Sound proofing floor


I am at the point that I don't need to modify or purchase anything else. But I am considering sound proofing the floor for the sake of my neighbors which know that I will lower the volume when they ask. I am considering raising the floor and making that raised floor decoupled from the room and insulated.
Any ideas?
pedrillo
Emailist,
I had that in mind- using the mass loaded vinyl on the floor.
Larryi,
I plan on using that vinyl on the walls as well.
My challenge is this: I will build the floor out of plywood and it will be supported at both ends. The span is about 11'(that's the width of the room), so I'll have a joint some where in the middle which will be staggered, and will be forced to use some lumber 2x4 or other. If I stand the 2x4 on edge to keep the floor from springing to low in the middle my floor gets thicker, something I don't want. So I was thinking towards the middle of the span installing srings of a sort? Foam? Rubber? Sorbothane?
But what will it feel like to walk on? And if I am sitting in the middle of the floor and the raised floor sinks to the spring material then it defeats the purpose of the raised floor which is suppose to be decoupled. Any suggestions. How much air do I need between the raised and existing floors to stop the sound from passing through?
In the end I think I will be installing the raised floor joists on edge.
If you have a layout of your equipment and furniture that you will be using it would be a big help in determining placement of minimal support for your added floor.
Don't forget to use T&G ply & glue the joints with something like PL400.
Instead of mass loaded vinyl try to find the heaviest cheapest vinyl flooring on sale(sized to fit room as one piece) and pick up the heaviest "used" foam u/l from a flooring contractor(it normally just goes in the garbage).
Glue the foam to the floor and lay the vinyl over it-gluing the vinyl only to the walls all around to prevent leakage. Relaxed vinyl is vastly more effective.
A layer of vinyl directly on the floor beneath the u/l would be an excellent economical improvement as well.
I will be very interested to follow your endeavour.(I would not recommend lifting your original floor, not worth it, but highly recommend you eliminate any squeaks before you start-and if I were doing it I would rescrew the original floor as a first step using 1&3/4 inch deck screws. Rattles would be very annoying. If the result is not quite adaquate the next step would be to work on the ceiling below. Cheers. Pete
Psacanli,
Thank you!
One other concern of mines(I know, it never ends) is the outgassing from the foam. I am not a health nut, actually a quite balanced health oriented individual. The outgassing is an important concern though, and in the winter when the stack effect forces air and vapors to move upwards it'll just end up saturating my living space. So I am hesitant with not just the foam but most materials that are being considered. I think the vinyl will not present as big an issue as foam would. The outgassing concern is what has kept me from going forward with this project as it has been on my mind for a while. Any suggestions Psacanli?
In addition to what I just posted: Something I was considering was cotton batting to avoid the outgassing issue.
I appreciate your concern Pedrillo & I think it's wise to considerate those eventualities.
I did mention we want the vinyl to be 1 solid piece and also to seal it to the walls(PL 400 will work permanently). I believe the vinyl will slow any outgassing significantly enough that normal routine ventilation will be adaquate. Let's face it most homes are carpeted and the outgassing will move through carpet much easier (faster) than thru vinyl. In addition you will want your plywood floor to be airtight as well-providing a second barrier. So, I think it should be okay. I was not aware of the cotton batting option but I imagine it would be pretty good.