5 Smart Tips for Soundproofing Windows

Overcome outdoor noise with these window soundproofing strategies.

5 Tips for Soundproofing Windows

Photo: istockphoto.com

Whether it’s highway traffic, loud neighbors, or birds chirping, some sounds from the outside world are bound to disrupt your daily activities, especially if the noise intrudes when you’re in a bedroom or other area intended as a sanctuary or workspace. While you can’t control what goes on outside, you can block or at least reduce the noise by soundproofing windows using the techniques detailed here, either alone or in combination. Read on to attain inner peace!

RELATED: 11 DIYs for a Soundproofed Home

1. Install window inserts.

If you live in an environment with heavy noise pollution, such as honking car horns, wailing sirens, or blasting music from next door, utilizing soundproofing window inserts is the most effective way to reduce the cacophony. These glass inserts are installed in the window frame about five inches in front of the interior face of your existing window. The air space between the insert and the window keeps most sound vibrations from passing through the glass, resulting in greater noise-reduction benefits than double-pane windows (more on these ahead) alone. The most effective inserts are made of laminated glass—a thick glass consisting of two layers of glass with an intervening layer of plastic that effectively blocks vibrations.

On the Sound Transmission Class (STC) scale that reflects the decibel reduction in noise volume that a window provides, soundproof windows typically measure between 48 and 54—the higher the STC, the greater the noise-reduction benefit. At the upper end, this means that a 98-decibel (db) outside noise (e.g., a motorcycle engine) is heard at only 44 db indoors (98 minus 54), which is no louder than a typical indoor conversation. You’ll get more noise reduction benefits by installing an insert in front of a single-pane window than a double-pane window. This is because the STC of a double-pane window is often higher to begin with, so an insert won’t increase its overall STC as substantially. An insert for one window typically costs between $350 and $800 installed, which is less than or equal to the cost of the next option for soundproofing windows: a window replacement.

2. Replace single-pane windows with double-pane equivalents.

If you experience moderate outdoor noise pollution, such as the occasional lawn mower or a passing car, you may wish to replace single-pane windows with double-pane windows. Single-pane pane windows, often found in homes 15 years old or older, have just a single piece of glass in the window frame, while double-pane windows, the standard in newer homes, consist of two pieces of glass with air between them. Single-pane windows provide no air barrier between the outside and the glass, so they permit virtually all outdoor sounds to vibrate through the glass, resulting in a noisy interior.

Single-pane windows have an STC of between 26 and 28—only a little over half that of soundproof windows. At the upper end of this range, the window would reduce the noise volume of a passing car (70 db) to 42 db (70 minus 28). In contrast, the air space between the individual panes of a double-pane window help halt the vibration of outdoor sounds through the glass, resulting in greater noise reduction benefit translating to an STC of 26 to 35. Compared with a single-pane window with an STC of 28, a double-pane window measuring in at 35 would reduce the noise volume of a passing car to only 35 db—offering a 7-decibel greater reduction in noise than the single-pane window (70 minus 35). While this may not seem like much, to the listener, a 7 db difference results in a perceived volume reduction of around 87 percent. Replacing one single-pane window with a double-pane equivalent will run you $350 to $900.

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Soundproofing Windows with Specialty Acoustic Caulk

Photo: istockphoto.com

3. Seal gaps along windows with acoustic caulk.

Small gaps between a window frame and an interior wall can let outdoor noise into your home and keep your windows from performing at their STC rating. A simple way to seal these gaps is to fill them with acoustic caulk (available from brands like Franklin International on Amazon). This noise-proof latex-based sealant helps reduce sound transmission and maintains the STC of windows but still allows you to open and close windows.

Applying acoustic caulk is the easiest and most inexpensive way to soundproof windows (a tube costs between $10 to $20). If there is already silicone caulk around the window frame, remove it with a putty knife. Cut a quarter-inch opening in the tip of the acoustic caulk tube with a utility knife, load the tube into a caulking gun, and pull the trigger of the gun to apply a thin bead of caulk in the gap between the interior window frame and interior wall.

Acoustic caulk readily bonds with most window frame and wall material, including wood and drywall. More flexible than regular silicone caulk, acoustic caulk won’t shrink or form new cracks over time as you operate your windows; it’s also ultra-durable, lasting for several years before requiring re-caulking. Though most often white, acoustic caulk is available in various colors; some products turn clear as they dry, while others remain their original color but can be painted to match the color of interior walls.

4. Hang sound-dampening curtains.

To soften noise as well as harsh glare, hang sound-dampening curtains (available on Amazon from brands like NICETOWN). Ranging from $20 to $100 or more, these curtains made of thick, heavy fabrics such as velvet usually have a lining made of materials like vinyl that absorb sound as it enters a room and minimize echoes, so that any sound you do hear indoors fades out quickly. Because these curtains dampen but do not block sound, they’re better suited for light noise pollution, such as crickets or birds chirping that may interrupt sleep.

Many of these window treatments also serve as quality blackout curtains, which have a foam backing that helps block out light. Curtains that absorb sound and block light are a great option for bedrooms and other spaces designed for sleep and relaxation and are especially popular with folks who work night shift hours and need to rest during the day.

Soundproofing Windows with Double Cell Blinds

Photo: amazon.com

5. Install double-cell shades.

Cellular shades (also known as honeycomb shades) consist of rows of cells—hexagonal tubes of fabric stacked on top of each other. These shades have several purposes: They block out light, prevent indoor heat gain in the summer and retain heat in winter, and absorb sound that vibrates into a room to reduce the echo. While single-cell shades have a single layer of cells, so absorb limited sound, double-cell shades (available on Amazon from brands like First Rate Blinds) have two layers of cells, and so absorb more sound. Like sound-dampening curtains, they’re best suited for people who experience low levels of noise pollution.

Can't hear yourself think?
Connect with a licensed soundproofing expert in your area and receive free, no-committment estimates for your project.