Soundproofing my friends basement?
Question:My friends and I are thinking about soundproofing my friends basement because when we have parties there it disturbs other residents. We obviously don't want this to happen so i was wondering how much it would cost if we bought soundproofing board from a home store and put it up in his basement. Also i would like to know how to do this in the most effective way possible. The basement is unfinished and of medium size.
Answers:
Before you take this on consider the following:
Soundproofing is really a question of cutting low frequency (bass) transmission. Highs and midrange are comparitively easy (basically seal the room and you're done). Cutting bass require decoupling of the inner surface from the other side so the sound is not transmitted through the wall or damping the wall by adding mass (or both).
Since you will need to build walls a good option is to use Resilient Sound Isolation Clips on the bottom of ceiling joists and on new stud walls, both with metal furring strips with one or two layers of drywall over them. You also need to fill the wall cavity and interjoist cavities with fiberglass insulation..
If you will be doing the work yourself consider "staggered studs". Basically, you build on a 2x6 top and bottom plate, with two lines of studs (for the inner and outer surface of the wall) staggered from each other so they don't touch, and again fill the cavity with fiberglass insualation. All openings must be sealed to prevent transmission of mid and high frequency sounds. Note that the commonest reason for failure of staggered stud soundproofing is unintentional bridging of the two surfaces ... so care is required.
Both approaches -- "RSI Clips" and staggered studs -- serve to decouple the inner wall surface from the existing/outer wall, reducing sound transmission by as much as 50-60 db (See links for detailed specs and expected
The outer edge of the new wall surface in each approach must be sealed with a non-hardening elastomeric caulking (Read the labels carefully at your local hardware / building supply store). And of course the new drywall will have to be taped and sanded then painted.
I built a home theatre in my basement and used the RSI Clips on the ceiling and staggered studs for the walls. I chose this approach because, excluding labour costs, RSIC is more expensive to do. If I had contracted the work I would have chosen RSICs for both since they are quicker to install. The results from both approaches were excellent ... when the sound is turned up in the HT if you are in another area of the house you can tell it is on but levels are not objectionable.
How much does it cost?
Well this depends on dimensions, which method you choose, and labour, lumber, insulation and hardware costs in your area.
In Canada the RSICs cost about $7.50 each (See second link for a spreadsheet to calculate your needs for your project). It will also depend on how you treat the floor.
I'll focus on the incremental cost of soundproofing over simply finishing the basement. In this case consider the ceiling as needing insulation ($0.50/sq ft), and RSIC clips (approx 0.2/ sq ft = $1.50/sq ft), furring strips ($015/sq ft) plus metal drywall screws and acoustic sealant... call it $2.50 / sq ft INCREMENTAL COST (i.e. no drywall or labour). Walls would be similar if using RSICs, or a bit less with staggered wall (double the number of studs @ local cost, $0.50/sq ft for insulation).
See the links for further details, including expected results for various installation options.
to cancel that much noise, the rafters need filled with insulation, not a single board screwed on. either normal R-32 or higher insulation and then a board and then drywall or directly into foam insulation.
either way, to make a room sound proof, you are talking about $5 a sq foot. So figure if basement is 20 x 15, that's 300 sq ft or about $1500 to sound proof it. This does not include labor of course.
Cheap effective way for party place. Rent a climate controlled 15 x 10 storage bin. Put down a old rug, some old chairs, an old stereo even a rabbit ear'd TV. Run extension cords to the outlets in the hall. Enjoy a private party.
Storage unit I rent for work, 3 bays down and in next building are 2 bands. They use it for practice and just jam out all the time in there. Walk outside and its barely 3% heard.
Nunoy... is right about the inulation and cost. Just don't try to save money by collecting discarded foam or other non-flame resistant materials to do this on the cheap.
fill the walls with sand.
maybe you could have a beach party theme and get it done for free
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