I'm trying to reduce the sound coming up through the floor from the flat below. It is mainly the low frequency stuff which gets through but get through it does. The building is a 1930's purpose built flat and the floor structure is a concrete slab about 150mm thick with a wooden raft on
50mmX50mm wooden battens fixed directly to the concrete floor with a cement filler. The original floor boards have been replace with 18mm chipboard sheets some time ago for other reasons. What I want to do is fill the space under the floor with something to absorb as much of the LF as possible. I am aware that what is needed is mass. Having read back over various postings that are still on the server their seems to be two main suggestions. One is a heavy aggregate such as sand and the other is high density Rockwool slabs. As the structure of the floor will permit me to use either of these options I was wondering which one people thought would be the better. I am also going to add a strip of 5mm dense foam between the top of the battens and the flooring boards.Steve
steve(underscore)hughes(underscore) snipped-for-privacy@hotmail.com