Closed cell foam for under subfloor

[Josh Wyatt]

Bob -
I recently purchased MLV to lay under the subfloor.  (To refresh - I have to tear up my hardwood floor due to water damage, so I am repairing the subfloor, laying down the MLV, and putting the wood on top).  We are starting in a few weeks.  I read about the guy who is doing something similar.  You mentioned to him that he could use a 'closed cell foam' product to reduce noise further.  What is this, where do I get it, and can I simply place it between my subfloor and the downstair neighbors ceiling?  
Thanks,
Josh

[boborther]

Josh,
The closed cell foams are generally used in the joist areas of the ceiling below. You would need to remove the ceiling in order to adhere the closed cell foam to the joists and the cavity areas below. The closed cell foams are used to seal off the dead air space in the cavities in the ceiling below. You would also want to cover the joists with this foam as it will cut down the vibration in the joists, and will also help isolate the wood joists from the new ceiling. The key is to seal off the dead air space below the floor and above the ceiling. This helps greatly on your soundproofing effort.
For more indepth information, go to the website and read up on the sound clips and resilient channels. These links will help you to understand the theories behind noise abatement in a floor or ceiling.
Thanks for the Post Josh.
Bob Orther
www.soundproofing.org
boborther@soundproofing.org
(760) 749-7049
For orders only (888) 942-7723