Soundproofing a BasementPosted on July 9, 2012 Tweet
If you are thinking about building a full apartment, a bedroom, or a recreation room in your basement, then it would be a good idea to consider the acoustics in this new space. This is likely to be an important factor as sound carries quite freely through the floor, walls and duct work. So, if you are starting with an unfinished basement, take advantage now and consider your sound-proofing options.
The first thing you need to consider for a basement soundproofing project is the type of insulation. There are many different types of batt insulation that claim to have good acoustic properties; if this is all your budget will accommodate, then by all means use this basic type of construction product. That said, the most effective product on the market for sound proofing is an open-cell spray foam. Why? Open-cell spray foam offers a density and cell structure that don’t easily allow sound to travel through it.
While the heading says soundproofing, the truth is that you are “sound deadening“. The ultimate way to dampen sound, essentially, is to build a room within a room with minimal connection between the two. Since this can be very costly, here are some suggestions that will allow you to achieve almost the same results at a fraction of the price:
Start by insulating between the floor joists. Then install 4” wide strips of ten test (or Tentest) every 16” going across the floor joists. Fasten the ten test strips with 2 screws on each side, at every joist. The next step is to install a resilient channel, also known as a “Res Bar,” on top of these strips with the screws on one side only, taking care not to crush the ten test. To fasten the channel, use 1” metal roofing screws as they come with rubber washers and will help bolster the sound dampening. The screws holding the channel should be positioned in the middle of the ten test strips.
(Wait: what is ten test or Tentest? This is a soft particle board usually sold in 4′X8′ sheets. This building material is used for exterior sheething in industrial buildings, barns, etc. It is available in two types, black and natural, with the black one being saturated with tar.)
Now you are ready to hang the drywall. You will use ⅝” drywall and screw it to the resilient channel with 1” screws. Or, a better option is QuietRock drywall which is available at Lowes and is specifically designed for sound proofing, but is about 5 times the price. When screwing the drywall to the channel you will want your screws to be positioned between the floor joists (in the void), as this will help eliminate sound transference. If your budget will allow it, you can then install another sheet of drywall over the first one using 2” screws. Once again, you want these screws to be positioned in the void between the floor joists while avoiding screwing them too close to the first ones. If you are starting from scratch, you can use this same method for the walls, which will greatly improve the sound deadening properties of the room.
Once the room has been built, you should avoid using hard surfaces for finishings like ceramic tiles, for example. Room furnishings should be soft to allow them to absorb noises. A soft wall and ceiling covering, such as fabric, will also help. Carpeting is also better than wood or tile to dampen noise.
Best of luck!