We have a client in Arizona who wanted us to build him a sound room with a living roof. A sound room you are all familiar with. A living roof may be an other issue. It was also a pleasant surprise for us.
A living roof is a roof designed to support 18″ of top soil and the watering and drainage system necessary to maintain this miniature ecosystem. Supporting 18″ of earth and water is no easy task, especially when the roof size is 25′ x 50′. That is 1875 cubic feet of earth at approximately 20 lbs. / cu. ft. is 37,500 pounds of earth, not to mention the piping for water and drainage. The roof must support 16 tons of earth and pipes.
Earth is an excellent barrier to external noise. Go into your basement and sit quietly. There you are surrounded on 4 sides by earth and concrete. In this project, the roof and 6′ up the 12′ side walls will also be covered with earth. So, in this project we have 1 1/2′ earth on the roof and six more feet of earth on each wall side. Now, we need concrete walls at the correct thickness to match the acoustical properties of 1 1/2′ of earth on the roof.
We determined that an 8″ poured concrete wall all around will meet all our structural issues for ceiling support and acoustical issues for sound transmission class ratings and all external noise measured calculations. The 8″ concrete shell will build a room that is 25′wide and 50′ long. The ceiling height is 12′. One could not ask for a better room size when it comes to acoustical issues that must be dealt with.
At 50′ in the length dimension, even a 20 Hz.wave, which is the lowest wave we usually work with in rooms has some room to run. No low frequency issues or any others for that matter when it comes to the 50″ length dimension.The 25′ width is also good for low frequency, but will give us a few issues. Those issues will be resolved through the use of our activated carbon technology which will be added to the inside walls. A ceiling height of 12′ only increases our room volume and is welcome for all forms of sound playback and recording.