction of all acoustic partitions.
It is basic physics, so for sound to conduct through a wall, it has to actually move (vibrate) the wall ever so slightly. As a heavier wall is harder to move than a lighter wall then it should vibrate less and turn let through less noise. Soundboard is one of the lowest cost sources of mass available and also one of the most commonly used. Wherever possible its best to use two layers of 12.5mm board with the correct laps to the boards. Although the wall will still vibrate it will be less due to the extra mass.
It’s worth noting that although the added mass improved things and it will be more difficult for sound to move this heavier wall, in many instances you will still hear low frequencies (bass noise) quite easily.
Our next blog covers the last – but not least) element of acoustic design – Damping. If you would like more information in regards to acoustic design and sound insulation testing, please contact us now at firstname.lastname@example.org or call Darren direct on 07775623464.