Millions of Americans live in apartments or townhomes where they share at least one wall with their neighbors. As people go about their day, their conversations, footsteps, music and children cause noise that may be heard in the apartments or homes next door. The good news is, there are ways to improve the acoustic properties of our homes and keep neighbor noise out.
To understand how noise is traveling from our neighbors' homes to our own, we must first take a look at how sound works. Sound creation starts when an object is set in motion, whether it's our vocal cords, footsteps on the floor, or the speakers in our televisions. When these objects move, they cause vibration, which forces nearby air particles away from the object. These air particles travel in the form of sound waves, continuing until they reach our ears. The inner workings of our ears help translate these waves into sounds we can interpret and understand.
We measure the strength of these sounds in the form of decibels (dB). The higher the decibel level for a sound, the louder it is to our ears. For humans, the lowest sound level we can interpret is 0 dB, and the highest level we can put up with without pain is around 120 dB. A normal conversation typically measures around 60 dB [source: Vanderheiden].
To deal with neighbor noise, we have to find ways to keep these sound waves from reaching our ears, or at the very least, slow them down. We do this by adding materials in our homes that block, absorb or isolate the sound waves, keeping unwanted noises out of our homes.
The extent to which we manage to block sounds from entering our homes can be measured in terms of its sound transmission class (STC). The STC rating of a product gives us a good estimate of how many decibels it can block from penetrating the surface. Many soundproofing products as well as regular construction materials are marketed by the level of their STC rating.
Let's take a look at some of the ways you can improve the STC ratings of your walls and keep noisy neighbors from getting you down.
Blocking Sound Through the Walls
As the largest point of connection to your neighbors, your walls are a major source of neighbor noise.
Fortunately, they're also one of the easiest things to fix when it comes to sound transmission. Let's start by taking a look at how walls are constructed, so we can see why noise is getting through and how we can stop it.
When contractors are building apartments or townhomes to sell, they're generally trying to keep construction costs as low as possible. To do this, they'll often construct walls in the cheapest way possible, with shared walls containing nothing more than some 2x4 studs with a layer of drywall on either side. In some buildings, they may add a layer of fiberglass batt insulation to help with noise and temperature control.
Luckily, there are many ways to improve the STC ratings on your walls and help block more sound. The quickest and cheapest solution is to add a single layer of regular 5/8" drywall over your existing walls. Simply screw it in place so that it attaches to the wood studs. This second sheet of drywall will increase the STC rating of your wall by about 10 points [source: Guardian].
For more extreme noise situations, try QuietRock. This drywall product uses special technology that keeps sound waves from penetrating your walls. It has the same fire-resistant capabilities as regular drywall, but by adding just a single layer to your existing walls, you can take your STC ratings up to an average of 58. Add two layers, and your walls will be around STC 80. At that level, your neighbors could start a rock band in their home and you'd barely notice [source: Quiet Solution].
Finally, if you'd like to reduce sound without adding drywall, consider hanging panels wrapped in fabric. One of the most popular products for blocking sound in apartments is called Homasote. It's a lightweight composite product made of recycled newspapers and cellulose fibers. By wrapping Homasote panels in a nice fabric, you can reduce the noise coming through your walls by about 20 percent, while adding to your home's décor [source: Homasote].
Of course, your walls aren't the only paths that noise can take to your home. Read on to the next section to learn how to block noise from upstairs neighbors, as well as how to soundproof your doors and windows.
Blocking Sounds in Floors and Ceilings
We've looked at how to block neighbor noises that are coming through your walls, but what if the noise is coming from above or below? Whether it's heavy footsteps or loud stereos, noise from those living on other floors can really be a pain. To help reduce these noises, we must look for ways to block sound waves, or at least slow them down as much as possible.
Let's start with the floor. If noise from downstairs neighbors is coming through your floors, your first step should be to add carpeting to help dull the sounds. There's no need to fully carpet the floor, as even a selection of scatter rugs will help. To further reduce sound transmission, add carpet padding to new or existing carpets. Go with the thickest padding you can find that is compatible with your carpet. If you plan to install new laminate, engineered, or wood floors at any point, be sure to choose a model with a built-in layer of insulation.
Carpeting and padding still not enough to keep the noise down? Try Green Glue. Green Glue is a viscoelastic compound that's used to block sound in walls, floors and ceilings. Green Glue is an incredibly effective sound blocker, eliminating about 90 percent of noise [source: Green Glue].
For noise that's coming from upstairs, install a drop ceiling in your home. Use resilient channel, and invest in acoustical tile that's designed to block noise. Because the drop ceiling is situated below the original drywall ceiling, the plenum space in between helps isolate noises from footsteps or similar sounds. The acoustical tile itself helps absorb and dissipate the remainder of the noise before it gets into your home.
