How To Soundproof a Room With Caulking

Perhaps it’s the dog or the new baby in the other room, your partner likes to watch late-night talk shows in another room while you’re trying to sleep, or someone in the family is playing music or an instrument all hours of the day and night. Whatever it is, the sound is bothering you and you need to soundproof your room.

While soundproofing involves a battery of several tactics—some of them quite elaborate—there is one surprisingly easy and inexpensive way to cut down on the sound: soundproof caulking. It's a very cheap fix and for very little effort, caulking can reduce outside sound by as much as 15 percent, though it's best when used in conjunction with other methods, such as weatherstripping under doors and around windows. It doesn't seem like soundproof caulk should work, but it does. It's as simple as applying caulking to cracks in walls and floorboards, around windows, and even around electrical covers.

Acoustic Caulk vs. Regular Caulk

You'll achieve better results if you use acoustic caulk (also called acoustical sound sealant or noise-proofing sealant) instead of regular silicone caulk. Though acoustic caulk costs more than regular silicone caulk, it's worth the cost. Acoustic caulk is a latex-based product (not silicone-based like regular caulk) and it stays flexible rather than hardening, so it won't shrink or cause gaps and cracks that would otherwise let sound escape. Silicone sealant is good to keep air from getting through cracks but isn't usually good for soundproofing.

Soundproofing Tips and Tricks

Reducing Airflow Helps Reduce Sound

Professional soundproofing is highly expensive. It involves adding insulating materials and extra drywall—or replacing existing wall materials with new and more expensive materials. It often involves other people and special tools: contractors and consultants and decibel meters. All of that means more expense, time, and effort.

One easier way to cut down on the transmission of sound is to reduce airflow. Physics tells us that sound is borne by air since sound is vibration traveling through the air. Wind promotes the transmission of sound even more.

If this seems improbable, it's easy to conduct a simple test of this notion. Crack open a window by 1/2-inch or even as narrow as 1/4-inch. Take note of the sound level in the room. Shut the window and notice how the sound changes.

Locating Cracks That Allow Sound

Think of the room that you want quieter as having air flowing into it from the outside. How is the air coming into your room? The gaps between outlet boxes and drywall are one area. Another area: gaps under doors. If the sound is coming from outside, airflow coming through or around windows is another place to look.

Even these very narrow seeps of air carry sound. Remember that sound is caused by vibrations traveling through the air. The type of thinking that is used to detect cold air coming into your house is the same type of thinking needed to detect sound carried by airflow. So where is it coming from?

• Through or around receptacle boxes
• Through ceiling receptacle lights
• Cracks above windows or doors
• Poorly fitting windows
• Misaligned doors
• Gaps in wall insulation
• Thin wall patches (holes in walls patched not with drywall but with fiberglass patch material)
• Cracks in floorboards

Using a Thermal Camera to Locate Sound

Since cracks that permit cold air are the same cracks that permit sound, use a tool that contractors employ to find out where the cold air is coming from—a thermal camera.

Low-cost thermal cameras are available. They simply plug into your smartphone. Through the camera's app, all of the cold air entering your home will be identified in darker colors like blue or green.

You can only use a thermal camera when there is a sharp contrast between the inside and outside temperatures. Given that, fall or winter are the best months to use a thermal camera to locate cracks that permit both cold air and sound.

Before You Begin

Caulk, weatherstripping, and insulation are fitted into every available crack that neighbors the exterior or a particularly noisy adjacent room. Depending on the surface, you may want to use painter's caulk since it can be painted over to match the surrounding surface. If the cracks are exterior-facing, use exterior-grade silicone caulking.