Basement ceiling soundproofing

[martin1b]

I'm in the process of finishing my basement and want to prevent sound from going between the basement and upstairs. My primary concern is hearing talking, music or TV upstairs when played downstairs or kids screaming.

The basement is a pretty open design and am wondering if that will hamper any sound deading work I do. Also, I'm concerned about sound from the stairs passing down.

My joists are 20.5 apart and the cavity is 18" deep. I was considering r30 insulation, or Roxul S&S. Also was considering Type X drywall on the ceiling. Im not interested in using resilient channel as my ceiling is low already and I'm a tall guy. Every inch of ceiling height counts for me.

Any thoughts on my approach?

[martin1b]

Should I use Roxul or fiberglass insulation to drown out sound between levels?

[martin1b]

OR do I forget Roxul or insulation and go with green glue and double drywall (1/2). Price would be comparable to Roxul.

[Randy S]

you most definitely need to insulate, do not leave the cavity hollow.

if you do not use channel then you want to go with 2 layers of 5/8" type X drywall with green glue.
you have to get the mass up in order to reduce air borne noise.

with out channel you do not get impact or low frequency reduction.

Randy S.
760-752-3030

[martin1b]

Thanks for the reply Randy. I'm on a budget and am trying to stop sound transmission between levels, such as talking. I can clearly hear conversations in the floor above me. Impact noise would be a bonus but not required.

To do this, would be GG/DD be the best way? RC and 1 sheet is doable and probably less expensive than GG/DD but does that only stop impact noise?  Also, how much insulation should I add AND can I use fiberglass insulation?

Bill

[Randy S]

Bill,

You can use fiberglass since you are doing minor soundproofing..Mass is what you need and as much as you can put in..

you need to at least double the weight to see a 5db drop (40% of human speech) the more the mass the better the reduction.

The channel allows for complex structure and improves basic direct applied systems.

Randy S.