Soundproofing of apartments?

[Joshua Mast]

I have a duplex that is divided up by floors: apartment 1 is on floor one and apartment 2 is on floor two. I have an issue with sound travel between the two floors. I got one of those dreaded 10:30pm tenant calls last night with complaints on the sound. I have had this property for 7 years, and, in general, the issues don’t present themselves if the tenants are going to bed around the same time. The bottom tenant is original and doesn’t complain much; until this last tenant moved in. She tends to goto bed around 9:30-10:00, but the tenant above her has put their office in the room above the 1st floor bedroom and will work sometimes until 2am. No issues except she will use a rolling chair, may drop things, may play music, etc. as much as I try, they just can’t seem to get along. I am curious about different methods to address this issue - soundproofing/dampening, ask them to move their office to a different room, get new tenants, etc. I had looked into having insulation blown into the ceiling but am not sure if it will be very effective. Any help is appreciated! Josh

[Shaun C.]

My first property was a top/down duplex in which I was the lower unit. I really, REALLY wanted to punch the previous owner who added the 2nd floor in the face for not putting in ANY kind of insulation or isolation clips on the 1st floor ceiling after living there for 3 years. These problems will keep coming up, and the only real way to deal with it is to fix it.

I am an architect and a builder, so through my research the best thing to do would be to blow in cellulose into the ceiling cavity, and then install sound isolation clips and install another layer of 5/8" drywall. A large project if you ask me, with little to no gains in rent produced. You can also forgo the clips and just do the blown in with another layer of 5/8" drywall with green glue sandwiched in between and that would be my recommendation. In your area, you could probably get the project done for about $3-4k when all is said and done. But again, with minimal increase in rent. It will keep tenants longer however.