If you don't like the look of drop ceilings or aren't willing to invest in one, you can simply double up the drywall on your existing ceiling. Use resilient channel to create a space between the two layers, as this is a great way to isolate sound waves. For further sound reduction, add a layer of Green Glue or an acoustical mat product between the drywall layers [source Manfredini].
If all of the above techniques are out of your budget, simply drape a nice fabric across the ceiling in a decorative manner. The fabric will help to absorb and dissipate a bit of the noise from above.
Read on to the next section to learn how to block sound coming through doors, windows, and ductwork.
Blocking Sound from Doors
Sound waves will spread to any place there's an opening into your home or spots where sound-deadening materials aren't sufficient. The major culprits for this problem are doors, windows and ductwork systems. Fortunately, increasing the sound reduction capabilities of these surfaces is relatively cheap and simple.
Many apartment dwellers complain about noise from the hallways passing into their homes. To solve this problem, residents can invest in STC-rated doors. The average hollow-core apartment door has an STC rating of between 20 and 25 [source: CR Mayer]. This means that even the average conversation taking place in the halls can be heard inside of your apartment with relative clarity. STC doors are available at ratings as high as 55 [source: Krieger]. The drawback to STC-rated doors is that they're fairly heavy and expensive, and may require special hardware beyond that currently on your door. Many apartments may not even allow tenants to replace their doors.
For a simpler and more affordable way to keep noise from coming through your doorways, consider the use of sound seals. These are neoprene or vinyl strips that are installed around the door to seal any open spaces. Cheap stick-on versions are effective, but for a longer-lasting solution, look for seals that can be screwed in place. They are a bit more expensive, but they won't keep falling like stick-on types can.
To further seal your door, add a metal threshold and surface-mounted door bottom seal to the door. Both of these items can be installed within a few minutes, but will greatly reduce the amount of noise that enters from under the door.
Blocking Sound from Windows and Ductwork
Windows are another major source of neighbor noise, especially in a townhome. The average double pane window has an STC of only around 26 [source: Cmar]. There are several ways to improve this rating. First, in situations where windows are a significant source of noise, the resident can replace standard windows with STC-rated varieties, available up to STC 56.
While STC windows are very effective, they can also be expensive and impractical for many people. If this is the case, consider using sound seals instead. Window seal kits are available at most home improvement stores, and are very affordable. They can be installed quickly without the use of special tools, and they can make a big difference in sound transmission. While you're applying your seals, be sure to caulk any cracks or joints you see. Use a clear or matching shade of caulk to trace around the window frame both inside and outside of the home.
For a low-tech solution to neighbor noise passing through the windows, try hanging heavy curtains that run from the floor to the ceiling. Heavy fabric can do quite a bit to dissipate sound. Add a few large, leafy plants near your windows as well. Remember, every bit of sound control you include adds up to reduce the total noise level.
What if noise from your neighbors is traveling into your home through the ductwork? This scenario can be particularly annoying because the sound tends to be amplified in the tight metal space. To combat this problem, wrap your ducts with acoustical insulation, or replace the sections nearest the air grilles and vents with lined duct sections. Another solution is to replace your regular metal grilles with lined versions, or to ask your landlord about adding sound attenuators to the ducts.
And now you're ready to cozy up in your nice, quiet apartment. Sleep well!
Related HowStuffWorks Articles
- Cmar, David S. Acousticical Windows. September 2005. May 7, 2009.http://www.phaseto.com/acoustical_windows.htm
- Green Glue. Third Party Transmission Loss Reports. 2005. May 8, 2009.http://www.homasote.com/Products/440-Soundbarrier.aspx
- Guardian Insulation. Sound Transmission Class Information. Date Unknown. May 8, 2009.http://www.guardianbp.com/docs/STCbatt.pdf
- Homasote Company. 440 Soundbarrier Product Data. 2009. May 7, 2009.http://www.homasote.com/Products/440-Soundbarrier.aspx
- Krieger Doors. Krieger Soundproof Doors. 2009. May 7, 2009.http://www.kriegerproducts.com/acoustical/
- Manfredini, Lou. "Neighbors too loud? Indoor Noise Solutions." Today Show. September 20, 2007. May 8, 2009.http://today.msnbc.msn.com/id/20874484
- Quiet Solution. Quiet Rock Product Data. December 14, 2007. May 7, 2009.http://www.quietsolution.com/QRock545THX_dsheet.pdf
- STC Ratings. STC Ratings for Various Wall Assemblies. 2004. May 8, 2009.http://www.stcratings.com/assemblies.html
- Vanderheiden, Gregg. About Decibels. Date Unknown. May 7, 2009http://trace.wisc.edu/docs/2004-About-dB