Author Topic: Basment soundproofing ideas  (Read 5594 times)


  • Guest
Basment soundproofing ideas
« on: January 05, 2010, 09:11:35 PM »
Hi, I've been doing quite a bit of research into isolating the noise in my upcoming basement family room from the living areas upstairs, but I have a few questions that I've gotten mixed answers to. Right now the plan is to hang 5/8 gypsum on RC-2, try that for a while and if we still have problems, green glue a second layer of 5/8 gypsum to the ceiling.

1. Would there be a benefit in placing closed cell foam on the drywall back, between the RC-2 strips?

2. If the walls are simple 2x4's+1/2" gypsum construction and are connected to the floor trusses above, will soundproofing the ceiling be a waste of time?

3. Is it worth it to caulk the gaps between the sheets of plywood in the subfloor?

4. When using multiple lengths of RC-2, Should the end be flush to one another or should I leave a gap?

5. The sides of the soffits are made of 1/2" OSB and are roughly 12" high, do I need RC-2 on this, since the sound would have to travel through ~12" of wood? What would be the best way to soundproof soffits without reducing headroom?

Thanks in advance, this site has already been a great resource.


  • Guest
Re: Basment soundproofing ideas
« Reply #1 on: January 05, 2010, 09:52:41 PM »
Hey nulrich; I don't have any answers for you but you asked some great questions and I eagerly await replies to your post. I'm doing an almost identical job to yours and the presently open ceiling in our basement is of the engineered, glued & screwed type that contains ducting and wiring, so not much point, in my opinion, in trying to insulate the space there, but perhaps there's another opinion to this? 

Randy S

  • Guest
Re: Basment soundproofing ideas
« Reply #2 on: July 23, 2010, 03:28:38 PM »
Well, I missed this post and I apologize.
To answer your questions below.

1.) covering the entire back side of the drywall with 1/4" ssp foam mat is a huge addition to the overall stc rating of the system. Not only will it add STC value it will also improve decoupling between the RC2 and drywall. And it will also provide more absorption in the cavity.
2) No it will not be a waste of time however you will experience a flank value..this value will be less then what is directly transmitting below.
3.)Yes every chance you can get to seal gaps air tight make your overall system that much better. If air can move easliy then sound has to work harder.
4) a connection is normally done between joist so we overlap.
5) you must fur out soffits...and this would be an ideal place to use 1/4" ssp foam mat with th RC channel.


  • Guest
Re: Home soundproofing Tips
« Reply #3 on: September 02, 2010, 06:15:48 AM »
Hi, I am posting soundproofing tips for you. Hope you will find it helpful.

For most people, the home is a respite from the outer world. It is a place where one goes for rest, peace and quiet. But, a lot of people are not fortunate enough to be living in quite suburbia; instead, they might have noisy neighbors, heavy traffic flow or even train lines or airports close to their homes. Things might be the other way round too. For instance, a person may be interested in playing drums or bagpipes, or may have a home theater system which is likely to disturb the neighbors. In such cases, soundproofing a house becomes the best option to avoid noisy disturbances.

There are three main techniques to home soundproofing, all of which work on the principle that sound waves keep traveling until they hit some resistance and that the volume of sound fades as it travels. For soundproofing walls, the first and the easiest way is to create space in the rooms. Large rooms stop sounds from traveling. But if this is not possible, then cheap soundproofing options can be availed by placing heavy furniture around the house. Heavy items absorb sound and act as a resistance to sound waves. Commonplace household items and building materials such as sofas, thick curtains and even marble slabs act as good soundproofing material.

The third soundproofing option is to get a house professionally insulated. Professional insulaters use double paned windows to minimize noise travel. Window plugs are filled in the gaps to make sure that the room is completely impervious to sound invasion. Also, soundproofing ceilings as well as walls are necessary in order to make a room quiet. For this, layers of thin drywalls are added in between rooms so that they can absorb the sound waves. At times, wallpapers can also act as good sound absorbents. For soundproofing floors, the best option is to get thick carpets which muffle footsteps.

Appropriate soundproofing not only prevents outside sound from entering the house, but also prevents unwanted sounds from disturbing the neighborhood. That’s why it becomes important for home owners to use the correct soundproofing products and techniques to make their haven a comfort zone - away from the intrusion of unwanted noises.

Randy S

  • Guest
Re: Basment soundproofing ideas
« Reply #4 on: September 02, 2010, 05:39:31 PM »
Normally I would remove such a post due to the fact the information can cause confusion.

1)" Large rooms stop sounds from traveling. " not completely true, the higher the ceilings or cathedral ceilings/vaulted could increase echo and amplify secondary reflections in a room.
2)"Commonplace household items and building materials such as sofas, thick curtains and even marble slabs act as good soundproofing material." This would be used for absorption for sound with in a room not soundproofing. These are 2 different processes, you must be able to contain/control sound in order for absorption to have noticable affects. example: if I grab one of my pyramid panels and run outside with it how can you tell its doing anything? so in order to see value you would need to add enough absorption material with in that room to see a noticable change. min. 30% of surface area.
3)"For this, layers of thin drywalls are added in between rooms so that they can absorb the sound waves. At times, wallpapers can also act as good sound absorbents." If this was the case we would not be in business! picture the drywall as a speaker, picture the screws like speaker wire and picture the studs like the amplifier. This is the true path sound takes the fastest so just by screwing in more drywall what are you really doing? decoupling has and will always be the first rule in soundproofing. As for wallpaper, forget it.
Make sure your getting sound advise before you waste time and money. Doing the job right the first time really does pay off in the long run.