Acoustics Issue between floors in my rental property (duplex)

[David Espana]

I have a duplex built in the 1950s. I would like to fix an acoustic issue where impact and airborne noise travels easily from the upper unit to the lower unit (units are separately rented). Noise from poor acoustics has caused problems mostly for the lower unit tenants (from impact noise such as from tenant upstairs walking and airborne noise such as talking (yelling sometimes), music, tv, etc) and has caused tenants to want to move out due to the noise issue. 

I looked online for construction techniques to substantially reduce noise and would like to get your input if you addressed acoustics issues with your rental property or if you have expertise in how to address this issue. 

I am considering removing the existing ceiling drywall in the lower unit to expose the wood studs. Any holes, gaps, or other openings would be filled in with acoustical glue (such as Green Glue) or acoustical putty. Next, fill all the spaces between the wood studs with soundproof insulation such as Roxul Safe & Sound. Next, add resilient channels and then attach drywall to the resilient channels. 

In regard to adding drywall, I will have to consider using perhaps soundproof drywall (such as Quiet Rock) or adding two layers with drywall (maybe even add a layer of Green Glue between the drywall).  Also, for good measure, I want to consider whether or not to add a layer of Mass Loaded Vynil (2 lb) after installing Safe&Sound insulation but before adding the resilient channels and drywall. 

Further, should I soundproof the exterior walls in addition to the ceiling. 

Your input and feedback would be greatly appreciated 

Thank you, 

Dave

[Nathan Gesner]

It's an expensive under-taking. I have an apartment complex that is very problematic. If it's really quiet downstairs, you can literally hear a regular conversation upstairs. Walking sounds like someone stomping. Closing a kitchen cabinet sounds like someone is slamming it. Very frustrating.

Rather than tear the place down to the studs and spend tens of thousands trying to reduce noise, we simply warn everyone HEAVILY before they rent. They still express frustration, but they accept it because they've been warned. I haven't had anyone try to terminate a lease specifically because of noise.